Washington University in St Louis School of Medicine. 2003
Brewer Science Library website.
Brewer Science Library website.
2003;Accessed May 28, 2003
ATC. Antithrombotic Trialists' Collaboration 2002.
ATC. Antithrombotic Trialists' Collaboration 2002.
Fibrinogen: associations with cardiovascular events in an outpatient clinic.
Acevedo M, Foody JM, Pearce GL, et al.
Am Heart J. 2002 Feb; 143(2):277-82.
BACKGROUND: Fibrinogen, known to influence the coagulation process, is an independent risk factor for coronary artery disease (CAD). However, its association with myocardial infarction (MI) and its predictive potential for short-term mortality, in an ongoing clinical practice, has not been characterized. OBJECTIVES: In a high-risk outpatient practice we sought to demonstrate whether baseline fibrinogen levels related to MI rather than CAD alone, and whether baseline serum fibrinogen levels predicted mortality over a short-term follow-up. METHODS AND RESULTS: From a total of 2126 patients with baseline fibrinogen measurements (mean age, 56 +/- 12 years, 35% female), 1187 patients with CAD (n = 606 with MI) and 939 patients without CAD were evaluated in an active preventive cardiology unit of a large city hospital. Logistic regression models were used to determine the association of fibrinogen with differing CAD presentations. Fibrinogen quartile showed a significant correlation with CAD both univariately and after adjustment for Framingham risk score (odds ratio [OR] = 1.22, P <.001). Fibrinogen levels were significantly associated with the presence of CAD and history of MI (adjusted OR = "1.25," P =".001)." Fibrinogen did not show a significant association to CAD when MI was not considered in the analysis (OR = "1.01," P =".82)." In this same clinical cohort, after a mean follow-up of 24 +/- 13 months, 41 patients had died. Consistent with the observed association with MI, fibrinogen quartile showed a graded independent relation to mortality in a cohort of both men and women (hazard ratio = "1.81," P <.001). CONCLUSIONS: In the clinical setting of an outpatient clinic, fibrinogen was directly associated with the presence of MI and was revealed to be an independent short-term predictor of mortality
Breast Cancer Facts and Figures 2003/2004.
ACS (American Cancer Society).
Angioplasty, Percutaneous Transluminal Coronary (PTCA) 2002a.
Aspirin Resistance Increases Risk of Death .
2002;2002b Mar 26.
Cholesterol-Lowering Drugs: AHA Recommendation.
2004;2004b Jan 7
Lyon Diet Heart Study.
Ten-year follow-up of survival and myocardial infarction in the randomized Coronary Artery Surgery Study.
Alderman EL, Bourassa MG, Cohen LS, et al.
Circulation. 1990 Nov; 82(5):1629-46.
The Coronary Artery Surgery Study (CASS) randomized 780 patients to an initial strategy of coronary surgery or medical therapy. Of medically randomized patients, 6% had surgery within 6 months and a total of 40% had surgery by 10 years. At 10 years, there was no difference in cumulative survival (medical, 79% vs. surgical, 82%; NS) and no difference in percentage free of death and nonfatal myocardial infarction (medical, 69% vs. surgical, 66%; NS). Patients with an ejection fraction of less than 0.50 exhibited a better survival with initial surgery treatment (medical, 61% vs. surgical, 79%; p = 0.01). Conversely, patients with an ejection fraction greater than or equal to 0.50 exhibited a higher proportion free of death and myocardial infarction with initial medical therapy (medical, 75% vs. surgical, 68%; p = 0.04) although long-term survival remained unaffected (medical, 84% vs. surgical, 83%; p = 0.75). There were no significant differences either in survival and freedom from nonfatal myocardial infarction, whether stratified on presence of heart failure, age, hypertension, or number of vessels diseased. Thus, 10-year follow-up results confirm earlier reports from CASS that patients with left ventricular dysfunction exhibit long-term benefit from an initial strategy of surgical treatment. Patients with mild stable angina and normal left ventricular function randomized to initial medical treatment (with an option for later surgery if symptoms progress) have survival equivalent to those patients randomized to initial surgery
[Inflammatory mechanisms, arteriosclerosis and ischemic stroke: clinical data and perspectives].
Alvaro-Gonzalez LC, Freijo-Guerrero MM, Sadaba-Garay F.
Rev Neurol. 2002 Sep 1; 35(5):452-62.
OBJECTIVE: The atherosclerosis is the most common cause of death and disability in developed countries by causing ischemic cardiopathic and stroke. The ischemic atherotrombotic stroke is the most frequent form of the last one. In this sense we review herein the mechanisms underlying the artherosclerotic process. DEVELOPMENT: It is understood as an inflammatory disease, by taking into account the widely accepted hypothesis by Ross: it was firstly stated in structural terms, as macrophages and T/B linfocities were present in the arterial wall from the first stages of the disease (fatty streak) to the last and complicated ones. The starting point is a functional endothelial damage, secondary to mechanical or vascular risk factors and called response to injury hypothesis . The next step is an inflammatory cascade that involves humoral (citokines, growth factors) and cellular (increased quimiotaxis, adherece and infiltration of inflamatory cells) mechanisms. They interact among them, outbalanced and in a progresssive way that leads to the final fibroproliferative response. Every stage has his own inflammatory components and interactive pathways. The following elements are outstanding in this process: 1) Adhesion molecules, including E selectin, ICAM 1 and VCAM 1, that are increased locally in the plaques and as circulating elements; plaquetary receptors of the type IIb/IIIa are integrins wich belong to the same family; 2) Citokines with either proinflammatory activity like IL 1, the TNF a and linfocitary ligands like the CD 40, or with antiinflammatory activity like the gamma interpheron; 3) Growth factors, with plaquetary (PDGF) and fibroblastic (FGF) variants as the cornerstone; 4) Markers of systemic inflammation, overall plasma C reactive protein and fibrinogen, that predict the risk of stroke and cardiovascular death; IL 6, complement, thrombin and heat shock proteins (HSP) would act in a similar but less conclusive way. CONCLUSIONS: The evidences of the pivotal role of the inflammation in the stroke allow to develop therapeutical strategies to prevent the disease: fostering natural antiinflamatory mechanisms, or inhibiting inflammatory elements by selective (monoclonal antibodies) or non selective (IIb/IIIa receptors, antiinflammatory drugs) pathways are distinctily glimpsed, ongoing or fully developed
Carvedilol: The New Role of Beta Blockers in Congestive Heart Failure .
American Family Physician.
American Family Physician. 1998
Trace elements and cardiovascular diseases.
Acta Pharmacol Toxicol (Copenh). 1986; 59 Suppl 7:317-24.
Evidence linking marginal intakes of the trace elements, chromium, copper, zinc and selenium, with abnormal lipid metabolism and ultimately cardiovascular diseases is accumulating from both animal and human studies. Chromium supplementation of normal adult men, as well as diabetics, has been reported to increase high density lipoprotein cholesterol and decrease triglycerides and total cholesterol. Subjects with the highest total cholesterol and triglycerides usually respond the most to supplemental chromium. Improvements in lipid metabolism, as well as those in glucose metabolism, appear to be related to improvements in insulin efficiency due likely to increased receptor number. Animal studies also indicate that improvements in serum cholesterol, aortic lipids and plaque formations due to supplemental chromium are associated with decreased circulating insulin. Insufficient dietary copper also leads to elevated lipid levels and impaired heart function. Animal studies indicate an obvious degradation of the heart muscles. Zinc appears to function in cardiovascular diseases primarily via its antagonism with copper. Selenium may also affect cardiovascular diseases since selenium is postulated to be involved in platelet aggregation. These data demonstrate that the trace elements, chromium, copper, and selenium, have beneficial effects on risk factors associated with cardiovascular diseases suggesting that a decreased risk of cardiovascular disease may be achieved by adequate intake of trace elements
Coronary artery surgery study (CASS): a randomized trial of coronary artery bypass surgery. Comparability of entry characteristics and survival in randomized patients and nonrandomized patients meeting randomization criteria.
J Am Coll Cardiol. 1984; 3(1):114-28.
Altern Med Rev. 2003; 8(2):193-6.
Effects of soy isoflavones on atherosclerosis: potential mechanisms.
Anthony MS, Clarkson TB, Williams JK.
Am J Clin Nutr. 1998 Dec; 68(6 Suppl):1390S-3S.
It has long been recognized that coronary heart disease rates are lower in Japan, where soy consumption is common, than in Western countries. In experimental studies, atherosclerosis was reduced in animals fed diets containing soy protein compared with those fed diets with animal protein. Recently, several lines of evidence have suggested that the components of soy protein that lower lipid concentrations are extractable by alcohol (eg, the isoflavones genistein and daidzein). We recently evaluated the relative effect of the soy protein versus the alcohol-extractable components of soy on cardiovascular disease and its risk factors. Young male and female cynomolgus monkeys were fed diets that contained either 1) casein-lactalbumin as the source of protein (casein), 2) soy protein isolate from which the isoflavones were alcohol extracted (SPI-), or 3) isoflavone-intact soy protein (SPI+). The SPI+ group had significant improvements in LDL cholesterol and HDL cholesterol. Only HDL cholesterol was significantly improved in the SPI- group males compared with the casein group. The casein group had the most atherosclerosis, the SPI+ group had the least, and the SPI- group was intermediate but did not differ significantly from the casein group. Potential mechanisms by which soy isoflavones might prevent atherosclerosis include a beneficial effect on plasma lipid concentrations, antioxidant effects, antiproliferative and antimigratory effects on smooth muscle cells, effects on thrombus formation, and maintenance of normal vascular reactivity
Comparative study of policosanol, aspirin and the combination therapy policosanol-aspirin on platelet aggregation in healthy volunteers.
Arruzazabala ML, Valdes S, Mas R, et al.
Pharmacol Res. 1997 Oct; 36(4):293-7.
A randomized, double-blind, placebo-controlled study was conducted in 43 healthy volunteers to compare the effects of policosanol (20 mg day-1), aspirin (ASA) (100 mg day-1) and combination therapy (policosanol 20 mg day-1 plus ASA 100 mg day-1) on platelet aggregation. The healthy volunteers were randomly treated for 7 days. Both, platelet aggregation and coagulation time were measured at baseline and after therapy. When policosanol was administered platelet aggregation induced by ADP (37.3%), epinephrine (32.6%) and collagen (40.5%) were significantly reduced. Meanwhile, aspirin significantly reduced platelet aggregation induced by collagen (61.4%) and epinephrine (21.9%) but not ADP-induced aggregation. Combined therapy significantly inhibited aggregation induced by all the agonists reaching the highest reductions of platelet aggregation induced by collagen (71.3%) and epinephrine (57.5%). Coagulation time did not change significantly in any group. No subject withdrew from the trial. Four volunteers reported mild adverse experiences during the study: three ASA-treated cases referred headache, epigastralgia and nose bleeding, meanwhile one patient receiving combination therapy reported gum bleeding. The present results demonstrate that policosanol (20 mg day-1) is as effective as ASA (100 mg day-1). Moreover, combination therapy shows some advantages compared with the respective monotherapies
Collaborative meta-analysis of randomised trials of antiplatelet therapy for prevention of death, myocardial infarction, and stroke in high risk patients.
ATC (Antithrombotic Trialists' Collaboration).
Antithrombotic Trialists' Collaboration. 2002;BMJ 2002 Jan 12, 324(7329):71-86.
C-reactive protein and coronary artery disease.
Jpn Heart J. 2002; 43(6):607-19.
C-reactive protein and coronary artery disease.
Auer J, Berent R, Lassnig E, et al.
Jpn Heart J. 2002 Nov; 43(6):607-19.
Evidence suggests that inflammation plays a key role in the pathogenesis of atherosclerosis. The chronic inflammatory process can develop to an acute clinical event by the induction of plaque rupture and therefore cause acute coronary syndromes. The aim of this study was to determine the serum levels of the circulating acute-phase reactant C-reactive protein (CRP), which is a sensitive indicator of inflammation, in patients with chronic stable coronary artery disease (CAD) and acute coronary syndromes (ACS). We studied 56 subjects: 1) 25 consecutive patients (18 men, 7 women; mean age, 68.5 +/- 14.3 years, range, 40-86) with unstable angina (UA) or acute myocardial infarction (AMI); 2) 31 consecutive patients (25 men, 6 women; mean age 64 +/- 12.7; range, 47-83, years) with signs and symptoms of clinically stable CAD. High-sensitivity-C-reactive protein (hs-CRP) levels were determined with a commercially available enzyme-linked immunoassay method. In patients with unstable angina and AMI before reperfusion therapy, CRP levels were not significantly different to those in patients with stable CAD (5.96 +/- 2.26 versus 4.35 +/- 2.6 mg/L; P = 0.12), but tended to be higher in patients with unstable angina and AMI. Baseline CRP levels in the subgroup of patients with AMI (6.49 +/- 2.28 mg/L) were significantly higher than levels in patients with stable CAD (4.35 +/- 2.6 mg/L; P = 0.02). CRP levels in patients with unstable angina and AMI were measured four times during a 72-hour period (0, 12, 24, and 72 hours). The lowest value was observed at baseline and differed significantly from values measured at any other time of the observation period (P < 0.001; 5.96 +/- 2.26; 9.5 +/- 9.04, 18.25 +/- 11.02; 20.25 +/- 10.61). CRP levels after 12, 24, and 72 hours were also significantly different to the initial values for patients with stable CAD (P < 0.01). There was no correlation between CRP and creatine kinase (CK), CK-MB isoenzyme, or troponin I positivity as markers for the extent of the myocardial injury during the observation period. Baseline levels of serum CRP tended to be higher in patients with unstable angina or AMI but were not significantly different from levels in patients with chronic stable CAD. In the subgroup of patients with AMI, baseline CRP levels were significantly higher than the levels in patients with stable CAD. CRP as a marker of inflammation is significantly increased in patients with AMI and unstable angina shortly after the onset of symptoms (after a period of 12 hours), supporting the hypothesis of an activation of inflammatory mechanisms in patients with an acute coronary syndrome or AMI
Ginger: inhibition of thromboxane synthetase and stimulation of prostacyclin: relevance for medicine and psychiatry.
Med Hypotheses. 1986 Jul; 20(3):271-8.
Ginger, the common spice, has recently been found to act as a potent inhibitor of thromboxane synthetase, raising levels of prostacyclin, without a concomitant rise in PGE2 or PGF2 alpha. Indications for use of ginger to replace either thromboxane inhibitors having serious side effects or prostacyclin are given
Italian multicenter study on the safety and efficacy of coenzyme Q10 as adjunctive therapy in heart failure. CoQ10 Drug Surveillance Investigators.
Baggio E, Gandini R, Plancher AC, et al.
Mol Aspects Med. 1994; 15 Suppl:s287-s294.
Digitalis, diuretics and vasodilators are considered the standard therapy for patients with congestive heart failure, for which treatment is tailored according to the severity of the syndrome and the patient profile. Apart from the clinical seriousness, heart failure is always characterized by an energy depletion status, as indicated by low intramyocardial ATP and coenzyme Q10 levels. We investigated safety and clinical efficacy of Coenzyme Q10 (CoQ10) adjunctive treatment in congestive heart failure which had been diagnosed at least 6 months previously and treated with standard therapy. A total of 2664 patients in NYHA classes II and III were enrolled in this open noncomparative 3-month postmarketing study in 173 Italian centers. The daily dosage of CoQ10 was 50-150 mg orally, with the majority of patients (78%) receiving 100 mg/day. Clinical and laboratory parameters were evaluated at the entry into the study and on day 90; the assessment of clinical signs and symptoms was made using from two-to seven-point scales. The results show a low incidence of side effects: 38 adverse effects were reported in 36 patients (1.5%) of which 22 events were considered as correlated to the test treatment. After three months of test treatment the proportions of patients with improvement in clinical signs and symptoms were as follows: cyanosis 78.1%, oedema 78.6%, pulmonary rales 77.8%, enlargement of liver area 49.3%, jugular reflux 71.81%, dyspnoea 52.7%, palpitations 75.4%, sweating 79.8%, subjective arrhytmia 63.4%, insomnia 662.8%, vertigo 73.1% and nocturia 53.6%. Moreover we observed a contemporary improvement of at least three symptoms in 54% of patients; this could be interpreted as an index of improved quality of life
The Truth About Cholesterol.
Betaine lowers elevated s-adenosylhomocysteine levels in hepatocytes from ethanol-fed rats.
Barak AJ, Beckenhauer HC, Mailliard ME, et al.
J Nutr. 2003 Sep; 133(9):2845-8.
Previous studies showed that chronic ethanol administration inhibits methionine synthase activity, resulting in impaired homocysteine remethylation to form methionine. This defect in homocysteine remethylation was shown to increase plasma homocysteine and to interfere with the production of hepatic S-adenosylmethionine (SAM) in ethanol-fed rats. These changes were shown to be reversed by the administration of betaine, an alternative methylating agent. This study was undertaken to determine additional effects of ethanol on methionine metabolism and their functional consequences. The influences of methionine loading and betaine supplementation were also evaluated. Adult Wistar rats were fed ethanol or a control Lieber-DeCarli liquid diet for 4 wk, and metabolites of the methionine cycle were measured in vitro in isolated hepatocytes under basal and methionine-supplemented conditions. S-Adenosylhomocysteine (SAH) concentrations were elevated in hepatocytes isolated from ethanol-fed rats compared with controls and in hepatocytes from both groups when supplemented with methionine. The addition of betaine to the methionine-supplemented incubation media reduced the elevated SAH levels. The decrease in the intracellular SAH:SAM ratio due to ethanol consumption inhibited the activity of the liver-specific SAM-dependent methyltransferase, phosphatidylethanolamine methyltransferase. Our data indicate that betaine, by remethylating homocysteine and removing SAH, overcomes the detrimental effects of ethanol consumption on methionine metabolism and may be effective in correcting methylation defects and treating liver diseases
Dietary supplement with vitamin C prevents nitrate tolerance.
Bassenge E, Fink N, Skatchkov M, et al.
J Clin Invest. 1998 Jul 1; 102(1):67-71.
Enhanced formation of superoxide radicals has been proposed to play a major role in the development of nitrate tolerance in humans. We tested the effects of vitamin C (Vit-C) supplementation on glyceroltrinitrate (GTN)-induced hemodynamic effects during 3-d nonintermittent transdermal administration of GTN (0.4 mg/h) in nine healthy subjects. Tolerance development was monitored by changes in arterial pressure, dicrotic digital pulse pressure, and heart rate. Studies with GTN, Vit-C, or GTN/Vit-C were successively carried out at random in three different series in the same subjects. GTN treatment caused an immediate rise in arterial conductivity (a/b ratio of dicrotic pulse), but within 2 d of initiating GTN, the a/b ratio progressively decreased and reached basal levels. In addition, there was a progressive loss of the orthostatic decrease in blood pressure. However, coadministration of Vit-C and GTN fully maintained the GTN-induced changes in the orthostatic blood pressure, and the rise of a/b ratio was augmented by 310% for the duration of the test period. Changes in vascular tolerance in GTN-treated subjects were paralleled by upregulation of the activity of isolated platelets, which was also reversed by Vit-C administration. These findings demonstrate that dietary supplementation with Vit-C eliminates vascular tolerance and concomitant upregulation of ex vivo-washed platelet activity during long-term nonintermittent administration of GTN in humans
Verapamil is associated with an increased risk of cancer in the elderly: the Rotterdam study.
Beiderbeck-Noll AB, Sturkenboom MC, van der Linden PD, et al.
Eur J Cancer. 2003 Jan; 39(1):98-105.
The association between the use of calcium channel blockers (CCB) and cancer has received ample attention, but is still controversial. In this study, we have tested the hypothesis that the observed association between CCB and cancer in earlier studies could be explained by residual confounding or by misclassification of exposure because of the use of cross-sectional data on drug use. Data from the Rotterdam Study, a prospective population-based cohort study in the municipal area Ommoord, were used. The study population consisted of a cohort of 3204 participants aged 71 years or older who were followed from a baseline interview in the period 1991-1993 for the occurrence of incident cancer. Data on drug use were gathered at baseline and through the seven community pharmacies which served the Ommoord region during the study period between 1 January 1991 and 1 January 1999. Incident cancer events were gathered from a nationwide registry of hospitalisation data and from a specialised cancer centre in the Rotterdam region. We performed three analyses. First, we followed the method, and adjusted for the same risk factors, as in the earlier studies. In the second analysis, we included all risk factors that were univariately associated with cancer in the Rotterdam Study. In the third analysis, we included exposure to CCBs as time-varying co-variates, while adjusting for potential confounders. The relative risk (RR) of cancer associated with CCB was 1.4 (95% Confidence Interval (CI): 0.9-2.0) in the first analysis and lowered to 1.2 (95% CI: 0.8-1.8) upon adjustment for the different co-variates in the second. In both analyses, however, verapamil was significantly associated with cancer with RRs of 2.1 (95% CI: 1.1-4.0) and 2.0 (1.01-3.9), respectively, whereas no associations were found with the other CCB in this study, i.e. diltiazem and nifedipine. A significantly increased risk of cancer was found for intermediate daily doses of verapamil and diltiazem. Intake of other antihypertensives such as beta-blocking agents, diuretics and ACE-inhibitors was not associated with cancer. In the third analysis with exposure to CCB as time-varying co-variates, the risk increase was non-significant for use of 2 years or less, 1.0 (95% CI: 0.7-1.5), and for use for a cumulative period of more than 2 years, 1.3 (95% CI: 0.8-2.0). However, in all models the hazard ratio was statistically significantly increased for verapamil, but not for diltiazem and nifedipine. On the basis of these analyses, we found no increase in cancer in users of diltiazem and nifedipine, nor in users of other antihypertensives. In line with earlier studies, however, we found an increased risk of cancer in users of verapamil. At variance with the conclusions from several other studies, we think that it is too early to conclude that CCB are not associated with cancer
Berkeley Heart Lab: Frequently Asked Questions.
Berkeley Heart Lab.
Complement and atherogenesis: binding of CRP to degraded, nonoxidized LDL enhances complement activation.
Arteriosclerosis, Thrombosis, and Vascular Biology. 1999;(19):2348-54.
Apolipoprotein A-I(Milano) and apolipoprotein A-I(Paris) exhibit an antioxidant activity distinct from that of wild-type apolipoprotein A-I.
Bielicki JK, Oda MN.
Biochemistry. 2002 Feb 12; 41(6):2089-96.
Apolipoprotein A-I(Milano) (apoA-I(Milano)) and apoA-I(Paris) are rare cysteine variants of apoA-I that produce a HDL deficiency in the absence of cardiovascular disease in humans. This paradox provides the basis for the hypothesis that the cysteine variants possess a beneficial activity not associated with wild-type apoA-I (apoA-I(WT)). In this study, a unique antioxidant activity of apoA-I(Milano) and apoA-I(Paris) is described. ApoA-I(Milano) was twice as effective as apoA-I(Paris) in preventing lipoxygenase-mediated oxidation of phospholipids, whereas apoA-I(WT) was poorly active. Antioxidant activity was observed using the monomeric form of the variants and was equally effective before and after initiation of oxidative events. ApoA-I(Milano) protected phospholipid from reactive oxygen species (ROS) generated via xanthine/xanthine oxidase (X/Xo) but failed to inhibit X/Xo-induced reduction of cytochrome c. These results indicate that apoA-I(Milano) was unable to directly quench ROS in the aqueous phase. There were no differences between lipid-free apoA-I(Milano,) apoA-I(Paris), and apoA-I(WT) in mediating the efflux of cholesterol from macrophages, indicating that the cysteine variants interacted normally with the ABCA1 efflux pathway. The results indicate that incorporation of a free thiol within an amphipathic alpha helix of apoA-I confers an antioxidant activity distinct from that of apoA-I(WT). These studies are the first to relate gain of function to rare cysteine mutations in the apoA-I primary sequence
Atherosclerosis and Other Forms of Arteriosclerosis (Lab 2).
[Lipid metabolism in atherogenesis].
Bobkova D, Poledne R.
Cesk Fysiol. 2003 Feb; 52(1):34-41.
Lipoprotein (LP) metabolism plays a pivotal role in atherogenesis. Breakdown of triglyceride (TG) rich lipoproteins, both of exogenous--chylomicrones and endogenous--very low density lipoproteiny (VLDL) produces remnant lipoproteins after repeated action of lipoprotein lipase (LPL). Atherogenity of remnant lipoprotein has been proved. Also atheroprotective high density lipoproteins (HDL) are produced from surface of TG rich lipoproteins during their lipolysis. Protective role of HDL particles in atherogenesis is manifested by reverse cholesterol transport from all extrahepatic cells to the liver including cells of the arterial wall. Plasma concentration of atherogenic low density lipoproteins (LPL) is regulated by the production rate of VLDL in the liver on the one hand and their utilization by selective LDL receptors (mainly in the liver) on the other hand. Number of functioning LDL receptors is regulated genetically (gene for own LDL receptor and gene for both ligands--apoprotein B and apoprotein E) and also by environmental factors. Diet low in saturated fat and cholesterol and rich in dietary fibres increases number of LDL receptors and consequently decreases LDL cholesterol concentration. Monocytes entering arterial wall when intravasal and then subendothelial concentration of LDL is increased absorb LDL and predominantly oxidized LDL by scavenger receptors. During this repeated process they are changed to macrophages, residual macrophages and foam cells. Production of foam cells represents a starting point in atherogenesis but their high presence is typical also for advanced vulnerable atherosclerotic lesions, which are prone to rupture producing clinical complication--myocardial infarction and stroke
Beta-adrenergic blocking agents in heart failure: benefits of vasodilating and non-vasodilating agents according to patients' characteristics: a meta-analysis of clinical trials.
Bonet S, Agusti A, Arnau JM, et al.
Arch Intern Med. 2000 Mar 13; 160(5):621-7.
BACKGROUND: In patients with heart failure, beta-adrenergic blocking agents reduce overall and cardiovascular mortality. This meta-analysis aimed at clarifying their effect on sudden death, the magnitude of their benefit according to the cause of heart failure, and whether there is any difference between vasodilating and nonvasodilating agents. METHODS: Randomized, clinical trials were included if they evaluated a beta-adrenergic blocking agent without intrinsic sympathomimetic activity, included a control group receiving placebo or standard treatment, evaluated mortality on an intention-to-treat basis, and lasted at least 8 weeks. RESULTS: Twenty-one trials with 5,849 patients (3,130 receiving beta-blockers) were included. Median length of treatment was 6 months. Most patients had mild or moderate heart failure and were treated with angiotensin-converting enzyme inhibitors, diuretics, and digitalis. The beta-blockers significantly reduced overall mortality, cardiovascular mortality, and mortality due to pump failure and sudden death by 34% to 39%. The decrease in overall mortality in patients with ischemic heart disease (IHD) (30%) was no different from that among patients with non-IHD (26%) (P = .08). The reduction in overall mortality was greater with vasodilating than with nonvasodilating agents (45% vs 27%; P = .007), particularly in patients without IHD (62%), compared with those with IHD (22%; P =.03). CONCLUSIONS: In patients with heart failure, beta-blockers reduce total and cardiovascular mortality at the expense of a decrease in mortality due to pump failure and sudden death. The magnitude of the benefit is similar in patients with IHD and in those with non-IHD. Vasodilating beta-blockers have a greater effect on overall mortality than nonvasodilating agents, particularly in patients with non-IHD
The effect of vitamin C on blood lipids, fibrinolytic activity and platelet adhesiveness in patients with coronary artery disease.
Atherosclerosis. 1980 Feb; 35(2):181-7.
Forty patients with past history myocardial infarction were divided into three groups. Group I served as controls, while Groups II and III were given respectively, 1 g and 2 g vitamin C daily, divided in two doses. Samples were collected initially, and then every 2 months during the 6-month period of vitamin C administration and finally 2 months after stopping vitamin C. Vitamin C, 0.5 g twice daily (Group II), increased serum ascorbic acid by about 22% (P less than 0.05). However, no significant changes were observed in fibrinolytic activity or blood lipids. When the dose of vitamin C was doubled, serum ascorbic acid increased by about 96% and fibrinolytic activity increased by 45% (P less than 0.01), while the platelet adhesive index decreased by 27% (P less than 0.01). The serum cholesterol level dropped by 12% (P less than 0.05) and a significant decrease in serum beta lipoproteins and an increase in the alpha fraction was also seen. A further 40 patients with acute myocardial infarction were divided into two groups; one received 2 g vitamin C daily for the first 20 days and the other received a placebo. Blood samples were collected every 10th day during the 40-day follow up. Vitamin C administration increased fibrinolytic activity by 62.5%, while serum ascorbic acid rose by 94%
Level of fibrinogen and risk of fatal and non-fatal stroke. EUROSTROKE: a collaborative study among research centres in Europe.
Bots ML, Elwood PC, Salonen JT, et al.
J Epidemiol Community Health. 2002 Feb; 56 Suppl 1:i14-i18.
BACKGROUND: It is well established that raised levels of fibrinogen increase the risk of coronary heart disease. For stroke, however, data are much more limited and restricted to overall stroke. This study investigated the association between fibrinogen and fatal, non-fatal, haemorrhagic and ischaemic stroke in three European cohorts participating in EUROSTROKE. METHODS: EUROSTROKE is a collaborative project among ongoing European cohort studies on incidence and risk factors of stroke. EUROSTROKE is designed as a nested case-control study. For each stroke case, two controls were sampled. Strokes were classified according to MONICA criteria or reviewed by a panel of four neurologists. Recently, data on stroke and fibrinogen became available from cohorts in Cardiff (79 cases/194 controls), Kuopio (74/124), and Rotterdam (62/203). Results were adjusted for age, sex, smoking, and systolic blood pressure. RESULTS: The risk of stroke gradually increased with increasing fibrinogen levels: the odds ratios per quartile increase were 1.08 (95% CI 0.63 to 1.84), 1.91 (1.12 to 3.26) and 2.78 (1.64 to 4.72), respectively. This association was similar for ischaemic (n=138) and haemorrhagic stroke (n=25). Associations between fibrinogen and stroke were similar across strata of smoking, diabetes mellitus, previous myocardial infarction, and HDL cholesterol. The odds ratio, however, tended to increase with increasing systolic blood pressure: from 1.21 among those with a systolic pressure <120 mm Hg to 1.99 among subjects with a systolic pressure of 160 mm Hg or above. CONCLUSION: This analysis of the EUROSTROKE project indicates that fibrinogen is a powerful predictor of stroke. Results did not disclose a differential in this relation of fibrinogen and fatal or non-fatal stroke, or with type of stroke (ischaemic or haemorrhagic)
Folate, vitamin B12, and neuropsychiatric disorders.
Nutr Rev. 1996 Dec; 54(12):382-90.
Folate and vitamin B12 are required both in the methylation of homocysteine to methionine and in the synthesis of S-adenosylmethionine. S-adenosylmethionine is involved in numerous methylation reactions involving proteins, phospholipids, DNA, and neurotransmitter metabolism. Both folate and vitamin B12 deficiency may cause similar neurologic and psychiatric disturbances including depression, dementia, and a demyelinating myelopathy. A current theory proposes that a defect in methylation processes is central to the biochemical basis of the neuropsychiatry of these vitamin deficiencies. Folate deficiency may specifically affect central monoamine metabolism and aggravate depressive disorders. In addition, the neurotoxic effects of homocysteine may also play a role in the neurologic and psychiatric disturbances that are associated with folate and vitamin B12 deficiency
The evolution of aging: a new approach to an old problem of biology.
Med Hypotheses. 1998 Sep; 51(3):179-221.
Most gerontologists believe aging did not evolve, is accidental, and is unrelated to development. The opposite viewpoint is most likely correct. Genetic drift occurs in finite populations and leads to homozygosity in multiple-alleled traits. Episodic selection events will alter random drift towards homozygosity in alleles that increase fitness with respect to the selection event. Aging increases population turnover, which accelerates the benefit of genetic drift. This advantage of aging led to the evolution of aging systems (ASs). Periodic predation was the most prevalent episodic selection pressure in evolution. Effective defenses to predation that allow exceptionally long lifespans to evolve are shells, extreme intelligence, isolation, and flight. Without episodic predation, aging provides no advantage and aging systems will be deactivated to increase reproductive potential in unrestricted environments. The periodic advantage of aging led to the periodic evolution of aging systems. Newer aging systems co-opted and added to prior aging systems. Aging organisms should have one dominant, aging system that co-opts vestiges of earlier-evolved systems as well as vestiges of prior systems. In human evolution, aging systems chronologically emerged as follows: telomere shortening, mitochondrial aging, mutation accumulation, senescent gene expression (AS#4), targeted somatic tissue apoptotic-atrophy (AS#5), and female reproductive tissue apoptotic-atrophy (AS#6). During famine or drought, to avoid extinction, reproduction is curtailed and aging is slowed or somewhat reversed to postpone or reverse reproductive senescence. AS#4-AS#6 are gradual and reversible aging systems. The life-extending/rejuvenating effects of caloric restriction support the idea of aging reversibility. Development and aging are timed by the gradual loss of cytosine methylation in the genome. Methylated cytosines (5mC) inhibit gene transcription, and deoxyribonucleic acid (DNA) cleavage by restriction enzymes. Cleavage inhibition prevents apoptosis, which requires DNA fragmentation. Free radicals catalyze the demethylation of 5mC while antioxidants catalyze the remethylation of cytosine by altering the activity of DNA methyltransferases. Hormones act as either surrogate free radicals by stimulating the cyclic adenosine monophosphate (cAMP) pathway or as surrogate antioxidants through cyclic guanosine monophosphate (cGMP) pathway stimulation. Access to DNA containing 5mC inhibited developmental and aging genes and restriction sites is allowed by DNA helicase strand separation. Tightly wound DNA does not allow this access. The DNA helicase generates free radicals during strand separation; hormones either amplify or counteract this effect. Caloric restriction slows or reverses the aging process by increasing melatonin levels, which suppresses reproductive and free radical hormones, while increasing antioxidant hormone levels. Cell apoptosis during CR leads to somatic wasting and a release of DNA, which increases bioavailable cGMP. The rapid aging diseases of progeria, the three diseases: (xeroderma pigmentosum (XP), Cockayne syndrome(CS), and ataxia telangiectasia (AT)), and Werner's syndrome are related to or caused by defects in three separate DNA helicases. The rapid aging diseases caused by mitochondrial malfunctions mirror those seen in XP, CS, and AT. Comparing these diseases allows for assignment of the different symptoms of aging to their respective aging systems. Follicle-stimulating hormone (FSH) demethylates the genes of AS#4, luteinizing hormone (LH) of AS#5, and estrogen of AS#6 while cortisol may act cooperatively with FSH and LH, and 5-alpha dihydrotestosterone (DHT) with FSH in these role. The Werner's DNA helicase links timing of the age of puberty, menopause, and maximum lifespan in one mechanism. Telomerase is under hormonal control. Most cancers likely result from malfunctions in the programmed apoptosis of AS#5 and AS#6. (ABSTRACT TRUNCATED)
Dr. Braly's Optimum Health Program.
Orotates and the Mineral Transporters of Dr. Nieper (Sharpe, E.).
Brewer Science Library.
2003;2003 May 28
Predictors of mortality and mortality from cardiac causes in the bypass angioplasty revascularization investigation (BARI) randomized trial and registry. For the BARI Investigators.
Brooks MM, Jones RH, Bach RG, et al.
Circulation. 2000 Jun 13; 101(23):2682-9.
BACKGROUND: The impact of percutaneous transluminal coronary angioplasty (PTCA) and coronary artery bypass grafting (CABG) on long-term mortality rates in the presence of various demographic, clinical, and angiographic factors is uncertain in the population of patients suitable for both procedures. METHODS AND RESULTS: In the Bypass Angioplasty Revascularization Investigation (BARI) randomized trial and registry, 3610 patients who were eligible to receive PTCA and CABG were revascularized between 1989 and 1992. Multivariate Cox models were used to identify factors associated with 5-year mortality and cardiac mortality, with particular attention to factors that interact with treatment. Diabetic patients receiving insulin had higher mortality and cardiac mortality rates with PTCA compared with CABG (relative risk [RR] 1.78 and 2.63, respectively, P<0.001), and patients with ST elevation had higher cardiac mortality rates with CABG than with PTCA (RR 4.08, P<0.001). Factors most strongly associated with high overall mortality rates were insulin-treated diabetes, congestive heart failure, kidney failure, and older age. Black race was also associated with higher mortality rates (RR 1.49, P="0.019)." CONCLUSIONS: A set of variables was identified that could be used to help select a revascularization procedure and to evaluate risk of long-term mortality in the population of patients considering revascularization
Underuse of aspirin in a referral population with documented coronary artery disease.
Califf RM, DeLong ER, Ostbye T, et al.
Am J Cardiol. 2002 Mar 15; 89(6):653-61.
Despite substantial evidence that antiplatelet therapy saves lives and reduces adverse events in patients with coronary artery disease (CAD), use of the most widely available and lowest cost antiplatelet agent, aspirin, continues to be disappointingly low. In a large database of patients with known CAD, we (1) explored trends in the use of aspirin over time, (2) characterized patients most likely to take aspirin regularly, and (3) estimated the effectiveness of aspirin use by examining long-term outcomes. Using patients entered in the Duke Databank for Cardiovascular Diseases, we explored the use of aspirin from 1969 to 1999. More than 25,000 patients were sent a questionnaire that included several questions about medication use, including 1 question specifically about aspirin. Patients who failed to respond to the questionnaire received a follow-up telephone call. Aspirin use increased substantially over the most recent 4 years in the study, from 59% in 1995 to 81% in 1999. Predictors of aspirin use included younger age, male sex, being a nonsmoker, and having had a myocardial infarction or revascularization procedure. Patients who never took aspirin had a risk ratio for death of 1.85 compared with patients who regularly took aspirin. Despite the well-known beneficial effects of aspirin, too many patients without contraindications to aspirin fail to take it regularly. The health care system currently lacks effective methods to ensure that patients who have CAD have adequate follow-up concerning aspirin use
Effects of policosanol and pravastatin on lipid profile, platelet aggregation and endothelemia in older hypercholesterolemic patients.
Castano G, Mas R, Arruzazabala ML, et al.
Int J Clin Pharmacol Res. 1999; 19(4):105-16.
This randomized, double-blind study was undertaken to compare the effects of policosanol and pravastatin administered at 10 mg/day on lipid profile, platelet aggregation and endothelemia in older patients with type II hypercholesterolemia and high coronary risk. After 6 weeks on a lipid-lowering diet, patients with low-density lipoprotein (LDL) cholesterol levels > 3.4 mmol/l were randomized to receive, under double-blind conditions, policosanol or pravastatin 10 mg tablets that were taken with the evening meal for 8 weeks. Policosanol significantly (p < 0.00001) lowered LDL-cholesterol (19.3%), total cholesterol (13.9%) and the ratios of LDL-cholesterol/high-density lipoprotein (HDL)-cholesterol (28.3%) and total cholesterol/HDL-cholesterol (24.4%). Pravastatin significantly (p < 0.00001) lowered LDL-cholesterol (15.6%), total cholesterol (11.8%) and the ratios (p < 0.0001) of LDL-cholesterol/HDL-cholesterol (18.9%) and total cholesterol/HDL-cholesterol (15.7%). Policosanol, but not pravastatin, significantly increased (p < 0.001) levels of HDL-cholesterol (18.4%) and reduced (p < 0.01) triglycerides (14.1%). Policosanol was more effective (p < 0.05) than pravastatin in inhibiting platelet aggregation induced by all agonists and it significantly reduced (p < 0.0001) platelet aggregation induced by arachidonic acid at 1.5 and 3 mmol/l by 42.2% and 69.5%, respectively, platelet aggregation induced by collagen 0.5 microgram/ml (p < 0.05) (16.6%) and that induced by adenosine diphosphate 1 mumol/l (p < 0.01) (20.3%). Pravastatin significantly reduced (p < 0.001) (27%) only platelet aggregation induced by arachidonic acid 3 mmol/l. Both drugs significantly decreased (p < 0.00001) endothelemia levels but final values were significantly lower (p < 0.001) in the policosanol than in the pravastatin group. Both treatments were safe and well tolerated. Pravastatin significantly (p < 0.01) increased serum levels of alanine amine transferase but individual values remained within normal. Two patients on pravastatin discontinued the study because of adverse experiences (myocardial infarction and jaundice, respectively). In conclusion, the effects of policosanol (10 mg/day) on lipid profile, platelet aggregation and endothelemia in older patients with type II hypercholesterolemia and high coronary risk are more favorable than those induced by the same doses of pravastatin
Effects of policosanol on older patients with hypertension and type II hypercholesterolaemia.
Castano G, Mas R, Fernandez JC, et al.
Drugs R D. 2002; 3(3):159-72.
OBJECTIVE: This study was conducted to investigate the effects of policosanol administered for 12 months on the lipid profile of older patients with hypertension and type II hypercholesterolaemia and no history of coronary heart disease (CHD) or cerebrovascular disease. PATIENTS AND PARTICIPANTS: 589 older male and female patients with hypertension and type II hypercholesterolaemia and no history of CHD or cerebrovascular disease were included. METHODS: This was a prospective, randomised, double-blind, placebo-controlled study in parallel groups treated with policosanol (5 to 10 mg/day) for 1 year. After 6 weeks on a standard step I cholesterol-lowering diet, 589 patients were randomised to policosanol (5 mg) or placebo tablets, to be taken once daily for 12 months. The dosage was doubled to 10 mg/day if total cholesterol values were > 6.1 mmol/L after 6 months of therapy. RESULTS: Policosanol significantly (p < 0.00001) lowered serum low-density lipoprotein-cholesterol (LDL-C) [20.5%], total cholesterol (TC) [15.4%], triglycerides (11.9%), LDL-C/high-density lipoprotein-cholesterol (HDL-C) ratio [22.2%] and TC/HDL-C ratio (20.1%), and increased (p < 0.0001) HDL-C (12.7%). The frequency of vascular and all-cause serious adverse events (SAEs) was lower (p < 0.05) in the policosanol recipients (two vascular SAEs, 0.7%; five all-cause SAEs, 1.7%) than in the placebo recipients (six vascular SAEs, 2.0%; 12 all-cause SAEs, 4.1%). Similarly, total adverse events (AEs) were less frequent in the policosanol-treated group (29; 9.8%) compared with the placebo group (52; 17.7%) [p < 0.01]. Three placebo recipients and no policosanol recipents died during the study as a result of myocardial infarction (two patients) and sudden cardiac arrest (one). Policosanol was well tolerated, and no drug-related disturbances in safety indicators were found. Policosanol significantly decreased systolic blood pressure (BP) compared with baseline and placebo, which could be an additional advantage in this population at high coronary risk. CONCLUSIONS: Policosanol administered long term is effective in lowering LDL-C and TC as well as increasing HDL-C levels in older patients with hypertension and type II hypercholesterolaemia without a history of CHD or cerebrovascular disease. In addition, policosanol treatment also shows benefits in the occurrence of SAEs of vascular aetiology, on the general AE profile and the reduction of BP in treated patients compared with baseline
Comparison of the efficacy and tolerability of policosanol with atorvastatin in elderly patients with type II hypercholesterolaemia.
Castano G, Mas R, Fernandez L, et al.
Drugs Aging. 2003; 20(2):153-63.
