Life Extension Magazine

Life Extension Magazine August 2007

Abstracts

Oral health

Periodontal infections and cardiovascular disease: the heart of the matter.

BACKGROUND: Oral infection models have emerged as useful tools to study the hypothesis that infection is a cardiovascular disease (CVD) risk factor. Periodontal infections are a leading culprit, with studies reporting associations between periodontal disease and CVD. The results, however, have varied, and it often is unclear what conclusions can be drawn from these data. SUMMARY: An association exists between periodontal disease and CVD. It is unknown, however, whether this relationship is causal or coincidental. Early studies predominantly used nonspecific clinical and radiographic definitions of periodontal disease as surrogates for infectious exposure. While most studies demonstrated positive associations between periodontal disease and CVD, not all studies were positive, and substantial variations in results were evident. More recent studies have enhanced the specificity of infectious exposure definitions by measuring systemic antibodies to selected periodontal pathogens or by directly measuring and quantifying oral microbiota from subgingival dental plaque. Results from these studies have shown positive associations between periodontal disease and CVD. CONCLUSIONS: Evidence continues to support an association among periodontal infections, atherosclerosis and vascular disease. Ongoing observational and focused pilot intervention studies may inform the design of large-scale clinical intervention studies. Recommending periodontal treatment for the prevention of atherosclerotic CVD is not warranted based on scientific evidence. Periodontal treatment must be recommended on the basis of the value of its benefits for the oral health of patients, recognizing that patients are not healthy without good oral health. However, the emergence of periodontal infections as a potential risk factor for CVD is leading to a convergence in oral and medical care that can only benefit the patients and public health.

J Am Dent Assoc. 2006 Oct;137 Suppl:14S-20S

Bone health and oral health.

BACKGROUND: Low bone mass in the skeleton, which increases the risk of osteoporotic fracture, also may be associated with periodontal bone loss and tooth loss. Osteoporosis and periodontal disease share several common risk factors, including older age, smoking and perhaps insufficient dietary intakes of calcium and vitamin D. CONCLUSION: Research supports the idea that osteoporosis independently influences alveolar bone height loss. Strategies for reducing osteoporosis risk also may help retard alveolar bone loss. Meeting dietary intake recommendations for calcium and vitamin D is one strategy that is appropriate for a broad segment of the population. CLINICAL IMPLICATIONS: A healthy lifestyle has multiple benefits for the mouth and throughout the body. Dental professionals can play a role in preventing osteoporosis by reinforcing this message.

J Am Dent Assoc. 2007 May;138(5):616-9

Professional oral health care by dental hygienists reduced respiratory infections in elderly persons requiring nursing care.

OBJECTIVES: Respiratory infection is a major cause of death in the elderly. We have evaluated the role of professional oral health care (POHC) by dental hygienists in reducing respiratory infections in elderly persons requiring nursing care. METHODS: Two populations of elderly persons, one receiving POHC and one not, were examined to determine numbers of microorganisms, potent pathogens of respiratory infection, enzymatic activity in saliva, fevers, prevalence of fatal aspiration pneumonia and prevalence of influenza. RESULTS: In the first population, we found a high prevalence of potent respiratory pathogens such as Staphylococcus species, Pseudomonas aeruginosa and Candida albicans. Patients who received POHC showed a lower prevalence for these pathogens than those who did not. The ratio of fatal aspiration pneumonia in POHC patients was significantly lower than that in patients without POHC (non-POHC) over a 24-month period (P < 0.05). The prevalence of a fever of 37.8 degrees C or more in POHC patients was significantly lower than that in the non-POHC group (P < 0.05). In the second study population, we investigated the effects of POHC on infection with influenza over a 6-month period. In the POHC group, neuraminidase and trypsin-like protease activities decreased, and one of 98 patients was diagnosed with influenza; whereas, in the non-POHC group, nine of 92 patients were diagnosed with influenza. The relative risk of developing influenza while under POHC was 0.1 (95% CI 0.01-0.81, P = 0.008). CONCLUSION: These results suggest that POHC by dental hygienists is effective in preventing respiratory infections in elderly persons requiring nursing care.

Int J Dent Hyg. 2007 May;5(2):69-74

Punica granatum (pomegranate) extract is active against dental plaque.