BACKGROUND: Hypercholesterolaemia is a risk factor for coronary heart disease (CHD). Clinical studies have shown that lowering elevated serum total cholesterol (TC) levels, and particularly low density lipoprotein-cholesterol (LDL-C) levels, reduces the frequency of coronary morbidity and deaths, whereas high serum levels of high density lipoprotein-cholesterol (HDL-C) protect against CHD. Policosanol is a cholesterol-lowering drug purified from sugar cane wax with a therapeutic dosage range from 5-20 mg/day. Atorvastatin is an HMG-CoA reductase inhibitor which across its dosage range (10-80 mg/day) has shown significantly greater lipid-lowering effects than all previously marketed statins. OBJECTIVE: This study was undertaken to compare the efficacy and tolerability of policosanol with atorvastatin in older patients with type II hypercholesterolaemia. PATIENTS AND METHODS: This randomised, single-blind, parallel-group study was conducted in older patients (60-80 years) with type II hypercholesterolaemia. After 4 weeks on a cholesterol-lowering diet, 75 patients were randomised to policosanol or atorvastatin 10mg tablets taken once daily with the evening meal for 8 weeks. An interim and final check-up were performed at 4 and 8 weeks, respectively, after treatment was initiated. RESULTS: At 4 (p < 0.0001) and 8 (p < 0.00001) weeks, policosanol 10 mg/day significantly lowered serum LDL-C levels by 17.5 and 23.1%, respectively compared with baseline; corresponding values for atorvastatin were 28.4 and 29.8%. At study completion, policosanol significantly (p < 0.0001) reduced serum TC (16.4%), LDL-C/HDL-C ratio (25.5%) and TC/HDL-C ratio (19.3%), as well as (p < 0.001) triglyceride levels (15.4%). Atorvastatin significantly (p < 0.0001) decreased serum TC (22.6%), LDL-C/HDL-C (26.2%) and TC/HDL-C (19.8%) ratios, as well as (p < 0.001) triglyceride levels (15.5%). Atorvastatin was significantly more effective than policosanol in reducing LDL-C and TC, but similar in reducing both atherogenic ratios and triglyceride levels. Policosanol, but not atorvastatin, significantly (p < 0.05) increased serum HDL-C levels by 5.3%. Both treatments were well tolerated. At study completion, atorvastatin mildly, but significantly (p < 0.05) increased creatine phosphokinase (CPK) and creatinine, whereas policosanol significantly reduced AST and glucose (p < 0.01) and CPK (p < 0.05) levels. All individual values, however, remained within normal limits. Three atorvastatin but no policosanol patients withdrew from the study because of adverse events: muscle cramps (1 patient), gastritis (1 patient) and uncontrolled hypertension, abdominal pain and myalgia (1 patient). Overall, no policosanol and seven atorvastatin patients (18.9%) reported a total of nine mild or moderate adverse events during the study (p < 0.01). CONCLUSIONS: This study shows that policosanol (10 mg/day) administered for 8 weeks was less effective than atorvastatin (10 mg/day) in reducing serum LDL-C and TC levels in older patients with type II hypercholesterolaemia. Policosanol, but not atorvastatin, however, significantly increased serum HDL-C levels, whereas both drugs similarly reduced atherogenic ratios and serum triglycerides. Policosanol was better tolerated than atorvastatin as revealed by patient withdrawal analysis and overall frequency of adverse events. Nevertheless, further studies must be conducted in larger sample sizes and using dose-titration methods to achieve target lipid levels in order to reach wider conclusions
Cyclooxygenase inhibitors and the antiplatelet effects of aspirin.
Catella-Lawson F, Reilly MP, Kapoor SC, et al.
N Engl J Med. 2001 Dec 20; 345(25):1809-17.
BACKGROUND: Patients with arthritis and vascular disease may receive both low-dose aspirin and other nonsteroidal antiinflammatory drugs. We therefore investigated potential interactions between aspirin and commonly prescribed arthritis therapies METHODS: We administered the following combinations of drugs for six days: aspirin (81 mg every morning) two hours before ibuprofen (400 mg every morning) and the same medications in the reverse order; aspirin two hours before acetaminophen (1000 mg every morning) and the same medications in the reverse order; aspirin two hours before the cyclooxygenase-2 inhibitor rofecoxib (25 mg every morning) and the same medications in the reverse order; enteric-coated aspirin two hours before ibuprofen (400 mg three times a day); and enteric-coated aspirin two hours before delayed-release diclofenac (75 mg twice daily) RESULTS: Serum thromboxane B(2) levels (an index of cyclooxygenase-1 activity in platelets) and platelet aggregation were maximally inhibited 24 hours after the administration of aspirin on day 6 in the subjects who took aspirin before a single daily dose of any other drug, as well as in those who took rofecoxib or acetaminophen before taking aspirin. In contrast, inhibition of serum thromboxane B(2) formation and platelet aggregation by aspirin was blocked when a single daily dose of ibuprofen was given before aspirin, as well as when multiple daily doses of ibuprofen were given. The concomitant administration of rofecoxib, acetaminophen, or diclofenac did not affect the pharmacodynamics of aspirin CONCLUSIONS: The concomitant administration of ibuprofen but not rofecoxib, acetaminophen, or diclofenac antagonizes the irreversible platelet inhibition induced by aspirin. Treatment with ibuprofen in patients with increased cardiovascular risk may limit the cardioprotective effects of aspirin
Cedars-Sinai Heart Center.
Safety and anti-inflammatory activity of curcumin: a component of tumeric (Curcuma longa).
J Altern Complement Med. 2003 Feb; 9(1):161-8.
INTRODUCTION: Tumeric is a spice that comes from the root Curcuma longa, a member of the ginger family, Zingaberaceae. In Ayurveda (Indian traditional medicine), tumeric has been used for its medicinal properties for various indications and through different routes of administration, including topically, orally, and by inhalation. Curcuminoids are components of tumeric, which include mainly curcumin (diferuloyl methane), demethoxycurcumin, and bisdemethoxycurcmin. OBJECTIVES: The goal of this systematic review of the literature was to summarize the literature on the safety and anti-inflammatory activity of curcumin. METHODS: A search of the computerized database MEDLINE (1966 to January 2002), a manual search of bibliographies of papers identified through MEDLINE, and an Internet search using multiple search engines for references on this topic was conducted. The PDR for Herbal Medicines, and four textbooks on herbal medicine and their bibliographies were also searched. RESULTS: A large number of studies on curcumin were identified. These included studies on the antioxidant, anti-inflammatory, antiviral, and antifungal properties of curcuminoids. Studies on the toxicity and anti-inflammatory properties of curcumin have included in vitro, animal, and human studies. A phase 1 human trial with 25 subjects using up to 8000 mg of curcumin per day for 3 months found no toxicity from curcumin. Five other human trials using 1125-2500 mg of curcumin per day have also found it to be safe. These human studies have found some evidence of anti-inflammatory activity of curcumin. The laboratory studies have identified a number of different molecules involved in inflammation that are inhibited by curcumin including phospholipase, lipooxygenase, cyclooxygenase 2, leukotrienes, thromboxane, prostaglandins, nitric oxide, collagenase, elastase, hyaluronidase, monocyte chemoattractant protein-1 (MCP-1), interferon-inducible protein, tumor necrosis factor (TNF), and interleukin-12 (IL-12). CONCLUSIONS: Curcumin has been demonstrated to be safe in six human trials and has demonstrated anti-inflammatory activity. It may exert its anti-inflammatory activity by inhibition of a number of different molecules that play a role in inflammation
Vitamin E and atherosclerosis.
J Nutr. 1998 Oct; 128(10):1593-6.
Vitamin E was advocated as an effective treatment for heart disease by Dr. Even Shute of London, Ontario more than 50 years ago. His pioneering claims, which were unacceptable to the medical community at large, have been confirmed by recent findings from epidemiologic studies and clinical trials. This review integrates our current knowledge of atherogenesis with the biological functions of vitamin E. The response-to-injury hypothesis explains atherosclerosis as a chronic inflammatory response to injury of the endothelium, which leads to complex cellular and molecular interactions among cells derived from the endothelium, smooth muscle and several blood cell components. Inflammatory and other stimuli trigger an overproduction of free radicals, which promote peroxidation of lipids in LDL trapped in the subendothelial space. Products of LDL oxidation are bioactive, and they induce endothelial expression and secretion of cytokines, growth factors and several cell surface adhesion molecules. The last-mentioned are capable of recruiting circulating monocytes and T lymphocytes into the intima where monocytes are differentiated into macrophages, the precursor of foam cells. In response to the growth factors and cytokines, smooth muscle cells proliferate in the intima, resulting in the narrowing of the lumen. Oxidized LDL can also inhibit endothelial production of prostacyclin and nitric oxide, two potent autacoids that are vasodilators and inhibitors of platelet aggregation. Evidence is presented that vitamin E is protective against the development of atherosclerosis. Vitamin E enrichment has been shown to retard LDL oxidation, inhibit the proliferation of smooth muscle cells, inhibit platelet adhesion and aggregation, inhibit the expression and function of adhesion molecules, attenuate the synthesis of leukotrienes and potentiate the release of prostacyclin through up-regulating the expression of cytosolic phospholipase A2 and cyclooxygenase. Collectively, these biological functions of vitamin E may account for its protection against the development of atherosclerosis
Cardiovascular effects of testosterone: implications of the "male menopause"?
Channer KS, Jones TH.
Heart. 2003 Feb; 89(2):121-2.
A relatively low blood concentration of testosterone in the older man may have adverse effects on atherosclerosis, and explain the higher incidence of coronary heart disease in the male
The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure: the JNC 7 report.
Chobanian AV, Bakris GL, Black HR, et al.
JAMA. 2003 May 21; 289(19):2560-72.
"The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure" provides a new guideline for hypertension prevention and management. The following are the key messages(1) In persons older than 50 years, systolic blood pressure (BP) of more than 140 mm Hg is a much more important cardiovascular disease (CVD) risk factor than diastolic BP; (2) The risk of CVD, beginning at 115/75 mm Hg, doubles with each increment of 20/10 mm Hg; individuals who are normotensive at 55 years of age have a 90% lifetime risk for developing hypertension; (3) Individuals with a systolic BP of 120 to 139 mm Hg or a diastolic BP of 80 to 89 mm Hg should be considered as prehypertensive and require health-promoting lifestyle modifications to prevent CVD; (4) Thiazide-type diuretics should be used in drug treatment for most patients with uncomplicated hypertension, either alone or combined with drugs from other classes. Certain high-risk conditions are compelling indications for the initial use of other antihypertensive drug classes (angiotensin-converting enzyme inhibitors, angiotensin-receptor blockers, beta-blockers, calcium channel blockers); (5) Most patients with hypertension will require 2 or more antihypertensive medications to achieve goal BP (<140/90 mm Hg, or <130/80 mm Hg for patients with diabetes or chronic kidney disease); (6) If BP is more than 20/10 mm Hg above goal BP, consideration should be given to initiating therapy with 2 agents, 1 of which usually should be a thiazide-type diuretic; and (7) The most effective therapy prescribed by the most careful clinician will control hypertension only if patients are motivated. Motivation improves when patients have positive experiences with and trust in the clinician. Empathy builds trust and is a potent motivator. Finally, in presenting these guidelines, the committee recognizes that the responsible physician's judgment remains paramount
Angioplasty: A Patient Guide 2001 Aug 31.
2001;2001 Aug 31
Curcumin-containing diet inhibits diethylnitrosamine-induced murine hepatocarcinogenesis.
Chuang SE, Kuo ML, Hsu CH, et al.
Carcinogenesis. 2000 Feb; 21(2):331-5.
Curcumin has been widely used as a spice and coloring agent in foods. Recently, curcumin was found to possess chemopreventive effects against skin cancer, forestomach cancer, colon cancer and oral cancer in mice. Clinical trials of curcumin for prevention of human cancers are currently ongoing. In this study, we examine the chemopreventive effect of curcumin on murine hepatocarcinogenesis. C3H/HeN mice were injected i.p. with N-diethylnitrosamine (DEN) at the age of 5 weeks. The curcumin group started eating 0.2% curcumin-containing diet 4 days before DEN injection until death. The mice were then serially killed at the scheduled times to examine the development of hepatocellular carcinoma (HCC) and changes in intermediate biological markers. At the age of 42 weeks, the curcumin group, as compared with the control group (DEN alone), had an 81% reduction in multiplicity (0.5 versus 2.57) and a 62% reduction in incidence (38 versus 100%) of development of HCC. A series of intermediate biological markers were examined by western blot. While hepatic tissues obtained from the DEN-treated mice showed a remarkable increase in the levels of p21(ras), PCNA and CDC2 proteins, eating a curcumin-containing diet reversed the levels to normal values. These results indicate that curcumin effectively inhibits DEN-induced hepatocarcinogenesis in the mouse. The underlying mechanisms of the phenomenon and the feasibility of using curcumin in the chemoprevention of human HCC should be further explored
Cholesterol Fighter in a Bottle: Niacin-Bound Chromium 2001.
Cholesterol Fighter in a Bottle: Niacin-bound Chromium 2004.
Effect of curcumin on the aryl hydrocarbon receptor and cytochrome P450 1A1 in MCF-7 human breast carcinoma cells.
Ciolino HP, Daschner PJ, Wang TT, et al.
Biochem Pharmacol. 1998 Jul 15; 56(2):197-206.
We examined the interaction of curcumin, a dietary constituent and chemopreventive compound, with the carcinogen activation pathway mediated by the aryl hydrocarbon receptor (AhR) in MCF-7 mammary epithelial carcinoma cells. Curcumin caused a rapid accumulation of cytochrome P450 1A1 (CYP1A1) mRNA in a time- and concentration-dependent manner, and CYP1A1 monooxygenase activity increased as measured by ethoxyresorufin-O-deethylation. Curcumin activated the DNA-binding capacity of the AhR for the xenobiotic responsive element of CYP1A1 as measured by the electrophoretic-mobility shift assay (EMSA). Curcumin was able to compete with the prototypical AhR ligand 2,3,7,8-tetrachlorodibenzo-p-dioxin for binding to the AhR in isolated MCF-7 cytosol, indicating that it interacts directly with the receptor. Although curcumin could activate the AhR on its own, it partially inhibited the activation of AhR, as measured by EMSA, and partially decreased the accumulation of CYP1A1 mRNA caused by the mammary carcinogen dimethylbenzanthracene (DMBA). Curcumin competitively inhibited CYP1A1 activity in DMBA-treated cells and in microsomes isolated from DMBA-treated cells. Curcumin also inhibited the metabolic activation of DMBA, as measured by the formation of DMBA-DNA adducts, and decreased DMBA-induced cytotoxicity. These results suggest that the chemopreventive effect of curcumin may be due, in part, to its ability to compete with aryl hydrocarbons for both the AhR and CYP1A1. Curcumin may thus be a natural ligand and substrate of the AhR pathway
Stenting and Intra-Coronary Radiation.
Columbia Weill Cornell Heart Institute.
New York: New York Presbyterian/University Hospitals of Columbia and Cornell. 2003
Amino acid metabolism. In Textbook of Biochemistry with Clinical Correlations.
2002; Fifth Edition
New developments in the use of niacin for treatment of hyperlipidemia: new considerations in the use of an old drug.
Crouse JR, III.
Coron Artery Dis. 1996 Apr; 7(4):321-6.
Niacin has been used for many years to treat hyperlipidemia. It has been shown to reduce coronary death and non-fatal myocardial infarction and, in a separate analysis of long-term (15-year) follow-up, all cause mortality. It reduces total cholesterol, low density lipoprotein cholesterol (LDL-C) and triglycerides and increases high density lipoprotein cholesterol (HDL-C). Sustained-release niacin may be associated with more dramatic changes in LDL-C and triglyceride, whereas the short acting preparation causes greater increases in HDL-C. The increase of HDL-C occurs at a lower dose (1500 mg/day) than the reduction of LDL-C (> 1500 mg/day). Niacin also favorably influences other lipid parameters including lipoprotein(a) [Lp(a)], alimentary lipemia, familial defective apolipoprotein B-100 and small dense LDL. Combination of niacin with a bile acid sequestrant or a reductase inhibitor represents a powerful lipid-altering regimen. Whereas the reductase inhibitors and bile acid binding resins primarily affect LDL-C, the combined therapy has a synergistic effect to reduce LDL-C and, in addition, the niacin reduces triglycerides and increases HDL-C. The major drawback in the use of niacin is associated side effects (flushing and palpitations) and toxicity (worsening of diabetes control, exacerbation of peptic ulcer disease, gout, hepatitis). Niacin has a long history of use as a lipid lowering agent and has several attractive features. Unfortunately, the side effect profile of this agent warrants its use only in patients with marked dyslipidemia in whom side effects and potential toxicity are closely monitored
Keep Cholesterol as Low as Possible.
Deficiencies of folate and vitamin B(6) exert distinct effects on homocysteine, serine, and methionine kinetics.
Cuskelly GJ, Stacpoole PW, Williamson J, et al.
Am J Physiol Endocrinol Metab. 2001 Dec; 281(6):E1182-E1190.
Folate and vitamin B(6) act in generating methyl groups for homocysteine remethylation, but the kinetic effects of folate or vitamin B(6) deficiency are not known. We used an intravenous primed, constant infusion of stable isotope-labeled serine, methionine, and leucine to investigate one-carbon metabolism in healthy control (n = 5), folate-deficient (n = 4), and vitamin B(6)-deficient (n = 5) human subjects. The plasma homocysteine concentration in folate-deficient subjects [15.9 +/- 2.1 (SD) micromol/l] was approximately two times that of control (7.4 +/- 1.7 micromol/l) and vitamin B(6)-deficient (7.7 +/- 2.1 micromol/l) subjects. The rate of methionine synthesis by homocysteine remethylation was depressed (P = 0.027) in folate deficiency but not in vitamin B(6) deficiency. For all subjects, the homocysteine remethylation rate was not significantly associated with plasma homocysteine concentration (r = -0.44, P = 0.12). The fractional synthesis rate of homocysteine from methionine was positively correlated with plasma homocysteine concentration (r = 0.60, P = 0.031), and a model incorporating both homocysteine remethylation and synthesis rates closely predicted plasma homocysteine levels (r = 0.85, P = 0.0015). Rates of homocysteine remethylation and serine synthesis were inversely correlated (r = -0.89, P < 0.001). These studies demonstrate distinctly different metabolic consequences of vitamin B(6) and folate deficiencies
Cost-effectiveness of vitamin E therapy in the treatment of patients with angiographically proven coronary narrowing (CHAOS trial). Cambridge Heart Antioxidant Study.
Davey PJ, Schulz M, Gliksman M, et al.
Am J Cardiol. 1998 Aug 15; 82(4):414-7.
Epidemiologic studies have suggested that vitamin E (alpha-tocopherol) may play a preventive role in reducing the incidence of atherosclerosis. The aim of this paper was to conduct a cost-effectiveness analysis of vitamin E supplementation in patients with coronary artery disease using data from the Cambridge Heart Antioxidant Study (CHAOS). The study compared cost-effectiveness in the context of Australian and United States (US) health care utilization. The main clinical outcome used in the economic evaluation was the incidence of acute myocardial infarction (AMI) which was nonfatal. Utilization of health care resources was estimated by conducting a survey of Australian clinicians and published Australian and US cost data. Cost savings of $127 (A$181) and $578/patient randomized to vitamin E therapy compared with patients receiving placebo were found for Australian and US settings, respectively. Savings in the vitamin E group were due primarily to reduction in hospital admissions for AMI. This occurred because the vitamin E group had a 4.4% lower absolute risk of AMI than did the placebo group. Less than 10% of health care costs in the Australian evaluation was due to vitamin E ($150 [A$214/patient]). Our economic evaluation indicates that vitamin E therapy in patients with angiographically proven atherosclerosis is cost-effective in the Australian and US settings
De Milto L.
Green tea epigallocatechin-3-gallate inhibits platelet signalling pathways triggered by both proteolytic and non-proteolytic agonists.
Deana R, Turetta L, Donella-Deana A, et al.
Thromb Haemost. 2003 May; 89(5):866-74.
Epigallocatechin-3-gallate (EGCG), a component of green tea, inhibits human platelet aggregation and cytosolic [Ca(2+)](c) increases more strongly when these processes are induced by thrombin than by the non-proteolytic thrombin receptor activating peptide (TRAP), thromboxane mimetic U46619, or fluoroaluminate. In line with the previously demonstrated EGCG anti-proteolytic activity, a marked inhibition on aggregation is obtained by pre-incubation of thrombin with EGCG prior to addition to cellular suspension. The catechin also reduces cellular Ca(2+) influx following thapsigargin-induced calcium emptying of endoplasmic reticulum, and the agonist-promoted cellular protein tyrosine phosphorylation. Both tyrosine kinases Syk and Lyn, immuno-precipitated from stimulated platelets, are greatly inhibited upon cellular pre-incubation with EGCG, which also inhibits the in vitro auto-phosphorylation and exogenous activity of these two enzymes purified from rat spleen. Both thrombin-induced aggregation and [Ca(2+)](c) increase are reduced in platelets from rats that drank green tea solutions. It is concluded that EGCG inhibits platelet activation, by hindering the thrombin proteolytic activity, and by reducing the agonist-induced [Ca(2+)](c) increase through inhibition of Syk and Lyn activities
[The plasma antioxidant status and trace elements in patients with familial hypercholesterolemia treated with LDL-apheresis].
Delattre J, Lepage S, Jaudon MC, et al.
Ann Pharm Fr. 1998; 56(1):18-25.
Oxidation of low density lipoprotein is involved in the pathogenesis of atherosclerosis. Epidemiological studies suggest a negative correlation between the occurrence of cardiovascular diseases and blood concentrations of lipophilic antioxidants such as vitamin A and E and beta-carotene. Trace elements such as selenium, zinc and copper are involved in the activity of antioxidant enzymes: glutathione peroxidase and superoxide dismutase. The aim of this work was to determine the antioxidant and trace elements status of patients with very severe hypercholesterolemia and who were treated by dextran sulphate low density lipoprotein apheresis, in comparison with two control populations: one constituted by normocholesterolemic subjects and the other by hypercholesterolemic patients before treatment. Our results showed that, as compared with normocholesterolemic subjects, patients treated by LDL-apheresis were not deficient in vitamin E, beta-carotene and copper but had low plasma levels of selenium, zinc and vitamin A. The low selenium and vitamin A levels were due to the treatment by LDL-apheresis by itself, while the hypercholesterolemia of these patients might have provoked the low plasma levels of zinc. This study pointed out the interest of a supplement of selenium, zinc and vitamin A in patients treated by LDL-apheresis
Vitamin supplementation reduces blood homocysteine levels: a controlled trial in patients with venous thrombosis and healthy volunteers.
den Heijer M, Brouwer IA, Bos GM, et al.
Arterioscler Thromb Vasc Biol. 1998 Mar; 18(3):356-61.
Hyperhomocysteinemia is a risk factor for atherosclerosis and thrombosis and is inversely related to plasma folate and vitamin B12 levels. We assessed the effects of vitamin supplementation on plasma homocysteine levels in 89 patients with a history of recurrent venous thrombosis and 227 healthy volunteers. Patients and hyperhomocysteinemic (homocysteine level >16 micromol/L) volunteers were randomized to placebo or high-dose multivitamin supplements containing 5 mg folic acid, 0.4 mg hydroxycobalamin, and 50 mg pyridoxine. A subgroup of volunteers without hyperhomocysteinemia was also randomized into three additional regimens of 5 mg folic acid, 0.5 mg folic acid, or 0.4 mg hydroxycobalamin. Before and after the intervention period, blood samples were taken for measurements of homocysteine, folate, cobalamin, and pyridoxal-5'-phosphate levels. Supplementation with high-dose multivitamin preparations normalized plasma homocysteine levels (< or = "16" micromol/L) in 26 of 30 individuals compared with 7 of 30 in the placebo group. Also in normohomocysteinemic subjects, multivitamin supplementation strongly reduced homocysteine levels (median reduction, 30%; range, -22% to 55%). In this subgroup the effect of folic acid alone was similar to that of multivitamin: median reduction, 26%; range, -2% to 52% for 5 mg folic acid and 25%; range, -54% to 40% for 0.5 mg folic acid. Cobalamin supplementation had only a slight effect on homocysteine lowering (median reduction, 10%; range, -21% to 41%). Our study shows that combined vitamin supplementation reduces homocysteine levels effectively in patients with venous thrombosis and in healthy volunteers, either with or without hyperhomocysteinemia. Even supplementation with 0.5 mg of folic acid led to a substantial reduction of blood homocysteine levels
Textbook of Biochemistry with Clinical Correlates 2002.
Images in cardiovascular medicine. A case of free-floating left atrial thrombus in mitral valve stenosis.
Di Napoli P, Di Giovanni P, Muoio G, et al.
Ital Heart J. 2000 Jul; 1(7):500-1.
Antiplatelet drugs in secondary prevention of stroke.
Int J Clin Pract. 1998 Mar; 52(2):91-7.
Stroke is a leading cause of long-term disability and death in developed countries. The primary medical strategy for secondary prevention of stroke is antiplatelet therapy. Although the clinical value of acetylsalicylic acid (ASA) is well recognised for preventing secondary stroke, several questions remain. What is the optimal dose of ASA to prevent stroke? Would combining ASA with another antiplatelet drug increase efficacy? Do new agents currently under development offer additional benefits? Many of the recent clinical trials address these questions. This review article summarises the results of these trials in the context of evolving strategies for stroke prevention, including the management of recurrent transient ischaemic attacks (TIAs), side-effects of ASA, and economic issues
Antioxidant properties of aged garlic extract: an in vitro study incorporating human low density lipoprotein.
Dillon SA, Burmi RS, Lowe GM, et al.
Life Sci. 2003 Feb 21; 72(14):1583-94.
Oxidation of low-density lipoprotein (LDL) has been recognized as playing an important role in the development and progression of atherosclerotic heart disease. Human LDL was isolated and challenged with a range of oxidants either in the presence or absence of AGE or its diethyl ether extract. Oxidative modification of the LDL fraction using CuSO(4), 5-lipoxygenase and xanthine/xanthine oxidase was monitored by both the appearance of thiobarbituric-acid substances (TBA-RS) and an increase in electrophoretic mobility.This study indicates that AGE is an effective antioxidant as it scavenged superoxide ions and reduced lipid peroxide formation in cell free assays. Superoxide production was completely inhibited in the presence of a 10% (v/v) aqueous preparation of AGE and reduced by 34% in the presence of a 10% (v/v) diethyl ether extract of AGE. The presence of 10% (v/v) diethyl ether extract of AGE significantly reduced Cu(2+) and 15-lipoxygenase-mediated lipid peroxidation of isolated LDL by 81% and 37%, respectively. In addition, it was found that AGE also had the capacity to chelate copper ions. In contrast, the diethyl ether extract of AGE displayed no copper binding capacity, but demonstrated distinct antioxidant properties. These results support the view that AGE inhibits the in vitro oxidation of isolated LDL by scavenging superoxide and inhibiting the formation of lipid peroxides. AGE was also shown to reduce LDL oxidation by the chelation of Cu(2+). Thus, AGE may have a role to play in preventing the development and progression of atherosclerotic disease
Will the 'good fairies' please prove to us that vitamin E lessens human degenerative disease?
Free Radic Res. 1997 Jun; 26(6):565-83.
Recent research about the role of free radical derivatives of oxygen and nitrogen in biological systems has highlighted the possibility that antioxidants, such as vitamin E, that prevent these processes in vitro may be capable of carrying out a similar function in living organisms in vivo. There is increasing evidence that free radical reactions are involved in the early stages, or sometimes later on, in the development of human diseases, and it is therefore of particular interest to inquire whether vitamin E and other antioxidants, which are found in the human diets, may be capable of lowering the incidence of these diseases. Put simply, the proposition is that by improving human diets by increasing the quantity in them of antioxidants, it might be possible to reduce the incidence of a number of degenerative diseases. Of particular significance to these considerations is the likely role of the primary fat-soluble dietary antioxidant vitamin E in the prevention of degenerative diseases such as arteriosclerosis, which is frequently the cause of consequent heart attacks or stroke, and prevention of certain forms of cancer, as well as several other diseases. Substantial evidence for this proposition now exists, and this review is an attempt to give a brief account of the present position. Two kinds of evidence exist; on the one hand there is very substantial basic science evidence which indicates an involvement of free radical events, and a preventive role for vitamin E, in the development of human disease processes. On the other hand, there is also a large body of human epidemiological evidence which suggests that incidence of these diseases is lowered in populations having a high level of antioxidants, such as vitamin E, in their diet, or who have taken steps to enhance their level of intake of the vitamin by taking dietary supplements. There is also some evidence which suggests that intervention with dietary supplements of vitamin E can result in a lowered risk of disease, in particular of cardiovascular disease, which is a major killer disease among the developed nations of the world. The intense interest in this subject recently has as its objective the possibility that, by making some simple alterations to dietary lifestyle, or by enhancing the intake of vitamin E by fortification of foods, or by dietary supplements, it may be possible to reduce substantially the risk of a large amount of common, highly disabling human disease. By this simple means, therefore it may be possible to improve substantially the quality of human life, in particular for people of advancing years
Dietary linolenic acid and carotid atherosclerosis: the National Heart, Lung, and Blood Institute Family Heart Study.
Djousse L, Folsom AR, Province MA, et al.
Am J Clin Nutr. 2003 Apr; 77(4):819-25.
BACKGROUND: Dietary intake of linolenic acid is associated with a lower risk of cardiovascular disease mortality. However, it is unknown whether linolenic acid is associated with a lower risk of carotid atherosclerosis. OBJECTIVE: The objective was to examine the association between dietary linolenic acid and the presence of atherosclerotic plaques and the intima-media thickness of the carotid arteries. DESIGN: In a cross-sectional design, we studied 1575 white participants of the National Heart, Lung, and Blood Institute Family Heart Study who were free of coronary artery disease, stroke, hypertension, and diabetes mellitus. High-resolution ultrasound was used to assess intima-media thickness and the presence of carotid plaques beginning 1 cm below to 1 cm above the carotid bulb. We used logistic regression and a generalized linear model for the analyses. RESULTS: From the lowest to the highest quartile of linolenic acid intake, the prevalence odds ratio (95% CI) of a carotid plaque was 1.0 (reference), 0.47 (0.30, 0.73), 0.38 (0.22, 0.66), and 0.49 (0.26, 0.94), respectively, in a model that adjusted for age, sex, energy intake, waist-to-hip ratio, education, field center, smoking, and the consumption of linoleic acid, saturated fat, fish, and vegetables. Linoleic acid, fish long-chain fatty acids, and fish consumption were not significantly related to carotid artery disease. Linolenic acid was inversely related to thickness of the internal and bifurcation segments of the carotid arteries but not to the common carotid artery. CONCLUSION: Higher consumption of total linolenic acid is associated with a lower prevalence odds of carotid plaques and with lesser thickness of segment-specific carotid intima-media thickness
Primary prevention of acute coronary events with lovastatin in men and women with average cholesterol levels: results of AFCAPS/TexCAPS. Air Force/Texas Coronary Atherosclerosis Prevention Study.
Downs JR, Clearfield M, Weis S, et al.
JAMA. 1998 May 27; 279(20):1615-22.
CONTEXT: Although cholesterol-reducing treatment has been shown to reduce fatal and nonfatal coronary disease in patients with coronary heart disease (CHD), it is unknown whether benefit from the reduction of low-density lipoprotein cholesterol (LDL-C) in patients without CHD extends to individuals with average serum cholesterol levels, women, and older persons. OBJECTIVE: To compare lovastatin with placebo for prevention of the first acute major coronary event in men and women without clinically evident atherosclerotic cardiovascular disease with average total cholesterol (TC) and LDL-C levels and below-average high-density lipoprotein cholesterol (HDL-C) levels. DESIGN: A randomized, double-blind, placebo-controlled trial. SETTING: Outpatient clinics in Texas. PARTICIPANTS: A total of 5608 men and 997 women with average TC and LDL-C and below-average HDL-C (as characterized by lipid percentiles for an age- and sex-matched cohort without cardiovascular disease from the National Health and Nutrition Examination Survey [NHANES] III). Mean (SD) TC level was 5.71 (0.54) mmol/L (221  mg/dL) (51 st percentile), mean (SD) LDL-C level was 3.89 (0.43) mmol/L (150  mg/dL) (60th percentile), mean (SD) HDL-C level was 0.94 (0.14) mmol/L (36  mg/dL) for men and 1.03 (0.14) mmol/L (40  mg/dL) for women (25th and 16th percentiles, respectively), and median (SD) triglyceride levels were 1.78 (0.86) mmol/L (158  mg/dL) (63rd percentile). INTERVENTION: Lovastatin (20-40 mg daily) or placebo in addition to a low-saturated fat, low-cholesterol diet. MAIN OUTCOME MEASURES: First acute major coronary event defined as fatal or nonfatal myocardial infarction, unstable angina, or sudden cardiac death. RESULTS: After an average follow-up of 5.2 years, lovastatin reduced the incidence of first acute major coronary events (1 83 vs 116 first events; relative risk [RR], 0.63; 95% confidence interval [CI], 0.50-0.79; P<.001), myocardial infarction (95 vs 57 myocardial infarctions; RR, 0.60; 95% CI, 0.43-0.83; P=".002)," unstable angina (87 vs 60 first unstable angina events; RR, 0.68; 95% CI, 0.49-0.95; P=".02)," coronary revascularization procedures (157 vs 106 procedures; RR, 0.67; 95% CI, 0.52-0.85; P=".001)," coronary events (215 vs 163 coronary events; RR, 0.75; 95% CI, 0.61-0.92; P =".006)," and cardiovascular events (255 vs 194 cardiovascular events; RR, 0.75; 95% CI, 0.62-0.91; P = ".003)." Lovastatin (20-40 mg daily) reduced LDL-C by 25% to 2.96 mmol/L (115 mg/dL) and increased HDL-C by 6% to 1.02 mmol/L (39 mg/dL). There were no clinically relevant differences in safety parameters between treatment groups. CONCLUSIONS: Lovastatin reduces the risk for the first acute major coronary event in men and women with average TC and LDL-C levels and below-average HDL-C levels. These findings support the inclusion of HDL-C in risk-factor assessment, confirm the benefit of LDL-C reduction to a target goal, and suggest the need for reassessment of the National Cholesterol Education Program guidelines regarding pharmacological intervention
Human homocysteine catabolism: three major pathways and their relevance to development of arterial occlusive disease.
Dudman NP, Guo XW, Gordon RB, et al.
J Nutr. 1996 Apr; 126(4 Suppl):1295S-300S.
Two separate metabolic pathways that methylate homocysteine to methionine are known in humans, utilizing, respectively, 5-methyltetrahydrofolate and betaine as methyl donors. Deficiency of the folate-dependent methylation system is linked to hyperhomocysteinemia. Our data suggest that this deficiency leads to concurrent metabolic down-regulation of homocysteine transsulfuration that may contribute to hyperhomocysteinemia. By contrast, no instances have been reported of hyperhomocysteinemia resulting from deficiencies of betaine-dependent homocysteine methylation. Long-term betaine supplementation of 10 patients, who had pyridoxine-resistant homocystinuria and gross hyperhomocysteinemia due to deficiency of cystathionine beta-synthase activity, caused a substantial lowering of plasma homocysteine, which has now been maintained for periods of up to 13 years. Betaine had to be taken regularly because the effect soon disappeared when treatment was stopped. In conclusion, depressed activity of the transsulfuration pathway may contribute to hyperhomocysteinemia because of primary deficiencies of enzymes of either the transsulfuration or of the folate-dependent methylation pathways. Stimulation of betaine-dependent homocysteine remethylation causes a commensurate decrease in plasma homocysteine that can be maintained as long as betaine is taken
The inhibitory effect of curcumin, genistein, quercetin and cisplatin on the growth of oral cancer cells in vitro.
Elattar TM, Virji AS.
Anticancer Res. 2000 May; 20(3A):1733-8.
Epidemiological evidence indicates that plant derived flavonoids and other phenolic antioxidants protect against heart disease and cancer. In the current investigation utilizing human oral squamous carcinoma cell line (SCC-25), we have evaluated the potency of three different plant phenolics, viz., curcumin, genistein and quercetin in comparison with that of cisplatin on growth and proliferation of SCC-25. Test agents were dissolved in DMSO and incubated in triplicates in 25 cm2 flasks in DMEM- HAM's F-12 (50:50)supplemented with 10% calf serum and antibiotics in an atmosphere 5% CO2 in air for 72 hours cell growth was determined by counting the number of cells in a hemocytometer. Cell proliferation was determined by measuring DNA synthesis by the incorporation of [3H]-thymidine in nuclear DNA. Cisplatin (0.1, 1.0, 10.0 microM) and curcumin (0.1, 1.0, 10.0 microM) induced significant dose-dependent inhibition in both cell growth as well as cell proliferation. Genistein and quercetin (1.0, 10.0, 100.0 microM) had biphasic effect, depending on their concentrations, on cell growth as well as cell proliferation. Based on these findings, it is concluded that curcumin is considerably more potent than genistein and quercetin, but cisplatin is five fold more potent than curcumin in inhibition of growth and DNA synthesis in SCC-25
Men with coronary artery disease have lower levels of androgens than men with normal coronary angiograms.
English KM, Mandour O, Steeds RP, et al.
Eur Heart J. 2000 Jun; 21(11):890-4.
AIMS: High androgen levels are presumed by many to explain the male predisposition to coronary artery disease. However, natural androgens inhibit male atherosclerosis(1). Our aim was to determine whether levels of androgens differ between men with and without coronary artery disease. METHODS AND RESULTS: Ninety male subjects (60 with positive, and 30 with negative coronary angiograms) were recruited. Early morning, fasting blood samples were taken from each patient and free, total and bioavailable testosterone, sex hormone binding globulin, oestradiol, and lipids were measured. Bioavailable testosterone was assayed using a modified technique. Free androgen index was calculated. Men with coronary artery disease had significantly lower levels of free testosterone (mean (standard deviation)); 47.95 (13.77) vs 59.87 (26. 05) pmol. l(-1), P=0.027), bioavailable testosterone; 2.55 (0.77) vs 3.26 (1.18) nmol. l(-1), P=0.005 and free androgen index; 37.8 (10. 4) vs 48.47 (18.3), P=0.005, than controls. After controlling for differences in age and body mass index the differences in free androgen index and bioavailable testosterone remained statistically significant (P=0.008 and P=0.013, respectively). CONCLUSION: Men with coronary artery disease have significantly lower levels of androgens than normal controls, challenging the preconception that physiologically high levels of androgens in men account for their increased relative risk for coronary artery disease
Vitamin C intake and mortality among a sample of the United States population.
Enstrom JE, Kanim LE, Klein MA.
Epidemiology. 1992 May; 3(3):194-202.
We examined the relation between vitamin C intake and mortality in the First National Health and Nutrition Examination Survey (NHANES I) Epidemiologic Follow-up Study cohort. This cohort is based on a representative sample of 11,348 noninstitutionalized U.S. adults age 25-74 years who were nutritionally examined during 1971-1974 and followed up for mortality (1,809 deaths) through 1984, a median of 10 years. An index of vitamin C intake has been formed from detailed dietary measurements and use of vitamin supplements. The relation of the standardized mortality ratio (SMR) for all causes of death to increasing vitamin C intake is strongly inverse for males and weakly inverse for females. Among those with the highest vitamin C intake, males have an SMR (95% confidence interval) of 0.65 (0.52-0.80) for all causes, 0.78 (0.50-1.17) for all cancers, and 0.58 (0.41-0.78) for all cardiovascular diseases; females have an SMR of 0.90 (0.74-1.09) for all causes, 0.86 (0.55-1.27) for all cancers, and 0.75 (0.55-0.99) for all cardiovascular diseases. Comparisons are made relative to all U.S. whites, for whom the SMR is defined to be 1.00. There is no clear relation for individual cancer sites, except possibly an inverse relation for esophagus and stomach cancer among males. The relation with all causes of death among males remains after adjustment for age, sex, and 10 potentially confounding variables (including cigarette smoking, education, race, and disease history)
n-3 Fatty acids and 5-y risks of death and cardiovascular disease events in patients with coronary artery disease.
Erkkila AT, Lehto S, Pyorala K, et al.
Am J Clin Nutr. 2003 Jul; 78(1):65-71.
BACKGROUND: Data on the association of n-3 fatty acid content in serum lipids with mortality in patients with coronary artery disease (CAD) are limited. OBJECTIVE: We hypothesized that a high proportion of n-3 fatty acids in serum lipids would be associated with reduced risks of death and coronary events in patients with established CAD. DESIGN: We measured dietary intakes via food records and the fatty acid composition of serum cholesteryl esters (CEs) in 285 men and 130 women with CAD (x age: 61 y; range: 33-74 y). The patients participating in the EUROASPIRE (European Action on Secondary Prevention through Intervention to Reduce Events) study were followed up for 5 y. RESULTS: During the follow-up, 36 patients died, 21 had myocardial infarctions, and 12 had strokes. The relative risks (RRs) of death adjusted for cardiovascular disease risk factors for subjects in the highest tertile of fatty acids in CEs compared with those in the lowest tertile were 0.33 (95% CI: 0.11, 0.96) for alpha-linolenic acid, 0.33 (0.12, 0.93) for eicosapentaenoic acid, and 0.31 (0.11, 0.87) for docosahexaenoic acid (P for trend = 0.063, 0.056, and 0.026, respectively). A high proportion of eicosapentaenoic acid in CEs was associated with a low risk of CAD death. Compared with no consumption, consumption of fish tended to be associated with a lower risk of death [1-57 g/d, RR = 0.50 (0.20, 1.28); > 57 g/d, RR = 0.37 (0.14, 1.00); P for trend = 0.059]. CONCLUSION: High proportions of n-3 fatty acids in serum lipids are associated with a substantially reduced risk of death
Fibrinogen as a cardiovascular risk factor: a meta-analysis and review of the literature.
Ernst E, Resch KL.
Ann Intern Med. 1993 Jun 15; 118(12):956-63.
PURPOSE: To evaluate the possibility that fibrinogen represents a cardiovascular risk factor. DATA IDENTIFICATION: A computerized literature search (1980 to 1992) identified all published epidemiologic studies on fibrinogen and cardiovascular disease. Clinical and basic research data were found by separate searches. References of all papers thus obtained were studied and relevant papers included. STUDY SELECTION: Six prospective epidemiologic studies were included in a meta-analysis (one study was excluded because the study population was non-representative). Clinical papers were reviewed separately for other evidence of causation. DATA EXTRACTION: The correlation of fibrinogen levels on the subsequent incidence of myocardial infarction, stroke, and peripheral arterial occlusive disease was assessed and the causality of the association was analyzed. Calculations were made to examine fibrinogen level (in tertiles) versus cardiovascular risk. Odds ratios of high versus low tertile were computed. RESULTS OF DATA ANALYSIS: All prospective studies showed that fibrinogen was associated with subsequent myocardial infarction or stroke. A total of 92,147 person-years was covered by these investigations. Odds ratios varied between 1.8 (95% CI, 1.2 to 2.5) in the Framingham and 4.1 (CI, 2.3 to 6.9) in the GRIPS study, with a summary odds ratio of 2.3 (CI, 1.9 to 2.8). Associations existed between fibrinogen and other cardiovascular risk factors, but after multivariate analysis, only the association between fibrinogen and cardiovascular events remained. The majority of the preconditions for causality were fulfilled, indicating that fibrinogen is pathophysiologically related to cardiovascular events. CONCLUSIONS: Fibrinogen can be considered a major cardiovascular risk factor. Future studies of cardiovascular morbidity and death should include this variable
The effect of nisoldipine as compared with enalapril on cardiovascular outcomes in patients with non-insulin-dependent diabetes and hypertension.
Estacio RO, Jeffers BW, Hiatt WR, et al.
N Engl J Med. 1998 Mar 5; 338(10):645-52.
BACKGROUND: It has recently been reported that the use of calcium-channel blockers for hypertension may be associated with an increased risk of cardiovascular complications. Because this issue remains controversial, we studied the incidence of such complications in patients with non-insulin-dependent diabetes mellitus and hypertension who were randomly assigned to treatment with either the calcium-channel blocker nisoldipine or the angiotensin-converting-enzyme inhibitor enalapril as part of a larger study. METHODS: The Appropriate Blood Pressure Control in Diabetes (ABCD) Trial is a prospective, randomized, blinded trial comparing the effects of moderate control of blood pressure (target diastolic pressure, 80 to 89 mm Hg) with those of intensive control of blood pressure (diastolic pressure, 75 mm Hg) on the incidence and progression of complications of diabetes. The study also compared nisoldipine with enalapril as a first-line antihypertensive agent in terms of the prevention and progression of complications of diabetes. In the current study, we analyzed data on a secondary end point (the incidence of myocardial infarction) in the subgroup of patients in the ABCD Trial who had hypertension. RESULTS: Analysis of the 470 patients in the trial who had hypertension (base-line diastolic blood pressure, > or = 90 mm Hg) showed similar control of blood pressure, blood glucose and lipid concentrations, and smoking behavior in the nisoldipine group (237 patients) and the enalapril group (233 patients) throughout five years of follow-up. Using a multiple logistic-regression model with adjustment for cardiac risk factors, we found that nisoldipine was associated with a higher incidence of fatal and nonfatal myocardial infarctions (a total of 24) than enalapril (total, 4) (risk ratio, 9.5; 95 percent confidence interval, 2.7 to 33.8). CONCLUSIONS: In this population of patients with diabetes and hypertension, we found a significantly higher incidence of fatal and nonfatal myocardial infarction among those assigned to therapy with the calcium-channel blocker nisoldipine than among those assigned to receive enalapril. Since our findings are based on a secondary end point, they will require confirmation
Hyperhomocysteinemia: an additional cardiovascular risk factor.
Fanapour PC, Yug B, Kochar MS.
WMJ. 1999 Dec; 98(8):51-4.
Over the past few years, a substantial body of evidence has accumulated that indicates hyperhomocysteinemia as a significant risk factor for cardiovascular disease. Hyperhomocysteinemia arises from a lack of key enzymes or vitamins such as methylenetetrahydrofolate reductase, vitamin B6, and folate which are involved in homocysteine metabolism. Heavy coffee consumption is also known to elevate homocysteine levels. The adverse effects associated with hyperhomocysteinemia are extensive. It increases risk of myocardial infarction, cardiovascular-related morbidity and mortality, peripheral vascular disease, atherosclerosis, coronary heart disease, and cerebrovascular disease. Its seriousness as a risk factor has been equated to hypercholesterolemia and smoking, two leading causes for cardiovascular disease. It also has been shown to produce a multiplicative effect with these and other risk factors such as hypertension. Two major hypotheses have been proposed to explain how homocysteine induces its harmful effects. It can damage endothelial cells lining the vasculature, allowing plaque formation. Simultaneously, it interferes with the vasodilatory effect of endothelial derived nitric oxide. Also, homocysteine has been found to promote vascular smooth muscle cells hypertrophy. Both of these processes induce vessel occlusion. Maintaining a normal plasma level of homocysteine as a means to prevent cardiovascular disease appears promising. This is achieved through increased intake of folate and vitamin B6 through diet or supplementation. Despite the overwhelming evidence suggesting homocysteine as a significant risk factor, no long-term prospective studies have been completed to demonstrate that folate and vitamin B6 can prevent cardiovascular disease related morbidity and mortality in patients with hyperhomocysteinemia. Homocysteine is a key metabolite in amino acid synthesis. During the process of methylation, S-adenosylmethionine (Ado Met), derived from methionine, is converted to S-Adenosylhomocysteine (Figure 1). This product is quickly hydrolyzed to form homocysteine and adenosine. Homocysteine can undergo 1 of 3 reactions depending on the status of the organism. If cysteine levels are inadequate, homocysteine utilizes the coenzyme pyridoxal phosphate (vitamin B6) to condense with serine, forming the intermediate cystathionine. Subsequent reactions with cystathionine lead to the formation of cysteine. When methionine levels are low, homocysteine is remethylated in a reaction involving the coenzyme N5-methyltetrahydrofolate or betaine. Finally, when both amino acids are in adequate supply, homocysteine is cleaved by the enzyme homocysteine desulthydrase (cystathionase) to form a-ketobutyrate, ammonia, and H2S. Thus, homocysteine's physiological role is to assist in maintaining sulfur-amino acid homeostasis. Beyond these metabolic processes, homocysteine is beginning to be recognized as a significant risk factor for cardiovascular disease including atherosclerosis, coronary artery disease, cerebrovascular disease, and myocardial infarction
New Health Claim Proposed for Relationship of Soy Protein and Coronary Heart Disease.
1998;1998 Nov 10
Fibrinolytic and antithrombotic action of bromelain may eliminate thrombosis in heart patients.
Med Hypotheses. 1980 Nov; 6(11):1123-33.
It has been established that a bromelain plasminogen activator will produce plasmin in rat experiments. In addition the plasmin cleaves Hageman factor in a way that leads to a strong release of kallikrein but a weak release of thrombin. A possible mechanism is suggested to explain how the body can maintain thrombin at a level too low to cause platelet aggregation but adequate to stimulate release of prostaglandins and enzymes for more than 24 hours from a single dose of the pineapple enzymes. Since bromelain therapy leads to formation of platelets with increased resistance to aggregation, it is obvious that the dominant endogenous prostaglandins being produced must be from the group that increases platelet cyclicAMP levels (prostacyclin, PGE1, etc.). The combination of fibrinolytic and antithrombic properties appear to be effective and two large scale tests on heart patients have shown a practically complete elimination of thrombosis
Hypercholesterolemia decreases nitric oxide production by promoting the interaction of caveolin and endothelial nitric oxide synthase.
Feron O, Dessy C, Moniotte S, et al.
J Clin Invest. 1999 Mar; 103(6):897-905.
Hypercholesterolemia is a central pathogenic factor of endothelial dysfunction caused in part by an impairment of endothelial nitric oxide (NO) production through mechanisms that remain poorly characterized. The activity of the endothelial isoform of NO synthase (eNOS) was recently shown to be modulated by its reciprocal interactions with the stimulatory Ca2+-calmodulin complex and the inhibitory protein caveolin. We examined whether hypercholesterolemia may reduce NO production through alteration of this regulatory equilibrium. Bovine aortic endothelial cells were cultured in the presence of serum obtained from normocholesterolemic (NC) or hypercholesterolemic (HC) human volunteers. Exposure of endothelial cells to the HC serum upregulated caveolin abundance without any measurable effect on eNOS protein levels. This effect of HC serum was associated with an impairment of basal NO release paralleled by an increase in inhibitory caveolin-eNOS complex formation. Similar treatment with HC serum significantly attenuated the NO production stimulated by the calcium ionophore A23187. Accordingly, higher calmodulin levels were required to disrupt the enhanced caveolin-eNOS heterocomplex from HC serum-treated cells. Finally, cell exposure to the low-density lipoprotein (LDL) fraction alone dose-dependently reproduced the inhibition of basal and stimulated NO release, as well as the upregulation of caveolin expression and its heterocomplex formation with eNOS, which were unaffected by cotreatment with antioxidants. Together, our data establish a new mechanism for the cholesterol-induced impairment of NO production through the modulation of caveolin abundance in endothelial cells, a mechanism that may participate in the pathogenesis of endothelial dysfunction and the proatherogenic effects of hypercholesterolemia
Methionine metabolism in mammals. Distribution of homocysteine between competing pathways.
Finkelstein JD, Martin JJ.
J Biol Chem. 1984 Aug 10; 259(15):9508-13.
Using an in vitro system which contained enzymes, substrates, and other reactants at concentrations which approximated the in vivo conditions in rat liver, we measured the simultaneous product formation by three enzymes which utilize homocysteine. In the control system, 5-methyltetrahydrofolate homocysteine methyltransferase, betaine homocysteine methyltransferase, and cystathionine beta-synthase accounted for 27, 27, and 46%, respectively, of the homocysteine consumed. Subsequent studies demonstrated that the adaptation from a high protein diet to a low protein diet is achieved by a significant increase in betaine homocysteine methyltransferase, and 83% reduction in cystathionine synthase, and a total decrease of 55% in the consumption of homocysteine. S-Adenosylmethionine, by activating cystathionine synthase, contributes significantly to the regulation of the pathway
Methionine metabolism in mammals. Adaptation to methionine excess.
Finkelstein JD, Martin JJ.
J Biol Chem. 1986 Feb 5; 261(4):1582-7.
We conducted a systematic evaluation of the effects of increasing levels of dietary methionine on the metabolites and enzymes of methionine metabolism in rat liver. Significant decreases in hepatic concentrations of betaine and serine occurred when the dietary methionine was raised from 0.3 to 1.0%. We observed increased concentrations of S-adenosylhomocysteine in livers of rats fed 1.5% methionine and of S-adenosylmethionine and methionine only when the diet contained 3.0% methionine. Methionine supplementation resulted in decreased hepatic levels of methyltetrahydrofolate-homocysteine methyltransferase and increased levels of methionine adenosyltransferase, betaine-homocysteine methyltransferase, and cystathionine synthase. We used these data to simulate the regulatory locus formed by the enzymes which metabolize homocysteine in livers of rats fed 0.3% methionine, 1.5% methionine, and 3.0% methionine. In comparison to the model for the 0.3% methionine diet group, the model for the 3.0% methionine animals demonstrates a 12-fold increase in the synthesis of cystathionine, a 150% increase in flow through the betaine reaction, and a 550% increase in total metabolism of homocysteine. The concentrations of substrates and other metabolites are significant determinants of this apparent adaptation
Therapeutic profile and mechanism of action of artichoke leaf extract: hypolipemic, antioxidant, hepatoprotective and choleretic properties.
Phytomedicine. 1996;(Suppl. 1):50.
Antidyspeptic and lipid lowering effect of an extract from artichoke leaves, results of clinical trials on efficacy and tulerability of Hepar-SL in 553 patients.
Z Allg Med. 2004;(73):3-19.
Lovastatin decreases coenzyme Q levels in humans.
Folkers K, Langsjoen P, Willis R, et al.
Proc Natl Acad Sci U S A. 1990 Nov; 87(22):8931-4.
Lovastatin is clinically used to treat patients with hypercholesterolemia and successfully lowers cholesterol levels. The mechanism of action of lovastatin is inhibition of 3-hydroxy-3-methylglutaryl-coenzyme A reductase, an enzyme involved in the biosynthesis of cholesterol from acetyl-CoA. Inhibition of this enzyme could also inhibit the intrinsic biosynthesis of coenzyme Q10 (CoQ10), but there have not been definitive data on whether lovastatin reduces levels of CoQ10 as it does cholesterol. The clinical use of lovastatin is to reduce a risk of cardiac disease, and if lovastatin were to reduce levels of CoQ10, this reduction would constitute a new risk of cardiac disease, since it is established that CoQ10 is indispensable for cardiac function. We have conducted three related protocols to determine whether lovastatin does indeed inhibit the biosynthesis of CoQ10. One protocol was done on rats, and is reported in the preceding paper [Willis, R. A., Folkers, K., Tucker, J. L., Ye, C.-Q., Xia, L.-J. & Tamagawa, H. (1990) Proc. Natl. Acad. Sci. USA 87, 8928-8930]. The other two protocols are reported here. One involved patients in a hospital, and the other involved a volunteer who permitted extraordinary monitoring of CoQ10 and cholesterol levels and cardiac function. All data from the three protocols revealed that lovastatin does indeed lower levels of CoQ10. The five hospitalized patients, 43-72 years old, revealed increased cardiac disease from lovastatin, which was life-threatening for patients having class IV cardiomyopathy before lovastatin or after taking lovastatin. Oral administration of CoQ10 increased blood levels of CoQ10 and was generally accompanied by an improvement in cardiac function. Although a successful drug, lovastatin does have side effects, particularly including liver dysfunction, which presumably can be caused by the lovastatin-induced deficiency of CoQ10
Does exercise reduce inflammation? Physical activity and C-reactive protein among U.S. adults.
Epidemiology. 2002 Sep; 13(5):561-8.
BACKGROUND: Physical activity may lower the risk for coronary heart disease by mitigating inflammation, which plays a key role in the pathophysiology of atherosclerosis. The purpose of this study was to examine the association between physical activity and C-reactive protein concentration in a national sample of the U.S. population. METHODS: The analytic sample included 13,748 participants >or=20 years of age in the National Health and Nutrition Examination Survey III (1988-1994) with complete data for the main study variables. RESULTS: After adjusting for age, sex, ethnicity, education, work status, smoking status, cotinine concentration, hypertension, body mass index, waist-to-hip ratio, high-density lipoprotein cholesterol concentration, and aspirin use, the odds ratios for elevated C-reactive protein concentration (dichotomized at the >or=85th percentile of the sex-specific distribution) were 0.98 (95% confidence interval = 0.78-1.23), 0.85 (0.70-1.02), and 0.53 (0.40-0.71) for participants who engaged in light, moderate, and vigorous physical activity, respectively, during the previous month compared with participants who did not engage in any leisure-time physical activity. In addition, leisure-time physical activity was positively associated with serum albumin concentration and inversely associated with both log-transformed plasma fibrinogen concentration and log-transformed white blood cell count. CONCLUSIONS: These results add to mounting evidence that physical activity may reduce inflammation, which is a critical process in the pathogenesis of cardiovascular disease
AAP News. 1997;1997 Jul 32(7):4.
Healthy Gums For A Healthy Heart.
AAP News 1997. 1997;1997 Jul. 32(7):4.
Curcumin trial finds no activity.
Gilden D, Smart T.
GMHC Treat Issues. 1996 Feb; 10(2):9.
Clinical trial experience with extended-release niacin (Niaspan): dose-escalation study.
Am J Cardiol. 1998 Dec 17; 82(12A):35U-8U.
Niacin is a useful lipid-modifying drug because it (1) decreases low-density lipoprotein (LDL) cholesterol, total cholesterol, triglycerides, and lipoprotein(a), and (2) raises high-density lipoprotein (HDL) cholesterol. Its use tends to be limited by side effects and inconvenient dosing regimens. The availability of an extended-release preparation (Niaspan-which has safety and efficacy similar to immediate-release niacin but which can be given once a day) provides an opportunity to increase the use of this effective lipid-modifying agent. To study the safety and efficacy of escalating doses of extended-release niacin, hyperlipidemic patients were randomly assigned to placebo or Niaspan. A forced dose-titration was done with the dosage increasing by 500 mg every 4 weeks to a maximum of 3,000 mg/day. Niaspan showed dose-related changes in total, LDL, and HDL cholesterol levels, triglycerides, cholesterol/HDL ratio, and lipoprotein(a). At a dosage of 2,000 mg/day, total cholesterol decreased by 12.1%, LDL cholesterol by 16.7%, triglycerides by 34.5%, and lipoprotein(a) by 23.6%; HDL cholesterol increased by 25.8%. Flushing was the most commonly reported side effect; flushing episodes tended to decrease with time despite an increasing dose of niacin. Of the reported side effects, only pruritus and rash were significantly different between the 2 groups. Aspartate aminotransferase, lactate dehydrogenase, and uric acid increased in a dose-dependent fashion, but fasting blood sugar increased by about 5% across most dosages. Two subjects had aspartate aminotransferase levels greater than twice the upper limit of normal, but there were no subjects in whom transaminases increased to 3 times the upper limit of normal. Women tended to have a greater LDL cholesterol response to the medication and also experienced more side effects, especially at higher dosages. Thus, the use of lower dosages of niacin may be desirable in women. The results of this dose-escalation study show beneficial effects of Niaspan on the entire lipid profile. At the maximum recommended dosage of 2,000 mg/day, all lipid and lipoprotein levels changed in desirable directions. Side effects (other than flushing) and blood chemistries were comparable to those seen with immediate-release niacin
Persistent C-reactive protein elevation predicts restenosis after stent implantation.
Eur Heart J. 2000;(21):1152-8.
Results of a second-opinion program for coronary artery bypass graft surgery.
Graboys TB, Headley A, Lown B, et al.
JAMA. 1987 Sep 25; 258(12):1611-4.
Second opinions for surgical procedures are now being sought by patients or are required by insurance carriers. We examined outcomes among 88 patients (76 men; average age, 59 years) referred for a second opinion as to the need for coronary artery bypass graft surgery. All patients had undergone coronary arteriography, which disclosed in 63 (72%) multivessel coronary artery disease, while in the remaining 25 patients single-vessel disease involved the left anterior descending coronary artery. Continuation of medical therapy was recommended for 74 (84%) of the 88 patients. Sixty of these 74 patients chose this option and continued to receive medical therapy without any fatalities during a follow-up period of 27.8 months. The remaining 14 patients elected to cross over to surgical therapy at an average of 11.3 months from the second opinion. We conclude that second opinions for selected, motivated patients slated for coronary artery bypass graft operation afford a significant and safe option. Moreover, a majority of patients will adhere to a second opinion recommending medical therapy, thus reducing the need for surgical intervention by as much as 50%. Since the study was based on a small sample size of self-selected patients, these data require caution in extrapolating to the general population with coronary artery disease
Heart and Estrogen/progestin Replacement Study (HERS): design, methods, and baseline characteristics.
Grady D, Applegate W, Bush T, et al.
Control Clin Trials. 1998 Aug; 19(4):314-35.
The Heart and Estrogen/progestin Replacement Study (HERS) is a randomized, double-blind, placebo-controlled trial designed to test the efficacy and safety of estrogen plus progestin therapy for prevention of recurrent coronary heart disease (CHD) events in women. The participants are postmenopausal women with a uterus and with CHD as evidenced by prior myocardial infarction, coronary artery bypass graft surgery, percutaneous transluminal coronary angioplasty, or other mechanical revascularization or at least 50% occlusion of a major coronary artery. Between February 1993 and September 1994, 20 HERS centers recruited and randomized 2763 women. Participants ranged in age from 44 to 79 years, with a mean age of 66.7 (SD 6.7) years. Most participants were white (89%), married (57%), and had completed high school or some college (80%). As expected, the prevalence of coronary risk factors was high: 62% were past or current smokers, 59% had hypertension, 90% had serum LDL-cholesterol of 100 mg/dL or higher, and 23% had diabetes. Each woman was randomly assigned to receive one tablet containing 0.625 mg conjugated estrogens plus 2.5 mg medroxyprogesterone acetate daily or an identical placebo. Participants will be evaluated every 4 months for an average of 4.2 years for the occurrence of CHD events (CHD death and nonfatal myocardial infarction). We will also assess other major CHD endpoints, including revascularization and hospitalization for unstable angina. The primary analysis will compare the rate of CHD events in women assigned to active treatment with the rate in those assigned to placebo. The trial was designed to have power greater than 90% to detect a 35% reduction in the incidence of CHD events, assuming a 50% lag in effect for 2 years and a 5% annual event rate in the placebo group. The design, analysis, and conduct of the study are controlled by the Steering Committee of Principal Investigators and coordinated at the University of California, San Francisco. HERS is the largest trial of any intervention to reduce the risk of recurrent CHD events in women with heart disease and is the first controlled trial to seek evidence of the efficacy and safety of postmenopausal hormone therapy to prevent recurrent CHD events
Plasma homocysteine as a risk factor for vascular disease. The European Concerted Action Project.
Graham IM, Daly LE, Refsum HM, et al.
JAMA. 1997 Jun 11; 277(22):1775-81.
CONTEXT: Elevated plasma homocysteine is a known risk factor for atherosclerotic vascular disease, but the strength of the relationship and the interaction of plasma homocysteine with other risk factors are unclear. OBJECTIVE: To establish the magnitude of the vascular disease risk associated with an increased plasma homocysteine level and to examine interaction effects between elevated plasma homocysteine level and conventional risk factors. DESIGN: Case-control study. SETTING: Nineteen centers in 9 European countries. PATIENTS: A total of 750 cases of atherosclerotic vascular disease (cardiac, cerebral, and peripheral) and 800 controls of both sexes younger than 60 years. MEASUREMENTS: Plasma total homocysteine was measured while subjects were fasting and after a standardized methionine-loading test, which involves the administration of 100 mg of methionine per kilogram and stresses the metabolic pathway responsible for the irreversible degradation of homocysteine. Plasma cobalamin, pyridoxal 5'-phosphate, red blood cell folate, serum cholesterol, smoking, and blood pressure were also measured. RESULTS: The relative risk for vascular disease in the top fifth compared with the bottom four fifths of the control fasting total homocysteine distribution was 2.2 (95% confidence interval, 1.6-2.9). Methionine loading identified an additional 27% of at-risk cases. A dose-response effect was noted between total homocysteine level and risk. The risk was similar to and independent of that of other risk factors, but interaction effects were noted between homocysteine and these risk factors; for both sexes combined, an increased fasting homocysteine level showed a more than multiplicative effect on risk in smokers and in hypertensive subjects. Red blood cell folate, cobalamin, and pyridoxal phosphate, all of which modulate homocysteine metabolism, were inversely related to total homocysteine levels. Compared with nonusers of vitamin supplements, the small number of subjects taking such vitamins appeared to have a substantially lower risk of vascular disease, a proportion of which was attributable to lower plasma homocysteine levels. CONCLUSIONS: An increased plasma total homocysteine level confers an independent risk of vascular disease similar to that of smoking or hyperlipidemia. It powerfully increases the risk associated with smoking and hypertension. It is time to undertake randomized controlled trials of the effect of vitamins that reduce plasma homocysteine levels on vascular disease risk
Physical performance support with combined phytotherapy. Ginseng, whitethorn and mixed pollen combination against stress.
Therapiewoche. 1996; 46(25):1421-5.
Co-enzyme Q10: a new drug for cardiovascular disease.
Greenberg S, Frishman WH.
J Clin Pharmacol. 1990 Jul; 30(7):596-608.
Co-enzyme Q10 (ubiquinone) is a naturally occurring substance which has properties potentially beneficial for preventing cellular damage during myocardial ischemia and reperfusion. It plays a role in oxidative phosphorylation and has membrane stabilizing activity. The substance has been used in oral form to treat various cardiovascular disorders including angina pectoris, hypertension, and congestive heart failure. Its clinical importance is now being established in clinical trails worldwide
Primed, constant infusion with [2H3]serine allows in vivo kinetic measurement of serine turnover, homocysteine remethylation, and transsulfuration processes in human one-carbon metabolism.
Gregory JF, III, Cuskelly GJ, Shane B, et al.
Am J Clin Nutr. 2000 Dec; 72(6):1535-41.
BACKGROUND: One-carbon metabolism involves both mitochondrial and cytosolic forms of folate-dependent enzymes in mammalian cells, but few in vivo data exist to characterize the biochemical processes involved. OBJECTIVE: We conducted a stable-isotopic investigation to determine the fates of exogenous serine and serine-derived one-carbon units in homocysteine remethylation in hepatic and whole-body metabolism. DESIGN: A healthy man aged 23 y was administered [2,3,3-(2)H(3)]serine and [5,5,5-(2)H(3)]leucine by intravenous primed, constant infusion. Serial plasma samples were analyzed to determine the isotopic enrichment of free glycine, serine, leucine, methionine, and cystathionine. VLDL apolipoprotein B-100 served as an index of liver free amino acid labeling. RESULTS: [(2)H(1)]Methionine and [(2)H(2)]methionine were labeled through homocysteine remethylation. We propose that [(2)H(2)]methionine occurs by remethylation with [(2)H(2)]methyl groups (as 5-methyltetrahydrofolate) formed only from cytosolic processing of [(2)H(3)]serine, whereas [(2)H(1)]methionine is formed with labeled one-carbon units from mitochondrial oxidation of C-3 serine to [(2)H(1)]formate to yield cytosolic [(2)H(1)]methyl groups. The labeling pattern of cystathionine formed from homocysteine and labeled serine suggests that cystathionine is derived mainly from a serine pool different from that used in apolipoprotein B-100 synthesis. CONCLUSIONS: The appearance of both [(2)H(1)]- and [(2)H(2)]methionine forms indicates that both cytosolic and mitochondrial metabolism of exogenous serine generates carbon units in vivo for methyl group production and homocysteine remethylation. This study also showed the utility of serine infusion and indicated functional roles of cytosolic and mitochondrial compartments in one-carbon metabolism
Cholesterol: The Devil Is in the Details: Apolipoproteins Provide Advanced Warning of Death from Heart Attack.
2001;2001 Jan 9 9
Gene May Affect Impact of Estrogen Therapy on Cholesterol 2002.
AIMilano apoprotein identification of the complete kindred and evidence of a dominant genetic transmission.
Gualandri V, Franceschini G, Sirtori CR, et al.
Am J Hum Genet. 1985 Nov; 37(6):1083-97.
The AIMilano apoprotein variant is associated with a marked reduction of high density lipoprotein (HDL) cholesterol levels and with increased triglyceridemia. In spite of the low HDL-cholesterol (HDL-Ch), carriers do not generally show clinical signs of atherosclerosis. The biochemical disorder is linked to a molecular change in apoprotein AI, that is, an arg----cys substitution in the 173 position, thus allowing the formation of AIMilano-AIMilano dimers and AIMilano-AII complexes. The origin of the variant gene has been located in Limone sul Garda, a small community in Northern Italy (about 1,000 individuals). This community has a genetic, biochemical, and clinical individuality, consequent to its isolation up to a few years ago; the citizens show highly uniform alimentary habits and elevated consanguinity. The complete population of the small village was sampled, and, by the use of an analytical isoelectric focusing technique for the detection of the mutant, a total of 33 living carriers, ranging in age from 2 to 81 yrs, were identified. Analysis of the genealogic tree of the complete family groups showed that the apoprotein (apo) AIMilano is transmitted as an autosomal dominant trait, all carriers coming from a single mating couple, living in the eighteenth century. The carriers are heterozygous for the apoprotein variant
[Hyperhomocysteinemia: an independent risk factor or a simple marker of vascular disease?. 1. Basic data].
Guilland JC, Favier A, Potier dC, et al.
Pathol Biol (Paris). 2003 Mar; 51(2):101-10.
Recent epidemiological studies have suggested that hyperhomocysteinemia is associated with increased risk of vascular disease. Homocysteine is a sulphur-containing amino acid whose metabolism stands at the intersection of two pathways: remethylation to methionine, which requires folate and vitamin B12 (or betaine in an alternative reaction); and transsulfuration to cystathionine which requires vitamin B6. The two pathways are coordinated by S-adenosylmethionine which acts as an allosteric inhibitor of the methylenetetrahydrofolate reductase (MTHFR) and as an activator of cystathionine beta-synthase (CBS). Hyperhomocysteinemia arises from disrupted homocysteine metabolism. Severe hyperhomocysteinemia is due to rare genetic defects resulting in deficiencies in CBS, MTHFR, or in enzymes involved in methyl cobalamine synthesis and homocysteine methylation. Mild hyperhomocysteinemia seen in fasting condition is due to mild impairment in the methylation pathway (i.e. folate or B12 deficiencies or MTHFR thermolability). Post-methionine-load hyperhomocysteinaemia may be due to heterozygous cystathionine-beta-synthase defect or B6 deficiency. Patients with homocystinuria and severe hyperhomocysteinemia develop arterial thrombotic events, venous thromboembolism, and more seldom premature arteriosclerosis. Experimental evidence suggests that an increased concentration of homocysteine may result in vascular changes through several mechanisms. High levels of homocysteine induce sustained injury of arterial endothelial cells, proliferation of arterial smooth muscle cells and enhance expression/activity of key participants in vascular inflammation, atherogenesis, and vulnerability of the established atherosclerotic plaque. These effects are supposed to be mediated through its oxidation and the concomitant production of reactive oxygen species. Other effects of homocysteine include: impaired generation and decreased bioavailability of endothelium-derived relaxing factor/nitric oxide; interference with many transcription factors and signal transduction; oxidation of low-density lipoproteins; lowering of endothelium-dependent vasodilatation. In fact, the effect of elevated homocysteine appears multifactorial affecting both the vascular wall structure and the blood coagulation system
Impact of controlling risk factors after myocardial infarction.
Guize L IMHPLTLHJ.
Arch Mal Coeur Vaiss. 1995;(3):51-7.
Aspirin use and all-cause mortality among patients being evaluated for known or suspected coronary artery disease: A propensity analysis.
Gum PA, Thamilarasan M, Watanabe J, et al.
JAMA. 2001 Sep 12; 286(10):1187-94.
CONTEXT: Although aspirin has been shown to reduce cardiovascular morbidity and short-term mortality following acute myocardial infarction, the association between its use and long-term all-cause mortality has not been well defined. OBJECTIVES: To determine whether aspirin is associated with a mortality benefit in stable patients with known or suspected coronary disease and to identify patient characteristics that predict the maximum absolute mortality benefit from aspirin. DESIGN AND SETTING: Prospective, nonrandomized, observational cohort study conducted between 1990 and 1998 at an academic medical institution, with a median follow-up of 3.1 years. PATIENTS: Of 6174 consecutive adults undergoing stress echocardiography for evaluation of known or suspected coronary disease, 2310 (37%) were taking aspirin. Patients with significant valvular disease or documented contraindication to aspirin use, including peptic ulcer disease, renal insufficiency, and use of nonsteroidal anti-inflammatory drugs, were excluded. MAIN OUTCOME MEASURE: All-cause mortality according to aspirin use. RESULTS: During 3.1 years of follow-up, 276 patients (4.5%) died. In a simple univariable analysis, there was no association between aspirin use and mortality (4.5% vs 4.5%). However, after adjustment for age, sex, standard cardiovascular risk factors, use of other medications, coronary disease history, ejection fraction, exercise capacity, heart rate recovery, and echocardiographic ischemia, aspirin use was associated with reduced mortality (hazard ratio [HR], 0.67; 95% confidence interval [CI], 0.51-0.87; P =.002). In further analysis using matching by propensity score, 1351 patients who were taking aspirin were at lower risk for death than 1351 patients not using aspirin (4% vs 8%, respectively; HR, 0.53; 95% CI, 0.38-0.74; P =.002). After adjusting for the propensity for using aspirin, as well as other possible confounders and interactions, aspirin use remained associated with a lower risk for death (adjusted HR, 0.56; 95% CI, 0.40-0.78; P<.001). The patient characteristics associated with the most aspirin-related reductions in mortality were older age, known coronary artery disease, and impaired exercise capacity. CONCLUSION: Aspirin use among patients undergoing stress echocardiography was independently associated with reduced long-term all-cause mortality, particularly among older patients, those with known coronary artery disease, and those with impaired exercise capacity
Design and development of integrase inhibitors as anti-HIV agents.
Gupta SP, Nagappa AN.
Curr Med Chem. 2003 Sep; 10(18):1779-94.
A review is presented on different categories of compounds that have been studied for the inhibition of the HIV-1 integrase to develop anti-HIV agents. These compounds are: oligonucleotides (double-stranded, triplex, and G-quartet), curcumin analogues, polyhydroxylated aromatic compounds, diketo acids, caffeoyl- and galloyl - based compounds, hydrazides and amides, tetracyclines, and depsides and depsidones. For all these compounds, the important structural features essential for the inhibition of the integrase are pointed out
Effect of topical application of coenzyme Q10 on adult periodontitis.
Hanioka T, Tanaka M, Ojima M, et al.
Mol Aspects Med. 1994; 15 Suppl:s241-s248.
Topical application of Coenzyme Q10 (CoQ10) to the periodontal pocket was evaluated with and without subgingival mechanical debridement. Ten male patients with adult periodontitis participated and 30 periodontal pockets were selected. During the first 3 weeks, the patients did not receive any periodontal therapy except the topical application of CoQ10. After the first 3-week period, root planning and subgingival scaling were performed in all sites. CoQ10 was applied in 20 of the pockets once a week for a period of 6 weeks. Soybean oil was applied to the remaining 10 sites as a control. In the first 3-week period, significant reductions in gingival crevicular fluid flow, probing depth and attachment loss were found only at experimental sites. After mechanical subgingival debridement, significant decreases in the plaque index, gingival crevicular fluid flow, probing depth and attachment loss were found both at experimental and control sites. However, significant improvements in the modified gingival index, bleeding on probing and peptidase activity derived from periodontopathic bacteria were observed only at experimental sites. These results suggest that topical application of CoQ10 improves adult periodontitis not only as a sole treatment but also in combination with traditional nonsurgical periodontal therapy
Effects of aspirin treatment on survival in non-insulin-dependent diabetic patients with coronary artery disease. Israeli Bezafibrate Infarction Prevention Study Group.
Harpaz D, Gottlieb S, Graff E, et al.
Am J Med. 1998 Dec; 105(6):494-9.
PURPOSE: The benefit of aspirin treatment among diabetic patients with chronic coronary artery disease is not well established. The purpose of this study was to assess the effect of aspirin on cardiac and total mortality in a large cohort of diabetic patients with established coronary artery disease and to compare it with the effect of aspirin in nondiabetic counterparts. PATIENTS AND METHODS: In this observational study among patients screened for participation in the Bezafibrate Infarction Prevention Study, the effects of aspirin treatment in 2,368 non-insulin-dependent diabetic patients with coronary artery disease were compared to those in 8,586 nondiabetic patients. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated with proportional hazards models. RESULTS: Fifty-two percent of diabetic patients and 56% of nondiabetic patients reported aspirin therapy. After 5.1 +/- 1.3 (mean +/- SD) years of follow-up, the absolute benefit per 100 patients treated with aspirin was greater in diabetic patients than in nondiabetic patients (cardiac mortality benefit: 5.0 versus 2.1, and all-cause mortality benefit: 7.8 versus 4.1). Overall cardiac mortality among diabetic patients treated with aspirin was 10.9% versus 15.9% in the nonaspirin group (P < 0.001), and all-cause mortality was 18.4% and 26.2% (P < 0.001). After adjustment for possible confounders, treatment with aspirin was an independent predictor of reduced overall cardiac (HR = "0.8;" 95% CI: 0.6-1.0) and all-cause mortality (HR = "0.8;" 95% CI: 0.7-0.9) among diabetic patients, similar to those in nondiabetic patients. CONCLUSION: Treatment with aspirin was associated with a significant reduction in cardiac and total mortality among non-insulin-dependent diabetic patients with coronary artery disease. The absolute benefit of aspirin was greater in diabetic patients than in those without diabetes
Aspirin for the primary prevention of stroke and other major vascular events: meta-analysis and hypotheses.
Hart RG, Halperin JL, McBride R, et al.
Arch Neurol. 2000 Mar; 57(3):326-32.
BACKGROUND: Aspirin therapy reduces stroke by about 25% for persons with atherosclerotic vascular disease, but the effect in those without clinically apparent vascular disease is distinctly different. OBJECTIVE: To define the effect of aspirin use on stroke and other major vascular events when given for primary prevention to persons without clinically recognized vascular disease. DATA SOURCES AND EXTRACTION: Systematic review of randomized clinical trials and large prospective observational cohort studies examining the relation between aspirin use and stroke in persons at low intrinsic risk. Studies were identified by a computerized search of the English-language literature. DATA SYNTHESIS: Five randomized trials of primary prevention included 52 251 participants randomized to aspirin doses ranging from 75 to 650 mg/d; the mean overall stroke rate was 0.3% per year during an average follow-up of 4.6 years. Meta-analysis revealed no significant effect on stroke (relative risk = 1.08; 95% confidence interval, 0.95-1.24) contrasting with a decrease in myocardial infarction (relative risk = 0.74; 95% confidence interval, 0.68-0.82). The lack of reduction of stroke by aspirin for primary prevention was incompatible with its protective effect against stroke in patients with manifest vascular disease (P = .001). Intracranial hemorrhage was increased by the regular use of aspirin (relative risk = 1.35; P = .03), similarly for both primary and secondary prevention. In 4 large observational studies, self-selected use of aspirin was consistently associated with higher rates of stroke. CONCLUSIONS: The effect of aspirin therapy on stroke differs between individuals based on the presence or absence of overt vascular disease, in contrast with the consistent reduction in myocardial infarction by aspirin therapy observed in all populations. We hypothesize that the effect of aspirin therapy on stroke for persons with major risk factors for vascular disease may be intermediate between a substantial decrease for those with manifest vascular disease and a possible small increase for healthy persons due to accentuated intracranial hemorrhage. When aspirin is given for primary prevention of vascular events, available data support using 75 to 81 mg/d
Hyperhomocysteinemia, vascular function and atherosclerosis: effects of vitamins.
Cardiovasc Drugs Ther. 2002 Sep; 16(5):391-9.
Homocysteine is a metabolic product of methyl group donation by the amino acid methionine. Moderate elevation of plasma homocysteine (>15 microM) is most commonly caused by B-vitamin deficiencies, especially folic acid, B(6) and B(12). Genetic factors, certain drugs and renal impairment may also contribute. Homocysteine has several potentially deleterious vascular actions. These include increased oxidant stress, impaired endothelial function, stimulation of mitogenesis, and induction of thrombosis. Homocysteine also appears to increase arterial pressure. In humans, experimental induction of hyperhomocysteinemia by methionine loading rapidly causes profound impairment of endothelium-dependent dilatation in both resistance and conduit arteries. This endothelial dysfunction can be reversed by administration of antioxidants. Epidemiological evidence suggests that homocysteine acts as an independent risk factor for atherosclerosis, thrombosis and hypertension. Prospective studies have shown that elevated plasma homocysteine concentrations in the top quintile of the population (>12 microM) increase risk of cardiovascular disease by about 2-fold. There are currently no data available from randomized, controlled trials of the effects of lowering plasma homocysteine on atherothrombotic events. Nonetheless, it would seem appropriate to screen for and treat hyperhomocysteinemia in individuals with progressive or unexplained atherosclerosis. Folic acid and vitamins B(6) and B(12) are the mainstay of therapy. Treatment of moderately elevated plasma homocysteine in patients without atherosclerosis should be deferred until the completion of randomized outcome trials
An overview of the 4 randomized trials of aspirin therapy in the primary prevention of vascular disease.
Hebert PR, Hennekens CH.
Arch Intern Med. 2000 Nov 13; 160(20):3123-7.
BACKGROUND: In the primary prevention of cardiovascular disease, in contrast to the recommendations of the American College of Chest Physicians and the American Heart Association, the US Food and Drug Administration recently stated that there was insufficient evidence to judge whether aspirin therapy decreases the risk of a first myocardial infarction. OBJECTIVE: To perform an overview of the 4 primary prevention trials of aspirin therapy to obtain the most reliable estimates of the effects of aspirin therapy on various vascular disease end points. METHODS AND RESULTS: These 4 trials included more than 51,000 subjects and 2284 important vascular events. Those assigned to aspirin therapy experienced significant reductions of 32% (95% confidence interval [CI], 21%-41%) for nonfatal myocardial infarction and 13% (95% CI, 5%-19%) for any important vascular event. There were possible small but nonsignificant increases in risks of vascular disease-related death (1%; 95% CI, -12% to 16%) and nonfatal stroke (8%; 95% CI, -12% to 33%). When strokes were subdivided by type, there was no significant effect of aspirin therapy on the risk of ischemic stroke, but, while based on small numbers, there was a 1.7-fold apparent increase (95% CI, 6%-269%) in the risk of hemorrhagic stroke, which did achieve statistical significance. CONCLUSIONS: For the primary prevention of vascular disease, aspirin therapy confers significant beneficial effects on first myocardial infarction and, as a result, on any important vascular event; these effects are clinically important. Whether there is any reduction in vascular disease-related death or stroke associated with treatment remains unclear because of inadequate numbers of events in the primary prevention trials completed to date. More data on hemorrhagic stroke are also needed. In addition, randomized trial data, especially in women but also in men, are needed to help to formulate a rational public health policy for individuals at usual risk. Meanwhile, these data provide evidence for a significant benefit of aspirin therapy in the primary prevention of myocardial infarction
Is the response of serum lipids and lipoproteins to postmenopausal hormone replacement therapy modified by ApoE genotype?
Heikkinen AM, Niskanen L, Ryynanen M, et al.
Arterioscler Thromb Vasc Biol. 1999 Feb; 19(2):402-7.
Postmenopausal hormone replacement therapy (HRT) has favorable effects on the serum lipid profile, and it also decreases the risk of cardiovascular diseases. The apolipoprotein E genotype has influence on serum levels of lipids and lipoproteins; apoE allele epsilon4 (apoE4) is associated with high total and LDL cholesterol levels. Genotype also influences the lipid responses to treatment with diet and statins, but the effect of HRT in different apoE genotypes is unknown. We studied the effects of HRT on the concentrations of serum lipids in apoE4-positive early postmenopausal women (genotypes 3/4 and 4/4) compared with apoE4-negative women (genotypes 2/3 and 3/3) in a population-based, prospective 5-year study. In all, 232 early postmenopausal women were randomized into 2 treatment groups: an HRT group (n=116), which received a sequential combination of 2 mg estradiol valerate (E2Val) from day 1 to 21 and 1 mg cyproterone acetate (CPA) from day 12 to 21 (Climen), and a placebo group (n=116), which received 500 mg/d calcium lactate. Serum concentrations of total, LDL, and HDL cholesterol and triglycerides were measured at baseline and after 2 and 5 years of treatment. A total of 154 women completed the final analysis. During the follow-up period, serum total cholesterol and LDL cholesterol concentrations decreased in the HRT group in apoE4-negative women (8.1% and 17.1%, respectively; P<0.001) but did not change in the HRT group in apoE4-positive women or in the placebo group. Serum HDL cholesterol concentrations decreased in the placebo group (apoE4-negative, 3.9%, P="0.015;" apoE4-positive, 8.1%, P="0.004)" but did not change significantly in the HRT group. Serum triglyceride levels tended to increase in both study groups and genotypes (15.1% to 36.2%, P<0.038 to 0.001), but no differences were observed between the study groups or genotypes, respectively. Our finding was that in postmenopausal Finnish women LDL cholesterol levels in apoE4-negative subjects respond more favorably to HRT than those in apoE4-positive subjects. This finding has potential importance in postmenopausal women with hypercholesterolemia, if confirmed in other studies
Flavonoid intake and long-term risk of coronary heart disease and cancer in the seven countries study.
Hertog MG, Kromhout D, Aravanis C, et al.
Arch Intern Med. 1995 Feb 27; 155(4):381-6.
OBJECTIVE: To determine whether flavonoid intake explains differences in mortality rates from chronic diseases between populations. DESIGN: Cross-cultural correlation study. SETTING/PARTICIPANTS: Sixteen cohorts of the Seven Countries Study in whom flavonoid intake at baseline around 1960 was estimated by flavonoid analysis of equivalent food composites that represented the average diet in the cohorts. MAIN OUTCOME MEASURES: Mortality from coronary heart disease, cancer (various sites), and all causes in the 16 cohorts after 25 years of follow-up. RESULTS: Average intake of antioxidant flavonoids was inversely associated with mortality from coronary heart disease and explained about 25% of the variance in coronary heart disease rates in the 16 cohorts. In multivariate analysis, intake of saturated fat (73%; P = 0.0001), flavonoid intake (8%, P = .01), and percentage of smokers per cohort (9%; P = .03) explained together, independent of intake of alcohol and antioxidant vitamins, 90% of the variance in coronary heart disease rates. Flavonoid intake was not independently associated with mortality from other causes. CONCLUSIONS: Average flavonoid intake may partly contribute to differences in coronary heart disease mortality across populations, but it does not seem to be an important determinant of cancer mortality
Different Types of Angioplasty.
HIP (Health Information Publications).
Guggul (Commiphora mukul).
HMS (Harvard Medical School).
2003;2003 Sep 3.
S-allyl cysteine reduces oxidant load in cells involved in the atherogenic process.
Ho SE, Ide N, Lau BH.
Phytomedicine. 2001 Jan; 8(1):39-46.
Oxidation of low-density lipoprotein (LDL) and activation of the pleiotropic transcription factor nuclear factor kappa B (NF-kappaB), are often the chemical and molecular alterations associated with the development of the atherosclerotic lesion. We have reported previously on the antioxidant properties of a garlic compound, S-allyl cysteine (SAC), and its ability to inhibit damage caused by oxidative stress in bovine endothelial cells. In this study, the antioxidant effects of SAC were further determined, using several in vitro assay systems. First, we determined the effect of SAC on Cu2+-induced oxidation of LDL. Varying concentrations of SAC were co-incubated with a standardized Cu2+/LDL solution, and LDL-oxidation was then ascertained by determining the formation of thiobarbituric acid reactive substances (TBARS). SAC inhibited LDL-oxidation at an optimum concentration of 1 mM. In another experiment, we determined the effects of SAC on oxidized-LDL (ox-LDL) activation of J774 murine macrophages and human umbilical vein endothelial cells (HUVEC). Cells were grown on 96-well plates, preincubated with SAC at 37 degrees C and 5% CO2 for 24 h, washed, and exposed to ox-LDL for 24 h. Levels of hydrogen peroxide (H2O2) were determined by a fluorometric assay. In both cell lines, SAC exhibited dose-dependent inhibition of H2O2 formation. We also studied the effects of SAC on NF-kappaB activation in HUVEC using tumor necrosis factor-a (TNF-alpha) or H2O2 as stimulators. Cells were grown in 75 cm2 flasks at 37 degrees C and 5% CO2 and were preincubated with SAC 24 h before stimulation with TNF-alpha or H2O2. Nuclear extracts were then prepared and NF-kappaB activation was determined using an electrophoretic mobility shift assay with a 32P-labeled probe. SAC exhibited dose-dependent inhibition of NF-kappaB activation. Our data suggest that SAC may act via antioxidant mechanisms to inhibit the atherogenic process
Methioninase: a therapeutic for diseases related to altered methionine metabolism and transmethylation: cancer, heart disease, obesity, aging, and Parkinson's disease.
Hum Cell. 1997 Mar; 10(1):69-80.