In the present work, we studied the effect of the hydroalcoholic extract (HAE) from Punica granatum (pomegranate) fruits on dental plaque microorganisms. The study was conducted on 60 healthy patients (33 females and 27 males, with age ranging from 9 to 25 years) using fixed orthodontic appliances, and randomly distributed into 3 groups of 20 patients each. The first group (control) used distilled water, while the second and third groups used chlorhexidine (standard) and HAE as mouth-rinses, respectively. The dental plaque material was collected from each patient, before and after a 1-min mouth-rinse with 15 ml of either distilled water, chlorhexidine or HAE. In both dental plaque collections, the material was removed from patients without oral hygiene, for 24 h (no tooth brushing). Dental plaque samples were diluted in phosphate buffered saline (PBS) plated on Mueller-Hinton agar, and incubated for 48 h, at 37 degrees C. Results, expressed as the number of colony forming units per milliliter (CFU/mL), show that the HAE was very effective against dental plaque microorganisms, decreasing the CFU/ml by 84% (CFU x 10(5)), before mouth-rinse: 154.0 +/- 41.18; after mouthrinse: 25.4 +/- 7.76). While similar values were observed with chlorhexidine, used as standard and positive control (79% inhibition), only an 11% inhibition of CFU/ml was demonstrated in the distilled water group, negative control (CFU x 10(5)), before mouth-rinse: chlorhexidine, 208.7 +/- 58.81 and distilled water, 81.1 +/- 10.12; after mouth-rinse: chlorhexidine, 44.0 +/- 15.85 and distilled water, 71.9 +/- 8.68). The HAE presented also an antibacterial activity against selected microorganisms, and may be a possible alternative for the treatment of dental plaque bacteria.

J Herb Pharmacother. 2006;6(2):79-92

Dental plaque formation and salivary mutans streptococci in schoolchildren after use of xylitol-containing chewing gum.

OBJECTIVE: The aim of this study was to investigate the effect of a fixed daily dose of xylitol on mutans streptococci in saliva and the amount of visible dental plaque. A second aim was to explore if the possible effects differed between children with and without caries experience. METHODS: The study was designed as a double-blind randomized controlled trial with two parallel arms. All pupils (n=149) in grades 1-6 in a comprehensive school in northern Sweden were invited, and 128 children (mean age=12.7 years) consented to participate. The children were stratified as having caries experience (DMFS/dmfs>or=1) or not before the random allocation to a test or control group. The control group (A) was given two pellets containing sorbitol and maltitol three times daily for 4 weeks, and the test group (B) received corresponding pellets with xylitol as single sweetener (total dose=6.18 g day). Clinical scoring and saliva samples were collected at baseline and immediately after the test period. The outcome measures were visible plaque index, salivary mutans streptococci counts and salivary lactic acid production. RESULTS: The amount of visible plaque was significantly reduced in both groups after 4 weeks (P<0.05). Likewise, the sucrose-induced lactic acid formation in saliva diminished in both groups (P<0.05). The proportion of mutans streptococci decreased significantly in the test group compared to baseline, but not in the control group (P<0.05). The alterations in the test group seemed most prominent among children without previous caries experience. CONCLUSIONS: The results suggest that chewing gum with xylitol or sorbitol/maltitol can reduce the amount of dental plaque and acid production in saliva in schoolchildren, but only the xylitol-containing gum may also interfere with the microbial composition.

Int J Paediatr Dent. 2007 Mar;17(2):79-85

Periodontal disease—the emergence of a risk for systemic conditions: pre-term low birth weight.

This paper addresses the problem of adverse pregnancy outcome in relation to periodontal disease. There is compelling evidence that a link exists between pre-term low birth weight (PLBW) and periodontitis. Although 25% to 50% of PLBW deliveries occur without any known aetiology, there is increasing evidence that infection may play a significant role in pre-term delivery. A model explaining the plausible relationship is proposed based upon the concept of infection leading to a cascade of inflammatory reactions associated with pre-term labour and periodontal disease. Current evidence has pointed to an interest in dental intervention studies to control periodontal disease as one of the potential strategies to reduce pre-term labour. This paper reviews the potential association between periodontal infection and adverse pregnancy outcomes.

Ann Acad Med Singapore. 2005 Jan;34(1):111-6

Periodontal disease and mortality in type 2 diabetes.