Methionine metabolism and transmethylation are central to the metabolism and differentiation of all known cells. In enkaryotic organisms, methionine metabolism and transmethylation are of paramount importance in modification and regulation of proteins, lipids, and nucleic acids. The differential methylation of genes regulates their expression in the myriad of cells in eukaryotic organisms. Disruption and abnormalities in methionine metabolism and transmethylation seems to be associated with the major diseases of mankind, including cancer, heart disease, aging, obesity, and Parkinson's disease. In this review, we describe how aberrant and abnormal methionine metabolism and transmethylation are related to these major diseases. Most importantly, we review and hypothesize how the developing therapeutic recombination methioninase (rMETase) can be utilized to cure or prevent all of these diseases
Vitamin C improves endothelial function of conduit arteries in patients with chronic heart failure.
Hornig B, Arakawa N, Kohler C, et al.
Circulation. 1998 Feb 3; 97(4):363-8.
BACKGROUND: Chronic heart failure (CHF) is associated with endothelial dysfunction including impaired endothelium-mediated, flow-dependent dilation (FDD). There is evidence for increased radical formation in CHF, raising the possibility that nitric oxide is inactivated by radicals, thereby impairing endothelial function. To test this hypothesis, we determined the effect of the antioxidant vitamin C on FDD in patients with CHF. METHODS AND RESULTS: High-resolution ultrasound and Doppler was used to measure radial artery diameter and blood flow in 15 patients with CHF and 8 healthy volunteers. Vascular effects of vitamin C (25 mg/min IA) and placebo were determined at rest and during reactive hyperemia (causing endothelium-mediated dilation) before and after intra-arterial infusion of N-monomethyl-L-arginine (L-NMMA) to inhibit endothelial synthesis of nitric oxide. Vitamin C restored FDD in patients with heart failure after acute intra-arterial administration (13.2+/-1.7% versus 8.2+/-1.0%; P<.01) and after 4 weeks of oral therapy (11.9+/-0.9% versus 8.2+/-1.0%; P<.05). In particular, the portion of FDD mediated by nitric oxide (ie, inhibited by L-NMMA) was increased after acute as well as after chronic treatment (CHF baseline: 4.2+/-0.7%; acute: 9.1+/-1.3%; chronic: 7.3+/-1.2%; normal subjects: 8.9+/-0.8%; P<.01). CONCLUSIONS: Vitamin C improves FDD in patients with CHF as the result of increased availability of nitric oxide. This observation supports the concept that endothelial dysfunction in patients with CHF is, at least in part, due to accelerated degradation of nitric oxide by radicals
Characterization of homocysteine metabolism in the rat kidney.
House JD, Brosnan ME, Brosnan JT.
Biochem J. 1997 Nov 15; 328 ( Pt 1):287-92.
Epidemiological studies have provided strong evidence that an elevated plasma homocysteine concentration is an important independent risk factor for cardiovascular disease. We have shown, in the rat, that the kidney is a major site for the removal and subsequent metabolism of plasma homocysteine [Bostom, Brosnan, Hall, Nadeau and Selhub (1995) Atherosclerosis 116, 59-62]. To characterize the role of the kidney in homocysteine metabolism further, we measured the disappearance of homocysteine in isolated renal cortical tubules of the rat. Renal tubules metabolized homocysteine primarily through the transulphuration pathway, producing cystathionine and cysteine (78% of homocysteine disappearance). Methionine production accounted for less than 2% of the disappearance of homocysteine. Cystathionine, and subsequently cysteine, production rates, as well as the rate of disappearance of homocysteine, were sensitive to the level of serine in the incubation medium, as increased serine concentrations permitted higher rates of cystathionine and cysteine production. On the basis of enrichment profiles of cystathionine beta-synthase and cystathionine gamma-lyase, in comparison with marker enzymes of known location, we concluded that cystathionine beta-synthase was enriched in the outer cortex, specifically in cells of the proximal convoluted tubule. Cystathionine gamma-lyase exhibited higher enrichment patterns in the inner cortex and outer medulla, with strong evidence of an enrichment in cells of the proximal straight tubule. These studies indicate that factors that influence the transulphuration of homocysteine may influence the renal clearance of this amino acid
Optimizing beta-blocker use after myocardial infarction.
Howard PA, Ellerbeck EF.
Am Fam Physician. 2000 Oct 15; 62(8):1853-6.
Although beta-adrenergic blockers can significantly reduce mortality after a myocardial infarction, these agents are prescribed to only a minority of patients. Underutilization of beta blockers may be attributed, in part, to fear of adverse effects, especially in the elderly and in patients with concomitant disorders such as diabetes or heart failure. However, studies have shown that such patients are precisely the ones who derive the greatest benefit from beta blockade. Advancing age or the presence of potentially complicating disease states is usually not a justification for withholding beta-blocker therapy. With use of cardioselective agents and through careful dosing and monitoring, the benefits of beta blockers after myocardial infarction far outweigh the potential risks in most patients
Randomized trial of estrogen plus progestin for secondary prevention of coronary heart disease in postmenopausal women. Heart and Estrogen/progestin Replacement Study (HERS) Research Group.
Hulley S, Grady D, Bush T, et al.
JAMA. 1998 Aug 19; 280(7):605-13.
CONTEXT: Observational studies have found lower rates of coronary heart disease (CHD) in postmenopausal women who take estrogen than in women who do not, but this potential benefit has not been confirmed in clinical trials. OBJECTIVE: To determine if estrogen plus progestin therapy alters the risk for CHD events in postmenopausal women with established coronary disease. DESIGN: Randomized, blinded, placebo-controlled secondary prevention trial. SETTING: Outpatient and community settings at 20 US clinical centers. PARTICIPANTS: A total of 2763 women with coronary disease, younger than 80 years, and postmenopausal with an intact uterus. Mean age was 66.7 years. INTERVENTION: Either 0.625 mg of conjugated equine estrogens plus 2.5 mg of medroxyprogesterone acetate in 1 tablet daily (n = 1380) or a placebo of identical appearance (n = 1383). Follow-up averaged 4.1 years; 82% of those assigned to hormone treatment were taking it at the end of 1 year, and 75% at the end of 3 years. MAIN OUTCOME MEASURES: The primary outcome was the occurrence of nonfatal myocardial infarction (MI) or CHD death. Secondary cardiovascular outcomes included coronary revascularization, unstable angina, congestive heart failure, resuscitated cardiac arrest, stroke or transient ischemic attack, and peripheral arterial disease. All-cause mortality was also considered. RESULTS: Overall, there were no significant differences between groups in the primary outcome or in any of the secondary cardiovascular outcomes: 172 women in the hormone group and 176 women in the placebo group had MI or CHD death (relative hazard [RH], 0.99; 95% confidence interval [CI], 0.80-1.22). The lack of an overall effect occurred despite a net 11% lower low-density lipoprotein cholesterol level and 10% higher high-density lipoprotein cholesterol level in the hormone group compared with the placebo group (each P<.001). Within the overall null effect, there was a statistically significant time trend, with more CHD events in the hormone group than in the placebo group in year 1 and fewer in years 4 and 5. More women in the hormone group than in the placebo group experienced venous thromboembolic events (34 vs 12; RH, 2.89; 95% CI, 1.50-5.58) and gallbladder disease (84 vs 62; RH, 1.38; 95% CI, 1.00-1.92). There were no significant differences in several other end points for which power was limited, including fracture, cancer, and total mortality (131 vs 123 deaths; RH, 1.08; 95% CI, 0.84-1.38). CONCLUSIONS: During an average follow-up of 4.1 years, treatment with oral conjugated equine estrogen plus medroxyprogesterone acetate did not reduce the overall rate of CHD events in postmenopausal women with established coronary disease. The treatment did increase the rate of thromboembolic events and gallbladder disease. Based on the finding of no overall cardiovascular benefit and a pattern of early increase in risk of CHD events, we do not recommend starting this treatment for the purpose of secondary prevention of CHD. However, given the favorable pattern of CHD events after several years of therapy, it could be appropriate for women already receiving this treatment to continue
Apolipoprotein E4 and coronary heart disease in middle-aged men who smoke: a prospective study.
Humphries SE, Talmud PJ, Hawe E, et al.
Lancet. 2001 Jul 14; 358(9276):115-9.
BACKGROUND: The common isoforms of apolipoprotein E (apoE), E2, E3, and E4, are important determinants of plasma lipid concentrations, and the epsilon4 allele is associated with raised risk of coronary heart disease. We investigated whether the effect of smoking on coronary heart disease risk is affected by APOE genotype. METHODS: We enrolled 3052 middle-aged men who were free of coronary heart disease for prospective cardiovascular surveillance in the second Northwick Park Heart Study (NPHSII). Smoking habit was ascertained at baseline and yearly by questionnaire. APOE genotype was identified by PCR and restriction enzyme digestion. Endpoints were fatal coronary heart disease, non-fatal myocardial infarction, and coronary artery surgery and silent myocardial infarction at follow-up. FINDINGS: During 18836 person years of surveillance, 96 men had an acute myocardial infarction, 26 needed coronary artery surgery, and 14 had silent myocardial infarctions. Compared with never-smokers, risk of coronary heart disease in ex-smokers was 1.34 (95% CI 0.86-2.08) and in smokers it was 1.94 (1.25-3.01). This risk was independent of other classic risk factors. In never-smokers, risk was closely similar in men with different genotypes. Risk in men homozygous for the epsilon3 allele was 1.74 (1.10-2.77) in ex-smokers and 1.68 (1.01-2.83) in smokers, whereas in men carrying the epsilon4 allele risk was 0.84 (0.40-1.75) and 3.17 (1.82-5.50), respectively, with no significant differences in risk in the epsilon2 carriers. For the epsilon3 group, the genotype effect on risk was no longer significant after adjustment for classic risk factors (including plasma lipids). However, even after adjustment, smokers who were carriers of the epsilon4 allele, showed significantly raised risk of coronary heart disease compared with the non-smoking group (2.79, 1.59-4.91, epsilon4-smoking interaction p=0.007). INTERPRETATION: Smoking increases the risk of coronary heart disease in men of all genotypes but particularly in men carrying the epsilon4 allele
Warfarin, aspirin, or both after myocardial infarction.
Hurlen M, Abdelnoor M, Smith P, et al.
N Engl J Med. 2002 Sep 26; 347(13):969-74.
BACKGROUND: The role of antithrombotic therapy in secondary prevention after myocardial infarction is well established. Although the available literature suggests that warfarin is superior to aspirin, aspirin is currently the more widely used drug. We studied the efficacy and safety of warfarin, aspirin, or both after myocardial infarction. METHODS: In a randomized, multicenter trial in 3630 patients, 1216 received warfarin (in a dose intended to achieve an international normalized ratio [INR] of 2.8 to 4.2), 1206 received aspirin (160 mg daily), and 1208 received aspirin (75 mg daily) combined with warfarin (in a dose intended to achieve an INR of 2.0 to 2.5). The mean duration of observation was four years. RESULTS: The primary outcome, a composite of death, nonfatal reinfarction, or thromboembolic cerebral stroke, occurred in 241 of 1206 patients receiving aspirin (20.0 percent), 203 of 1216 receiving warfarin (16.7 percent; rate ratio as compared with aspirin, 0.81; 95 percent confidence interval, 0.69 to 0.95; P=0.03), and 181 of 1208 receiving warfarin and aspirin (15.0 percent; rate ratio as compared with aspirin, 0.71; 95 percent confidence interval, 0.60 to 0.83; P=0.001). The difference between the two groups receiving warfarin was not statistically significant. Episodes of major, nonfatal bleeding were observed in 0.62 percent of patients per treatment-year in both groups receiving warfarin and in 0.17 percent of patients receiving aspirin (P<0.001). CONCLUSIONS: Warfarin, in combination with aspirin or given alone, was superior to aspirin alone in reducing the incidence of composite events after an acute myocardial infarction but was associated with a higher risk of bleeding
Garlic compounds protect vascular endothelial cells from oxidized low density lipoprotein-induced injury.
Ide N, Lau BH.
J Pharm Pharmacol. 1997 Sep; 49(9):908-11.
Oxidation of low density lipoprotein (LDL) has been recognized as playing an important role in the initiation and progression of atherosclerosis. In this study, the effects of aged garlic extract and one of its major compounds, S-allylcysteine, on oxidized LDL-induced cell injury were studied. Pulmonary artery endothelial cells were pre-incubated with the garlic extract (1, 2.5 and 5 mg mL-1) or S-allylcysteine (0.1, 1, 10 and 20 mM) at 37 degrees C and 5% CO2 for 24 h, washed, and then exposed to 0.1 mg mL-1 oxidized LDL for 24 h. Lactate dehydrogenase release as an index of membrane damage, methylthiazol tetrazolium assay for cell viability and thiobarbituric acid reactive substances indicating lipid peroxidation were determined. Preincubation of endothelial cells with the extract or S-allylcysteine significantly prevented membrane damage, loss of cell viability and lipid peroxidation. The data indicate that these compounds can protect vascular endothelial cells from injury caused by oxidized LDL, and suggest that they may be useful for prevention of atherosclerosis
Aged garlic extract attenuates intracellular oxidative stress.
Ide N, Lau BH.
Phytomedicine. 1999 May; 6(2):125-31.
Oxidation of low density lipoprotein (LDL) has been recognized as playing an important role in the initiation and progression of atherosclerosis. We recently reported that aged garlic extract (AGE) inhibited LDL oxidation and minimized oxidized LDL-induced cell injury. In this study, the antioxidant effects of AGE were further examined using bovine pulmonary artery endothelial cells (PAEC) and murine macrophages. Lactate dehydrogenase (LDH) release, as an index of membrane injury, and intracellular glutathione (GSH) levels were determined. Oxidized LDL (Ox-LDL) caused an increase of LDH release and depletion of GSH. Pretreatment with AGE prevented these changes. AGE exhibited an inhibition of Ox-LDL-induced peroxides in PAEC. AGE suppressed peroxides in murine Macrophage (J774 cells) dose-dependently. The J774 cells were also incubated with AGE, interferon-gamma (IFN-gamma) and lipopolysaccharide (LPS) and nitric oxide (NO) production was measured. AGE inhibited NO production in J774 cells. In a cell free system, AGE was shown to scavenge H2O2 dose-dependently. Our data demonstrate that AGE can protect the endothelial cells from oxidized LDL-induced injury by preventing depletion of intracellular GSH and by removing peroxides. AGE also reduces levels of NO and peroxides in macrophages. These data suggest that AGE is a useful protective agent against cytotoxicity associated with Ox-LDL and NO, and it may thus be useful for the prevention of atherosclerosis and cardiovascular diseases
S-allylcysteine attenuates oxidative stress in endothelial cells.
Ide N, Lau BH.
Drug Dev Ind Pharm. 1999 May; 25(5):619-24.
Oxidation of low-density lipoprotein (LDL) has been recognized as playing an important role in the initiation and progression of atherosclerosis. We recently reported that S-allylcysteine (SAC), one of the major compounds in the aged garlic extract (AGE), inhibited LDL oxidation and minimized oxidized LDL-induced cell injury. In this study, the antioxidant effects of SAC were further determined using several in vitro assay systems. Pulmonary artery endothelial cells (PAECs) were preincubated with SAC at 37 degrees C and 5% CO2 for 24 hr, washed, and then exposed to 0.1 mg/ml oxidized LDL for 24 hr. Lactate dehydrogenase (LDH) release, as an index of membrane injury, and intracellular glutathione (GSH) level were determined. Oxidized LDL caused an increase of LDH release and depletion of GSH. Pretreatment with SAC prevented these changes. Peroxides were measured directly in 24-well plates using a fluorometric assay. SAC dose-dependently inhibited oxidized LDL-induced release of peroxides in PAEC. In a cell-free system, SAC was shown to scavenge hydrogen peroxide. Our data demonstrate that SAC can protect endothelial cells from oxidized LDL-induced injury by removing peroxides and preventing the intracellular GSH depletion and suggest that this compound may be useful for the prevention of atherosclerosis
Garlic compounds minimize intracellular oxidative stress and inhibit nuclear factor-kappa b activation.
Ide N, Lau BH.
J Nutr. 2001 Mar; 131(3s):1020S-6S.
Oxidative modification of LDL has been recognized as playing an important role in the initiation and progression of atherosclerosis. In this study, we determined the effects of aged garlic extract (AGE) and its major compound, S-allylcysteine (SAC), on oxidized LDL (Ox-LDL)-induced injury in endothelial cells (EC). Lactate dehydrogenase (LDH) release as an index of membrane damage, methylthiazol tetrazoium (MTT) assay for cell viability and thiobarbituric acid reactive substances (TBARS) indicating lipid peroxidation were measured. Ox-LDL caused an increase of LDH release, loss of cell viability and TBARS formation. Both AGE and SAC prevented all of these changes. To elucidate the mechanism, effects of AGE or SAC on intracellular glutathione (GSH) level in EC, and release of peroxide from EC and macrophages (M Phi) were determined. Ox-LDL depleted intracellular GSH and increased release of peroxides. Both AGE and SAC inhibited these changes. Effects of SAC on hydrogen peroxide (H(2)O(2)) or tumor necrosis factor (TNF)-alpha-induced nuclear factor (NF)-kappa B activation were determined. Pretreatment of EC with SAC inhibited NF-kappa B activation. We demonstrated that both AGE and SAC can protect EC from Ox-LDL-induced injury by preventing intracellular GSH depletion in EC and by minimizing release of peroxides from EC and M Phi. SAC also inhibited H(2)O(2)- or TNF-alpha-induced NF-kappa B activation. Our data suggest that AGE and its main compound, SAC, may be useful for prevention of atherosclerosis
Effects of intravenous perilla oil emulsion on nutritional status, polyunsaturated fatty acid composition of tissue phospholipids, and thromboxane A2 production in streptozotocin-induced diabetic rats.
Ikeda A, Inui K, Fukuta Y, et al.
Nutrition. 1995 Sep; 11(5):450-5.
The effects of a perilla oil (PO) emulsion rich in alpha-linolenic acid, administered by intravenous infusion, on nutritional status, fatty acid composition, and thromboxane A2 production were compared with those of a soybean oil (SO) emulsion in streptozotocin-induced diabetic rats given a fat-free diet for 7 days. The PO emulsion improved body weight gain and nitrogen balance compared with the SO emulsion and reduced thromboxane A2 production by platelets. The PO emulsion also increased the proportion of eicosapentaenoic acid, but decreased that of arachidonic acid, in liver and serum phospholipids. Plasma insulin concentrations and blood biochemical indices were similar in the two groups. An intravenously infused PO emulsion effectively reduces thromboxane A2 production through changes in the fatty acid composition of liver and serum phospholipids, as with oral administration, and improves the nutritional status of diabetic rats
Food and Nutrition Board. Dietary Reference Intakes: Thiamin, Riboflavin, Niacin, Vitamin B 6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline 1998.
IM (Institute of Medicine).
Systolic hypertension, arterial stiffness, and vascular damage: role of the renin-angiotensin system.
Izzo JL, Jr.
Blood Press Monit. 2000; 5 Suppl 2:S7-11.
The field of hypertension is entering an exciting new era in which new concepts in basic and clinical science are being rapidly translated into new recommendations for clinical practice. It is now readily apparent that an age-related increase in stiffness of the walls of the large arteries causes the predominant hemodynamic characteristic of hypertension in later life: increased systolic blood pressure. Systolic hypertension is now recognized to have greater prognostic significance than diastolic hypertension, and it is also known that the effective treatment of systolic hypertension confers a proportional benefit in risk reduction. A rapidly advancing knowledge of vascular biology has revealed that the renin-angiotensin system plays a central role in the pathogenesis of vascular hypertrophy and arterial stiffness. Angiotensin-converting enzyme inhibitors have been shown to reduce arterial stiffness to a greater degree than diuretics or beta-blockers. The pharmacologic interruption of the renin-angiotensin system may therefore confer previously unrecognized benefits on age-related vascular damage, providing special benefits in systolic hypertension
Hyperglucagonemia in rats results in decreased plasma homocysteine and increased flux through the transsulfuration pathway in liver.
Jacobs RL, Stead LM, Brosnan ME, et al.
J Biol Chem. 2001 Nov 23; 276(47):43740-7.
An elevated plasma level of homocysteine is a risk factor for the development of cardiovascular disease. The purpose of this study was to investigate the effect of glucagon on homocysteine metabolism in the rat. Male Sprague-Dawley rats were treated with 4 mg/kg/day (3 injections per day) glucagon for 2 days while control rats received vehicle injections. Glucagon treatment resulted in a 30% decrease in total plasma homocysteine and increased hepatic activities of glycine N-methyltransferase, cystathionine beta-synthase, and cystathionine gamma-lyase. Enzyme activities of the remethylation pathway were unaffected. The 90% elevation in activity of cystathionine beta-synthase was accompanied by a 2-fold increase in its mRNA level. Hepatocytes prepared from glucagon-injected rats exported less homocysteine, when incubated with methionine, than did hepatocytes of saline-treated rats. Flux through cystathionine beta-synthase was increased 5-fold in hepatocytes isolated from glucagon-treated rats as determined by production of (14)CO(2) and alpha-[1-(14)C]ketobutyrate from l-[1-(14)C]methionine. Methionine transport was elevated 2-fold in hepatocytes isolated from glucagon-treated rats resulting in increased hepatic methionine levels. Hepatic concentrations of S-adenosylmethionine and S-adenosylhomocysteine, allosteric activators of cystathionine beta-synthase, were also increased following glucagon treatment. These results indicate that glucagon can regulate plasma homocysteine through its effects on the hepatic transsulfuration pathway
Curcumin: clinical trial finds no antiviral effect.
AIDS Treat News. 1996 Mar 1;(no 242):1-2.
Elevation in S-adenosylhomocysteine and DNA hypomethylation: potential epigenetic mechanism for homocysteine-related pathology.
James SJ, Melnyk S, Pogribna M, et al.
J Nutr. 2002 Aug; 132(8 Suppl):2361S-6S.
Chronic nutritional deficiencies in folate, choline, methionine, vitamin B-6 and/or vitamin B-12 can perturb the complex regulatory network that maintains normal one-carbon metabolism and homocysteine homeostasis. Genetic polymorphisms in these pathways can act synergistically with nutritional deficiencies to accelerate metabolic pathology associated with occlusive heart disease, birth defects and dementia. A major unanswered question is whether homocysteine is causally involved in disease pathogenesis or whether homocysteinemia is simply a passive and indirect indicator of a more complex mechanism. S-Adenosylmethionine and S-adenosylhomocysteine (SAH), as the substrate and product of methyltransferase reactions, are important metabolic indicators of cellular methylation status. Chronic elevation in homocysteine levels results in parallel increases in intracellular SAH and potent product inhibition of DNA methyltransferases. SAH-mediated DNA hypomethylation and associated alterations in gene expression and chromatin structure may provide new hypotheses for pathogenesis of diseases related to homocysteinemia
Nicotinic acid treatment shifts the fibrinolytic balance favourably and decreases plasma fibrinogen in hypertriglyceridaemic men.
Johansson JO, Egberg N, Asplund-Carlson A, et al.
J Cardiovasc Risk. 1997 Jun; 4(3):165-71.
BACKGROUND: Nicotinic acid in gram doses decreases cholesterol and triglyceride concentrations in plasma, but the effect on haemostatic function is not known. METHODS: Twenty-three men with hypertriglyceridaemia were treated with 4 g nicotinic acid daily for 6 weeks. Tests for haemostatic function and serum lipoproteins were performed before and at the end of the period of treatment. RESULTS: Treatment with nicotinic acid had the expected effect on lipoprotein concentrations: it reduced the serum concentrations of triglyceride and the three major density fractions of triglyceride (very low density lipoprotein (VLDL), low density lipoprotein (LDL) and high density lipoprotein (HDL)). The VLDL cholesterol concentration was reduced, but that of HDL cholesterol was increased (all P<0.0001). The lipoprotein(a) (Lp(a)) concentration decreased significantly (P<0.01). The total fibrinolytic activity was increased by nicotinic acid treatment as indicated by decreases in plasminogen activator inhibitor-1 activity from 34.3 to 23.8 U/ml (P<0.01) and in alpha2-antiplasmin activity from 1.10 to 0.97 U/ml (P<0.01). The plasma fibrinogen concentration decreased from 3.55 to 3.01 U/ml (P<0.01). Multvariate analysis showed that the changes in alpha2-antiplasmin and Lp(a) concentrations could explain 53% of the change in plasma fibrinogen, suggesting that increased plasmin mobilization could be responsible for the decrease in plasma fibrinogen. CONCLUSION: This study of hypertriglyceridaemic men has shown that long-term treatment with nicotinic acid not only corrects serum lipoprotein abnormalities, but also reduces the fibrinogen concentration in plasma and stimulates fibrinolysis
Effects of coenzyme Q10 on exercise tolerance in chronic stable angina pectoris.
Kamikawa T, Kobayashi A, Yamashita T, et al.
Am J Cardiol. 1985 Aug 1; 56(4):247-51.
The effects of coenzyme Q10(CoQ10) on exercise performance were studied in 12 patients, average age 56 years, with stable angina pectoris. The study involved a double-blind, placebo-controlled, randomized, crossover protocol, using multistage treadmill exercise tests. CoQ10(150 mg/day in 3 daily doses) was administered orally for 4 weeks, tended to reduce anginal frequency from 5.3 +/- 4.9 to 2.5 +/- 3.3 attacks for 2 weeks and nitroglycerin consumption from 2.6 +/- 2.8 to 1.3 +/- 1.7 tablets for 2 weeks compared with patients receiving the placebo, but the reduction was not statistically significant. Exercise time increased from 345 +/- 102 seconds with placebo to 406 +/- 114 seconds during CoQ10 treatment (p less than 0.05). The time until 1 mm of ST-segment depression occurred increased from 196 +/- 76 seconds with placebo to 284 +/- 104 seconds during CoQ10 treatment (p less than 0.01). During the exercise test, ST-segment depression, heart rate and pressure-rate product at the same and at the maximal workload showed no significant difference between patients after placebo and CoQ10 administration. The average CoQ10 plasma concentration increased from 0.95 +/- 0.48 microgram/ml to 2.20 +/- 0.98 microgram/ml after CoQ10 treatment. This increase was significantly related to the increase in exercise duration (r = 0.68, p less than 0.001). Only 1 patient had a loss of appetite, but continued therapy. This study suggests that CoQ10 is a safe and promising treatment for angina pectoris
Antithrombotic activities of green tea catechins and (-)-epigallocatechin gallate.
Kang WS, Lim IH, Yuk DY, et al.
Thromb Res. 1999 Nov 1; 96(3):229-37.
The antithrombotic activities and mode of action of green tea catechins (GTC) and (-)-epigallocatechin gallate (EGCG), a major compound of GTC, were investigated. Effects of GTC and EGCG on the murine pulmonary thrombosis in vivo, human platelet aggregation in vitro, and ex vivo, and coagulation parameters were examined. GTC and EGCG prevented death caused by pulmonary thrombosis in mice in vivo in a dose-dependent manner. They significantly prolonged the mouse tail bleeding time of conscious mice. They inhibited adenosine diphosphate- and collagen-induced rat platelet aggregation ex vivo in a dose-dependent manner. GTC and EGCG inhibited ADP-, collagen-, epinephrine-, and calcium ionophore A23187-induced human platelet aggregation in vitro dose dependently. However, they did not change the coagulation parameters such as activated partial thromboplastin time, prothrombin time, and thrombin time using human citrated plasma. These results suggest that GTC and EGCG have the antithrombotic activities and the modes of antithrombotic action may be due to the antiplatelet activities, but not to anticoagulation activities
Antiplatelet activity of green tea catechins is mediated by inhibition of cytoplasmic calcium increase.
Kang WS, Chung KH, Chung JH, et al.
J Cardiovasc Pharmacol. 2001 Dec; 38(6):875-84.
We have previously reported that green tea catechins (GTC) display a potent antithrombotic activity, which might be due to antiplatelet rather than anticoagulation effects. In the current study, we investigated the antiplatelet mechanism of GTC. We tested the effects of GTC on the aggregation of human platelets and on the binding of fluorescein isothiocyanate-conjugated fibrinogen to human platelet glycoprotein (GP) IIb/IIIa. GTC inhibited the collagen-, thrombin-, adenosine diphosphate (ADP)-, and calcium ionophore A23187-induced aggregation of washed human platelets, with 50% inhibitory concentration values of 0.64, 0.52, 0.63, and 0.45 mg/ml, respectively. GTC significantly inhibited fibrinogen binding to human platelet surface GPIIb/IIIa complex but failed to inhibit binding to purified GPIIb/IIIa complex. These results indicate that the antiplatelet activity of GTC may be due to inhibition of an intracellular pathway preceding GPIIb/IIIa complex exposure. We also investigated the effects of GTC on intracellular calcium levels, which are critical in determining the activation status of platelets and on induction of platelet aggregation by thapsigargin, which is a selective inhibitor of the Ca(2+)-ATPase pump. Pretreatment of human platelets with GTC significantly inhibited the rise in intracellular Ca(2+) concentration induced by thrombin treatment, and GTC significantly inhibited the thapsigargin-induced platelet aggregation. We also examined the effect of GTC on the second messenger, inositol 1,4,5-triphosphate (IP(3)). GTC significantly inhibited the phosphoinositide breakdown induced by thrombin. Taken together, these observations suggest that the antiplatelet activity of GTC is be mediated by inhibition of cytoplasmic calcium increase, which leads to the inhibition of fibrinogen-GPIIb/IIIa binding via the activation of Ca(2+)-ATPase and inhibition of IP(3) formation
The relationship between risk factor levels and presence of coronary artery calcification is dependent on apolipoprotein E genotype.
Kardia SL, Haviland MB, Ferrell RE, et al.
Arterioscler Thromb Vasc Biol. 1999 Feb; 19(2):427-35.
An important research question in the study of the genetics of coronary artery disease (CAD) is whether information about genetic variation will improve our ability to predict CAD beyond established risk factors. This question is especially relevant to the goal of identifying young, asymptomatic adults with coronary atherosclerosis who would benefit most from interventions to reduce risk. Coronary artery calcification (CAC) detected by electron-beam computed tomography is a relatively new method for detecting coronary atherosclerosis in asymptomatic individuals that has been shown to be a more accurate indicator of coronary atherosclerosis in asymptomatic individuals than other noninvasive techniques. In a study of asymptomatic women (n=169) and men (n=160) between the ages of 20 and 59 representative of the Rochester, Minnesota population, we used logistic regression to ask whether the most common Apolipoprotein (Apo) E genotypes (epsilon3/2, epsilon3/3, and epsilon4/3) predict the presence of CAC. The addition of information about ApoE genotypes to logistic models containing each separate risk factor did not improve prediction of CAC (P>0.10 in both women and men). However, there was significant evidence (P<0.10) that associations between variation in the probability of having CAC and variation in body mass index, plasma total cholesterol, and plasma ApoB in men and body mass index, plasma triglycerides, plasma ApoA1, and plasma ApoE in women were dependent on ApoE genotype. Thus, variation in the gene coding for ApoE may play a role in determining the contribution of established risk factors to risk of CAC
Green tea flavonoids inhibit the LDL oxidation in osteogenic disordered rats fed a marginal ascorbic acid in diet.
Kasaoka S, Hase K, Morita T, et al.
J Nutr Biochem. 2002 Feb; 13(2):96-102.
Osteogenic Disorder Shionogi (ODS) rats can not synthesize ascorbic acid (AA). We have examined the capacity of green tea flavonoids (GTF) to modify low-density lipoprotein (LDL) oxidation in ODS rats with dietary AA restriction. In the first experiment, ODS rats were fed diets containing 300 (AA300 diet) or 0 (AA0 diet) mg AA/kg diets for 20 d. In comparison with the AA300 diet, the AA0 diet significantly decreased the concentrations of plasma AA and alpha-tocopherol in LDL and significantly shortened the lag time of LDL oxidation in vitro. In the second experiment, ODS rats were fed one of the following three diets: the AA300 diet, the diet containing 25 mg AA (AA25, marginal AA)/kg diet (AA25 diet), or the diet containing 25 mg AA + 8 g GTF/kg diet (AA25 + GTF diet) for 20 d. Plasma AA concentration were significantly lower in rats fed AA25 compared with AA300 but not in those fed AA25 + GTF. LDL oxidation lag time was significantly longer in rats fed AA25 + GTF compared with the other two groups. Lag time for LDL oxidation was significantly and positively correlated with LDL alpha-tocopherol (r = 0.6885, P = 0.0191). These results suggest that dietary flavonoids suppress the LDL oxidation through the sparing effect on LDL alpha-tocopherol and/or plasma AA when AA intake is marginal in the ODS rats
Chemopreventive effect of curcumin, a naturally occurring anti-inflammatory agent, during the promotion/progression stages of colon cancer.
Kawamori T, Lubet R, Steele VE, et al.
Cancer Res. 1999 Feb 1; 59(3):597-601.
Curcumin, derived from the rhizome of Curcuma longa L. and having both antioxidant and anti-inflammatory properties, inhibits chemically induced carcinogenesis in the skin, forestomach, and colon when it is administered during initiation and/or postinitiation stages. This study was designed to investigate the chemopreventive action of curcumin when it is administered (late in the premalignant stage) during the promotion/progression stage of colon carcinogenesis in male F344 rats. We also studied the modulating effect of this agent on apoptosis in the tumors. At 5 weeks of age, groups of male F344 rats were fed a control diet containing no curcumin and an experimental AIN-76A diet with 0.2% synthetically derived curcumin (purity, 99.9%). At 7 and 8 weeks of age, rats intended for carcinogen treatment were given s.c. injections of azoxymethane (AOM) at a dose rate of 15 mg/kg body weight per week. Animals destined for the promotion/progression study received the AIN-76A control diet for 14 weeks after the second AOM treatment and were then switched to diets containing 0.2 and 0.6% curcumin. Premalignant lesions in the colon would have developed by week 14 following AOM treatment. They continued to receive their respective diets until 52 weeks after carcinogen treatment and were then sacrificed. The results confirmed our earlier study in that administration of 0.2% curcumin during both the initiation and postinitiation periods significantly inhibited colon tumorigenesis. In addition, administration of 0.2% and of 0.6% of the synthetic curcumin in the diet during the promotion/progression stage significantly suppressed the incidence and multiplicity of noninvasive adenocarcinomas and also strongly inhibited the multiplicity of invasive adenocarcinomas of the colon. The inhibition of adenocarcinomas of the colon was, in fact, dose dependent. Administration of curcumin to the rats during the initiation and postinitiation stages and throughout the promotion/progression stage increased apoptosis in the colon tumors as compared to colon tumors in the groups receiving AOM and the control diet. Thus, chemopreventive activity of curcumin is observed when it is administered prior to, during, and after carcinogen treatment as well as when it is given only during the promotion/progression phase (starting late in premalignant stage) of colon carcinogenesis
Homocysteine, MTHFR 677C-->T polymorphism, and risk of ischemic stroke: results of a meta-analysis.
Kelly PJ, Rosand J, Kistler JP, et al.
Neurology. 2002 Aug 27; 59(4):529-36.
BACKGROUND: Data are conflicting concerning risk for ischemic stroke associated with hyperhomocyst(e)inemia (hyper-Hcy) and a common polymorphism in the gene encoding 5,10-methylenetetrahydrofolate reductase (MTHFR 677C-->T), which predisposes to hyper-Hcy in vivo. METHODS: Search of MEDLINE, Science Citation Index, and abstracts of conference proceedings revealed relevant articles. Exposure was defined as follows: 1) prevalence of hyper-Hcy; 2) absolute difference in the mean Hcy concentration between subjects with and without ischemic stroke; and 3) the MTHFR TT genotype frequency. Outcome was defined as ischemic stroke with or without neuroimaging. Inclusion criteria were retrospective and prospective studies with reported odds ratios (OR) or hazard ratios (HR) or arithmetic mean Hcy levels. Exclusion criteria were absence of OR or HR, outcome defined as carotid atherosclerosis or intima-media thickening, stroke in patients younger than 18 years old, and studies in languages other than English. Statistical analyses for between-study heterogeneity and pooled risk estimates were performed using Stata software (Stata Corporation, College Station, TX). RESULTS: Among 16 studies (1,487 stroke and 2,554 nonstroke cases), the pooled mean Hcy level in patients with ischemic stoke was 2.32 micromol/L (95% CI, 1.6 to 3.04; p < 0.001) greater than that in those without ischemic stroke. Among 14 included studies (1,769 stroke and 7,400 nonstroke cases), the pooled OR estimate of ischemic stroke associated with hyper-Hcy was 1.79 (95% CI, 1.61 to 2.0; p < 0.001). Among 19 included studies (2,788 stroke and 3,962 nonstroke cases), the OR associated with the TT genotype was 1.23 (95% CI, 0.96 to 1.58; p = "0.1)." CONCLUSION: These data support an association between mild-to-moderate hyper-Hcy and ischemic stoke. The MTHFR TT genotype may have a small influence in determining susceptibility to ischemic stoke
Epidemiologic review of the calcium channel blocker drugs. An up-to-date perspective on the proposed hazards.
Kizer JR, Kimmel SE.
Arch Intern Med. 2001 May 14; 161(9):1145-58.
In the setting of soaring popularity, postmarketing studies of calcium channel blockers came to suggest an increase in a variety of major adverse end points. The evidence, however, was largely observational, and large-scale trials capable of addressing the concerns were wanting. Clinical trials now support the safety and efficacy of the long-acting dihydropyridines for patients with both uncomplicated and diabetic hypertension, although conventional therapies and, in the latter case, angiotensin-converting enzyme inhibitors have superior proof of benefit. By contrast, short-acting dihydropyridines should be avoided. In the acute coronary syndromes, beta-blockers remain the treatment of choice; the evidence for nondihydropyridines remains inconclusive. Stable angina calls for beta-blockers as first-line therapy and nondihydropyridines as second-line therapy, whereas in ventricular dysfunction, safety data for nondihydropyridines are lacking. Initial reports of cancer, bleeding, and suicide have been contradicted by subsequent data, making the associations uncertain or unlikely. Remaining questions await completion of ongoing trials to better define the indications for these agents
Coronary heart disease: the zinc/copper hypothesis.
Am J Clin Nutr. 1975 Jul; 28(7):764-74.
Epidemiologic and metabolic data are consanant with the hypothesis thata metabolic imbalance in regard to zinc and copper ia a major factor in the etiology of coronary heart disease. This metabolic imbalance is either a relative or an absoulte deficincey of copper characterized by a high ratio of zinc to copper. The imbalance results in hypercholesterolemia and increased mortaility die to coronary heart disease. The imbalance can occur due to the amounts of zince and copper in human food, to lack of protective substances in food or drinking water and to alterations in physiological status that produce adverse changes in the distribution of zinc and copper in certain important organs. Because no other agent, with the possible exception of cholesterol, has been related so closely to tisk, the ratio of zinc to copper may be the preponderant factor in the etiology of coronary heart disease
Antioxidant vitamin intake and coronary mortality in a longitudinal population study.
Knekt P, Reunanen A, Jarvinen R, et al.
Am J Epidemiol. 1994 Jun 15; 139(12):1180-9.
Oxidation of lipoproteins is hypothesized to promote atherosclerosis and, thus, a high intake of antioxidant nutrients may protect against coronary heart disease. The relation between the intakes of dietary carotene, vitamin C, and vitamin E and the subsequent coronary mortality was studied in a cohort of 5,133 Finnish men and women aged 30-69 years and initially free from heart disease. Food consumption was estimated by the dietary history method covering the total habitual diet during the previous year. Altogether, 244 new fatal coronary heart disease cases occurred during a mean follow-up of 14 years beginning in 1966-1972. An inverse association was observed between dietary vitamin E intake and coronary mortality in both men and women with relative risks of 0.68 (p for trend = 0.01) and 0.35 (p for trend < 0.01), respectively, between the highest and lowest tertiles of the intake. Similar associations were observed for the dietary intake of vitamin C and carotenoids among women and for the intake of important food sources of these micronutrients, i.e., of vegetables and fruits, among both men and women. The associations were not attributable to confounding by major nondietary risk factors of coronary heart disease, i.e., age, smoking, serum cholesterol, hypertension, or relative weight. The results support the hypothesis that antioxidant vitamins protect against coronary heart disease, but it cannot be excluded that foods rich in these micronutrients also contain other constituents that provide the protection
Gingerol, a novel cardiotonic agent, activates the Ca2+-pumping ATPase in skeletal and cardiac sarcoplasmic reticulum.
Kobayashi M, Shoji N, Ohizumi Y.
Biochim Biophys Acta. 1987 Sep 18; 903(1):96-102.
Gingerol, isolated as a potent cardiotonic agent from the rhizome of ginger, stimulated the Ca2+-pumping activity of fragmented sarcoplasmic reticulum (SR) prepared from rabbit skeletal and dog cardiac muscles. The extravesicular Ca2+ concentrations of the heavy fraction of the fragmented SR (HSR) were measured directly with a Ca2+ electrode to examine the effect of gingerol on the SR. Gingerol (3-30 microM) accelerated the Ca2+-pumping rate of skeletal and cardiac SR in a concentration-dependent manner. The rate of 45Ca2+ uptake of HSR was also increased markedly by 30 microM gingerol without affecting the 45Ca2+ efflux from HSR. Furthermore, gingerol activated Ca2+-ATPase activities of skeletal and cardiac SR (EC50, 4 microM). The activation of SR Ca2+-ATPase activity by gingerol (30 microM) was completely reversed by 100-fold dilution with the fresh saline solution. Kinetic analysis of activating effects of gingerol suggests that the activation of SR Ca2+-ATPase is uncompetitive and competitive with respect to Mg . ATP at concentrations of 0.2-0.5 mM and above 1 mM, respectively. Kinetic analysis also suggests that the activation by gingerol is mixed-type with respect to free Ca2+ and this enzyme is activated probably due to the acceleration of enzyme-substrate complex breakdown. Gingerol had no significant effect on sarcolemmal Ca2+-ATPase, myosin Ca2+-ATPase, actin-activated myosin ATPase and cAMP-phosphodiesterase activities, indicating that the effect of gingerol is rather specific to SR Ca2+-ATPase activity. Gingerol may provide a valuable chemical tool for studies aimed at clarifying the regulatory mechanisms of SR Ca2+-pumping systems and the causal relationship between the Ca2+-pumping activity of SR and muscle contractility
Late-life depression: how to treat patients with comorbid chronic illness. Interview by Alice V. Luddington.
Geriatrics. 1999 May; 54(5):56-61.
In persons age 65 and older, the incidence of depression increases with the degree of physical health problems. Higher levels of mortality among depressed patients may be attributed to psychological stress, which triggers the production of cortisol by the adrenal glands and thereby adversely affects the immune system. Some 70 to 90% of late-life depression is undiagnosed; this often occurs if the patient's depressive symptoms could be attributed to other medical problems. Screening for depression can be done in the primary care office in about 1 minute. Older patients with mild depression may need no more than a counselor with good listening skills. Moderate to severe depression may require antidepressant therapy, usually with very low initial doses. An epidemic of depression that is expected in the next century will require physicians to utilize community resources to care for the aging 'baby-boom' generation
Fibrinogen and coronary risk.
Curr Cardiol Rep. 1999 Jul; 1(2):112-8.
The notion that fibrinogen is strongly, consistently, and independently related to coronary risk has been widely accepted. The evidence is based on numerous prospective epidemiological studies and clinical observations. However, the reasons why fibrinogen is elevated in coronary disease and in atherosclerosis are only incompletely understood. All cells involved in the atherogenetic process are able to produce cytokines which induce an acute phase reaction. The potential pathophysiologic mechanisms by which elevated fibrinogen levels mediate coronary risk are manifold: It forms the substrate for thrombin and represents the final step in the coagulation cascade; it is essential for platelet aggregation; it modulates endothelial function; it promotes smooth muscle cell proliferation and migration; it interacts with the binding of plasminogen with its receptor; and finally it represents a major acute phase protein. Whether or not fibrinogen is causally involved in atherothrombogenesis still remains to be determined, and even though other unsolved issues await conclusive answers, fibrinogen has emerged as an important additional marker of coronary risk
Plasminogen-activator inhibitor type 1 and coronary artery disease.
Kohler HP, Grant PJ.
N Engl J Med. 2000 Jun 15; 342(24):1792-801.
Gingerols and related analogues inhibit arachidonic acid-induced human platelet serotonin release and aggregation.
Koo KL, Ammit AJ, Tran VH, et al.
Thromb Res. 2001 Sep 1; 103(5):387-97.
Gingerols, the active components of ginger (the rhizome of Zingiber officinale, Roscoe), represent a potential new class of platelet activation inhibitors. In this study, we examined the ability of a series of synthetic gingerols and related phenylalkanol analogues (G1-G7) to inhibit human platelet activation, compared to aspirin, by measuring their effects on arachidonic acid (AA)-induced platelet serotonin release and aggregation in vitro. The IC(50) for inhibition of AA-induced (at EC(50)=0.75 mM) serotonin release by aspirin was 23.4+/-3.6 microM. Gingerols and related analogues (G1-G7) inhibited the AA-induced platelet release reaction in a similar dose range as aspirin, with IC(50) values between 45.3 and 82.6 microM. G1-G7 were also effective inhibitors of AA-induced human platelet aggregation. Maximum inhibitory (IC(max)) values of 10.5+/-3.9 and 10.4+/-3.2 microM for G3 and G4, respectively, were approximately 2-fold greater than aspirin (IC(max)=6.0+/-1.0 microM). The remaining gingerols and related analogues maximally inhibited AA-induced platelet aggregation at approximately 20-25 microM. The mechanism underlying inhibition of the AA-induced platelet release reaction and aggregation by G1-G7 may be via an effect on cyclooxygenase (COX) activity in platelets because representative gingerols and related analogues (G3-G6) potently inhibited COX activity in rat basophilic leukemia (RBL-2H3) cells. These results provide a basis for the design of more potent synthetic gingerol analogues, with similar potencies to aspirin, as platelet activation inhibitors with potential value in cardiovascular disease
The antiatherosclerotic effect of Allium sativum.
Koscielny J, Klussendorf D, Latza R, et al.
Atherosclerosis. 1999 May; 144(1):237-49.
In a randomized, double-blind, placebo-controlled clinical trial, the plaque volumes in both carotid and femoral arteries of 152 probationers were determined by B-mode ultrasound. Continuous intake of high-dose garlic powder dragees reduced significantly the increase in arteriosclerotic plaque volume by 5-18% or even effected a slight regression within the observational period of 48 months. Also the age-dependent representation of the plaque volume shows an increase between 50 and 80 years that is diminished under garlic treatment by 6-13% related to 4 years. It seems even more important that with garlic application the plaque volume in the whole collective remained practically constant within the age-span of 50-80 years. These results substantiated that not only a preventive but possibly also a curative role in arteriosclerosis therapy (plaque regression) may be ascribed to garlic remedies
Food consumption patterns in the 1960s in seven countries.
Kromhout D, Keys A, Aravanis C, et al.
Am J Clin Nutr. 1989 May; 49(5):889-94.
At the end of the 1950s the Seven Countries Study was designed to investigate the relations between diet and cardiovascular diseases. Sixteen cohorts were selected in Finland, Greece, Italy, Japan, The Netherlands, United States, and Yugoslavia. During the 1960s food consumption data were collected from random samples of these cohorts by use of the record method. In Finland the intake of milk, potatoes, edible fats, and sugar products was very high. A similar but lower intake pattern was observed in The Netherlands. Fruit, meat, and pastry consumption was high in the United States; cereal and alcoholic drink consumption was high in Italy; and bread consumption high in Yugoslavians except for those in Belgrade. In Greece the intake of olive oil and fruit was high and the Japanese cohorts were characterized by a high consumption of fish, rice, and soy products. These differences in food consumption patterns have lessened during the past 25 y
Relation of C-reactive protein and coronary heart disease in the MRFIT nested case-control study. Multiple Risk Factor Intervention Trial.
Kuller LH, Tracy RP, Shaten J, et al.
Am J Epidemiol. 1996 Sep 15; 144(6):537-47.
The authors measured the relation between C-reactive protein, alpha 1 acid glycoprotein and albumin, an acute phase protein, and subsequent risk of myocardial infarction and coronary heart disease death in a nested case-control study among the Multiple Risk Factor Intervention Trial (MRFIT) participants. There were 98 myocardial infarction cases, 148 coronary heart disease deaths, and 491 controls. The cases and controls were followed for up to 17 years for deaths and 6-7 years for myocardial infarction cases and controls. There was a significant association between available distribution of C-reactive protein and subsequent coronary heart disease mortality. For smokers at baseline, the risk of coronary heart disease deaths in quartile 4 of C-reactive protein as compared with quartile 1 was 4.3 (95% confidence interval 1.74-10.8). The association persisted when adjusted for characteristics related to smoking and smoking cessation during the trial and to pulmonary function. There was no relation between alpha 1 acid glycoprotein and either myocardial infarction or coronary heart disease death. Albumin was inversely related to coronary heart disease death only for deaths that occurred between 7 and 13 years after baseline, consistent with previous MRFIT analyses. This is the first prospective study in "healthy but high risk individuals" to document the relation between C-reactive protein and coronary heart disease mortality
The effect of dietary fat, antioxidants, and pro-oxidants on blood lipids, lipoproteins, and atherosclerosis.
Kwiterovich PO, Jr.
J Am Diet Assoc. 1997 Jul; 97(7 Suppl):S31-S41.
A number of primary and secondary prevention trials, including angiographic studies, have indicated that a decrease in dietary saturated fat and cholesterol produces a decrease in the blood levels of cholesterol and low-density lipoprotein (LDL) cholesterol, leading to a decrease in coronary artery disease (CAD). Increasing evidence indicates that the oxidation of LDL in human beings is atherogenic. Of the three major antioxidants, vitamin E, beta carotene, and vitamin C, the evidence is strongest that vitamin E (at a minimum dose of 100 IU/day) has a strong and independent inverse association with CAD. Selenium and flavonoids also have antioxidant properties, but their association with CAD in human beings is equivocal. Two prooxidants, homocysteine and iron, have been found to be associated with CAD. Blood homocysteine levels can be lowered significantly by an increase in dietary folic acid. Clinical trials are needed to assess expeditiously the effect of antioxidants, particularly vitamin E, and of folic acid on CAD and atherosclerosis. The substitution of monounsaturated fat for saturated fat lowers LDL and makes it less susceptible to oxidation without decreasing high-density lipoprotein (HDL) cholesterol. Studies in transgenic mice indicate that apolipoprotein A-I, the major protein of HDL, may inhibit the oxidation of LDL. Dietary trans fatty acids at the level consumed by many Americans can increase LDL cholesterol and may decrease HDL cholesterol. Individuals who have CAD or have family members who have premature CAD have delayed clearance of dietary fat, as judged by studies of postprandial triglyceride metabolism. The importance of decreasing dietary saturated fat and cholesterol is well established, but a number of other factors appear to influence the risk of CAD significantly and provide important areas for future investigation to improve prevention and treatment through better nutrition
The antiatherogenic role of high-density lipoprotein cholesterol.
Kwiterovich PO, Jr.
Am J Cardiol. 1998 Nov 5; 82(9A):13Q-21Q.
Landmark clinical studies in the past 5 years that demonstrated diminished mortality and first coronary events following lowering of low-density lipoprotein (LDL) cholesterol stimulated considerable interest in the medical community. Yet, high-density lipoprotein (HDL) cholesterol, which transports circulating cholesterol to the liver for clearance, clearly also exerts antiatherogenic effects. The Framingham Heart Study produced compelling epidemiologic evidence indicating that a low level of HDL cholesterol was an independent predictor of coronary artery disease (CAD). Emerging experimental and clinical findings are, collectively, now furnishing a solid scientific foundation for this relation. First, the reverse cholesterol transport pathway--including the roles of nascent (pre-beta) HDL, apolipoprotein A-I, lecithin-cholesterol acyltransferase (LCAT), cholesteryl ester transport protein, and hepatic uptake of cholesteryl ester from HDL by liver--is better understood. For example, the identification of a hepatic HDL receptor, SR-BI, suggests a mechanism of delivery of cholesteryl ester to liver that differs from the receptor-mediated uptake of LDL. Second, apolipoprotein A-I, the major protein component of HDL, and 2 enzymes on HDL, paraoxonase and platelet-activating factor acetylhydrolase appear to diminish the formation of the highly atherogenic oxidized LDL. Third, lower levels of HDL cholesterol are associated in a dose-response fashion with the severity and number of angiographically documented atherosclerotic coronary arteries. Fourth, low HDL cholesterol predicts total mortality in patients with CAD and desirable total cholesterol levels (<200 mg/dL). Fifth, low HDL cholesterol concentrations appear to be associated with increased rates of restenosis after percutaneous transluminal coronary angioplasty. In terms of elevating HDL cholesterol, cessation of cigarette smoking, reduction to ideal body weight, and regular aerobic exercise all appear important. Most medications used to treat dyslipidemias will raise HDL cholesterol levels modestly; however, niacin appears to have the greatest potential to do so, and can increase HDL cholesterol up to 30%. Recognizing these data, the most recent report of the National Cholesterol Education Program identified low HDL cholesterol as a CAD risk factor and recommended that all healthy adults be screened for both total cholesterol and HDL cholesterol levels
Effect of an odor-modified garlic preparation on blood lipids.
Lau B.H.S., Lam F., Wang-Cheng R.
Suppression of LDL oxidation by garlic.
J Nutr. 2001 Mar; 131(3s):985S-8S.
It has been known for several decades that hypercholesterolemia is a major risk factor for atherosclerosis and that lowering of cholesterol can significantly reduce risk for cardiovascular diseases. More recently, oxidation of LDL has been recognized as playing an important role in the initiation and progression of atherosclerosis. Oxidized LDL, but not native LDL, promotes vascular dysfunction by exerting direct cytotoxicity toward endothelial cells, by increasing chemotactic properties for monocytes, by transforming macrophages to foam cells via scavenger-receptors and by enhancing the proliferation of various cell types, e.g., endothelial cells, monocytes and smooth muscle cells; all of these events are recognized as contributing to atherogenesis. In this paper, experimental evidence is presented that shows that several garlic compounds can effectively suppress LDL oxidation in vitro. Short-term supplementation of garlic in human subjects has demonstrated an increased resistance of LDL to oxidation. These data suggest that suppressed LDL oxidation may be one of the powerful mechanisms accounting for the antiatherosclerotic properties of garlic
Creatine synthesis and transport systems in the male rat reproductive tract.
Lee H, Kim JH, Chae YJ, et al.
Biol Reprod. 1998 Jun; 58(6):1437-44.
Previous studies from this laboratory showed that high levels of guanidinoacetate methyltransferase are present in mouse testis and epididymis, whereas guanidinoacetate methyltransferase mRNA and protein are not detected in seminal vesicles where large amounts of creatine (Cr) and phosphocreatine are found (Lee et al., Biol Reprod 1994; 50:152-162). To further investigate the origin(s) of Cr in the male reproductive tract, the expression patterns of the three enzymes and a transporter involved in Cr metabolism were examined with rat reproductive tissues. Western blot analysis showed that expression of L-arginine:glycine amidinotransferase was limited to the kidney. On the other hand, high levels of the mRNAs for both guanidinoacetate methyltransferase and Sadenosylhomocysteine hydrolase were expressed in the testis and epididymis as well as the liver and kidney. Cr transporter mRNA was highly expressed in the seminal vesicle and vas deferens. These results suggest that the source of Cr in the male reproductive tract varies depending on the tissue; in the testes and epididymides, Cr is synthesized from guanidinoacetate, while in the seminal vesicles, Cr is transported from blood. Previous and present findings suggest the importance of Cr metabolism and/or transport for reproductive functions
A lethal misconception: you may not be taking the right vitamin supplements to adequately lower toxic homocysteine levels in the blood.
Life Extension Magazine. 1999 5(3):32-6.
Principles of Biochemistry.
Relation between use of antihypertensive medications and risk of breast carcinoma among women ages 65-79 years.
Li CI, Malone KE, Weiss NS, et al.
Cancer. 2003 Oct 1; 98(7):1504-13.
BACKGROUND: Limited data are available regarding the incidence of breast carcinoma among users of relatively recently introduced forms of antihypertensive therapy. Although it has been suggested that women who have taken calcium channel blockers (CCBs) have an increased risk and that women who have taken angiotensin-I-converting enzyme (ACE) inhibitors have a decreased risk, currently, no conclusions can be drawn. METHODS: A population-based case-control study of women ages 65-79 years was conducted in western Washington State. The responses of 975 women who were diagnosed with invasive breast carcinoma during 1997-1999 were compared with the responses of 1007 women in a control group. Associations between use of different types of antihypertensive medications and breast carcinoma incidence were evaluated using logistic regression. RESULTS: Overall, women who had ever used CCBs, beta-blockers, or ACE inhibitors did not have an altered risk of breast carcinoma relative to women who had never used antihypertensive medications. Although the use of immediate-release CCBs, thiazide diuretics, and potassium-sparing diuretics was associated with modestly increased risks of breast carcinoma (odds ratio [OR], 1.5; 95% confidence interval [95% CI], 1.0-2.1; OR, 1.4; 95% CI, 1.1-1.8; and OR, 1.6; 95% CI, 1.2-2.1, respectively), the absence of any trend in the size of excess risk with increasing duration or with current versus former use of these agents argues for a cautious interpretation. CONCLUSIONS: The use of particular types of antihypertensive medications, including immediate-release CCBs and certain diuretics, may increase the risk of breast carcinoma among older women. Additional studies are warranted to clarify these potential associations. Cancer 2003;98:1504-13
Complex effects of different green tea catechins on human platelets.
Lill G, Voit S, Schror K, et al.
FEBS Lett. 2003 Jul 10; 546(2-3):265-70.
Epigallocatechin gallate (EGCG), a major component of green tea, has been previously shown to inhibit platelet aggregation. The effects of other green tea catechins on platelet function are not known. Pre-incubation with EGCG concentration-dependently inhibited thrombin-induced aggregation and phosphorylation of p38 mitogen-activated protein kinase and extracellular signal-regulated kinases-1/2. In contrast EGCG stimulated tyrosine phosphorylation of platelet proteins, including Syk and SLP-76 but inhibited phosphorylation of focal adhesion kinase. Other catechins did not inhibit platelet aggregation. Interestingly, when EGCG was added to stirred platelets, a tyrosine kinase-dependent stimulation of platelet aggregation was observed. The two other catechins containing a galloyl group in the 3' position (catechin gallate, epicatechin gallate) also stimulated platelet aggregation, while catechins without a galloyl group (catechin, epicatechin) or the catechin with a galloyl group in the 2' position (epigallocatechin) did not
Complex effects of different green tea catechins on human platelets.
Lill G, Voit S, Schror K, et al.
FEBS Lett. 2003 Jul 10; 546(2-3):265-70.
Epigallocatechin gallate (EGCG), a major component of green tea, has been previously shown to inhibit platelet aggregation. The effects of other green tea catechins on platelet function are not known. Pre-incubation with EGCG concentration-dependently inhibited thrombin-induced aggregation and phosphorylation of p38 mitogen-activated protein kinase and extracellular signal-regulated kinases-1/2. In contrast EGCG stimulated tyrosine phosphorylation of platelet proteins, including Syk and SLP-76 but inhibited phosphorylation of focal adhesion kinase. Other catechins did not inhibit platelet aggregation. Interestingly, when EGCG was added to stirred platelets, a tyrosine kinase-dependent stimulation of platelet aggregation was observed. The two other catechins containing a galloyl group in the 3' position (catechin gallate, epicatechin gallate) also stimulated platelet aggregation, while catechins without a galloyl group (catechin, epicatechin) or the catechin with a galloyl group in the 2' position (epigallocatechin) did not
Markers of myocardial damage and inflammation in relation to long-term mortality in unstable coronary artery disease. FRISC Study Group. Fragmin during Instability in Coronary Artery Disease.
Lindahl B, Toss H, Siegbahn A, et al.
N Engl J Med. 2000 Oct 19; 343(16):1139-47.
BACKGROUND: In patients with unstable coronary artery disease, there is a relation between the short-term risk of death and blood levels of troponin T (a marker of myocardial damage) and C-reactive protein and fibrinogen (markers of inflammation). Using information obtained during an extension of the follow-up period in the Fragmin during Instability in Coronary Artery Disease trial, we evaluated the usefulness of troponin T, C-reactive protein, and fibrinogen levels and other indicators of risk as predictors of the long-term risk of death from cardiac causes. METHODS: Levels of C-reactive protein and fibrinogen at enrollment and the maximal level of troponin T during the first 24 hours after enrollment were analyzed in 917 patients included in a clinical trial of low-molecular-weight heparin in unstable coronary artery disease. The patients were followed for a mean of 37.0 months (range, 1.6 to 50.6). RESULTS: During follow-up, 1.2 percent of the 173 patients with maximal blood troponin T levels of less than 0.06 microg per liter died of cardiac causes, as compared with 8.7 percent of the 367 patients with levels of 0.06 to 0.59 microg per liter and 15.4 percent of the 377 patients with levels of at least 0.60 microg per liter (P=0.007 and P=0.001, respectively). The rates of death from cardiac causes were 5.7 percent among the 314 patients with blood C-reactive protein levels of less than 2 mg per liter, 7.8 percent among the 294 with levels of 2 to 10 mg per liter, and 16.5 percent among the 309 with levels of more than 10 mg per liter (P=0.29 and P=0.001, respectively). The rates of death from cardiac causes were 5.4 percent among the 314 patients with blood fibrinogen levels of less than 3.4 g per liter, 12.0 percent among the 300 with levels of 3.4 to 3.9 g per liter, and 12.9 percent among the 303 with levels of at least 4.0 g per liter (P=0.004 and P=0.69, respectively). In a multivariate analysis, levels of troponin T and C-reactive protein were independent predictors of the risk of death from cardiac causes. CONCLUSIONS: In unstable coronary artery disease, elevated levels of troponin T and C-reactive protein are strongly related to the long-term risk of death from cardiac causes. These markers are independent risk factors, and their effects are additive with respect to each other and other clinical indicators of risk
The importance of transmethylation reactions to methionine metabolism in sheep: effects of supplementation with creatine and choline.
Lobley GE, Connell A, Revell D.
Br J Nutr. 1996 Jan; 75(1):47-56.
The influence of administering the methylated products choline and creatine on methionine irreversible-loss rate (ILR) and recycling from homocysteine has been investigated in sheep fed close to energy and N equilibrium. Two methods to estimate methionine recycling were compared. The first involved [U-13C]methionine infused as part of a labelled amino acid mixture obtained from hydrolysed algal protein. In this approach the isotope dilution of methionine with all five C atoms labelled (m + 5) will represent the ILR which does not recycle through homocysteine, while that which includes molecules with C-1-C-4 labelled will allow for loss of the labelled methyl (5)-C atom and replacement by an unlabelled moiety in the remethylation of homocysteine. The second method involved a combined infusion of [1-13C]- and [S-methyl-2H3]methionine. These two approaches gave similar data for methionine ILR which does not include label recycled to the amino acid from homocysteine but differed for recycled methionine fluxes. Consequently the two procedures differed in the calculated extent of homocysteine methylation under control conditions (6 v. 28%). These extents of remethylation are within the range observed for the fed human subject, despite the fact that fewer dietary methyl groups are available for the ruminant. Using combined data from the infusions, significant depression of methionine recycling occurred in blood (P < 0.05), with a similar trend for plasma (P = "0.077)," when choline plus creatine were infused. Wool growth, assessed by intradermal injection of [35S]cysteine, was not altered by supplementation with the methylated products. From changes in the label pattern of free methionine in aortal, hepatic portal and hepatic venous blood during U-13C-labelled algal hydrolysate infusion, the major sites of homocysteine remethylation appear to be the portal-drained viscera and the liver. This was confirmed by analysis of free methionine enrichments in various tissues following dual infusion of [1-13C]- and [S-methyl-2H3]methionine, with the greatest activities occurring in rumen, jejunum and liver. Of the non-splanchnic tissues examined, only kidney exhibited substantial methionine cycling; none was detected in muscle, heart, lung and skin. The implications of methyl group provision under net production conditions are discussed
Vitamin E and vitamin C supplement use and risk of all-cause and coronary heart disease mortality in older persons: the Established Populations for Epidemiologic Studies of the Elderly.
Losonczy KG, Harris TB, Havlik RJ.
Am J Clin Nutr. 1996 Aug; 64(2):190-6.
We examined vitamin E and vitamin C supplement use in relation to mortality risk and whether vitamin C enhanced the effects of vitamin E in 11,178 persons aged 67-105 y who participated in the Established Populations for Epidemiologic Studies of the Elderly in 1984-1993. Participants were asked to report all nonprescription drugs currently used, including vitamin supplements. Persons were defined as users of these supplements if they reported individual vitamin E and/or vitamin C use, not part of a multivitamin. During the follow-up period there were 3490 deaths. Use of vitamin E reduced the risk of all-cause mortality [relative risk (RR) = 0.66; 95% CI: 0.53, 0.83] and risk of coronary disease mortality (RR = 0.53; 95% CI: 0.34, 0.84). Use of vitamin E at two points in time was also associated with reduced risk of total mortality compared with that in persons who did not use any vitamin supplements. Effects were strongest for coronary heart disease mortality (RR = 0.37; 95% CI: 0.15, 0.90). The RR for cancer mortality was 0.41 (95% CI: 0.15, 1.08). Simultaneous use of vitamins E and C was associated with a lower risk of total mortality (RR = 0.58; 95% CI: 0.42, 0.79) and coronary mortality (RR = 0.47; 95% CI: 0.25, 0.87). Adjustment for alcohol use, smoking history, aspirin use, and medical conditions did not substantially alter these findings. These findings are consistent with those for younger persons and suggest protective effects of vitamin E supplements in the elderly
On the pharmacology of bromelain: an update with special regard to animal studies on dose-dependent effects.
Planta Med. 1990 Jun; 56(3):249-53.
Bromelain, a standardized complex of proteases from the pineapple plant, is absorbed unchanged from the intestine of animals at a rate of 40%; in animal experiments it was found to have primarily anti-edema, antiinflammatory, and coagulation-inhibiting effects. These effects are due to an enhancement of the serum fibrinolytic activity and inhibition of the fibrinogen synthesis, as well as a direct degradation of fibrin and fibrinogen. Bromelain lowers kininogen and bradykinin serum and tissue levels and has an influence on prostaglandin synthesis, thus acting antiinflammatory. In in vitro and in animal studies, experimentally induced tumours could be inhibited by bromelain. Although many studies do not give extensive statistical data, the effects of bromelain in animal studies seem to be dose-dependent. Further investigations have to be carried out
A prospective study of fibrinogen and risk of myocardial infarction in the Physicians' Health Study.
Ma J, Hennekens CH, Ridker PM, et al.
J Am Coll Cardiol. 1999 Apr; 33(5):1347-52.
OBJECTIVES: We examined the association of baseline plasma fibrinogen with future risk of myocardial infarction (MI) in the Physicians' Health Study. BACKGROUND: Elevated plasma fibrinogen increases and low dose aspirin decreases risk of MI. However, prospective data are limited about their interrelationships. METHODS: Blood samples were prospectively collected at baseline from 14,916 men in the Physicians' Health Study, aged 40 to 84 years, who were randomly assigned to take aspirin (325 mg every other day) or placebo for 5 years. We measured baseline plasma fibrinogen among 199 incident cases of MI and 199 age- and smoking-matched control subjects free of cardiovascular disease at the time of the case's diagnosis. RESULTS: Cases had significantly higher baseline fibrinogen levels (geometric mean: 262 mg/dl) than did control subjects (245 mg/dl, p = 0.02). Those with high fibrinogen levels (> or =343 mg/dl, the 90th percentile distribution of the control subjects) had a twofold increase in MI risk (age- and smoking-adjusted relative risk = 2.09, 95% confidence interval = 1.15 to 3.78) compared with those with fibrinogen below 343 mg/dl. Adjustment for lipids and other coronary risk factors as well as randomized aspirin assignment did not materially change the result. Furthermore, we observed no interaction between fibrinogen level and aspirin treatment. CONCLUSIONS: Among these apparently healthy U.S. male physicians, fibrinogen is associated with increased risk of future MI independent of other coronary risk factors, atherogenic factors such as lipids and antithrombotics such as aspirin
Reduction of plasma homocyst(e)ine levels by breakfast cereal fortified with folic acid in patients with coronary heart disease.
Malinow MR, Duell PB, Hess DL, et al.
N Engl J Med. 1998 Apr 9; 338(15):1009-15.
BACKGROUND: The Food and Drug Administration (FDA) has recommended that cereal-grain products be fortified with folic acid to prevent congenital neural-tube defects. Since folic acid supplementation reduces levels of plasma homocyst(e)ine, or plasma total homocysteine, which are frequently elevated in arterial occlusive disease, we hypothesized that folic acid fortification might reduce plasma homocyst(e)ine levels. METHODS: To test this hypothesis, we assessed the effects of breakfast cereals fortified with three levels of folic acid, and also containing the recommended dietary allowances of vitamins B6 and B12, in a randomized, double-blind, placebo-controlled, crossover trial in 75 men and women with coronary artery disease. RESULTS: Plasma folic acid increased and plasma homocyst(e)ine decreased proportionately with the folic acid content of the breakfast cereal. Cereal providing 127 microg of folic acid daily, approximating the increased daily intake that may result from the FDA's enrichment policy, increased plasma folic acid by 31 percent (P=0.045) but decreased plasma homocyst(e)ine by only 3.7 percent (P= 0.24). However, cereals providing 499 and 665 microg of folic acid daily increased plasma folic acid by 64.8 percent (P<0.001) and 105.7 percent (P="0.001)," respectively, and decreased plasma homocyst(e)ine by 11.0 percent (P<0.001) and 14.0 percent (P="0.001)," respectively. CONCLUSIONS: Cereal fortified with folic acid has the potential to increase plasma folic acid levels and reduce plasma homocyst(e)ine levels. Further clinical trials are required to determine whether folic acid fortification may prevent vascular disease. Until then, our results suggest that folic acid fortification at levels higher than that recommended by the FDA may be warranted
Homocyst(e)ine, diet, and cardiovascular diseases: a statement for healthcare professionals from the Nutrition Committee, American Heart Association.
Malinow MR, Bostom AG, Krauss RM.
Circulation. 1999 Jan 5; 99(1):178-82.
AHA Science Advisory: Homocyst(e)ine, Diet, and Cardiovascular Diseases Statement for Healthcare Professionals From the Nutrition Committee, American Heart Association.
1999;1999 Jan 5
Follow-up on primary prevention trials.
Curr Opin Lipidol. 1998 Dec; 9(6):551-6.
Recent primary prevention trials demonstrated that cardiovascular morbidity and mortality benefits are not accompanied by adverse effects on overall mortality and morbidity in cohorts representing plasma cholesterol concentrations observed in the bulk of coronary artery disease. During the past year, further analyses of the West of Scotland Coronary Prevention Study have indicated that benefit requires a 25% reduction of LDL cholesterol and that such treatment is not very expensive when focussed on selected high-risk individuals. The Air Force/Texas Coronary Artery Prevention Study indicated that benefit is seen in individuals with even lower plasma lipid concentration. Although current treatment with lifestyle and lipid modifying drug management is successful in primary prevention, the unpredictable nature of coronary artery disease and the cost of drugs mitigate against direct application of drug management in persons with relatively low risk, but selective treatment should be undertaken in very high-risk settings. Future studies need to examine more specific at risk cohorts, test better targeted lipoprotein modification, test more risk factors and also examine whether changes in vascular function or markers of inflammation will predict a better outcome
Early protection against sudden death by n-3 polyunsaturated fatty acids after myocardial infarction: time-course analysis of the results of the Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto Miocardico (GISSI)-Prevenzione.
Marchioli R, Barzi F, Bomba E, et al.
Circulation. 2002 Apr 23; 105(16):1897-903.
BACKGROUND: Our purpose was to assess the time course of the benefit of n-3 polyunsaturated fatty acids (PUFAs) on mortality documented by the GISSI-Prevenzione trial in patients surviving a recent (<3 months) myocardial infarction. METHODS AND RESULTS: In this study, 11 323 patients were randomly assigned to supplements of n-3 PUFAs, vitamin E (300 mg/d), both, or no treatment (control) on top of optimal pharmacological treatment and lifestyle advice. Intention-to-treat analysis adjusted for interaction between treatments was carried out. Early efficacy of n-3 PUFA treatment for total, cardiovascular, cardiac, coronary, and sudden death; nonfatal myocardial infarction; total coronary heart disease; and cerebrovascular events was assessed by right-censoring follow-up data 12 times from the first month after randomization up to 12 months. Survival curves for n-3 PUFA treatment diverged early after randomization, and total mortality was significantly lowered after 3 months of treatment (relative risk [RR] 0.59; 95% CI 0.36 to 0.97; P="0.037)." The reduction in risk of sudden death was specifically relevant and statistically significant already at 4 months (RR 0.47; 95% CI 0.219 to 0.995; P="0.048)." A similarly significant, although delayed, pattern after 6 to 8 months of treatment was observed for cardiovascular, cardiac, and coronary deaths. CONCLUSIONS: The early effect of low-dose (1 g/d) n-3 PUFAs on total mortality and sudden death supports the hypothesis of an antiarrhythmic effect of this drug. Such a result is consistent with the wealth of evidence coming from laboratory experiments on isolated myocytes, animal models, and epidemiological and clinical studies
A Wise Man Tries Myrrh 2000 Nov 30. The Penn Current. University of Pennsylvania 10/25/2000Dr. Philippe Szapary.
The Penn Current. 2000;
Effectiveness of low-dose crystalline nicotinic acid in men with low high-density lipoprotein cholesterol levels.
Martin-Jadraque R, Tato F, Mostaza JM, et al.
Arch Intern Med. 1996 May 27; 156(10):1081-8.
BACKGROUND: Hypoalphalipoproteinemia (low serum concentration of high-density lipoprotein cholesterol [HDL-C]) is a common pattern of dyslipidemia associated with coronary heart disease. High doses of nicotinic acid effectively raise HDL-C levels in this condition, but they are commonly accompanied by side effects. The efficacy of low doses of nicotinic acid that may produce fewer side effects has not been adequately studied. OBJECTIVE: To determine the effects of low-dose nicotinic acid on HDL-C levels in patients with hypoalphalipoproteinemia. METHODS: Forty-four men with low HDL-C levels (< 1.03 mmol/L [< 40 mg/dL]) entered the study. Twenty-four patients otherwise had normal lipid levels, and 20 were moderately hypertriglyceridemic (range of plasma triglyceride levels, 2.82 to 5.64 mmol/L 250 to 500 mg/dL). The trial consisted of 3 phases; each phase lasted 8 weeks. The first phase was diet only (30% fat diet); in the second phase, crystalline nicotinic acid was added at 1.5 g/d; and in the third phase, the dose was increased to 3 g/d. RESULTS: Of the 44 patients who entered the study, 37 completed the low-dose phase (1.5 g/d); the remaining patients were withdrawn because of side effects to nicotinic acid. Four other patients who completed the low-dose phase were excluded from the higher dose phase because of side effects that developed when they were receiving the low dose. Ten other patients withdrew during the high-dose phase because of side effects. In both groups, responses to nicotinic acid therapy tended to be dose-dependent. For both groups, the higher dose generally produced a greater reduction in apolipoprotein B-containing lipoproteins and a greater rise in HDL-C levels. However, for both groups, the low dose of nicotinic acid gave an average 20% increase in HDL-C levels. CONCLUSIONS: A low dose (1.5 g/d) of crystalline nicotinic acid causes an average 20% increase in HDL-C levels and significantly lowers triglyceride levels in both normolipidemic and hyperlipidemic patients with low HDL-C levels. Although the changes induced by this dose are less than those that can be achieved by a higher dose, the lower dose is better tolerated. Nicotinic acid may be useful in combined drug therapy for secondary prevention of coronary heart disease, and if higher doses cannot be tolerated, use of a lower dose should still be useful for producing a moderate rise in HDL-C levels in patients with hypoalphalipoproteinemia
Vitamin B-6 deficiency in rats reduces hepatic serine hydroxymethyltransferase and cystathionine beta-synthase activities and rates of in vivo protein turnover, homocysteine remethylation and transsulfuration.
Martinez M, Cuskelly GJ, Williamson J, et al.
J Nutr. 2000 May; 130(5):1115-23.
Vitamin B-6 deficiency causes mild elevation in plasma homocysteine, but the mechanism has not been clearly established. Serine is a substrate in one-carbon metabolism and in the transsulfuration pathway of homocysteine catabolism, and pyridoxal phosphate (PLP) plays a key role as coenzyme for serine hydroxymethyltransferase (SHMT) and enzymes of transsulfuration. In this study we used [(2)H(3)]serine as a primary tracer to examine the remethylation pathway in adequately nourished and vitamin B-6-deficient rats [7 and 0.1 mg pyridoxine (PN)/kg diet]. [(2)H(3)]Leucine and [1-(13)C]methionine were also used to examine turnover of protein and methionine pools, respectively. All tracers were injected intraperitoneally as a bolus dose, and then rats were killed (n = 4/time point) after 30, 60 and 120 min. Rats fed the low-PN diet had significantly lower growth and plasma and liver PLP concentrations, reduced liver SHMT activity, greater plasma and liver total homocysteine concentration, and reduced liver S-adenosylmethionine concentration. Hepatic and whole body protein turnover were reduced in vitamin B-6-deficient rats as evidenced by greater isotopic enrichment of [(2)H(3)]leucine. Hepatic [(2)H(2)]methionine production from [(2)H(3)]serine via cytosolic SHMT and the remethylation pathway was reduced by 80.6% in vitamin B-6 deficiency. The deficiency did not significantly reduce hepatic cystathionine-beta-synthase activity, and in vivo hepatic transsulfuration flux shown by production of [(2)H(3)]cysteine from the [(2)H(3)]serine increased over twofold. In contrast, plasma appearance of [(2)H(3)]cysteine was decreased by 89% in vitamin B-6 deficiency. The rate of hepatic homocysteine production shown by the ratio of [1-(13)C]homocysteine/[1-(13)C]methionine areas under enrichment vs. time curves was not affected by vitamin B-6 deficiency. Overall, these results indicate that vitamin B-6 deficiency substantially affects one-carbon metabolism by impairing both methyl group production for homocysteine remethylation and flux through whole-body transsulfuration
Fibrinogen deposition at the postischemic vessel wall promotes platelet adhesion during ischemia-reperfusion in vivo.
Massberg S, Enders G, Matos FC, et al.
Blood. 1999 Dec 1; 94(11):3829-38.
Following ischemia-reperfusion (I/R), platelet adhesion is thought to represent the initial event leading to remodeling and reocclusion of the vasculature. The mechanisms underlying platelet adhesion to the endothelium have not been completely established. Endothelial cells rendered ischemic acquire a procoagulant phenotype, characterized by fibrinogen accumulation. Therefore, we evaluated whether fibrinogen deposition during I/R mediates platelet adhesion. Using fluorescence microscopy, fibrinogen deposition and the accumulation of platelets were assessed in vivo in a model of intestinal I/R (1.5 hours/60 minutes). Fibrinogen accumulated in arterioles and venules early after the onset of reperfusion. The deposition of fibrinogen colocalized with large numbers of adherent platelets (520 +/- 65 and 347 +/- 81 platelets/mm(2) in arterioles and venules). Pretreatment with an antifibrinogen antibody attenuated platelet adhesion. Intracellular adhesion molecule (ICAM)-1 served as a major receptor for fibrinogen, since fibrinogen deposition and platelet adhesion to the endothelial cell surface were markedly decreased in ICAM-1-deficient mice. The platelet alpha(IIb)/beta(3) integrin plays a key role in fibrinogen-dependent platelet accumulation, because (1) platelet adhesion involved RGD-recognition sequences, and (2) platelets isolated from a patient with Glanzmann's disease showed decreased interaction with the postischemic endothelium. Since platelets are demonstrated here to induce tyrosine phosphorylation in endothelial cells, platelet recruitment might contribute to the development of an inflammatory reaction during I/R
Bromelain: biochemistry, pharmacology and medical use.
Cell Mol Life Sci. 2001 Aug; 58(9):1234-45.
Bromelain is a crude extract from the pineapple that contains, among other components, various closely related proteinases, demonstrating, in vitro and in vivo, antiedematous, antiinflammatory, antithrombotic and fibrinolytic activities. The active factors involved are biochemically characterized only in part. Due to its efficacy after oral administration, its safety and lack of undesired side effects, bromelain has earned growing acceptance and compliance among patients as a phytotherapeutical drug. A wide range of therapeutic benefits has been claimed for bromelain, such as reversible inhibition of platelet aggregation, angina pectoris, bronchitis, sinusitis, surgical traumas, thrombophlebitis, pyelonephritis and enhanced absorption of drugs, particularly of antibiotics. Biochemical experiments indicate that these pharmacological properties depend on the proteolytic activity only partly, suggesting the presence of nonprotein factors in bromelain. Recent results from preclinical and pharmacological studies recommend bromelain as an orally given drug for complementary tumor therapy: bromelain acts as an immunomodulator by raising the impaired immunocytotoxicity of monocytes against tumor cells from patients and by inducing the production of distinct cytokines such as tumor necrosis factor-a, interleukin (Il)-1beta, Il-6, and Il-8. In a recent clinical study with mammary tumor patients, these findings could be partially confirmed. Especially promising are reports on animal experiments claiming an antimetastatic efficacy and inhibition of metastasis-associated platelet aggregation as well as inhibition of growth and invasiveness of tumor cells. Apparently, the antiinvasive activity does not depend on the proteolytic activity. This is also true for bromelain effects on the modulation of immune functions, its potential to eliminate burn debris and to accelerate wound healing. Whether bromelain will gain wide acceptance as a drug that inhibits platelet aggregation, is antimetastatic and facilitates skin debridement, among other indications, will be determined by further clinical trials. The claim that bromelain cannot be effective after oral administration is definitely refuted at this time
The Homocysteine Revolution (out of print); see also McCully, K.S., Weil, W. The Homocysteine Revolution: Medicine for the New Millennium.
Homocysteine, folate, vitamin B6, and cardiovascular disease.
JAMA. 1998 Feb 4; 279(5):392-3.
Repression of rat kidney L-arginine:glycine amidinotransferase synthesis by creatine at a pretranslational level.
McGuire DM, Gross MD, Van Pilsum JF, et al.
J Biol Chem. 1984 Oct 10; 259(19):12034-8.
The first committed reaction in the biosynthesis of creatine is catalyzed by the enzyme L-arginine:glycine amidinotransferase, commonly called transamidinase. Creatine, the end product of the biosynthetic pathway, is known to alter the levels of kidney transamidinase activity. Rats fed a diet containing 0.3% creatine had 26% of the kidney transamidinase activity of the rats fed a creatine-free diet. This reduction in transamidinase activity was correlated with a decrease in transamidinase protein in the creatine-fed rats. The relative synthetic rates and mRNA functional activities of transmidinase were measured in control and creatine-fed rats. The relative synthetic rate of transamidinase in creatine-fed rats was 21% of that found in the control animals. The functional transamidinase mRNA in creatine-fed rats was correspondingly reduced to 37% of the amount in the control animals. Thus, creatine affects transamidinase activity by altering its rate of synthesis at a pretranslational step and represents an example of end-product repression in a higher eukaryote
Gum Disease May Increase Risk of Second MI.
2000;2000 Nov 23
C-reactive protein: relation to total mortality, cardiovascular mortality and cardiovascular risk factors in men.
Mendall MA, Strachan DP, Butland BK, et al.
Eur Heart J. 2000 Oct; 21(19):1584-90.
BACKGROUND: There is much interest in reported associations between serum C-reactive protein and incident ischaemic heart disease. It is uncertain what this association represents. We aimed to assess the effect of confounding from a number of different sources in the Caerphilly Prospective Heart Disease Study and in particular whether the low grade inflammation indicated by C-reactive protein may be the mechanism whereby non-circulating risk factors may influence pathogenesis of ischaemic heart disease. Methods: Plasma specimens collected during 1979-83 from 1395 men with sufficient sample remaining were assayed for serum C-reactive protein by ELISA. Subsequent mortality and incident ischaemic heart disease events were ascertained from death certificates, hospital records and electrocardiographic changes at 5-yearly follow-up examinations. RESULTS: There was a positive association between C-reactive protein and incident ischaemic heart disease (P<0.005) mainly with fatal disease (P<0.002). There was also a positive association with all-cause mortality (P<0.0001). C-reactive protein was significantly associated with a number of non-circulating risk factors including body mass index (P<0.0001), smoking (P<0.0001), low forced expiratory volume in 1 s (P<0.0001), height (P="0.025)," low childhood social class (P="0.014)" and age (P="0.036)." C-reactive protein was also associated positively with circulating risk factors including viscosity, leukocyte count, fibrinogen (all P<0.0001) and insulin (P="0.0058)." After adjustment for non-circulating risk factors the association with all-incident ischaemic heart disease and ischaemic heart disease death became non-significant, but the association with all-cause mortality remained (P="0.033)." Further adjustment for fibrinogen however removed any hint of an increasing trend in odds for all three outcomes. CONCLUSION: C-reactive protein levels are raised in association with a variety of established cardiovascular risk factors. Neither C-reactive protein nor the systemic inflammation it represents appears to play a direct role in the development of ischaemic heart disease
Bromelain proteases reduce human platelet aggregation in vitro, adhesion to bovine endothelial cells and thrombus formation in rat vessels in vivo.
Metzig C, Grabowska E, Eckert K, et al.
In Vivo. 1999 Jan; 13(1):7-12.
The thiol protease, bromelain, an extract from pineapple stem, was suggested to have antithrombotic and anticoagulant activities in vivo. We studied the effects of bromelain on cell size distribution of isolated human platelets in vitro by Coulter Counter measurements. Preincubation of platelets with bromelain (10 micrograms/mL) completely prevented the thrombin (0.2 U/mL) induced platelet aggregation. Papain was less active in preventing platelet aggregation. In vitro, bromelain (0.1 microgram/mL) reduced the adhesion of bound, thrombin stimulated, fluorescent labeled platelets to bovine aorta endothelial cells. In addition, preincubation of platelets with bromelain, prior to thrombin, activation, reduced the platelet adhesion to the endothelial cells to the low binding value of unstimulated platelets. On the basis of mass concentrations, the proteases papain and trypsin were as effective as bromelain. Using a laser thrombosis model, the in vivo effects of orally and intraveneously applied bromelain on thrombus formation in rat mesenteric vessels were studied. Bromelain, orally applied at 60 mg/kg body weight, inhibited the thrombus formation in a time dependent manner, the maximum being after 2 hours in 11% of arterioles and 6% of venoles. Intravenous application at 30 mg/kg was slightly more active in reducing thrombus formation in arterioles (13%) and venoles (5%), suggesting that orally applied bromelain is biologically active. These results may help to explain some of the clinical effects observed after bromelain treatment in patients with thrombosis and related diseases
Vitamin E supplementation in patients with carotid atherosclerosis: reversal of altered oxidative stress status in plasma but not in plaque.
Micheletta F, Natoli S, Misuraca M, et al.
Arterioscler Thromb Vasc Biol. 2004 Jan; 24(1):136-40.
OBJECTIVE: Oxidative stress is believed to play a pivotal role in the initiation and progression of atherosclerosis. We analyzed whether vitamin E supplementation influences oxidative stress in plasma and atherosclerotic plaques of patients with severe atherosclerosis. METHODS AND RESULTS: In 16 patients who were candidates for carotid endarterectomy and in 32 age- and sex-matched controls, plasma levels of 7beta-hydroxycholesterol, 7-ketocholesterol, cholesterol, and vitamin E were measured. Patients were randomly allocated to standard treatment with or without 900 mg/d vitamin E. After 6 weeks of treatment, the reported variables were measured in plasma and plaques. The plasma vitamin E/cholesterol ratio was significantly lower in patients than in controls (3.05+/-0.6 versus 6.3+/-1.7 micromol/mmol cholesterol, P<0.001). Plasma 7beta-hydroxycholesterol was significantly higher in patients than in controls (5.0+/-1.04 versus 4.4+/-0.6 ng/mL, P<0.05). Patients who were given vitamin E supplementation showed a significant increase of plasma vitamin E with concomitant decrease of 7beta-hydroxycholesterol. Conversely, no treatment dependence was observed in oxysterol or vitamin E content of plaques. CONCLUSIONS: An imbalance between oxidative stress and antioxidant status is present in patients with advanced atherosclerosis. Vitamin E supplementation improves this imbalance in plasma but not in plaques
Enhancement by homocysteine of plasminogen activator inhibitor-1 gene expression and secretion from vascular endothelial and smooth muscle cells.
Midorikawa S, Sanada H, Hashimoto S, et al.
Biochem Biophys Res Commun. 2000 May 27; 272(1):182-5.