OBJECTIVE: Periodontal disease may contribute to the increased mortality associated with diabetes. RESEARCH DESIGN AND METHODS: In a prospective longitudinal study of 628 subjects aged > or =35 years, we examined the effect of periodontal disease on overall and cardiovascular disease mortality in Pima Indians with type 2 diabetes. Periodontal abnormality was classified as no or mild, moderate, and severe, based on panoramic radiographs and clinical dental examinations. RESULTS: During a median follow-up of 11 years (range 0.3-16), 204 subjects died. The age- and sex-adjusted death rates for all natural causes expressed as the number of deaths per 1,000 person-years of follow-up were 3.7 (95% CI 0.7-6.6) for no or mild periodontal disease, 19.6 (10.7-28.5) for moderate periodontal disease, and 28.4 (22.3-34.6) for severe periodontal disease. Periodontal disease predicted deaths from ischemic heart disease (IHD) (P trend = 0.04) and diabetic nephropathy (P trend < 0.01). Death rates from other causes were not associated with periodontal disease. After adjustment for age, sex, duration of diabetes, HbA1c, macroalbuminuria, BMI, serum cholesterol concentration, hypertension, electrocardiographic abnormalities, and current smoking in a proportional hazards model, subjects with severe periodontal disease had 3.2 times the risk (95% CI 1.1-9.3) of cardiorenal mortality (IHD and diabetic nephropathy combined) compared with the reference group (no or mild periodontal disease and moderate periodontal disease combined). CONCLUSIONS: Periodontal disease is a strong predictor of mortality from IHD and diabetic nephropathy in Pima Indians with type 2 diabetes. The effect of periodontal disease is in addition to the effects of traditional risk factors for these diseases.

Diabetes Care. 2005 Jan;28(1):27-32

The prevalence of inflammatory periodontitis is negatively associated with serum antioxidant concentrations.

Chronic periodontitis is an inflammatory disease that affects the supporting tissues of the teeth. It is initiated by specific bacteria within the plaque biofilm and progresses due to an abnormal inflammatory-immune response to those bacteria. Periodontitis is the major cause of tooth loss and is also significantly associated with an increased risk of stroke, type-2 diabetes and atheromatous heart disease. Oxidative stress is reported in periodontitis both locally and peripherally (serum), providing potential mechanistic links between periodontitis and systemic inflammatory diseases. It is therefore important to examine serum antioxidant concentrations in periodontal health/disease, both at an individual species and total antioxidant (TAOC) level. To determine whether serum antioxidant concentrations were associated with altered relative risk for periodontitis, we used multiple logistic regression for dual case definitions (both mild and severe disease) of periodontitis in an analysis of 11,480 NHANES III adult participants (>20 y of age). Serum concentrations of vitamin C, bilirubin, and TAOC were inversely associated with periodontitis, the association being stronger in severe disease. Vitamin C and TAOC remained protective in never-smokers. Higher serum antioxidant concentrations were associated with lower odds ratios for severe periodontitis of 0.53 (CI, 0.42,0.68) for vitamin C, 0.65 (0.49,0.93) for bilirubin, and 0.63 (0.47,0.85) for TAOC. In the subpopulation of never-smokers, the protective effect was more pronounced: 0.38 (0.26,0.63, vitamin C) and 0.55 (0.33,0.93, TAOC). Increased serum antioxidant concentrations are associated with a reduced relative risk of periodontitis even in never-smokers.

J Nutr. 2007 Mar;137(3):657-64

Resolution of inflammation: a new paradigm for the pathogenesis of periodontal diseases.

The periodontal diseases are infectious diseases caused by predominantly Gram-negative bacteria. However, as our understanding of the pathogenesis of the periodontal diseases grows, it is becoming clear that most of the tissue damage that characterizes periodontal disease is caused by the host response to infection, not by the infectious agent directly. Investigation into the mechanism of action of host-mediated tissue injury has revealed that the neutrophil plays an important role in destruction of host tissues. In this paper, we review the biochemical pathways and molecular mediators that are responsible for regulation of the inflammatory response in diseases such as periodontitis, with a focus on lipid mediators of inflammation. Pro-inflammatory mediators, such as prostaglandins and leukotrienes, are balanced by counter-regulatory signals provided by a class of molecules called lipoxins. The role of lipoxins in the control and resolution of inflammation is discussed, as is the possibility of the development of new therapeutic strategies for the control and prevention of neutrophil-mediated tissue injury in inflammatory diseases like periodontitis.

J Dent Res. 2003 Feb;82(2):82-90

The effect of infections and vaccinations on stroke risk.

There is increasing evidence that, in addition to conventional risk factors, acute and chronic infectious diseases increase the risk of stroke. Acute infection, mainly respiratory, and both bacterial and viral infection, represent temporarily active trigger factors for cerebral ischemia. Chronic infectious diseases that may increase the risk of stroke include periodontitis, chronic bronchitis and infections with microbial antigens, such as Helicobacter pylori and Chlamydia pneumoniae. From observational studies, there is evidence that vaccination against influenza is associated with a reduced risk of stroke, myocardial infarction and all-cause mortality. This report provides an overview on the influence of infection on stroke risk and potential anti-infective strategies that may play a future role in stroke prevention.

Expert Rev Neurother. 2006 Feb;6(2):175-83