In order to elucidate the relationship between homocysteine and the fibrinolytic system, we examined the effect of homocysteine on plasminogen activator inhibitor-1 (PAI-1) and tissue-type plasminogen activator (tPA) gene expression and protein secretion in cultured human vascular endothelial and smooth muscle cells in vitro. PAI-1 mRNA and secreted protein levels were both enhanced by homocysteine in a dose dependent manner, with significant stimulation of PAI-1 secretion observed at concentrations greater than 0.5 mM homocysteine. In contrast, secretion and mRNA expression of tPA were not significantly altered by homocysteine stimulation. Secretion of TGFbeta (transforming growth factor beta) and TNFalpha (tumor necrosis factor alpha), possible regulators of PAI-1 expression and secretion, were not stimulated by treatment with 1.0 mM homocysteine. These results suggests that hyperhomocysteinemia-induced atherosclerosis and/or thrombosis may be caused by homocysteine-induced stimulation of PAI-1 gene expression and secretion in the vasculatures by a mechanism independent from paracrine-autocrine activity of TGFbeta and TNFalpha
Efficacy and tolerability of policosanol in hypercholesterolemic postmenopausal women.
Mirkin A, Mas R, Martinto M, et al.
Int J Clin Pharmacol Res. 2001; 21(1):31-41.
This randomized, double-blind, multicenter placebo-controlled study was conducted to investigate the efficacy and tolerability of policosanol, a cholesterol-lowering drug purified from sugar cane wax, in women who had experienced menopause and showed elevated serum total cholesterol and low density lipoprotein (LDL)-cholesterol levels despite a 6-week standard lipid-lowering diet. Thus, 56 eligible patients were randomized to receive placebo or policosanol 5 mg/day for 8 weeks and the dose was doubled to 10 mg/day during the next 8 weeks. Policosanol (5 and 10 mg/day) significantly decreased LDL-cholesterol (17.3% and 26.7%, respectively), total cholesterol (12.9% and 19.5%) as well as the ratios of LDL-cholesterol to high-density lipoprotein (HDL)-cholesterol (17.2% and 26.5%) and total cholesterol to HDL-cholesterol (16.3% and 21.0%) compared with baseline and placebo. HDL-cholesterol levels were significantly raised by 7.4% at study completion. No significant changes occurred in the lipid profile of the placebo group. The drug was safe and well tolerated. No drug-related adverse effects were observed. None of the patients administered policosanol but three of those administered placebo withdrew from the trial because of adverse effects: one due to a serious hypertensive status, one because of an allergic reaction (pruritus plus skin rash) and one due to gastrointestinal disturbances (nauseas plus vomiting). Eleven placebo patients reported 24 adverse effects compared with six policosanol patients who reported seven adverse effects (p < 0.05). In addition, five placebo (17.9%) and 13 policosanol patients (46.4%) (p < 0.05) reported improvements in habitual symptoms and health perception during the study. In conclusion, policosanol was effective and well tolerated in hypercholesterolemic postmenopausal women, showing additional benefits in the health perception of the study patients
Calcium Channel Blockers.
Study of the antiischemic action of EGb 761 in the treatment of peripheral arterial occlusive disease by TcPo2 determination.
Mouren X, Caillard P, Schwartz F.
Angiology. 1994 Jun; 45(6):413-7.
In a randomized, placebo-controlled, double-blind, parallel study of 20 patients, the antiischemic effect of EGb 761 (Ginkgo biloba Extract) was studied by measuring the transcutaneous partial pressure of oxygen (TcPo2) during exercise. Transcutaneous oximetry during exercise provides a good, noninvasive estimation of local arterial perfusion and constitutes a real index of local and regional capillary perfusion. Twenty patients between the ages of forty-four and seventy-three years suffering from claudicating atherosclerotic arterial occlusive disease in stage II according to the Leriche and Fontaine classification, diagnosed for more than a year and stable for three months, were included. The eligible patients received placebo for fifteen days under single-blind conditions. At the end of this preinclusion period, the eligibility criteria were checked and the patients were randomized to two treatment groups. The first group received 320 mg per day of EGb 761 for four weeks and the second group received placebo. The treadmill walking test was performed under standardized conditions at the same time of day and by the same investigator. In a comparison of the differences before and after treatment, the areas of ischemia decreased by 38% in the EGb 761 group but remained essentially stable (+5%) in the placebo group. This difference between groups is significant (F [1.18] = 4.91; P = 0.04) and the 95% confidence interval for the difference ranges from 0.89 to 3.87. This study confirmed significantly the rapid antiischemic action of EGb 761 and its value in the management of peripheral arterial occlusive disease at the stage of intermittent claudication
Daily supplementation with aged garlic extract, but not raw garlic, protects low density lipoprotein against in vitro oxidation.
Munday JS, James KA, Fray LM, et al.
Atherosclerosis. 1999 Apr; 143(2):399-404.
The oxidation of low density lipoprotein (LDL) is believed to be an important process in the development and progression of atherosclerosis. In this study, human subjects were supplemented daily with one of: 6 g raw garlic; 2.4 g aged garlic extract (AGE); or 0.8 g DL-alpha-tocopherol acetate for 7 days to determine the effect on the susceptibility of LDL particles to Cu2+-mediated oxidation. LDL isolated from subjects given either alpha-tocopherol or AGE, but not raw garlic, was significantly more resistant to oxidation than LDL isolated from subjects receiving no supplements. These results suggest that if antioxidants are proven to be antiatherogenic, AGE may be useful in preventing atherosclerotic disease
Important considerations in angina.
Nat Med J. 1999; 2(2):1-8.
Healing Power of Herbs .
Clogged arteries are not just a matter of the heart.
New Haven Register.
HDL therapy for the acute treatment of atherosclerosis.
Newton RS, Krause BR.
Atheroscler Suppl. 2002 Dec; 3(4):31-8.
Although pharmacologic intervention to treat atherosclerosis originally focused on lowering LDL-cholesterol levels as a therapeutic target, a number of intervention trials have also highlighted the powerful effect of elevating HDL-cholesterol levels to reduce cardiovascular morbidity and mortality. Although the mechanism(s) by which HDL beneficially alters the atherosclerotic disease process is (are) still unknown, it is presumed that high levels of HDL facilitate the efflux of cholesterol from the arterial wall, thereby enhancing the transport of cholesterol and other lipids from arteries back to the liver for biliary excretion as fecal sterols and bile acids. It has therefore been hypothesized that through a rapid facilitation of HDL mediated cholesterol efflux from arteries by infusion of synthetic apolipoprotein A-I (apoA-I)/phospholipid (A-I/PL) complexes, HDL therapy could have an acute therapeutic application to treat cardiovascular disease at the site of action, namely the vulnerable, unstable atherosclerotic plaque. Single high dose infusions and repeated injections of lower doses of apoA-I variants or mimetics complexed to phospholipids have produced remarkable effects on the progression and regression of atherosclerosis in animal models. The positive results of these preclinical experiments have compelled researchers to perform exploratory studies in human subjects in which reconstituted HDL and synthetic A-I/PL complexes are infused through a peripheral vein. These clinical studies are testing the hypothesis and the potential use of synthetic HDL as a new treatment modality for acute coronary syndromes. Given that there is an unmet medical need for new and more effective therapies to elevate HDL-cholesterol levels and improve HDL function, a historical review, update and discussion of the preclinical and clinical studies which support the use of HDL therapy for reducing cardiovascular morbidity and mortality is warranted
Facts about Dietary Supplements: Vitamin B6.
NIH (National Institutes of Health).
NHLBI Stops Trial of Estrogen Plus Progestin Due to Increased Breast Cancer Risk, Lack of Overall Benefit.
NIH (National Institutes of Health).
2002;2002 Jul 7
Heart and Vascular Diseases.
NIH (National Institutes of Health).
Effect of recombinant ApoA-I Milano on coronary atherosclerosis in patients with acute coronary syndromes: a randomized controlled trial.
Nissen SE, Tsunoda T, Tuzcu EM, et al.
JAMA. 2003 Nov 5; 290(17):2292-300.
CONTEXT: Although low levels of high-density lipoprotein cholesterol (HDL-C) increase risk for coronary disease, no data exist regarding potential benefits of administration of HDL-C or an HDL mimetic. ApoA-I Milano is a variant of apolipoprotein A-I identified in individuals in rural Italy who exhibit very low levels of HDL. Infusion of recombinant ApoA-I Milano-phospholipid complexes produces rapid regression of atherosclerosis in animal models. OBJECTIVE: We assessed the effect of intravenous recombinant ApoA-I Milano/phospholipid complexes (ETC-216) on atheroma burden in patients with acute coronary syndromes (ACS). DESIGN: The study was a double-blind, randomized, placebo-controlled multicenter pilot trial comparing the effect of ETC-216 or placebo on coronary atheroma burden measured by intravascular ultrasound (IVUS). SETTING: Ten community and tertiary care hospitals in the United States. PATIENTS: Between November 2001 and March 2003, 123 patients aged 38 to 82 years consented, 57 were randomly assigned, and 47 completed the protocol. INTERVENTIONS: In a ratio of 1:2:2, patients received 5 weekly infusions of placebo or ETC-216 at 15 mg/kg or 45 mg/kg. Intravascular ultrasound was performed within 2 weeks following ACS and repeated after 5 weekly treatments. MAIN OUTCOME MEASURES: The primary efficacy parameter was the change in percent atheroma volume (follow-up minus baseline) in the combined ETC-216 cohort. Prespecified secondary efficacy measures included the change in total atheroma volume and average maximal atheroma thickness. RESULTS: The mean (SD) percent atheroma volume decreased by -1.06% (3.17%) in the combined ETC-216 group (median, -0.81%; 95% confidence interval [CI], -1.53% to -0.34%; P =.02 compared with baseline). In the placebo group, mean (SD) percent atheroma volume increased by 0.14% (3.09%; median, 0.03%; 95% CI, -1.11% to 1.43%; P =.97 compared with baseline). The absolute reduction in atheroma volume in the combined treatment groups was -14.1 mm3 or a 4.2% decrease from baseline (P<.001). CONCLUSIONS: A recombinant ApoA-I Milano/phospholipid complex (ETC-216) administered intravenously for 5 doses at weekly intervals produced significant regression of coronary atherosclerosis as measured by IVUS. Although promising, these results require confirmation in larger clinical trials with morbidity and mortality end points
Clinical trials with gugulipid. A new hypolipidaemic agent.
NityaNand S, Srivastava JS, Asthana OP.
J Assoc Physicians India. 1989 May; 37(5):323-8.
Multicentric clinical trials of the efficacy of gugulipid conducted at Bombay, Bangalore, Delhi, Jaipur, Lucknow, Nagpur and Varanasi have been reported. Two hundred and five patients completed 12 week open trial with gugulipid in a dose of 500 mg tds after 8 week diet and placebo therapy. One patient showed gastrointestinal symptoms which did not necessitate withdrawal of the drug. A significant lowering of serum cholesterol (av. 23.6%) and serum triglycerides (av. 22.6%) was observed in 70-80% patients Double-blind, crossover study was completed in 125 patients with gugulipid therapy and in 108 patients with clofibrate therapy. Two patients had flu-like syndrome with clofibrate and opted out from the study. With gugulipid the average fall in serum cholesterol and triglycerides was 11 and 16.8% respectively and with clofibrate 10 and 21.6% respectively. The lipid lowering effect of both drugs became evident 3-4 week after starting the drug and had no relationship with age, sex, and concomitant drug intake. Hypercholesterolaemic patients responded better to gugulipid therapy than hypertriglyceridaemic patients who responded better to clofibrate therapy. In mixed hyperlipidaemic patients response to both drugs was comparable. HDL-cholesterol was increased in 60% cases who responded to gugulipid therapy. Clofibrate had no effect on HDL-cholesterol. A significant decrease in LDL-cholesterol was observed in the responder group to both drugs
Plasma homocysteine is regulated by phospholipid methylation.
Noga AA, Stead LM, Zhao Y, et al.
J Biol Chem. 2003 Feb 21; 278(8):5952-5.
Mild hyperhomocysteinemia is an independent risk factor for cardiovascular disease. Homocysteine, a non-protein amino acid, is formed from S-adenosylhomocysteine and partially secreted into plasma. A potential source for homocysteine is methylation of the lipid phosphatidylethanolamine to phosphatidylcholine by phosphatidylethanolamine N-methyltransferase in the liver. We show that mice that lack phosphatidylethanolamine N-methyltransferase have plasma levels of homocysteine that are approximately 50% of those in wild-type mice. Hepatocytes isolated from methyltransferase-deficient mice secrete approximately 50% less homocysteine. Rat hepatoma cells transfected with phosphatidylethanolamine N-methyltransferase secrete more homocysteine than wild-type cells. Thus, phosphatidylethanolamine N-methyltransferase is an important source of plasma homocysteine and a potential therapeutic target for hyperhomocysteinemia
Nutrition Notebook. Methionine 2000.
Total plasma homocysteine and cardiovascular risk profile. The Hordaland Homocysteine Study.
Nygard O, Vollset SE, Refsum H, et al.
JAMA. 1995 Nov 15; 274(19):1526-33.
OBJECTIVE--To estimate the relations between established cardiovascular risk factors and total homocysteine (tHcy) in plasma. DESIGN--Health examination survey by the Norwegian Health Screening Service in 1992 and 1993. SETTING--General community, Hordaland County of Western Norway. PARTICIPANTS--A total of 7591 men and 8585 women, 40 to 67 years of age, with no history of hypertension, diabetes, coronary heart disease, or cerebrovascular disease were included. MAIN OUTCOME MEASURE--Plasma tHcy level. RESULTS--The level of plasma tHcy was higher in men than in women and increased with age. In subjects 40 to 42 years old, geometric means were 10.8 mumol/L for 5918 men and 9.1 mumol/L for 6348 women. At age 65 to 67 years, the corresponding tHcy values were 12.3 mumol/L (1386 men) and 11.0 mumol/L (1932 women). Plasma tHcy level increased markedly with the daily number of cigarettes smoked in all age groups. Its relation to smoking was particularly strong in women. The combined effect of age, sex, and smoking was striking. Heavy-smoking men aged 65 to 67 years had a mean tHcy level 4.8 mumol/L higher than never-smoking women aged 40 to 42 years. Plasma tHcy level also was positively related to total cholesterol level, blood pressure, and heart rate and inversely related to physical activity. The relations were not substantially changed by multivariate adjustment, including intake of vitamin supplements, fruits, and vegetables. CONCLUSIONS--Elevated plasma tHcy level was associated with major components of the cardiovascular risk profile, ie, male sex, old age, smoking, high blood pressure, elevated cholesterol level, and lack of exercise. These findings should influence future studies on the etiology and pathogenesis of cardiovascular disease
Plasma homocysteine levels and mortality in patients with coronary artery disease.
Nygard O, Nordrehaug JE, Refsum H, et al.
N Engl J Med. 1997 Jul 24; 337(4):230-6.
BACKGROUND: Elevated plasma homocysteine levels are a risk factor for coronary heart disease, but the prognostic value of homocysteine levels in patients with established coronary artery disease has not been defined. METHODS: We prospectively investigated the relation between plasma total homocysteine levels and mortality among 587 patients with angiographically confirmed coronary artery disease. At the time of angiography in 1991 or 1992, risk factors for coronary disease, including homocysteine levels, were evaluated. The majority of the patients subsequently underwent coronary-artery bypass grafting (318 patients) or percutaneous transluminal coronary angioplasty (120 patients); the remaining 149 were treated medically. RESULTS: After a median follow-up of 4.6 years, 64 patients (10.9 percent) had died. We found a strong, graded relation between plasma homocysteine levels and overall mortality. After four years, 3.8 percent of patients with homocysteine levels below 9 micromol per liter had died, as compared with 24.7 percent of those with homocysteine levels of 15 micromol per liter or higher. Homocysteine levels were only weakly related to the extent of coronary artery disease but were strongly related to the history with respect to myocardial infarction, the left ventricular ejection fraction, and the serum creatinine level. The relation of homocysteine levels to mortality remained strong after adjustment for these and other potential confounders. In an analysis in which the patients with homocysteine levels below 9 micromol per liter were used as the reference group, the mortality ratios were 1.9 for patients with homocysteine levels of 9.0 to 14.9 micromol per liter, 2.8 for those with levels of 15.0 to 19.9 micromol per liter, and 4.5 for those with levels of 20.0 micromol per liter or higher (P for trend=0.02). When death due to cardiovascular disease (which occurred in 50 patients) was used as the end point in the analysis, the relation between homocysteine levels and mortality was slightly strengthened. CONCLUSIONS: Plasma total homocysteine levels are a strong predictor of mortality in patients with angiographically confirmed coronary artery disease
Hypertension and borderline isolated systolic hypertension increase risks of cardiovascular disease and mortality in male physicians.
O'Donnell CJ, Ridker PM, Glynn RJ, et al.
Circulation. 1997 Mar 4; 95(5):1132-7.
BACKGROUND: The objective of this study was to examine whether definite hypertension and borderline isolated systolic hypertension predict subsequent cardiovascular disease and mortality. METHODS AND RESULTS: This was a prospective cohort study with a mean follow-up of 11.7 years. The subjects were a group of 18,682 apparently healthy US men, aged 40 to 84 years, participating in the Physicians' Health Study, a randomized trial of low-dose aspirin and beta-carotene. The main outcome measures were total cardiovascular disease, myocardial infarction, stroke, cardiovascular death, and all-cause mortality. Hypertension was associated with substantially increased risks of total cardiovascular disease (relative risk [RR] 1.92; 95% confidence interval [CI], 1.70 to 2.18), myocardial infarction (RR,1.78; 95% CI, 1.49 to 2.13), stroke (RR, 2.19; 95% CI, 1.78 to 2.69), and cardiovascular death (RR, 2.10; 95% CI, 1.68 to 2.63). Borderline isolated systolic hypertension was associated with significantly increased risks of cardiovascular disease (RR, 1.32; 95% CI, 1.09 to 1.59), stroke (RR, 1.42; 95% CI, 1.04 to 1.93), and cardiovascular death (RR, 1.56; 95% CI, 1.13 to 2.15), as well as a possible but non-significant increased risk of myocardial infarction (RR, 1.26; 95% CI, 0.95 to 1.67). Hypertension and borderline isolated systolic hypertension were associated with significantly increased risks of 41% and 22%, respectively, for all-cause mortality. CONCLUSIONS: Hypertension as well as borderline isolated systolic hypertension are associated with elevated risks of cardiovascular diseases, especially stroke and cardiovascular death. Hypertension is associated with an increased risk of myocardial infarction, and borderline isolated systolic hypertension predicts a possible but more modest increase in risk. These data add to the existing evidence that hypertension is a major cardiovascular risk factor and extend the findings to borderline isolated systolic hypertension
Hypertension and borderline isolated systolic hypertension increase risks of cardiovascular disease and mortality in male physicians.
O'Donnell CJ, Ridker PM, Glynn RJ, et al.
Circulation. 1997 Mar 4; 95(5):1132-7.
BACKGROUND: The objective of this study was to examine whether definite hypertension and borderline isolated systolic hypertension predict subsequent cardiovascular disease and mortality. METHODS AND RESULTS: This was a prospective cohort study with a mean follow-up of 11.7 years. The subjects were a group of 18,682 apparently healthy US men, aged 40 to 84 years, participating in the Physicians' Health Study, a randomized trial of low-dose aspirin and beta-carotene. The main outcome measures were total cardiovascular disease, myocardial infarction, stroke, cardiovascular death, and all-cause mortality. Hypertension was associated with substantially increased risks of total cardiovascular disease (relative risk [RR] 1.92; 95% confidence interval [CI], 1.70 to 2.18), myocardial infarction (RR,1.78; 95% CI, 1.49 to 2.13), stroke (RR, 2.19; 95% CI, 1.78 to 2.69), and cardiovascular death (RR, 2.10; 95% CI, 1.68 to 2.63). Borderline isolated systolic hypertension was associated with significantly increased risks of cardiovascular disease (RR, 1.32; 95% CI, 1.09 to 1.59), stroke (RR, 1.42; 95% CI, 1.04 to 1.93), and cardiovascular death (RR, 1.56; 95% CI, 1.13 to 2.15), as well as a possible but non-significant increased risk of myocardial infarction (RR, 1.26; 95% CI, 0.95 to 1.67). Hypertension and borderline isolated systolic hypertension were associated with significantly increased risks of 41% and 22%, respectively, for all-cause mortality. CONCLUSIONS: Hypertension as well as borderline isolated systolic hypertension are associated with elevated risks of cardiovascular diseases, especially stroke and cardiovascular death. Hypertension is associated with an increased risk of myocardial infarction, and borderline isolated systolic hypertension predicts a possible but more modest increase in risk. These data add to the existing evidence that hypertension is a major cardiovascular risk factor and extend the findings to borderline isolated systolic hypertension
Eat right and take a multivitamin.
Oakley GP, Jr.
N Engl J Med. 1998 Apr 9; 338(15):1060-1.
Antihypertensive agents and the drug therapy of hypertension. In Goodman and Gilman's The Pharmacological Basis of Therapeutics 2001.
Possible mechanisms for the differential effects of high linoleate safflower oil and high alpha-linolenate perilla oil diets on platelet-activating factor production by rat polymorphonuclear leukocytes.
Oh-hashi K, Takahashi T, Watanabe S, et al.
J Lipid Mediat Cell Signal. 1997 Dec; 17(3):207-20.
As compared with high dietary linoleate safflower oil, high dietary alpha-linolenate perilla oil decreased platelet-activating factor (PAF) production by nearly half in calcium ionophore (CaI)-stimulated rat polymorphonuclear leukocytes (PMN). In the CaI-stimulated PMN from the perilla oil group, the accumulated amount of arachidonate (AA) plus eicosapentaenoate (EPA) was 30% less and that of lyso-PAF was 50% less, indicating that the decreased availability of lyso-PAF is a factor contributing to the relatively low PAF production. Consistently, eicosatetraynoic acid (ETYA), a dual inhibitor of cyclooxygenase and lipoxygenase, increased free fatty acids (FFA) and decreased PAF production possibly by decreasing the availability of lyso-PAF. Although, leukotrienes (LTs) have been proposed to stimulate PAF production synergistically, a potent LTB4 receptor antagonist, ONO-4057, decreased the formation of free fatty acids and LTB4, but stimulated PAF production somewhat, indicating that LTB4 may not stimulate PAF production in PMN. Lysophospholipid-induced transacylase (CoA-independent transacylase) activity in PMN homogenates was 25-30% lower in the perilla oil group but no significant differences were observed in the lyso-PAF acetyltransferase and PAF acetylhydrolase activities between the two dietary groups. Thus, decreased transacylase activity is another factor associated with the relatively low PAF production in the perilla oil group
Protective action on human LDL against oxidation and glycation by four organosulfur compounds derived from garlic.
Ou CC, Tsao SM, Lin MC, et al.
Lipids. 2003 Mar; 38(3):219-24.
Human LDL were used to study the protective action of four organosulfur compounds (diallyl sulfide, DAS; diallyl disulfide, DADS; S-ethylcysteine, SEC; N-acetylcysteine, NAC) derived from garlic against oxidation and glycation. The four organosulfur compounds significantly inhibited superoxide production by xanthine-xanthine oxidase (P < 0.05) and showed marked copper-chelating capability. DAS and DADS exhibited greater antioxidant activities against copper- and amphotericin B-induced LDL oxidation (P < 0.05) than SEC and NAC. However, SEC and NAC were more effective in sparing LDL alpha-tocopherol (P < 0.05). When oxidation was minimized, SEC was the most powerful agent against LDL glycation (P < 0.05); however, DADS was superior to other agents in suppressing both oxidation and glycation when LDL oxidation occurred simultaneously with glycation. These results suggest that the four organosulfur compounds derived from garlic are potent agents for protecting LDL against oxidation and glycation, and that they may benefit patients with diabetes mellitus or cardiovascular diseases by preventing complications
Lipoprotein-associated phospholipase A2 as an independent predictor of coronary heart disease. West of Scotland Coronary Prevention Study Group.
Packard CJ, O'Reilly DS, Caslake MJ, et al.
N Engl J Med. 2000 Oct 19; 343(16):1148-55.
BACKGROUND: Chronic inflammation is believed to increase the risk of coronary events by making atherosclerotic plaques in coronary vessels prone to rupture. We examined blood constituents potentially affected by inflammation as predictors of risk in men with hypercholesterolemia who were enrolled in the West of Scotland Coronary Prevention Study, a trial that evaluated the value of pravastatin in the prevention of coronary events. METHODS: A total of 580 men who had had a coronary event (nonfatal myocardial infarction, death from coronary heart disease, or a revascularization procedure) were each matched for age and smoking status with 2 control subjects (total, 1160) from the same cohort who had not had a coronary event. Lipoprotein-associated phospholipase A2, C-reactive protein, and fibrinogen levels, and the white-cell count were measured at base line, along with other traditional risk factors. The association of these variables with the risk of coronary events was tested in regression models and by dividing the range of values according to quintiles. RESULTS: Levels of C-reactive protein, the white-cell count, and fibrinogen levels were strong predictors of the risk of coronary events; the risk in the highest quintile of the study cohort for each variable was approximately twice that in the lowest quintile. However, the association of these variables with risk was markedly attenuated when age, systolic blood pressure, and lipoprotein levels were included in multivariate models. Levels of lipoprotein-associated phospholipase A2 (platelet-activating factor acetylhydrolase), the expression of which is regulated by mediators of inflammation, had a strong, positive association with risk that was not confounded by other factors. It was associated with almost a doubling of the risk in the highest quintile as compared with the lowest quintile. CONCLUSIONS: Inflammatory markers are predictors of the risk of coronary events, but their predictive ability is attenuated by associations with other coronary risk factors. Elevated levels of lipoprotein-associated phospholipase A2 appear to be a strong risk factor for coronary heart disease, a finding that has implications for atherogenesis and the assessment of risk
Calcium-channel blockade and incidence of cancer in aged populations.
Pahor M, Guralnik JM, Ferrucci L, et al.
Lancet. 1996 Aug 24; 348(9026):493-7.
BACKGROUND: Calcium-channel blockers can alter apoptosis, a mechanism for destruction of cancer cells. We examined whether the long-term use of calcium-channel blockers is associated with an increased risk of cancer. METHODS: Between 1988 and 1992 we carried out a prospective cohort study of 5052 people aged 71 years or more and who lived in three regions of Massachusetts, Iowa, and Connecticut USA. Those taking calcium-channel blockers (n = 451) were compared with all other participants (n = 4601). The incidence of cancer was assessed by survey of hospital discharge diagnoses and causes of death. These outcomes were validated by the cancer registry in the one region where it was available. Demographic variables, disability, cigarette smoking, alcohol consumption, blood pressure, body-mass index, use of other drugs, hospital admissions for other causes, and comorbidity were all assessed as possible confounding factors. FINDINGS: The hazard ratio for cancer associated with calcium-channel blockers (1549 person-years, 47 events) compared with those not taking calcium-channel blockers (17225 person-years, 373 events) was 1.72 (95% CI 1.27-2.34, p = 0.0005), after adjustment for confounding factors. A significant dose-response gradient was found. Hazard ratios associated with verapamil, diltiazem, and nifedipine did not differ significantly from each other. The results remained unchanged in community-specific analyses. The association between calcium-channel blockers and cancer was found with most of the common cancers. INTERPRETATION: Calcium-channel blockers were associated with a general increased risk of cancer in the study populations, which suggested a common mechanism. These observational findings should be confirmed by other studies
Direct proinflammatory effect of C-reactive protein on human endothelial cells.
Pasceri V, Willerson JT, Yeh ET.
Circulation. 2000 Oct 31; 102(18):2165-8.
BACKGROUND: The acute-phase reactant C-reactive protein (CRP) is an important risk factor for coronary heart disease. However, the possible effects of CRP on vascular cells are not known. METHODS AND RESULTS: We tested the effects of CRP on expression of adhesion molecules in both human umbilical vein and coronary artery endothelial cells. Expression of vascular cell adhesion molecule (VCAM-1), intercellular adhesion molecule (ICAM-1), and E-selectin was assessed by flow cytometry. Incubation with recombinant human CRP (10 microg/mL) for 24 hours induced an approximately 10-fold increase in expression of ICAM-1 and a significant expression of VCAM-1, whereas a 6-hour incubation induced significant E-selectin expression. Adhesion molecule induction was similar to that observed in endothelial cells activated with interleukin-1beta. In coronary artery endothelial cells, induction of ICAM-1 and VCAM-1 was already present at 5 microg/mL and reached a maximum at 50 microg/mL, at which point a substantial increase in expression of E-selectin was also evident. The CRP effect was dependent on presence of human serum in the culture medium, because no effect was seen in cells cultured with serum-free medium. In contrast, interleukin-1beta was able to induce adhesion molecule expression in the absence of human serum. CONCLUSIONS: CRP induces adhesion molecule expression in human endothelial cells in the presence of serum. These findings support the hypothesis that CRP may play a direct role in promoting the inflammatory component of atherosclerosis and present a potential target for the treatment of atherosclerosis
Supernutrition for Healthy Hearts.
New Type of Angioplasty Can Freeze Plaque, Unclog Arteries.
Baillieres Best Pract Res Clin Haematol. 1999 Sep; 12(3):451-77.
Homocysteine is a sulphur-containing amino acid that is derived primarily from protein of animal origin. Classical homocystinuria is an inherited metabolic disorder that arises from defects in either the re-methylation or trans-sulphuration pathways of homocysteine metabolism and leads to skeletal abnormalities, mental retardation and a high risk of vascular disease. In contrast, moderate hyperhomocysteinaemia is associated with an increased risk of both arterial and venous thrombotic disease but no other abnormalities. This increased risk appears to be independent of other conventional risk factors. Many cases of hyperhomocysteineaemia have been attributed to defects in the enzyme cystathionine-beta-synthase (CBS) but this accounts for less than 1.5% of cases. A thermolabile variant of the enzyme methylenetetrahydrofolate reductase (MTHFR) arises from a C --> T transition at nucleotide 677 in the MTHFR gene resulting in an alanine-to-valine substitution. While the mutation does not appear to be associated with an increased risk of vascular disease, it results in excessively high homocysteine levels in response to a low or low-normal serum folate. Supplementation of the diet with folate, B6 and B12 can reduce homocysteine levels and this is the mainstay of treatment. Supplementation of grain with folate is undertaken in the USA to reduce the risk of neural tube defects in pregnant women. However, by reducing plasma homocysteine levels, it is estimated that this will save up to 50,000 lives per annum
Individuals with Diseased Coronary Arteries May Show Signs of Atherosclerosis .
Are major risk factors for myocardial infarction the major predictors of degree of coronary artery disease in men?
Phillips GB, Pinkernell BH, Jing TY.
Metabolism. 2004 Mar; 53(3):324-9.
Although numerous cross-sectional studies have reported associations of hypertension, hypercholesterolemia, diabetes, smoking, and/or obesity with the presence of coronary artery disease (CAD), correlations of these risk factors for myocardial infarction (MI) with the degree or progression of CAD have been less consistent. Nevertheless, these risk factors are generally assumed to be major determinants not only of MI, but of the degree of CAD as well. The present study is an attempt to evaluate the relationship of major risk factors for MI to degree of CAD. From 182 men who underwent diagnostic coronary arteriography, the 154 with CAD were selected for study. These 154 patients were divided into 2 groups, those with hypertension, hypercholesterolemia, diabetes, smoking, and/or obesity (n = 121) and those with none of these risk factors (n = 33). The mean degree of CAD in the group with risk factors for MI (44.4%) and in the group without (50.6%) was not significantly different (P =.15); nor was the increase in CAD with age augmented by the presence of these risk factors. On multiple regression analysis, none of these risk factors was associated with degree of CAD. Three other variables that were considered in this study, age, high-density lipoprotein-cholesterol (HDL-C), and free testosterone (FT), did show an independent association with degree of CAD. These findings, together with the findings of previous studies from other laboratories, raise the possibility that in men selected for coronary arteriography, age, HDL-C, and FT may be stronger predictors of degree of CAD than are blood pressure, cholesterol, diabetes, smoking, and body mass index (BMI)
Physician's Weekly. 1998
The role of homocysteine, folate and other B-vitamins in the development of atherosclerosis.
Pietrzik K, Bronstrup A.
Arch Latinoam Nutr. 1997 Jun; 47(2 Suppl 1):9-12.
Recently, elevated homocysteine blood concentrations have been identified as an independent risk factor for the development of atherosclerotic lesions. The amino acid homocysteine is metabolized in the human body involving the vitamins folic acid, B12 and B6 as essential cofactors and coenzymes, respectively. There is an inverse relationship between the status of the relevant B-vitamins and the homocysteine blood concentration. Supplementation of these vitamins results in a significant reduction of the homocysteine level. Nutritive amounts seem to be sufficient to obtain this reduction, even in the case of elevated homocysteine levels
Artichoke leaf extract for treating hypercholesterolaemia.
Pittler MH, Thompson CO, Ernst E.
Cochrane Database Syst Rev. 2002;(3):CD003335.
BACKGROUND: Hypercholesterolaemia is directly associated with an increased risk for coronary heart disease and other sequelae of atherosclerosis. Artichoke leaf extract (ALE), which is available as an over-the-counter remedy, has been implicated in lowering cholesterol levels. Whether ALE is truly efficacious for this indication, however, is still a matter of debate. OBJECTIVES: To assess the evidence of ALE versus placebo or reference medication for treating hypercholesterolaemia defined as mean total cholesterol levels of at least 5.17 mmol/L (200 mg /dL). SEARCH STRATEGY: We searched MEDLINE, Embase, Amed, Cinahl, CISCOM and the Cochrane Controlled Trial Register. All databases were searched from their respective inception until June 2001. Reference lists of articles were also searched for relevant material. Manufacturers of preparations containing artichoke extract and experts on the subject were contacted and asked to contribute published and unpublished material. SELECTION CRITERIA: Randomized controlled trials of ALE mono-preparations compared with placebo or reference medication for patients with hypercholesterolaemia were included. Trials assessing ALE as one of several active components in a combination preparation or as a part of a combination treatment were excluded. DATA COLLECTION AND ANALYSIS: Data were extracted systematically and methodological quality was evaluated using a standard scoring system. The screening of studies, selection, data extraction and the assessment of methodological quality were performed independently by two reviewers. Disagreements in the evaluation of individual trials were resolved through discussion. MAIN RESULTS: Two randomised trials including 167 participants met all inclusion criteria. In one trial ALE reduced total cholesterol levels from 7.74 mmol/l to 6.31 mmol/l after 42 +/- 3 days of treatment whereas the placebo reduced cholesterol from 7.69 mmol/l to 7.03 mmol/l (p=0.00001). Another trial did state that ALE significantly (p<0.05) reduced blood cholesterol compared with placebo in a sub-group of patients with baseline total cholesterol levels of more than 230 mg/dl. Trial reports and post-marketing surveillance studies indicate mild, transient and infrequent adverse events. REVIEWER'S CONCLUSIONS: Few data from rigorous clinical trials assessing ALE for treating hypercholesterolaemia exist. Beneficial effects are reported, the evidence however is not compelling. The limited data on safety suggest only mild, transient and infrequent adverse events with the short term use of ALE. More rigorous clinical trials assessing larger patient samples over longer intervention periods are needed to establish whether ALE is an effective and safe treatment option for patients with hypercholesterolaemia
[Comparative effects of policosanol and two HMG-CoA reductase inhibitors on type II hypercholesterolemia].
Prat H, Roman O, Pino E.
Rev Med Chil. 1999 Mar; 127(3):286-94.
BACKGROUND: Policosanol is a new cholesterol lowering agent derived from sugar cane. AIM: To compare the cholesterol lowering efficacy of policosanol with HMG CoA inhibitors. PATIENTS AND METHODS: Patients with a LDL cholesterol over 160 mg/dl were studied. If, after 6 weeks of diet, cholesterol persisted elevated, they were doubly blind randomized to receive policosanol 10 mg/day (55 patients), lovastatin 20 mg/day (26 patients) or simvastatin 10 mg/day (25 patients). Serum cholesterol was measured again after 8 weeks of therapy. RESULTS: Initial demographic and laboratory data were similar among treatment groups. A 24% LDL cholesterol reduction was obtained with policosanol, compared with a 22% reduction with lovastatin and a 15% reduction with simvastatin. HDL cholesterol significantly increased in patients on policosanol and did not change in the other treatment groups. Adverse effects of policosanol were mild and unspecific. No changes in hepatic enzymes were observed. CONCLUSIONS: Policosanol is a safe and effective cholesterol reducing agent
Gender differences in the outcome of interventional cardiac procedures.
Presbitero P, Carcagni A.
Ital Heart J. 2003 Aug; 4(8):522-7.
Prior studies have reported significant gender differences in the procedural outcomes after elective percutaneous transluminal coronary angioplasty (PTCA). Many of these differences have been explained by the presence of more comorbidities and worse clinical characteristics such as older age, unstable angina, congestive heart failure, diabetes mellitus, and hypertension in women than in men. Moreover, women have a smaller vessel diameter, more coronary tortuosity and different plaque composition compared to men that can lead to a higher dissection rate and a greater number of procedural complications. Although early data on PTCA suggested worse immediate results in women than in men, more recent data suggest that this difference is less marked. The introduction of stents with a low profile and a higher tractability and pushability has allowed the extensive application of these devices even in small and tortuous vessels improving the outcome of PTCA. This improvement has been higher in women than in men leading to the equalization of the immediate outcome in the two sexes, even if the baseline characteristics remain worse in women. In particular, mortality and the need for urgent surgical revascularization have become extremely low without any differences between sexes. However, some authors have still found a higher incidence of complications in the first period after the procedure due to stent thrombosis in the stenting era. For this reason, meticulous antiplatelet treatment should be prescribed and drugs such as glycoprotein IIb/IIIa inhibitors may also be considered advisable to reduce the excess risk in the female population particularly in women with prothrombotic risk factors such as diabetes. At 6 and 12 months similar rates of death, late myocardial infarction, and repeated revascularization have been shown in the two sexes. Coronary stenting and the use of glycoprotein IIb/IIIa inhibitors have also improved the immediate results in patients with acute myocardial infarction (AMI) undergoing primary PTCA. Studies comparing the outcome differences between women and men with AMI and treated with primary PTCA are limited but all suggest that women benefit more than men from this procedure. The in-hospital mortality in patients with AMI is significantly higher in the female than in the male population with a higher incidence of intracranial hemorrhage in women among tissue-type plasminogen activator-treated patients. Vice versa, women and men have a similar or a slightly higher in-hospital mortality after primary PTCA without intracranial bleeding complications. For this reason, an earlier diagnosis of AMI, an earlier hospital admission and an earlier primary PTCA should be the aims of management in order to improve the outcome in women with AMI and to equalize the procedural results in the two sexes
Inflammatory markers of coronary risk.
N Engl J Med. 2000 Oct 19; 343(16):1179-82.
Effect of curcumin on serum and liver cholesterol levels in the rat.
Rao DS, Sekhara NC, Satyanarayana MN, et al.
J Nutr. 1970 Nov; 100(11):1307-15.
Hormonal regulation of cystathionine beta-synthase expression in liver.
Ratnam S, Maclean KN, Jacobs RL, et al.
J Biol Chem. 2002 Nov 8; 277(45):42912-8.
Homocysteine metabolism is altered in diabetic patients. Cystathionine beta-synthase (CBS), a key enzyme involved in the transsulfuration pathway, which irreversibly converts homocysteine to cysteine, catalyzes the condensation of serine and homocysteine to cystathionine. Studies in streptozotocin-induced diabetic rats have shown that CBS enzyme activity is elevated in the liver but not in the kidney, and this effect is reversed by insulin treatment. To determine whether these effects resulted from alterations at the level of gene transcription, CBS mRNA was measured in diabetic and insulin-treated diabetic rats. CBS mRNA levels were found to be markedly higher in streptozotocin-induced diabetic rat livers; these were reduced by insulin administration. In H4IIE cells, a rat hepatoma cell culture model, glucocorticoids increased the cellular levels of CBS enzyme protein and CBS mRNA; insulin inhibited this stimulatory effect. Treatment with insulin also decreased CBS levels in HepG2 cells, a human hepatoma cell line. Nuclear run-on experiments in the rat cells confirmed that stimulation of CBS gene expression by glucocorticoids and the inhibition by insulin occurred at the transcriptional level. Transient transfections of HepG2 cells with a CBS-1b promoter luciferase reporter construct showed that the promoter activity was decreased by 70% after insulin treatment. These results show that insulin has a direct role in regulating homocysteine metabolism. Altered insulin levels in diseases such as diabetes may influence homocysteine metabolism by regulating the hepatic transsulfuration pathway
Homocysteine and cardiovascular disease.
Refsum H, Ueland PM, Nygard O, et al.
Annu Rev Med. 1998; 49:31-62.
An elevated level of total homocysteine (tHcy) in blood, denoted hyperhomocysteinemia, is emerging as a prevalent and strong risk factor for atherosclerotic vascular disease in the coronary, cerebral, and peripheral vessels, and for arterial and venous thromboembolism. The basis for these conclusions is data from about 80 clinical and epidemiological studies including more than 10,000 patients. Elevated tHcy confers a graded risk with no threshold, is independent of but may enhance the effect of the conventional risk factors, and seems to be a particularly strong predictor of cardiovascular mortality. Hyperhomocysteinemia is attributed to commonly occurring genetic and acquired factors including deficiencies of folate and vitamin B12. Supplementation with B-vitamins, in particular with folic acid, is an efficient, safe, and inexpensive means to reduce an elevated tHcy level. Studies are now in progress to establish whether such therapy will reduce cardiovascular risk
Diet and stroke.
J Nutr Health Aging. 2001; 5(3):167-72.
In industrialized countries, stroke is the most frequent life-threatening neurological disorder. The mortality trend for stroke appears to be similar to that of coronary heart disease (CHD) in different countries. Thus the dietary changes that protect from CHD, may also protect from stroke. The purpose of the present paper is not to review exhaustively the associations between foodstuffs and stroke. It is rather to emphasize a few important relationships that may be conducive to efficient recommendations in Public Health. The intake of saturated fat, considered as the main environmental factor for CHD, does not appear to be also closely related to stroke. It has even been observed in the Framingham prospective study, that saturated fats were associated with a protective effect on stroke. The multivariate analysis of the ecological study reported in the present paper suggests that the villain for stroke could be the high intake of linoleic acid, the main polyunsaturated fatty acid prescribed through the world, to most of the CHD patients. Observation and intervention studies suggest that the fatty acid with the most efficient protective effect on stroke is alpha-linolenic acid (ALA) as for CHD clinical manifestations. Also similarly to CHD, fruit, vegetables and folic acid, may have important protective effect on stroke. Finally, at very moderate intake, alcohol may be related to a similar lowering on the risk of stroke as on that of CHD. Nevertheless alcohol, at high intake for intoxication (binge drinking) has been associated with up to a 10 fold increased in the risk of stroke. Finally, the diet recommendations suggested by the present analysis are similar to those used in the Lyon Diet Heart Study and in Finland, in the last 20 years. In both of these intervention studies mortality from CHD, cancer and stroke have been markedly reduced by more than 50 %
Plasma concentration of C-reactive protein and risk of developing peripheral vascular disease.
Ridker PM, Cushman M, Stampfer MJ, et al.
Circulation. 1998 Feb 10; 97(5):425-8.
BACKGROUND: Among apparently healthy men, elevated levels of C-reactive protein (CRP), a marker for systemic inflammation, predict risk of myocardial infarction and thromboembolic stroke. Whether increased levels of CRP are also associated with the development of symptomatic peripheral arterial disease (PAD) is unknown. METHODS AND RESULTS: Using a prospective, nested, case-control design, we measured baseline levels of CRP in 144 apparently healthy men participating in the Physicians' Health Study who subsequently developed symptomatic PAD (intermittent claudication or need for revascularization) and in an equal number of control subjects matched on the basis of age and smoking habit who remained free of vascular disease during a follow-up period of 60 months. Median CRP levels at baseline were significantly higher among those who subsequently developed PAD (1.34 versus 0.99 mg/L; P=.04). Furthermore, the risks of developing PAD increased significantly with each increasing quartile of baseline CRP concentration such that relative risks of PAD from lowest (referent) to highest quartile of CRP were 1.0, 1.3, 2.0, and 2.1 (Ptrend=.02). Compared with those with no clinical evidence of disease, the subgroup of case patients who required revascularization had the highest baseline CRP levels (median= 1.75 mg/L; P= .04); relative risks from lowest to highest quartile of CRP for this end point were 1.0, 1.8, 3.8, and 4.1 (Ptrend=.02). Risk estimates were similar after additional control for body mass index, hypercholesterolemia, hypertension, diabetes, and a family history of premature atherosclerosis. CONCLUSIONS: These prospective data indicate that among apparently healthy men, baseline levels of CRP predict future risk of developing symptomatic PAD and thus provide further support for the hypothesis that chronic inflammation is important in the pathogenesis of atherothrombosis
C-reactive protein and other markers of inflammation in the prediction of cardiovascular disease in women.
Ridker PM, Hennekens CH, Buring JE, et al.
N Engl J Med. 2000 Mar 23; 342(12):836-43.
BACKGROUND: Since inflammation is believed to have a role in the pathogenesis of cardiovascular events, measurement of markers of inflammation has been proposed as a method to improve the prediction of the risk of these events. METHODS: We conducted a prospective, nested case-control study among 28,263 apparently healthy postmenopausal women over a mean follow-up period of three years to assess the risk of cardiovascular events associated with base-line levels of markers of inflammation. The markers included high-sensitivity C-reactive protein (hs-CRP), serum amyloid A, interleukin-6, and soluble intercellular adhesion molecule type 1 (sICAM-1). We also studied homocysteine and a variety of lipid and lipoprotein measurements. Cardiovascular events were defined as death from coronary heart disease, nonfatal myocardial infarction or stroke, or the need for coronary-revascularization procedures. RESULTS: Of the 12 markers measured, hs-CRP was the strongest univariate predictor of the risk of cardiovascular events; the relative risk of events for women in the highest as compared with the lowest quartile for this marker was 4.4 (95 percent confidence interval, 2.2 to 8.9). Other markers significantly associated with the risk of cardiovascular events were serum amyloid A (relative risk for the highest as compared with the lowest quartile, 3.0), sICAM-1 (2.6), interleukin-6 (2.2), homocysteine (2.0), total cholesterol (2.4), LDL cholesterol (2.4), apolipoprotein B-100 (3.4), HDL cholesterol (0.3), and the ratio of total cholesterol to HDL cholesterol (3.4). Prediction models that incorporated markers of inflammation in addition to lipids were significantly better at predicting risk than models based on lipid levels alone (P<0.001). The levels of hs-CRP and serum amyloid A were significant predictors of risk even in the subgroup of women with LDL cholesterol levels below 130 mg per deciliter (3.4 mmol per liter), the target for primary prevention established by the National Cholesterol Education Program. In multivariate analyses, the only plasma markers that independently predicted risk were hs-CRP (relative risk for the highest as compared with the lowest quartile, 1.5; 95 percent confidence interval, 1.1 to 2.1) and the ratio of total cholesterol to HDL cholesterol (relative risk, 1.4; 95 percent confidence interval, 1.1 to 1.9). CONCLUSIONS: The addition of the measurement of C-reactive protein to screening based on lipid levels may provide an improved method of identifying persons at risk for cardiovascular events
Novel risk factors and markers for coronary disease.
Adv Intern Med. 2000; 45:391-418.
High-sensitivity C-reactive protein: potential adjunct for global risk assessment in the primary prevention of cardiovascular disease.
Circulation. 2001 Apr 3; 103(13):1813-8.
Inflammation plays a major role in atherothrombosis, and measurement of inflammatory markers such as high-sensitivity C-reactive protein (HSCRP) may provide a novel method for detecting individuals at high risk of plaque rupture. Several large-scale prospective studies demonstrate that HSCRP is a strong independent predictor of future myocardial infarction and stroke among apparently healthy men and women and that the addition of HSCRP to standard lipid screening may improve global risk prediction among those with high as well as low cholesterol levels. Because agents such as aspirin and statins seem to attenuate inflammatory risk, HSCRP may also have utility in targeting proven therapies for primary prevention. Inexpensive commercial assays for HSCRP are now available; they have shown variability and classification accuracy similar to that of cholesterol screening. Risk prediction algorithms using a simple quintile approach to HSCRP evaluation have been developed for outpatient use. Thus, although limitations inherent to inflammatory screening remain, available data suggest that HSCRP has the potential to play an important role as an adjunct for global risk assessment in the primary prevention of cardiovascular disease
Comparison of C-reactive protein and low-density lipoprotein cholesterol levels in the prediction of first cardiovascular events.
Ridker PM, Rifai N, Rose L, et al.
N Engl J Med. 2002 Nov 14; 347(20):1557-65.
BACKGROUND: Both C-reactive protein and low-density lipoprotein (LDL) cholesterol levels are elevated in persons at risk for cardiovascular events. However, population-based data directly comparing these two biologic markers are not available. METHODS: C-reactive protein and LDL cholesterol were measured at base line in 27,939 apparently healthy American women, who were then followed for a mean of eight years for the occurrence of myocardial infarction, ischemic stroke, coronary revascularization, or death from cardiovascular causes. We assessed the value of these two measurements in predicting the risk of cardiovascular events in the study population. RESULTS: Although C-reactive protein and LDL cholesterol were minimally correlated (r=0.08), base-line levels of each had a strong linear relation with the incidence of cardiovascular events. After adjustment for age, smoking status, the presence or absence of diabetes mellitus, categorical levels of blood pressure, and use or nonuse of hormone-replacement therapy, the relative risks of first cardiovascular events according to increasing quintiles of C-reactive protein, as compared with the women in the lowest quintile, were 1.4, 1.6, 2.0, and 2.3 (P<0.001), whereas the corresponding relative risks in increasing quintiles of LDL cholesterol, as compared with the lowest, were 0.9, 1.1, 1.3, and 1.5 (P<0.001). Similar effects were observed in separate analyses of each component of the composite end point and among users and nonusers of hormone-replacement therapy. Overall, 77 percent of all events occurred among women with LDL cholesterol levels below 160 mg per deciliter (4.14 mmol per liter), and 46 percent occurred among those with LDL cholesterol levels below 130 mg per deciliter (3.36 mmol per liter). By contrast, because C-reactive protein and LDL cholesterol measurements tended to identify different high-risk groups, screening for both biologic markers provided better prognostic information than screening for either alone. Independent effects were also observed for C-reactive protein in analyses adjusted for all components of the Framingham risk score. CONCLUSIONS: These data suggest that the C-reactive protein level is a stronger predictor of cardiovascular events than the LDL cholesterol level and that it adds prognostic information to that conveyed by the Framingham risk score
C-reactive protein and coronary heart disease: diagnostic and therapeutic implications for primary prevention.
Cardiovasc Toxicol. 2001; 1(2):153-7.
Coronary heart disease (CHD) is the leading cause of death in the industrialized world. Recent laboratory and clinical studies have shown that inflammation plays a pivotal role in the inception, progression, and destabilization of atheromas. The acute-phase reactant C-reactive protein (CRP) has been shown to reflect systemic and, perhaps, vascular inflammation and to predict future cardiovascular events in asymptomatic individuals. The relative risk associated with CRP is independent of other cardiovascular disease risk factors. High-sensitivity assays (hs-CRP) are needed for the measurement of CRP concentration for the purpose of predicting the risk of future coronary events. Available assays must be standardized because patients' results will be interpreted using population-based cutpoints. An algorithm for risk stratification incorporating hs-CRP and total cholesterol to high-density lipoprotein cholesterol ratio has been developed. Statin class drugs and aspirin appear to modulate CHD risk in those with increased hs-CRP concentration. Several prospective studies are now underway to specifically develop novel clinical utilities and therapeutic strategies for hs-CRP
High-sensitivity C-reactive protein: a novel and promising marker of coronary heart disease.
Rifai N, Ridker PM.
Clin Chem. 2001 Mar; 47(3):403-11.
BACKGROUND: Coronary heart disease remains the leading cause of morbidity and mortality in the industrialized world. Clinical and laboratory studies have shown that inflammation plays a major role in the initiation, progression, and destabilization of atheromas. C-Reactive protein (CRP), an acute phase reactant that reflects low-grade systemic inflammation, has been studied in a variety of cardiovascular diseases. APPROACH: Findings from prospective clinical trials were examined to determine the prognostic utility of CRP in acute coronary syndromes, and observations from epidemiological studies were reviewed to determine the ability of CRP to predict future first coronary events. The analytical considerations of CRP measurement in these clinical applications were also examined. CONTENT: In patients with established coronary disease, CRP has been shown to predict adverse clinical events. In addition, prospective studies have consistently shown that CRP is a strong predictor of future coronary events in apparently healthy men and women. The relative risk associated with CRP is independent of other cardiovascular disease risk factors. High-sensitivity CRP (hs-CRP) assays are needed for risk assessment of cardiovascular disease. Such assays are currently available but may require further standardization because patients' results will be interpreted using population-based cutpoints. Preventive therapies to attenuate coronary risk in individuals with increased hs-CRP concentrations include aspirin and statin-type drugs. SUMMARY: hs-CRP has prognostic utility in patients with acute coronary syndromes and is a strong independent predictor of future coronary events in apparently healthy subjects
Curcumin: a potential vaginal contraceptive.
Rithaporn T, Monga M, Rajasekaran M.
Contraception. 2003 Sep; 68(3):219-23.
The purpose of this investigation was to evaluate the sperm-immobilizing effects of curcumin, a plant-derived diferuloylmethane compound. Washed human healthy sperm were suspended in Ham's F10 and exposed to varying concentrations of curcumin. Sperm motility was evaluated and changes in sperm mitochondrial transmembrane potential (MTP) was quantified by flow cytometry. Incubation of normal human sperm with curcumin resulted in a dose- and time-dependent loss of sperm motility. At lower concentrations (30 g/mL), curcumin produced a significant (20%) decrease in sperm motility within 30 min without significant effects on sperm viability. An instantaneous (>50%) loss of sperm motility was observed with higher concentrations (300 g/mL) of curcumin and a total loss of sperm motility was achieved within 60 min. A significant reduction in sperm MTP was found with all doses of curcumin tested. Our results indicate that curcumin has a selective sperm-immobilizing effect, in addition to a previously studied anti-HIV property. This compound may have potential clinical applications as a novel intravaginal spermicidal agent for contraception and HIV prevention
Hyperhomocysteinemia and low pyridoxal phosphate. Common and independent reversible risk factors for coronary artery disease.
Robinson K, Mayer EL, Miller DP, et al.
Circulation. 1995 Nov 15; 92(10):2825-30.
BACKGROUND: High plasma homocysteine is associated with premature coronary artery disease in men, but the threshold concentration defining this risk and its importance in women and the elderly are unknown. Furthermore, although low B vitamin status increases homocysteine, the link between these vitamins and coronary disease is unclear. METHODS AND RESULTS: We compared 304 patients with coronary disease with 231 control subjects. Risk factors and concentrations of plasma homocysteine, folate, vitamin B12, and pyridoxal 5'-phosphate were documented. A homocysteine concentration of 14 mumol/L conferred an odds ratio of coronary disease of 4.8 (P < .001), and 5-mumol/L increments across the range of homocysteine conferred an odds ratio of 2.4 (P < .001). Odds ratios of 3.5 in women and of 2.9 in those 65 years or older were seen (P < .05). Homocysteine correlated negatively with all vitamins. Low pyridoxal 5'-phosphate (< 20 nmol/L) was seen in 10% of patients but in only 2% of control subjects (P < .01), yielding an odds ratio of coronary disease adjusted for all risk factors, including high homocysteine, of 4.3 (P < .05). CONCLUSIONS: Within the range currently considered to be normal, the risk for coronary disease rises with increasing plasma homocysteine regardless of age and sex, with no threshold effect. In addition to a link with homocysteine, low pyridoxal-5'-phosphate confers an independent risk for coronary artery disease
Coenzyme Q10 improves the tolerance of the senescent myocardium aerobic and ischemic stress: studies in rats and in human atrial tissue.
Rosenfeldt FL PSOR.
Rosenfeldt FL PSLANPRMORMSLWED.
Ann N Y Acad Sci. 2002;(959):355-9.
Risks and benefits of estrogen plus progestin in healthy postmenopausal women: principal results From the Women's Health Initiative randomized controlled trial.
Rossouw JE, Anderson GL, Prentice RL, et al.
JAMA. 2002 Jul 17; 288(3):321-33.
CONTEXT: Despite decades of accumulated observational evidence, the balance of risks and benefits for hormone use in healthy postmenopausal women remains uncertain. OBJECTIVE: To assess the major health benefits and risks of the most commonly used combined hormone preparation in the United States. DESIGN: Estrogen plus progestin component of the Women's Health Initiative, a randomized controlled primary prevention trial (planned duration, 8.5 years) in which 16608 postmenopausal women aged 50-79 years with an intact uterus at baseline were recruited by 40 US clinical centers in 1993-1998. INTERVENTIONS: Participants received conjugated equine estrogens, 0.625 mg/d, plus medroxyprogesterone acetate, 2.5 mg/d, in 1 tablet (n = 8506) or placebo (n = 8102). MAIN OUTCOMES MEASURES: The primary outcome was coronary heart disease (CHD) (nonfatal myocardial infarction and CHD death), with invasive breast cancer as the primary adverse outcome. A global index summarizing the balance of risks and benefits included the 2 primary outcomes plus stroke, pulmonary embolism (PE), endometrial cancer, colorectal cancer, hip fracture, and death due to other causes. RESULTS: On May 31, 2002, after a mean of 5.2 years of follow-up, the data and safety monitoring board recommended stopping the trial of estrogen plus progestin vs placebo because the test statistic for invasive breast cancer exceeded the stopping boundary for this adverse effect and the global index statistic supported risks exceeding benefits. This report includes data on the major clinical outcomes through April 30, 2002. Estimated hazard ratios (HRs) (nominal 95% confidence intervals [CIs]) were as follows: CHD, 1.29 (1.02-1.63) with 286 cases; breast cancer, 1.26 (1.00-1.59) with 290 cases; stroke, 1.41 (1.07-1.85) with 212 cases; PE, 2.13 (1.39-3.25) with 101 cases; colorectal cancer, 0.63 (0.43-0.92) with 112 cases; endometrial cancer, 0.83 (0.47-1.47) with 47 cases; hip fracture, 0.66 (0.45-0.98) with 106 cases; and death due to other causes, 0.92 (0.74-1.14) with 331 cases. Corresponding HRs (nominal 95% CIs) for composite outcomes were 1.22 (1.09-1.36) for total cardiovascular disease (arterial and venous disease), 1.03 (0.90-1.17) for total cancer, 0.76 (0.69-0.85) for combined fractures, 0.98 (0.82-1.18) for total mortality, and 1.15 (1.03-1.28) for the global index. Absolute excess risks per 10 000 person-years attributable to estrogen plus progestin were 7 more CHD events, 8 more strokes, 8 more PEs, and 8 more invasive breast cancers, while absolute risk reductions per 10 000 person-years were 6 fewer colorectal cancers and 5 fewer hip fractures. The absolute excess risk of events included in the global index was 19 per 10 000 person-years. CONCLUSIONS: Overall health risks exceeded benefits from use of combined estrogen plus progestin for an average 5.2-year follow-up among healthy postmenopausal US women. All-cause mortality was not affected during the trial. The risk-benefit profile found in this trial is not consistent with the requirements for a viable intervention for primary prevention of chronic diseases, and the results indicate that this regimen should not be initiated or continued for primary prevention of CHD
Genetic modulation of homocysteinemia.
Semin Thromb Hemost. 2000; 26(3):255-61.
With the identification of hyperhomocysteinemia as a risk factor for cardiovascular disease, an understanding of the genetic determinants of plasma homocysteine is important for prevention and treatment. It has been known for some time that homocystinuria, a rare inborn error of metabolism, can be due to genetic mutations that severely disrupt homocysteine metabolism. A more recent development is the finding that milder, but more common, genetic mutations in the same enzymes might also contribute to an elevation in plasma homocysteine. The best example of this concept is a missense mutation (alanine to valine) at base pair (bp) 677 of methylenetetrahydrofolate reductase (MTHFR), the enzyme that provides the folate derivative for conversion of homocysteine to methionine. This mutation results in mild hyperhomocysteinemia, primarily when folate levels are low, providing a rationale (folate supplementation) for overcoming the genetic deficiency. Additional genetic variants in MTHFR and in other enzymes of homocysteine metabolism are being identified as the cDNAs/genes become isolated. These variants include a glutamate to alanine mutation (bp 1298) in MTHFR, an aspartate to glycine mutation (bp 2756) in methionine synthase, and an isoleucine to methionine mutation (bp 66) in methionine synthase reductase. These variants have been identified relatively recently; therefore additional investigations are required to determine their clinical significance with respect to mild hyperhomocysteinemia and vascular disease
Update on antiplatelet therapy for stroke prevention.
Sacco RL, Elkind MS.
Arch Intern Med. 2000 Jun 12; 160(11):1579-82.
The high rates of mortality and long-term disability associated with ischemic stroke, coupled with its prevalence, necessitate good, long-term preventive strategies. Risk-factor management is effective for individuals with preclinical and clinical cerebrovascular disease. Patients suffering from a transient ischemic attack or stroke are particularly vulnerable to subsequent stroke. Most of these individuals are candidates for antiplatelet treatment to prevent a recurrence. Available antiplatelet therapies include aspirin, ticlopidine, and clopidogrel. The combination of low-dose aspirin plus extended-release dipyridamole has been shown to offer safe, effective antiplatelet therapy for appropriate patients. In the second European Stroke Prevention Study, the combination was found to be significantly more effective than either drug alone, at the cost of relatively few treatment-related adverse effects. This combination is currently recommended as one of the first-line treatments for stroke prevention after first transient ischemic attack or stroke
Impact of vitamin E on plasma asymmetric dimethylarginine (ADMA) in chronic kidney disease (CKD): a pilot study.
Saran R NJDAAEWJBRHGBDWWDLRS.
Nephrol Dial Transplant. 2003; 18(11):2415-20.
Homocysteine-betaine interactions in a murine model of 5,10-methylenetetrahydrofolate reductase deficiency.
Schwahn BC, Chen Z, Laryea MD, et al.
FASEB J. 2003 Mar; 17(3):512-4.
Hyperhomocysteinemia, a proposed risk factor for cardiovascular disease, is also observed in other common disorders. The most frequent genetic cause of hyperhomocysteinemia is a mutated methylenetetrahydrofolate reductase (MTHFR), predominantly when folate status is impaired. MTHFR synthesizes a major methyl donor for homocysteine remethylation to methionine. We administered the alternate choline-derived methyl donor, betaine, to wild-type mice and to littermates with mild or severe hyperhomocysteinemia due to hetero- or homozygosity for a disruption of the Mthfr gene. On control diets, plasma homocysteine and liver choline metabolite levels were strongly dependent on the Mthfr genotype. Betaine supplementation decreased homocysteine in all three genotypes, restored liver betaine and phosphocholine pools, and prevented severe steatosis in Mthfr-deficient mice. Increasing betaine intake did not further decrease homocysteine. In humans with cardiovascular disease, we found a significant negative correlation between plasma betaine and homocysteine concentrations. Our results emphasize the strong interrelationship between homocysteine, folate, and choline metabolism. Hyperhomocysteinemic Mthfr-compromised mice appear to be much more sensitive to changes of choline/betaine intake than do wild-type animals. Hyperhomocysteinemia, in the range of that associated with folate deficiency or with homozygosity for the 677T MTHFR variant, may be associated with disturbed choline metabolism
Essentials of Anatomy and Physiology.
Association between plasma homocysteine concentrations and extracranial carotid-artery stenosis.
Selhub J, Jacques PF, Bostom AG, et al.
N Engl J Med. 1995 Feb 2; 332(5):286-91.
BACKGROUND. Epidemiologic studies have identified hyperhomocysteinemia as a possible risk factor for atherosclerosis. We determined the risk of carotid-artery atherosclerosis in relation to both plasma homocysteine concentrations and nutritional determinants of hyperhomocysteinemia. METHODS. We performed a cross-sectional study of 1041 elderly subjects (418 men and 623 women; age range, 67 to 96 years) from the Framingham Heart Study. We examined the relation between the maximal degree of stenosis of the extracranial carotid arteries (as assessed by ultrasonography) and plasma homocysteine concentrations, as well as plasma concentrations and intakes of vitamins involved in homocysteine metabolism, including folate, vitamin B12, and vitamin B6. The subjects were classified into two categories according to the findings in the more diseased of the two carotid vessels: stenosis of 0 to 24 percent and stenosis of 25 to 100 percent. RESULTS. The prevalence of carotid stenosis of > or = 25 percent was 43 percent in the men and 34 percent in the women. The odds ratio for stenosis of > or = 25 percent was 2.0 (95 percent confidence interval, 1.4 to 2.9) for subjects with the highest plasma homocysteine concentrations (> or = 14.4 mumol per liter) as compared with those with the lowest concentrations (< or = "9.1" mumol per liter), after adjustment for sex, age, plasma high-density lipoprotein cholesterol concentration, systolic blood pressure, and smoking status (P < 0.001 for trend). Plasma concentrations of folate and pyridoxal-5'-phosphate (the coenzyme form of vitamin B6) and the level of folate intake were inversely associated with carotid-artery stenosis after adjustment for age, sex, and other risk factors. CONCLUSIONS. High plasma homocysteine concentrations and low concentrations of folate and vitamin B6, through their role in homocysteine metabolism, are associated with an increased risk of extracranial carotid-artery stenosis in the elderly
Annu Rev Nutr. 1999; 19:217-46.
Homocysteine is a sulfur amino acid whose metabolism stands at the intersection of two pathways: remethylation to methionine, which requires folate and vitamin B12 (or betaine in an alternative reaction); and transsulfuration to cystathionine, which requires pyridoxal-5'-phosphate. The two pathways are coordinated by S-adenosylmethionine, which acts as an allosteric inhibitor of the methylenetetrahydrofolate reductase reaction and as an activator of cystathionine beta-synthase. Hyperhomocysteinemia, a condition that recent epidemiological studies have shown to be associated with increased risk of vascular disease, arises from disrupted homocysteine metabolism. Severe hyperhomocysteinemia is due to rare genetic defects resulting in deficiencies in cystathionine beta synthase, methylenetetrahydrofolate reductase, or in enzymes involved in methyl-B12 synthesis and homocysteine methylation. Mild hyperhomocysteinemia seen in fasting conditions is due to mild impairment in the methylation pathway (i.e. folate or B12 deficiencies or methylenetetrahydrofolate reductase thermolability). Post-methionine-load hyperhomocysteinemia may be due to heterozygous cystathionine beta-synthase defect or B6 deficiency. Early studies with nonphysiological high homocysteine levels showed a variety of deleterious effects on endothelial or smooth muscle cells in culture. More recent studies with human beings and animals with mild hyperhomocysteinemia provided encouraging results in the attempt to understand the mechanism that underlies this relationship between mild elevations of plasma homocysteine and vascular disease. The studies with animal models indicated the possibility that the effect of elevated homocysteine is multifactorial, affecting both the vascular wall structure and the blood coagulation system
B vitamins, homocysteine, and neurocognitive function in the elderly.
Selhub J, Bagley LC, Miller J, et al.
Am J Clin Nutr. 2000 Feb; 71(2):614S-20S.
Evidence of the importance of the B vitamins folic acid, vitamin B-12, and vitamin B-6 for the well-being and normal function of the brain derives from data showing neurologic and psychologic dysfunction in vitamin deficiency states and in cases of congenital defects of one-carbon metabolism. The status of these vitamins is frequently inadequate in the elderly and recent studies have shown associations between loss of cognitive function or Alzheimer disease and inadequate B vitamin status. The question that arises is whether these B vitamin inadequacies contribute to such brain malfunctions or result from aging and disease. From a theoretical standpoint, these inadequacies could give rise to impairment of methylation reactions that are crucial to the health of brain tissue. In addition or perhaps instead, these inadequacies could result in hyperhomocysteinemia, a recently identified risk factor for occlusive vascular disease, stroke, and thrombosis, any of which may result in brain ischemia. Advances in the understanding of this putative relation between inadequate vitamin status and loss of cognitive function in the elderly are likely to be slow and may depend on the outcomes of both prospective studies and longitudinal studies in which nutritional intervention is provided before cognitive decline occurs
Cholesterol Update: Oxidized and Nonoxidized LDL Cholesterol Do We Have to Worry About Both?
[Pleiotropic effects of garlic].
Siegel G, Walter A, Engel S, et al.
Wien Med Wochenschr. 1999; 149(8-10):217-24.
Garlic as a herbal remedy reduces a multitude of risk factors which play a decisive role in the genesis and progression of arteriosclerosis: decrease in total and LDL-cholesterol, increase in HDL-cholesterol, reduction of serum triglyceride and fibrinogen concentration, lowering of arterial blood pressure and promotion of organ perfusion, and, finally, enhancement in fibrinolysis, inhibition of platelet aggregation, and diminution of plasma viscosity. In a prospective, 4-year clinical trial with primary endpoint 'arteriosclerotic plaque volume' it was proven not only a 9 to 18% reduction and 3% regression in plaque volume of the total collective under the influence of standardized garlic powder dragees (900 mg/die LI 111), but also of some facets of the phytopharmacologic pleiotropy of this herb: decrease in LDL level by 4%, increase in HDL concentration by 8%, and lowering in blood pressure by 7%. The reduction of arterial blood pressure is due to an additional opening of K(Ca) ion channels in the membrane of vascular smooth muscle cells that effects its hyperpolarization. This membrane hyperpolarization closes about 20% of the L-type Ca2+ channels, consequence of which is vasodilatation. In human coronary arteries, the increase in vascular diameter by 4% is closely associated with an improvement of coronary perfusion by 18%. These pleiotropic effects of garlic result in a reduction of relative cardiovascular risk for infarction and stroke by more than 50%
S-adenosyl-L-methionine: effects on brain bioenergetic status and transverse relaxation time in healthy subjects.
Silveri MM, Parow AM, Villafuerte RA, et al.
Biol Psychiatry. 2003 Oct 15; 54(8):833-9.
BACKGROUND: S-adenosyl-L-methionine is an effective treatment for clinical depression, although the mechanism underlying this effect is unclear. Presently, in vivo phosphorus magnetic resonance spectroscopy (31P MRS) and brain transverse relaxometry were employed to test if S-adenosyl-L-methionine supplementation alters brain bioenergetics and/or transverse relaxation time (T2RT) in a nondepressed cohort. If these magnetic resonance techniques are sensitive to S-adenosyl-L-methionine induced alterations in neurochemical processes, these methods may be used in cases of clinical depression to elucidate the mechanism underlying the antidepressant effect of S-adenosyl-L-methionine. METHODS: Twelve subjects self-administered 1600 mg of oral S-adenosyl-L-methionine daily. Phosphorus spectra and transverse relaxation time were acquired at baseline and after treatment using a 1.5 Tesla scanner. RESULTS: Phosphocreatine levels were significantly higher after treatment, whereas beta nucleoside triphosphate levels, predominantly adenosine triphosphate in brain, were significantly lower after treatment. A surprising gender difference in T2RT emerged after supplementation, with women exhibiting significantly lower T2RT than men. CONCLUSIONS: Alterations in phosphocreatine and beta nucleoside triphosphate are consistent with the report that S-adenosyl-L-methionine is involved in the production of creatine, which in turn is phosphorylated to phosphocreatine using adenosine triphosphate. These findings suggest that S-adenosyl-L-methionine alters parameters associated with cerebral bioenergetic status and that some effects of S-adenosyl-L-methionine (T2RT) occur in a gender-specific manner
Randomized, double-blind placebo-controlled trial of coenzyme Q10 in patients with acute myocardial infarction.
Singh RB, Wander GS, Rastogi A, et al.
Cardiovasc Drugs Ther. 1998 Sep; 12(4):347-53.
The effects of oral treatment with coenzyme Q10 (120 mg/d) were compared for 28 days in 73 (intervention group A) and 71 (placebo group B) patients with acute myocardial infarction (AMI). After treatment, angina pectoris (9.5 vs. 28.1), total arrhythmias (9.5% vs. 25.3%), and poor left ventricular function (8.2% vs. 22.5%) were significantly (P < 0.05) reduced in the coenzyme Q group than placebo group. Total cardiac events, including cardiac deaths and nonfatal infarction, were also significantly reduced in the coenzyme Q10 group compared with the placebo group (15.0% vs. 30.9%, P < 0.02). The extent of cardiac disease, elevation in cardiac enzymes, and oxidative stress at entry to the study were comparable between the two groups. Lipid peroxides, diene conjugates, and malondialdehyde, which are indicators of oxidative stress, showed a greater reduction in the treatment group than in the placebo group. The antioxidants vitamin A, E, and C and beta-carotene, which were lower initially after AMI, increased more in the coenzyme Q10 group than in the placebo group. These findings suggest that coenzyme Q10 can provide rapid protective effects in patients with AMI if administered within 3 days of the onset of symptoms. More studies in a larger number of patients and long-term follow-up are needed to confirm our results
Vitamins B6, B12, and folate: association with plasma total homocysteine and risk of coronary atherosclerosis.
Siri PW, Verhoef P, Kok FJ.
J Am Coll Nutr. 1998 Oct; 17(5):435-41.
OBJECTIVES: To investigate the association of status of vitamins B6, B12 and folate with plasma fasting total homocysteine (tHcy) and with risk of coronary atherosclerosis; and to establish whether associations between vitamins and risk of coronary atherosclerosis are mediated by tHcy. METHODS: The study population consisted of 131 patients with angiography-defined severe coronary atherosclerosis and 88 referents with no or minor coronary stenosis. Previous analyses in this study population have shown that fasting tHcy is an independent risk factor for coronary atherosclerosis. In the present analyses, using multiple linear regression, we estimated differences in tHcy concentrations between subjects in the lowest and highest quartiles of concentrations of each of the vitamins, adjusting for age, gender, total:HDL cholesterol ratio, smoking habits, alcohol intake, blood pressure, serum creatinine, body mass index and the two other vitamins. We used logistic regression analysis conditional on the set of potential confounders described above to study the association between vitamin concentration and risk of coronary atherosclerosis. By comparing these estimated odds ratios (ORs) with those that were additionally adjusted for fasting tHcy, we determined whether the vitamins exerted their effects on disease risk via homocysteine metabolism. RESULTS: Cases who were in the upper quartile of serum vitamin B12 and erythrocyte folate concentrations showed statistically significantly lower tHcy concentrations (-4.00 and -4.71 mumol/L, respectively) than those in the lowest quartile. Referents in the upper quartile of plasma B6 showed significantly lower tHcy concentrations (-2.36 mumol/L) than referents in the lowest quartile. Subjects in the lowest quartile of vitamin B12 concentrations had higher risk of coronary atherosclerosis (OR: 2.91; 95% CI: 1.10, 7.71) compared to those in the highest quartile. The ORs and 95% CIs for low B6 and low folate were 0.86 (95% CI: 0.33, 2.22) and 0.58 (95% CI: 0.23, 1.48), respectively. Additional adjustment for fasting tHcy weakened associations, although data indicated that low vitamin B12 concentration is a risk factor for coronary atherosclerosis, independently of tHcy. CONCLUSION: The presently accepted view that vitamin B6 mainly affects tHcy after methionine loading, and not fasting tHcy, is contradicted by our findings in referents. Low vitamin B12 concentrations were associated with an increased risk of coronary atherosclerosis, partly independently of tHcy. Although low folate status was a strong determinant of elevated tHcy concentrations, it was not associated with increased risk of coronary atherosclerosis
Fibrinogen, fibrin and fibrin degradation products in relation to atherosclerosis.
Clin Haematol. 1986 May; 15(2):355-70.
Many human atherosclerotic lesions, showing no evidence of fissure or ulceration, contain a large amount of fibrin which may be in the form of mural thrombus on the intact surface of the plaque, in layers within the fibrous cap, in the lipid-rich centre, or diffusely distributed throughout the plaque. Small mural thrombi are invaded by SMCs and collagen is deposited in patterns closely resembling the early proliferative gelatinous lesions. In experimental animals, thrombi are converted into lesions with all the characteristics of fibrous plaques, and in saphenous-vein bypass grafts, fibrin deposition is the main cause of wall thickening and occlusion. There seems little doubt that fibrin deposition can both initiate atherogenesis and contribute to the growth of plaques. Epidemiological studies indicate that increased levels of fibrinogen and clotting activity are associated with accelerated atherosclerosis, and although blood fibrinolytic activity has given inconsistent results, in arterial intima both fibrinolytic activity and plasminogen concentration are decreased in cardiovascular disease. Fibrin may stimulate cell proliferation by providing a scaffold along which cells migrate, and by binding fibronectin, which stimulates cell migration and adhesion. Fibrin degradation products, which are present in the intima, may stimulate mitogenesis and collagen synthesis, attract leukocytes, and alter endothelial permeability and vascular tone. In the advanced plaque fibrin may be involved in the tight binding of LDL and accumulation of lipid. Thus there is extensive evidence that enhanced blood coagulation is a risk factor not only for thrombotic occlusion, but also for atherogenesis. Enhanced blood coagulation frequently coexists with hyperlipidaemia and, together, these may have a synergistic effect on atherogenesis
Effect of oral curcumin administration on serum peroxides and cholesterol levels in human volunteers.
Soni KB, Kuttan R.
Indian J Physiol Pharmacol. 1992 Oct; 36(4):273-5.
The effect of curcumin administration in reducing the serum levels of cholesterol and lipid peroxides was studied in ten healthy human volunteers, receiving 500 mg of curcumin per day for 7 days. A significant decrease in the level of serum lipid peroxides (33%), increase in HDL Cholesterol (29%), and a decrease in total serum cholesterol (11.63%) were noted. As curcumin reduced serum lipid peroxides and serum cholesterol, the study of curcumin as a chemopreventive substance against arterial diseases is suggested
The effect of spices on cholesterol 7 alpha-hydroxylase activity and on serum and hepatic cholesterol levels in the rat.
Srinivasan K, Sambaiah K.
Int J Vitam Nutr Res. 1991; 61(4):364-9.
The effect of feeding curcumin, capsaicin, ginger, mustard, black pepper and cumin on cholesterol and bile acid metabolism was studied in rats. The activity of hepatic cholesterol-7 alpha-hydroxylase, the rate-limiting enzyme of bile acid biosynthesis, was significantly elevated in curcumin (turmeric), capsaicin (red pepper), ginger and mustard treated animals. The enzyme activity was comparable to controls in black pepper and cumin fed rats. Serum and liver microsomal cholesterol contents were significantly higher in the curcumin and capsaicin treated animals. Thus, this study has suggested that the spices--turmeric, red pepper, ginger and mustard can stimulate the conversion of cholesterol to bile acids, an important pathway of elimination of cholesterol from the body. However, simultaneous stimulation of cholesterol synthesis by the spice principles--curcumin and capsaicin suggests that there may not be any significant contribution of stimulation of bile acid biosynthesis to the hypocholesterolemic action of these spices, and the latter action may solely be due to interference with exogenous cholesterol absorption
Effects of aqueous extracts of onion, garlic and ginger on platelet aggregation and metabolism of arachidonic acid in the blood vascular system: in vitro study.
Prostaglandins Leukot Med. 1984 Feb; 13(2):227-35.
Aqueous extracts of onion, garlic and ginger were found to inhibit aggregation induced by ADP, epinephrine, collagen and arachidonate in a dose-dependent manner in vitro. In the case of onion and garlic extracts relatively much higher volumes were need to bring about even a modest inhibition (by ca. 13-18%) of thromboxane synthesis in washed platelets from labelled AA. On the other hand a good correlation was found between the amounts of ginger extract needed to inhibit platelet aggregation and those to inhibit platelet thromboxane synthesis. Ginger extract reduced also platelet prostaglandin-endoperoxides. A dose-related inhibition of platelet thromboxane- and prostaglandin (PGF2 alpha, PGE2 and PGD2) synthesis was affected by ginger extract. Extracts of onion, garlic and ginger inhibited biosynthesis of prostacyclin in rat aorta from labelled AA. Ginger extract mildly inhibited the synthesis of prostacyclin from endogenous pool of AA in rat aorta; the other two extracts were without effect
Anti-thrombotic effect of curcumin.
Srivastava R, Dikshit M, Srimal RC, et al.
Thromb Res. 1985 Nov 1; 40(3):413-7.
Effect of curcumin on platelet aggregation and vascular prostacyclin synthesis.
Srivastava R, Puri V, Srimal RC, et al.
Arzneimittelforschung. 1986 Apr; 36(4):715-7.
In vitro and ex vivo effects of 1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione (diferuloylmethane, curcumin) and acetylsalicylic acid (ASA) on the synthesis of prostacyclin (PGI2) and on platelet aggregation has been studied in rat. Both drugs inhibited adenosine diphosphate (ADP)-, epinephrine (adrenaline)- and collagen-induced platelet aggregation in monkey plasma. Pretreatment with ASA (25-100 mg/kg), but not curcumin (100-300 mg/kg), inhibited PGI2 synthesis in rat aorta. In the in vitro system, too, curcumin caused a slight increase in the synthesis of PGI2, while ASA inhibited it. Curcumin may, therefore, be preferable in patients prone to vascular thrombosis and requiring antiarthritic therapy
Methylation demand and homocysteine metabolism: effects of dietary provision of creatine and guanidinoacetate.
Stead LM, Au KP, Jacobs RL, et al.
Am J Physiol Endocrinol Metab. 2001 Nov; 281(5):E1095-E1100.
S-adenosylmethionine, formed by the adenylation of methionine via S-adenosylmethionine synthase, is the methyl donor in virtually all known biological methylations. These methylation reactions produce a methylated substrate and S-adenosylhomocysteine, which is subsequently metabolized to homocysteine. The methylation of guanidinoacetate to form creatine consumes more methyl groups than all other methylation reactions combined. Therefore, we examined the effects of increased or decreased methyl demand by these physiological substrates on plasma homocysteine by feeding rats guanidinoacetate- or creatine-supplemented diets for 2 wk. Plasma homocysteine was significantly increased (~50%) in rats maintained on guanidinoacetate-supplemented diets, whereas rats maintained on creatine-supplemented diets exhibited a significantly lower (~25%) plasma homocysteine level. Plasma creatine and muscle total creatine were significantly increased in rats fed the creatine-supplemented or guanidinoacetate-supplemented diets. The activity of kidney L-arginine:glycine amidinotransferase, the enzyme catalyzing the synthesis of guanidinoacetate, was significantly decreased in both supplementation groups. To examine the role of the liver in mediating these changes in plasma homocysteine, isolated rat hepatocytes were incubated with methionine in the presence and absence of guanidinoacetate and creatine, and homocysteine export was measured. Homocysteine export was significantly increased in the presence of guanidinoacetate. Creatine, however, was without effect. These results suggest that homocysteine metabolism is sensitive to methylation demand imposed by physiological substrates
A double-blind crossover study in moderately hypercholesterolemic men that compared the effect of aged garlic extract and placebo administration on blood lipids.
Steiner M, Khan AH, Holbert D, et al.
Am J Clin Nutr. 1996 Dec; 64(6):866-70.
A double-blind crossover study comparing the effect of aged garlic extract with a placebo on blood lipids was performed in a group of 41 moderately hypercholesterolemic men [cholesterol concentrations 5.7-7.5 mmol/L (220-290 mg/dL)]. After a 4-wk baseline period, during which the subjects were advised to adhere to a National Cholesterol Education Program Step I diet, they were started on 7.2 g aged garlic extract per day or an equivalent amount of placebo as a dietary supplement for a period of 6 mo, then switched to the other supplement for an additional 4 mo. Blood lipids, blood counts, thyroid and liver function measures, body weight, and blood pressure were followed over the entire study period. The major findings were a maximal reduction in total serum cholesterol of 6.1% or 7.0% in comparison with the average concentration during the placebo administration or baseline evaluation period, respectively. Low-density-lipoprotein cholesterol was also decreased by aged garlic extract, 4% when compared with average baseline values and 4.6% in comparison with placebo period concentrations. In addition, there was a 5.5% decrease in systolic blood pressure and a modest reduction of diastolic blood pressure in response to aged garlic extract. We conclude that dietary supplementation with aged garlic extract has beneficial effects on the lipid profile and blood pressure of moderately hypercholesterolemic subjects
Landmark perspective: Coronary atherosclerosis in soldiers. A clue to the natural history of atherosclerosis in the young.
JAMA. 1986 Nov 28; 256(20):2863-6.
Clinical experience of coenzyme Q10 to enhance intraoperative myocardial protection in coronary artery revascularization.
Sunamori M, Tanaka H, Maruyama T, et al.
Cardiovasc Drugs Ther. 1991 Mar; 5 Suppl 2:297-300.
Seventy-eight patients undergoing coronary artery bypass grafting (CABG) were compared retrospectively to evaluate whether pretreatment with coenzyme Q10 (CoQ) is effective in preventing left ventricular depression in early reperfusion following CABG. CoQ (5 mg/kg, intravenously) was given to 60 patients, 2 hours prior to the onset of cardiopulmonary bypass (CPB). CABG was performed using saphenous vein under CPB associated with cold cardioplegia in the standard fashion. Heart rate, mean arterial pressure, and cardiac index showed no significant difference between the CoQ and control groups. However, left ventricular stroke work index was significantly elevated at 6 and 10 hours of reperfusion following CABG in the CoQ-treated group compared with the controls. Serum MB-CK was lower at 0 and 6 hours of reperfusion in the CoQ group compared with the controls. These results suggest that pretreatment with intravenous CoQ is effective in preventing left ventricular depression in early reperfusion and in minimizing myocardial cellular injury during CABG followed by reperfusion
Effect of supplementation with vitamin E on LDL oxidizability and prevention of atherosclerosis.
Suzukawa M, Ayaori M, Shige H, et al.
Biofactors. 1998; 7(1-2):51-4.
Supplementation of LDL with vitamin E is thought to protect LDL from oxidative modification and prevent the development of atherosclerosis. Large epidemiological studies have revealed that vitamin E levels in plasma are inversely correlated to the incidence of coronary heart disease. Double-blind placebo-controlled trials have reported that supplementation with vitamin E decreases the incidence of coronary events in coronary heart disease (CHD) patients. However, it is not clear how high a dose of vitamin E is needed to prevent formation of atherosclerosis. In animal studies, a diet containing 0.125% vitamin E increased its levels in plasma two-fold and prevented formation of early atherosclerotic lesions in the thoracic aorta of hypercholesterolemic rabbits. Dose-response studies in humans have reported that 400 IU/day vitamin E increased its levels in plasma two-fold and prolonged the lag time before LDL oxidation. It has been reported that oxidizability of LDL was correlated to the atherosclerotic score of coronary angiography in CHD patients. About 400 IU/day vitamin E, which increases its levels two-fold and prolongs sufficiently the lag time before LDL oxidation, might be beneficial in decreasing the individual risk of CHD
Guggulipid for the treatment of hypercholesterolemia: a randomized controlled trial.
Szapary PO, Wolfe ML, Bloedon LT, et al.
JAMA. 2003 Aug 13; 290(6):765-72.
CONTEXT: Herbal extracts from Commiphora mukul (guggul) have been widely used in Asia as cholesterol-lowering agents, and their popularity is increasing in the United States. Recently, guggulsterones, the purported bioactive compounds of guggul, have been shown to be potent antagonists of 2 nuclear hormone receptors involved in cholesterol metabolism, establishing a plausible mechanism of action for the hypolipidemic effects of these extracts. However, there are currently no published safety or efficacy data on the use of guggul extracts in Western populations. OBJECTIVE: To study the short-term safety and efficacy of 2 doses of a standardized guggul extract (guggulipid, containing 2.5% guggulsterones) in healthy adults with hyperlipidemia eating a typical Western diet. DESIGN: Double-blind, randomized, placebo-controlled trial using a parallel design, conducted March 2000-August 2001. PARTICIPANTS AND SETTING: A total of 103 ambulatory, community-dwelling, healthy adults with hypercholesterolemia in the Philadelphia, Pa, metropolitan area. INTERVENTION: Oral, 3 times daily doses of standard-dose guggulipid (1000 mg), high-dose guggulipid (2000 mg), or matching placebo. MAIN OUTCOME MEASURES: Percentage change in levels of directly measured low-density lipoprotein cholesterol (LDL-C) after 8 weeks of therapy. Secondary outcome measures included levels of total cholesterol, high-density lipoprotein cholesterol (HDL-C), triglycerides, and directly measured very low-density lipoprotein cholesterol (VLDL-C), as well as adverse events reports and laboratory safety measures including electrolyte levels and hepatic and renal function. RESULTS: Compared with participants randomized to placebo (n = 36), in whom levels of LDL-C decreased by 5%, both standard-dose guggulipid (n = 33) and high-dose guggulipid (n = 34) raised levels of LDL-C by 4% (P =.01 vs placebo) and 5% (P =.006 vs placebo), respectively, at 8 weeks, for a net positive change of 9% to 10%. There were no significant changes in levels of total cholesterol, HDL-C, triglycerides, or VLDL-C in response to treatment with guggulipid in the intention-to-treat analysis. While guggulipid was generally well tolerated, 6 participants treated with guggulipid developed a hypersensitivity rash compared with none in the placebo group. CONCLUSIONS: Despite plausible mechanisms of action, guggulipid did not appear to improve levels of serum cholesterol over the short term in this population of adults with hypercholesterolemia, and might in fact raise levels of LDL-C. Guggulipid also appeared to cause a dermatologic hypersensitivity reaction in some patients
Fibrinolytic responses to moderate intensity exercise. Comparison of physically active and inactive men.
Szymanski LM, Pate RR.
Arterioscler Thromb. 1994 Nov; 14(11):1746-50.
The purposes of this study were to compare fibrinolytic responses to moderate intensity exercise in physically active and inactive men and during morning and evening exercise. Fourteen physically inactive men (mean age, 34.7 +/- 4.0 years) and 12 regularly active men (34.8 +/- 4.0 years) performed two exercise sessions, morning and evening, at 50% of maximal oxygen consumption. Tissue plasminogen activator (TPA) and plasminogen activator inhibitor-1 (PAI-1) activity were measured before and after exercise. Data were analyzed using a three-way ANOVA with repeated measures. TPA activity increased with exercise in both groups, although the active group demonstrated greater increases than the inactive group. Postexercise TPA activity was greater with evening than morning exercise. The inactive group exhibited greater PAI-1 activity than the active group. PAI-1 activity was higher during the morning than evening but did not change with exercise for either group. We conclude that moderate intensity exercise increases TPA activity in physically active and inactive men, with greater increases seen in active men, particularly during evening exercise. Moderate intensity exercise does not appear to affect PAI-1 activity. The lower PAI-1 activity in active men may be one mechanism whereby regular physical activity lowers the risk for coronary artery disease
Low-dose and high-dose acetylsalicylic acid for patients undergoing carotid endarterectomy: a randomised controlled trial. ASA and Carotid Endarterectomy (ACE) Trial Collaborators.
Taylor DW, Barnett HJ, Haynes RB, et al.
Lancet. 1999 Jun 26; 353(9171):2179-84.
BACKGROUND: Endarterectomy benefits certain patients with carotid stenosis, but benefits are lessened by perioperative surgical risk. Acetylsalicylic acid lowers the risk of stroke in patients who have experienced transient ischaemic attack and stroke. We investigated appropriate doses and the role of acetylsalicylic acid in patients undergoing carotid endarterectomy. METHODS: In a randomised, double-blind, controlled trial, 2849 patients scheduled for endarterectomy were randomly assigned 81 mg (n=709), 325 mg (n=708), 650 mg (n=715), or 1300 mg (n=717) acetylsalicylic acid daily, started before surgery and continued for 3 months. We recorded occurrences of stroke, myocardial infarction, and death. We compared patients on the two higher doses of acetylsalicylic acid with patients on the two lower doses. FINDINGS: Surgery was cancelled in 45 patients, none were lost to follow-up by 30 days, and two were lost by 3 months. The combined rate of stroke, myocardial infarction, and death was lower in the low-dose groups than in the high-dose groups at 30 days (5.4 vs 7.0%, p=0.07) and at 3 months (6.2 vs 8.4%, p=0.03). In an efficacy analysis, which excluded patients taking 650 mg or more acetylsalicylic acid before randomisation, and patients randomised within 1 day of surgery, combined rates were 3.7% and 8.2%, respectively, at 30 days (p=0.002) and 4.2% and 10.0% at 3 months (p=0.0002). INTERPRETATION: The risk of stroke, myocardial infarction, and death within 30 days and 3 months of endarterectomy is lower for patients taking 81 mg or 325 mg acetylsalicylic acid daily than for those taking 650 mg or 1300 mg
Clinical review 97: Potential health benefits of dietary phytoestrogens: a review of the clinical, epidemiological, and mechanistic evidence.
Tham DM, Gardner CD, Haskell WL.
J Clin Endocrinol Metab. 1998 Jul; 83(7):2223-35.
Phytoestrogens represent a family of plant compounds that have been shown to have both estrogenic and antiestrogenic properties. A variety of these plant compounds and their mammalian metabolic products have been identified in various human body fluids and fall under two main categories: isoflavones and lignans. A wide range of commonly consumed foods contain appreciable amounts of these different phytoestrogens. For example, soy and flax products are particularly good sources of isoflavones and lignans, respectively. Accumulating evidence from molecular and cellular biology experiments, animal studies, and, to a limited extent, human clinical trials suggests that phytoestrogens may potentially confer health benefits related to cardiovascular diseases, cancer, osteoporosis, and menopausal symptoms. These potential health benefits are consistent with the epidemiological evidence that rates of heart disease, various cancers, osteoporotic fractures, and menopausal symptoms are more favorable among populations that consume plant-based diets, particularly among cultures with diets that are traditionally high in soy products. The evidence reviewed here will facilitate the identification of what is known in this area, the gaps that exist, and the future research that holds the most potential and promise
Calcium Channel Blockers.
THI (Texas Heart Institute).
Angiotensin-Converting Enzyme (ACE) Inhibitors.
THI (Texas Heart Institute).
THI (Texas Heart Institute).
Hemostatic factors and the risk of myocardial infarction or sudden death in patients with angina pectoris. European Concerted Action on Thrombosis and Disabilities Angina Pectoris Study Group.
Thompson SG, Kienast J, Pyke SD, et al.
N Engl J Med. 1995 Mar 9; 332(10):635-41.
BACKGROUND. Increased levels of certain hemostatic factors may play a part in the development of acute coronary syndromes and may be associated with an increased risk of coronary events in patients with angina pectoris. METHODS. We conducted a prospective multicenter study of 3043 patients with angina pectoris who underwent coronary angiography and were followed for two years. Base-line measurements included the concentrations of selected hemostatic factors indicative of a thrombophilic state or endothelial injury. The results were analyzed in relation to the subsequent incidence of myocardial infarction or sudden coronary death. RESULTS. After adjustment for the extent of coronary artery disease and other risk factors, an increased incidence of myocardial infarction or sudden death was associated with higher base-line concentrations of fibrinogen (mean +/- SD, 3.28 +/- 0.74 g per liter in patients who subsequently had coronary events, as compared with 3.00 +/- 0.71 g per liter in those who did not; P = 0.01), von Willebrand factor antigen (138 +/- 49 percent vs. 125 +/- 49 percent, P = 0.05), and tissue plasminogen activator (t-PA) antigen (11.9 +/- 4.7 ng per milliliter vs. 10.0 +/- 4.2 ng per milliliter, P = 0.02). The concentration of C-reactive protein was also directly correlated with the incidence of coronary events (P = 0.05), except when we adjusted for the fibrinogen concentration. In patients with high serum cholesterol levels, the risk of coronary events rose with increasing levels of fibrinogen and C-reactive protein, but the risk remained low even given high serum cholesterol levels in the presence of low fibrinogen concentrations. CONCLUSIONS. In patients with angina pectoris, the levels of fibrinogen, von Willebrand factor antigen, and t-PA antigen are independent predictors of subsequent acute coronary syndromes. In addition, low fibrinogen concentrations characterize patients at low risk for coronary events despite increased serum cholesterol levels. Our data are consistent with a pathogenetic role of impaired fibrinolysis, endothelial-cell injury, and inflammatory activity in the progression of coronary artery disease
Natural antioxidants. III. Antioxidative components isolated from rhizome of Curcuma longa L.
Toda S, Miyase T, Arichi H, et al.
Chem Pharm Bull (Tokyo). 1985 Apr; 33(4):1725-8.
Folic acid fortification of the food supply. Potential benefits and risks for the elderly population.
Tucker KL, Mahnken B, Wilson PW, et al.
JAMA. 1996 Dec 18; 276(23):1879-85.
OBJECTIVE: To estimate the potential benefits and risks of food folic acid fortification for an elderly population. Benefits are expected through the improvement of folate and homocysteine status, but there is also a risk of masking or precipitating clinical manifestations related to vitamin B12 deficiency with increasing exposure to folic acid. DESIGN: Cross-sectional analysis, with projected change at various levels of folic acid fortification. SETTING: Participants in the Framingham Heart Study original cohort. PARTICIPANTS: A total of 747 subjects aged 67 to 96 years who both completed usable food frequency questionnaires and had blood concentrations of B vitamins and homocysteine measured. MAIN OUTCOME MEASURES: Projected blood folate and homocysteine concentrations and combined high folate intake and low plasma vitamin B12 concentration. RESULTS: Percentages of this elderly population with folate intake below 400 microg/d are projected to drop from 66% at baseline to 49% with 140 microg of folate per 100 g of cereal-grain product, to 32% with 280 microg, to 26% with 350 microg, and to 11% with 700 microg. Percentages with elevated homocysteine concentrations (>14 micromol/L) are projected to drop from 26% at baseline to 21% with 140 microg of folate per 100 g, to 17% with 280 microg, to 16% with 350 microg, and to 12% with 700 microg. Without fortification, the prevalence of combined high folate intake (>1000 microg/d) and low plasma vitamin B12 concentration (<185 pmol/L [<250 pg/mL]) was 0.1%. This is projected to increase to 0.4% with folate fortification levels of 140 to 350 microg/100 g and to 3.4% with 700 microg. CONCLUSION: The evidence suggests that, at the level of 140 microg/100 g of cereal-grain product mandated by the Food and Drug Administration, the benefits of folate fortification, through projected decreases in homocysteine level and heart disease risk, greatly outweigh the expected risks. However, quantification of the actual risks associated with vitamin B12 deficiency remains elusive. Before higher levels of folic acid fortification are implemented, further research is needed to better understand the clinical course of various forms of vitamin B12 deficiency, to measure the potential effect of high folate intake on this course, and to identify cost-effective approaches to the identification and treatment of all forms of vitamin B12 deficiency
Vitamin B-12, vitamin B-6, and folate nutritional status in men with hyperhomocysteinemia.
Ubbink JB, Vermaak WJ, van der MA, et al.
Am J Clin Nutr. 1993 Jan; 57(1):47-53.
We measured the vitamin B-6, vitamin B-12, and folic acid nutritional status in a group of apparently healthy men (n = 44) with moderate hyperhomocysteinemia (plasma homocysteine concentration > 16.3 mumol/L). Compared with control subjects (n = 274) with normal plasma homocysteine (< or = "16.3" mumol/L) concentrations, significantly lower plasma concentrations of pyridoxal-5'-phosphate (P < 0.001), cobalamin (P < 0.001), and folic acid (P = "0.004)" were demonstrated in hyperhomocysteinemic men. The prevalence of suboptimal vitamin B-6, B-12, and folate status in men with hyperhomocysteinemia was 25.0%, 56.8%, and 59.1%, respectively. In a placebo-controlled follow-up study, a daily vitamin supplement (10 mg pyridoxal, 1.0 mg folic acid, 0.4 mg cyanocobalamin) normalized elevated plasma homocysteine concentrations within 6 wk. Because hyperhomocysteinemia is implicated as a risk factor for premature occlusive vascular disease, appropriate vitamin therapy may be both efficient and cost-effective to control elevated plasma homocysteine concentrations
Chest, Heart and Stroke. Scotland Fund Coronary Balloon Angioplasty Research .
UE (University of Edinburgh).
Phytotherapy in cardiovascular diseases. Supportive therapy in early stages.
Med Fakultat, Abtsleitenweg 11. 1994; 44(29):1650-3.
Reversing Heart Failure: Cold Virus Could Make Gene Therapy Possible.
Evidence for synergism between chromium and nicotinic acid in the control of glucose tolerance in elderly humans.
Urberg M, Zemel MB.
Metabolism. 1987 Sep; 36(9):896-9.
Impaired glucose tolerance results from Cr restriction in animals, and Cr supplementation improves glucose tolerance in diabetic animals. These effects are presumably due to the role of Cr in glucose tolerance factor (GTF), a complex of Cr and nicotinic acid believed to facilitate insulin binding. Humans, however, do not uniformly respond to Cr supplementation. The present study was designed to evaluate the possibility that the failure results from inadequate levels of dietary nicotinic acid to serve as substrate for GTF synthesis. Sixteen healthy elderly volunteers were divided into three groups and given either 200 micrograms Cr, 100 mg nicotinic acid, or 200 micrograms Cr + 100 mg nicotinic acid daily for 28 days and evaluated on days 0 and 28. Fasting glucose and glucose tolerance were unaffected by either chromium or nicotinic acid alone. In contrast, the combined chromium-nicotinic acid supplement caused a 15% decrease in a glucose area integrated total (p less than .025) and a 7% decrease in fasting glucose. None of the treatments exerted any effect on fasting or one-hour insulin levels. Thus, these data suggest that the inability to respond to chromium supplementation may result from suboptimal levels of dietary nicotinic acid
A natural product that lowers cholesterol as an antagonist ligand for FXR.
Urizar NL, Liverman AB, Dodds DT, et al.
Science. 2002 May 31; 296(5573):1703-6.
Extracts of the resin of the guggul tree (Commiphora mukul) lower LDL (low-density lipoprotein) cholesterol levels in humans. The plant sterol guggulsterone [4,17(20)-pregnadiene-3,16-dione] is the active agent in this extract. We show that guggulsterone is a highly efficacious antagonist of the farnesoid X receptor (FXR), a nuclear hormone receptor that is activated by bile acids. Guggulsterone treatment decreases hepatic cholesterol in wild-type mice fed a high-cholesterol diet but is not effective in FXR-null mice. Thus, we propose that inhibition of FXR activation is the basis for the cholesterol-lowering activity of guggulsterone. Other natural products with specific biologic effects may modulate the activity of FXR or other relatively promiscuous nuclear hormone receptors
GUGULIPID: a natural cholesterol-lowering agent.
Urizar NL, Moore DD.
Annu Rev Nutr. 2003; 23:303-13.
The resin of the Commiphora mukul tree has been used in Ayurvedic medicine for more than 2000 years to treat a variety of ailments. Studies in both animal models and humans have shown that this resin, termed gum guggul, can decrease elevated lipid levels. The stereoisomers E- and Z-guggulsterone have been identified as the active agents in this resin. Recent studies have shown that these compounds are antagonist ligands for the bile acid receptor farnesoid X receptor (FXR), which is an important regulator of cholesterol homeostasis. It is likely that this effect accounts for the hypolipidemic activity of these phytosteroids
Role of policosanols in the prevention and treatment of cardiovascular disease.
Varady KA, Wang Y, Jones PJ.
Nutr Rev. 2003 Nov; 61(11):376-83.
Policosanols are a mixture of aliphatic alcohols derived from purified sugar cane. When administered at 5 to 20 mg/day, policosanols have been shown to decrease the risk of atheroma formation by reducing platelet aggregation, endothelial damage, and foam cell formation in animals. Additionally, policosanols have been shown to lower total and low-density lipoprotein (LDL) cholesterol levels by 13 to 23% and 19 to 31%, respectively, while increasing high-density lipoprotein (HDL) cholesterol from 8 to 29%. Policosanols are thought to improve lipid profiles by reducing hepatic cholesterol biosynthesis while enhancing LDL clearance. When compared with statins, policosanols exhibit comparable cholesterol-lowering effects at much smaller doses. The mixture is well tolerated when administered to animals; however, a more precise safety profile is needed for humans. In summary, policosanols are a promising resource in the prevention and therapy of cardiovascular disease (CVD), but these results need to be confirmed in independent laboratories
Prospective studies of homocysteine and cardiovascular disease.
Verhoef P, Stampfer MJ.
Nutr Rev. 1995 Oct; 53(10):283-8.
The link between vascular disease and elevated homocysteine levels has been recognized for more than 30 years, and an association with moderately elevated levels has been suspected for 20 years. The initial investigations were case series, cross-sectional, and case-control studies. Those studies consistently suggest a strong positive relationship between moderate hyperhomocysteinemia and risk of vascular disease. However, a major limitation of these types of study design is that the possibility of elevated homocysteine levels being influenced by the disease or its treatment cannot be ruled out. In case-control studies there is always concern about the appropriateness of the control group. These issues pose much less of a problem in prospective designs. Prospective studies also offer the opportunity to study various manifestations of cardiovascular disease at the same time. However, prospective studies tend to be more expensive and time-consuming, perhaps explaining the smaller number of prospective studies and why the first was not published until 1992. The distinct limitations and advantages of prospective studies are also reviewed
Homocysteine metabolism and risk of myocardial infarction: relation with vitamins B6, B12, and folate.
Verhoef P, Stampfer MJ, Buring JE, et al.
Am J Epidemiol. 1996 May 1; 143(9):845-59.
Elevated plasma homocyst(e)ine levels are an independent risk factor for vascular disease. In a case-control study, the authors studied the associations of fasting plasma homocyst(e)ine and vitamins, which are important cofactors in homocysteine metabolism, with the risk of myocardial infarction. The cases were 130 Boston area patients hospitalized with a first myocardial infarction and 118 population controls, less than 76 years of age, enrolled in 1982 and 1983. Dietary intakes of vitamins B6, B12, and folate were estimated from a food frequency questionnaire. After adjusting for sex and age, the authors found that the geometric mean plasma homocyst(e)ine level was 11% higher in cases compared with controls (p = 0.006). There was no clear excess of cases with extremely elevated levels. The age- and sex-adjusted odds ratio for each 3-mumol/liter (approximately 1 standard deviation) increase in plasma homocyst(e)ine was 1.35 (95% confidence interval 1.05-1.75; p trend = 0/007). After further control for several risk factors, the odds ratio was not affected, but the confidence interval was wider and the p value for trend was less significant. Dietary and plasma levels of vitamin B6 and folate were lower in cases than in controls, and these vitamins were inversely associated with the risk of myocardial infarction, independently of other potential risk factors. Vitamin B12 showed no clear association with myocardial infarction, although methylmalonic acid levels were significantly higher in cases. Comparing the mean levels of several homocysteine metabolites among cases and controls, the authors found that impairment of remethylation of homocyst(e)ine (dependent of folate and vitamin B12 rather than on vitamin B6-dependent transsulfuration) was the predominant cause of high homocyst(e)ine levels in cases. Accordingly, plasma folate and, to a lesser extent, plasma vitamin B12, but not vitamin B6, correlated inversely with plasma homocyst(e)ine, even for concentrations at the high end of normal values. These data provide further evidence that plasma homocyst(e)ine is an independent risk factor for myocardial infarction. In this population, folate was the most important determinant of plasma homocyst(e)ine, even in subjects with apparently adequate nutritional status of this vitamin
Plasma total homocysteine, B vitamins, and risk of coronary atherosclerosis.
Verhoef P, Kok FJ, Kruyssen DA, et al.
Arterioscler Thromb Vasc Biol. 1997 May; 17(5):989-95.
Epidemiological research has shown that elevated plasma total homocysteine (tHcy) is a risk factor for atherosclerotic disease. In the present case-control study, we investigated whether fasting or postmethionine-loading tHcy was a stronger predictor of risk of severe coronary atherosclerosis. Furthermore, we studied levels of B vitamins, which are involved in homocysteine metabolism. Subjects were recruited from men and women, aged 25 to 65 years, who underwent coronary angiography between June 1992 and June 1994 in a hospital in Rotterdam, The Netherlands. Cases (n=131) were defined as those with > or =90% occlusion in one and > or =40% occlusion in a second coronary artery, while control subjects (n=88) had <50% occlusion in only one coronary vessel. In addition, a population-based control group free from clinical cardiovascular disease (n="101)" was studied. Coronary patients were studied at least 2.5 months after angiography or other acute illness, such as myocardial infarction. After adjusting for age and sex differences between the groups, cases had 9% (P=".01)" higher geometric mean fasting and 7% (P=".04)" higher geometric mean postload tHcy than the combined control groups. Despite higher levels of tHcy for cases, their geometric mean levels of red cell folate and pyridoxal 5'-phosphate were higher than for control subjects, whereas plasma vitamin B12 was only slightly lower in cases. The frequency distribution of tHcy values in cases was slightly shifted toward the right, across the entire range, compared with the distribution in the combined control group. This was somewhat more obvious for fasting than postload tHcy levels. The odds ratio (OR) for severe coronary atherosclerosis (case status) for each 1 SD increase in fasting tHcy (5 micromol/L) was 1.3 (95% confidence interval [CI], 1.0-1.6), similar to the OR for each 1 SD increase (12 micromol/L) in postmethionine-loading tHcy (1.3 [95 CI, 1.0-1.7]), after adjustment for sex, age, and other potential confounders. Furthermore, there was a significant linear trend of increasing fasting tHcy with increasing number of occluded arteries (P=".01)," correcting for sex, age, and other potential confounders. Our data show a positive association between plasma tHcy and risk of severe coronary atherosclerosis, of similar strength for fasting and postload tHcy levels. The data suggest that the association exists over a wide range of tHcy levels, without a clear cutoff point below which there is no increased risk
Homocysteine, vitamin status and risk of vascular disease; effects of gender and menopausal status. European COMAC Group.
Verhoef P, Meleady R, Daly LE, et al.
Eur Heart J. 1999 Sep; 20(17):1234-44.
BACKGROUND: Elevated plasma total homocysteine (tHcy) is a known risk factor for vascular disease. Gender, age, and circulating levels of folate, vitamins B(6)and B(12)affect tHcy levels.Objectives To study associations of gender and age with levels of plasma tHcy, and to examine the relationships of tHcy and circulating levels of folate, vitamins B(6)and B(12)with risk of vascular disease in men and women (pre- and post-menopausal). MATERIAL AND METHODS: In a multicentre case-control study in Europe, 750 patients (544 men, 206 women) with documented vascular disease of the coronary, cerebral, or peripheral vessels and 800 control subjects (570 men, 230 women) were enrolled. Plasma tHcy levels (fasting and after methionine loading) and circulating levels of the vitamins were measured. Adjustment for age and centre was carried out for all statistical analyses, with additional adjustment for serum creatinine and vitamins for the tHcy comparisons between the sexes and between cases and controls. Risk analyses included adjustment for creatinine and traditional risk factors. Relationships between age, gender and tHcy were studied among control subjects only. RESULTS: Fasting tHcy levels were lower in women than in men. Levels of tHcy showed a positive association with age, for both sexes. In the post-menopausal age category, female post-methionine load tHcy levels surpassed levels of men. Elevation of tHcy (defined as >80th percentile of controls) appeared to be at least as strong a risk factor for vascular disease in women as in men, even before the menopause. For post-methionine load tHcy, there was a 40% stronger association with vascular disease in women than in men. In both sexes, but especially in pre-menopausal women, low circulating levels of vitamin B(6)conferred a two- to threefold increased risk of vascular disease, independent of tHcy. In men, but not in women, low (defined as <20th percentile of controls) circulating folate levels were associated with a 50% increased risk of vascular disease. CONCLUSIONS: Elevation of tHcy appears to be at least as strong a risk for vascular disease in women as men, even before the menopause. Our data indicate that associations of the various tHcy measurements (and the vitamins that determine them), with risks of vascular disease may differ between the sexes. The tHcy-independent relationship of vitamin B(6)with vascular disease indicates that it will be advisable to test the effects of vitamin B(6)in clinical trials
Effect of Commiphora mukul (gum guggulu) in patients of hyperlipidemia with special reference to HDL-cholesterol.
Verma SK, Bordia A.
Indian J Med Res. 1988 Apr; 87:356-60.
Low plasma ascorbic acid independently predicts the presence of an unstable coronary syndrome.
Vita JA, Keaney JF, Jr., Raby KE, et al.
J Am Coll Cardiol. 1998 Apr; 31(5):980-6.
OBJECTIVES: This study sought to investigate the relations between plasma antioxidant status, extent of atherosclerosis and activity of coronary artery disease. BACKGROUND: Previous studies indicate that increased antioxidant intake is associated with decreased coronary disease risk, but the underlying mechanisms remain controversial. METHODS: Plasma samples were obtained from 149 patients undergoing cardiac catheterization (65 with stable angina, 84 with unstable angina or a myocardial infarction within 2 weeks). Twelve plasma antioxidant/oxidant markers were measured and correlated with the extent of atherosclerosis and the presence of an unstable coronary syndrome. RESULTS: By multiple linear regression analysis, age (p < 0.001), diabetes mellitus (p < 0.001), male gender (p 50%), ascorbic acid concentration (OR 0.56, 95% CI 0.37 to 0.85, p = 0.008) and total plasma thiols (OR 0.52, 95% CI 0.34 to 0.80, p = 0.004) predicted the presence of an unstable coronary syndrome, whereas the extent of atherosclerosis did not. CONCLUSIONS: These data are consistent with the hypothesis that the beneficial effects of antioxidants in coronary artery disease may result, in part, by an influence on lesion activity rather than a reduction in the overall extent of fixed disease
Apolipoprotein E genotype and response of lipid levels to postmenopausal estrogen use.
Von Muhlen D, Barrett-Connor E, Kritz-Silverstein D.
Atherosclerosis. 2002 Mar; 161(1):209-14.
The allelic variation of Apolipoprotein E (ApoE) influences serum lipid levels. Postmenopausal estrogen replacement therapy (ERT) has favorable effects on the serum lipid profile. We examined the effect of ApoE genotype on lipid response to ERT in 692 community-dwelling women aged 60 and older. ApoE genotypes were categorized into three groups: ApoE 2 (E2/E2+E2/E3, n=94), ApoE 3 (E3/E3, n=430), and ApoE 4 (E3/E4+E4/E4, n=142). Compared to 497 women not using ERT, 169 women currently using ERT were younger (P=0.01), had lower levels of total cholesterol (TC; P=0.10) and low-density lipoprotein (P<0.001), higher levels of high-density lipoprotein (HDL; P<0.001) and triglycerides (TG; P="0.009)," and were more likely to have had a surgical menopause (P0.10). There was a significant interaction between ApoE 2 and ERT for HDL levels: women with ApoE 2 using ERT had the highest HDL levels, and women with ApoE 2 not using ERT had the lowest HDL levels (P=0.015). The unfavorable effect of ApoE 4 genotype on lipoproteins is not altered by HRT, but ApoE 2 genotype modulates the HDL-ERT association in older women
Betaine:homocysteine methyltransferase--a new assay for the liver enzyme and its absence from human skin fibroblasts and peripheral blood lymphocytes.
Wang JA, Dudman NP, Lynch J, et al.
Clin Chim Acta. 1991 Dec 31; 204(1-3):239-49.
Chronic elevation of plasma homocysteine is associated with increased atherogenesis and thrombosis, and can be lowered by betaine (N,N,N-trimethylglycine) treatment which is thought to stimulate activity of the enzyme betaine:homocysteine methyltransferase. We have developed a new assay for this enzyme, in which the products of the enzyme-catalysed reaction between betaine and homocysteine are oxidised by performic acid before being separated and quantified by amino acid analysis. This assay confirmed that human liver contains abundant betaine:homocysteine methyltransferase (33.4 nmol/h/mg protein at 37 degrees C, pH 7.4). Chicken and lamb livers also contain the enzyme, with respective activities of 50.4 and 6.2 nmol/h/mg protein. However, phytohaemagglutinin-stimulated human peripheral blood lymphocytes and cultured human skin fibroblasts contained no detectable betaine:homocysteine methyltransferase (less than 1.4 nmol/h/mg protein), even after cells were pre-cultured in media designed to stimulate production of the enzyme. The results emphasize the importance of the liver in mediating the lowering of elevated circulating homocysteine by betaine
Genotype-specific effects of smoking on risk of CHD.
Wang XL, Mahaney MC.
Lancet. 2001 Jul 14; 358(9276):87-8.
About Stroke 2003.
Washington University in St.Louis School of Medicine.
Randomized, double-blind, placebo-controlled study of the preventive effect of supplemental oral vitamin C on attenuation of development of nitrate tolerance.
Watanabe H, Kakihana M, Ohtsuka S, et al.
J Am Coll Cardiol. 1998 May; 31(6):1323-9.
OBJECTIVES: This study sought to evaluate the preventive effect of vitamin C, an antioxidant, on the development of nitrate tolerance. BACKGROUND: Decreased intracellular production of cyclic guanosine monophosphate (cGMP) is a mechanism of nitrate tolerance, and increased superoxide levels and reduced activation of guanylate cyclase have been observed in vitro. METHODS: In this double-blind, placebo-controlled study, 24 normal volunteers and 24 patients with ischemic heart disease (IHD) were randomized to receive either vitamin C (2 g three times daily [vitamin C group, n=12]) or placebo (placebo group, n=12). The vasodilator response to nitroglycerin was assessed with forearm plethysmography by measuring the change in FBF before and 5 min after sublingual administration of 0.3 mg of nitroglycerin. Blood samples were simultaneously obtained to measure platelet cGMP levels. FBF was measured, and blood sampling was performed serially at baseline (day 0), 3 days after administration of vitamin C or placebo (day 3) and 3 days after application of a 10-mg/24-h nitroglycerin tape concomitantly with oral vitamin C or placebo (day 6). RESULTS: There were no differences between the vitamin C and placebo groups in percent increases in FBF (%FBF) or platelet cGMP levels (%cGMP) after administration of sublingual nitroglycerin on day O (%FBF: normal volunteers 31+/-8 vs. 32+/-10; patients with IHD 32+/-9 vs. 32+/-8; %cGMP: normal volunteers 37+/-9 vs. 39+/-10; patients with IHD 38+/-10 vs. 39+/-10 [vitamin C group vs. placebo group]) or day 3 (%FBF: normal volunteers 32+/-9 vs. 33+/-9; patients with IHD 31+/-10 vs. 31+/-10; %cGMP: normal volunteers 36+/-8 vs. 37+/-9; patients with IHD 39+/-11 vs. 38+/-10 [vitamin C group vs. placebo group]). The %FBF and %cGMP in the placebo group were significantly lower on day 6 than in the vitamin C group (%FBF: normal volunteers 30+/-8 vs. 19 4, p < 0.01; patients with IHD 29+/-9 vs. 17+/-6, p < 0.01; %cGMP: normal volunteers 36 10 vs. 17+/-6, p < 0.01; patients with IHD 37+/-11 vs. 15+/-5, p < 0.01 [vitamin C group vs. placebo group]). CONCLUSIONS: These results indicate that combination therapy with vitamin C is potentially useful for preventing the development of nitrate tolerance
Does visual interpretation of the coronary arteriogram predict the physiologic importance of a coronary stenosis?
White CW, Wright CB, Doty DB, et al.
N Engl J Med. 1984 Mar 29; 310(13):819-24.
To assess visual interpretation of the coronary arteriogram as a means of predicting the physiologic effects of coronary obstructions in human beings, we compared caliper measurements of the degree of coronary stenosis with the reactive hyperemic response of coronary flow velocity studied with a Doppler technique at operation, after 20 seconds of coronary arterial occlusion. In 39 patients (44 vessels) with isolated, discrete coronary lesions varying in severity from 10 to 95 per cent stenosis, measurement of the percentage of stenosis from coronary angiograms was not significantly correlated (r = -0.25) with the reactive hyperemic response. Results were the same for obstructions in the left anterior descending, diagonal, and right coronary arteries. Underestimation of lesion severity occurred in 95 per cent of vessels with greater than 60 per cent stenosis of the diameter by arteriography. Both overestimation and underestimation of lesions with less than 60 per cent stenosis were common. These results, together with the high interobserver and intraobserver variability of standard visual analysis of angiograms, suggest that the physiologic effects of the majority of coronary obstructions cannot be determined accurately by conventional angiographic approaches. The need for improved analytical methods for the physiologic assessment of angiographically detected coronary obstructions is apparent
Gaining and Maintaining Total Health.
Gugulipid. Cautions .
About WHVC: History and Full Description 2004.
WHVC (Wisconsin Heart and Vascular Clinic).
Milwaukee, WI: Milwaukee/St Lukes. 2004
Homocystinuria due to cystathionine beta-synthase deficiency--the effects of betaine treatment in pyridoxine-responsive patients.
Wilcken DE, Dudman NP, Tyrrell PA.
Metabolism. 1985 Dec; 34(12):1115-21.
Homocystinuria due to cystathionine beta-synthase deficiency may be responsive to pyridoxine, a precursor of the cofactor pyridoxal phosphate, and the amount of residual enzyme activity present is the probable determinant of this. In six treated pyridoxine-responsive patients whose biochemical control of fasting plasma amino acid levels appeared optimal, we assessed the effects on plasma amino acids of standard oral methionine loads (4g/m2 of body area) before and after adding betaine (trimethylglycine) 6 g/d, to the treatment regimen of pyridoxine and folic acid. Our aim was to define the capacity of these patients to metabolize methionine and to determine whether betaine would effect a reduction in postload homocysteine levels. During the 24 hours after the methionine challenge all patients had higher plasma methionine and homocysteine and lower cysteine than did 17 normal subjects. After betaine these homocysteine responses were reduced to near normal, and there was a trend toward increased methionine. There was a direct correlation between premethionine fasting homocysteine and mean homocysteine responses during the 24 hours following the methionine load, both before (r = 0.79) and after betaine (r = 0.71). Betaine also increased plasma cysteine levels in patients with the more severe biochemical abnormalities. After betaine there were modest increases in plasma serine (mean increase 25%; P less than 0.025). Since the vascular complications of homocystinuria are related to increased plasma homocysteine, betaine therapy may reduce this risk in patients receiving a standard pyridoxine and folic acid regimen in whom there are abnormal homocysteine responses after a standard methionine load
B vitamins and homocysteine in cardiovascular disease and aging.
Wilcken DE, Wilcken B.
Ann N Y Acad Sci. 1998 Nov 20; 854:361-70.
The sulfur-containing amino acid, homocysteine, is formed from the essential amino acid methionine, and a number of B vitamins are involved in methionine metabolism. Pyridoxine, vitamin B6, is a cofactor for cystathionine beta synthase, which mediates the transformation of homocysteine to cystathionine, the initial step in the transsulfuration pathway and the urinary excretion of sulfur. In a normal diet there is conservation of the carbon skeleton, and about 50% of the homocysteine formed is remethylated to methionine via steps that require folic acid and vitamin B12. A deficiency of any of these three vitamins leads to modest homocyst(e)ine elevation, as does diminished renal function, both of which are common in the elderly. It is also established that homocyst(e)ine elevation of this order is associated with increased cardiovascular risk but is also associated with most established risk factors, although it is thought to be an independent contributor. In the inborn error of metabolism homocystinuria due to cystathionine beta synthase deficiency there is greatly increased circulating homocyst(e)ine and a clear association with precocious vascular disease. In about 50% of these patients there is a vascular event before the age of 30 years. The homocysteine-induced adverse vascular changes appear to result from endothelial and smooth muscle cell effects and increased thrombogenesis. We have documented a highly significant reduction in the occurrence of vascular events during 539 patient years of treatment in 32 patients with cystathionine beta synthase deficiency (mean age 30 years, range 9-66 years) by aggressive homocyst(e)ine lowering with pyridoxine, folic acid, and B12 (p = 0.0001). The 15 pyridoxine nonresponsive patients also received oral betaine. Although a cause and effect relationship is postulated for the increased cardiovascular risk associated with mild homocysteine elevation, a common cause of this elevation is the methylenetetrahydrofolate reductase C677T mutation. Homozygotes occur in about 11% of Caucasian populations. However, the mutation is not associated with increased coronary risk. Since mild homocysteine elevation is easily normalized by B vitamin supplementation, usually with folic acid, it remains for controlled clinical trials of this inexpensive therapy to determine whether normalizing mild homocyst(e)ine elevation reduces cardiovascular risk
Fibrinogen as a risk factor for stroke and myocardial infarction.
Wilhelmsen L, Svardsudd K, Korsan-Bengtsen K, et al.
N Engl J Med. 1984 Aug 23; 311(8):501-5.
To study the possible risk factors for cardiovascular disease, we collected data on plasma levels of coagulation factors, blood pressure, serum cholesterol, and smoking in a random sample of 792 men 54 years of age. During 13.5 years of follow-up, myocardial infarction occurred in 92 men, stroke in 37, and death from causes other than myocardial infarction or stroke in 60. The blood pressure, degree of smoking, serum cholesterol, and fibrinogen level measured at the base-line examination proved to be significant risk factors for infarction by univariate analyses during follow-up, and blood pressure and fibrinogen were risk factors for stroke. Fibrinogen and smoking were strongly related to each other. The relation between fibrinogen and infarction, and between fibrinogen and stroke, became weaker when blood pressure, serum cholesterol, and smoking habits were taken into account, but was still significant for stroke. Although causality cannot be inferred from these data, it is possible that the fibrinogen level plays an important part in the development of stroke and myocardial infarction
The appropriateness of performing coronary artery bypass surgery.
Winslow CM, Kosecoff JB, Chassin M, et al.
JAMA. 1988 Jul 22; 260(4):505-9.
Information about how appropriately procedures are performed is vital to the understanding of the impact of technology and to the success of efforts to channel its use appropriately. While the efficacy of coronary artery bypass surgery has been addressed in several large-scale, randomized trials, there is little information about how appropriately the procedure is actually being used in the community. We determined the appropriateness of coronary artery bypass surgeries performed in three randomly chosen hospitals in a western state. We determined appropriateness by comparing data obtained from a detailed medical record review with a list of 488 indications. This list, developed by a national panel of physicians, covered all possible reasons for performing the procedure. Three hundred eighty-six cases from the years 1979, 1980, and 1982 were examined. Fifty-six percent of the surgeries were performed for appropriate reasons, 30% for equivocal reasons, and 14% for inappropriate reasons. The percentage of appropriate surgeries varied by hospital, from 37% to 78%, but did not vary by patient age. Eliminating the performance of inappropriate procedures may lead to reductions in health care expenditures or to improved patient outcomes
About WHVC: History and Full Description.
Wisconsin Heart and Vascular Clinic.
Therapeutic effects of an androgenic preparation on myocardial ischemia and cardiac function in 62 elderly male coronary heart disease patients.
Wu SZ, Weng XZ.
Chin Med J (Engl ). 1993 Jun; 106(6):415-8.
The elevated estradiol/testosterone (E2/T) ratio had been proved to be a risk factor for coronary heart disease (CHD) in elderly men. We conducted a randomized placebo controlled crossover study on the effects of a new androgenic preparation "Andriol" in 62 elderly men with CHD over a period of 2.5 months. The results showed significant differences between Andriol- and placebo-treated groups at the end of this period: in the former, serum T level was elevated significantly (P 0.05), E2/T ratio was reduced (P < 0.05), angina pectoris (AP) was relieved (total effective rate, 77.4%), and myocardial ischemia in ECG and Holter recordings were improved (total effective rate, respectively 68.8% and 75%). Doppler echocardiography showed that 12 parameters of cardiac function were unchanged in both groups. No obvious side effect was found in those who took Andriol
Examination of the relation between periodontal health status and cardiovascular risk factors: serum total and high density lipoprotein cholesterol, C-reactive protein, and plasma fibrinogen.
Wu T, Trevisan M, Genco RJ, et al.
Am J Epidemiol. 2000 Feb 1; 151(3):273-82.
Using data from the Third National Health and Nutrition Examination Survey (1988-1994), the authors examined the relation between periodontal health and cardiovascular risk factors: serum total and high density lipoprotein cholesterol, C-reactive protein, and plasma fibrinogen. A total of 10,146 participants were included in the analyses of cholesterol and C-reactive protein and 4,461 in the analyses of fibrinogen. Periodontal health indicators included the gingival bleeding index, calculus index, and periodontal disease status (defined by pocket depth and attachment loss). While cholesterol and fibrinogen were analyzed as continuous variables, C-reactive protein was dichotomized into two levels. The results show a significant relation between indicators of poor periodontal status and increased C-reactive protein and fibrinogen. The association between periodontal status and total cholesterol level is much weaker. No consistent association between periodontal status and high density lipoprotein cholesterol was detectable. Similar patterns of association were observed for participants aged 17-54 years and those 55 years and older. In conclusion, this study suggests that total cholesterol, C-reactive protein, and fibrinogen are possible intermediate factors that may linkperiodontal disease to elevated cardiovascular risk
Erythrocyte selenium-glutathione peroxidase activity is lower in patients with coronary atherosclerosis.
Yegin A, Yegin H, Aliciguzel Y, et al.
Jpn Heart J. 1997 Nov; 38(6):793-8.
To obtain further insight into the role of erythrocyte antioxidant systems in the development of atherosclerosis, intraerythrocyte enzyme activities and selenium levels in erythrocytes were determined in 37 patients with angiographically proved coronary artery stenosis and 15 subjects with normal coronary angiograms as controls. In a preliminary study, the enzymatic activities of glucose-6-phosphate dehydrogenase (G6PD), glutathione reductase (GR) and selenium-dependent glutathione peroxidase (Se-GPx) were measured in both venous and arterial blood samples obtained from patients before angiography. The data of the preliminary study, which showed that only the Se-GPx decreased in the patients, led us to concentrate on the Se-GPx and Se levels to determine the changes in these variables. Our results showed that there was a decrease in both the activity of Se-GPx and Se levels in erythrocytes parallel to the increase in the severity of coronary artery disease. It was concluded that these parameters might be used as determinants in the assessment of the severity of the disease
Antioxidative activity of green tea polyphenol in cholesterol-fed rats.
Yokozawa T, Nakagawa T, Kitani K.
J Agric Food Chem. 2002 Jun 5; 50(12):3549-52.
This study investigated the effects of green tea polyphenol on the serum antioxidative activity and cholesterol levels of cholesterol-fed rats and compared them with those of probucol, an antioxidant hypocholesterolemic agent. To evaluate the antioxidative activity, the susceptibility to oxidative modification of low-density lipoprotein (LDL) isolated from the serum of cholesterol-fed rats was measured, as was the serum antioxidative activity using the spontaneous autoxidation system of brain homogenate. Administration of green tea polyphenol effectively inhibited LDL oxidation and elevated serum antioxidative activity to the same degree as probucol. However, higher amounts of polyphenol than probucol needed to be administered to reduce the total, free, and LDL cholesterol levels. Furthermore, green tea polyphenol increased the levels of high-density lipoprotein (HDL) cholesterol, leading to dose-dependent improvement of the atherogenic index, an effect that was not seen with probucol. Thus, green tea polyphenol may exert an antiatherosclerotic action by virtue of its antioxidant properties and by increasing HDL cholesterol levels
[Ginkgo--myth and reality].
Schweiz Rundsch Med Prax. 1995 Jan 3; 84(1):1-6.
Ginkgo biloba is one of the oldest, still existing plants. Extracts from its leaves were already used in ancient China whereas in the Western World, they have been utilized only since the Sixties when it became technically possible and feasible to isolate the essential substances of Ginkgo biloba. Pharmacologically, there are two groups of substances which are of some significance: the flavonoids, effective as oxygen-free radical scavengers, and the terpenes (i.e. the ginkgolides) with their highly specific action as platelet activating factor (PAF) inhibitors. Clinically important indications for Ginkgo biloba extracts are cerebral insufficiency and atherosclerotic disease of peripheral arteries of intermediate severity. In several placebo-controlled clinical studies, symptoms of cerebral insufficiency have been effectively and significantly influenced. Most of these investigations have examined the efficacy of Ginkgo biloba extracts such as EGb 761 and LI 1370
C-reactive protein-mediated low density lipoprotein uptake by macrophages: implications for atherosclerosis.
Zwaka TP, Hombach V, Torzewski J.
Circulation. 2001 Mar 6; 103(9):1194-7.
BACKGROUND: LDL and C-reactive protein (CRP) are important cardiovascular risk factors. Both LDL and CRP deposit in the arterial wall during atherogenesis. Stranded LDL is taken up by macrophages, causing foam cell formation. Because native LDL does not induce foam cell formation, we hypothesized that CRP may opsonize native LDL for macrophages. METHODS AND RESULTS: Monocytes were isolated from human blood and transformed into macrophages. CRP/LDL uptake was assessed by immunofluorescent labeling and the use of confocal laser scanning microscopy. Native LDL coincubated with CRP was taken up by macrophages by macropinocytosis. Uptake of the CRP/LDL coincubate was mediated by the CRP receptor CD32. CONCLUSIONS: We conclude that foam cell formation in human atherogenesis may be caused in part by uptake of CRP-opsonized native LDL