Life Extension Magazine May 2006
As We See It
Hidden Cardiac Risk Factors
By William Faloon
Despite significant advances in heart attack prevention over the past 35 years, cardiac disease remains the leading cause of death in the Western world.1
Conventional medical doctors routinely prescribe drugs that reduce potentially dangerous cholesterol and low-density lipoprotein (LDL) while sometimes boosting beneficial high-density lipoprotein (HDL). Although more people take cardiac drugs than ever before, hundreds of thousands of Americans still perish each year from heart failure while under a doctor’s care.
New members often ask us why their coronary arteries continue to narrow even when they have followed all the steps their cardiologist has prescribed. The answer is that atherosclerosis has multiple underlying causes. Unless every one of these risk factors is corrected, aging adults will continue to suffer epidemic levels of vascular diseases, including heart attack and stroke.
We at Life Extension long ago uncovered cardiac risks that mainstream doctors ignore. Recent scientific studies have validated that atherosclerosis is indeed a multifactorial process,2-5 and that taking aggressive preventive actions can dramatically reduce one’s chances of dying from cardiovascular disease.
Why Excess Fibrinogen Is So Dangerous
Fibrinogen, a protein produced by the liver, plays a role in the development of atherosclerotic plaque. Fibrinogen can also cause acute blood clot formation that may block a coronary artery (causing a heart attack) or a cerebral artery (causing an ischemic stroke).
Back in 1996, Life Extension published data indicating that high blood levels of fibrinogen predisposed people to heart attacks. In 2001, we reported on studies indicating that high levels of fibrinogen are also a significant risk factor for suffering a stroke.6-9
Numerous reports now link elevated fibrinogen to increased heart attack and stroke risk.10 One compelling study measured fibrinogen blood levels at baseline and then carefully tracked a large group of physicians over a period of several years.11 In physicians with fibrinogen levels higher than 343 (milligrams per deciliter of blood), heart attack risk doubled compared to physicians with a fibrinogen reading below this number.
Even after adjusting for other risk factors such as body mass index, diabetes, hypertension, alcohol consumption, and HDL there was an approximately twofold increase in heart attack risk among physicians with the higher fibrinogen levels. In the physician study subjects who were given 325 mg of aspirin every other day, heart attack rates were still twice as high in those with elevated fibrinogen (though aspirin did reduce heart attack incidence across all fibrinogen ranges). Study subjects who did not take aspirin and had higher fibrinogen levels had a startling 3.6-fold increase in heart attack incidence.11
The scientists who conducted this study stated that fibrinogen “appears to be an independent risk factor for cardiovascular disease.”11 This means that even if you control all other cardiac risk factors, if your fibrinogen level is over 343 mg/dL, this by itself could cause you to suffer a heart attack.
Elevated fibrinogen is not only a powerful predictor of who will develop coronary artery disease. A brand-new study shows that high fibrinogen foretells who is likely to die within 42 months of suffering a heart attack. According to the scientists who conducted this 2006 study, “fibrinogen levels were the only independent predictor of mortality...”12
Despite all of this scientific evidence, few doctors today bother to check their patients’ blood levels of fibrinogen. This may start to change.
Fibrinogen Finally Gets Mainstream Respect
The October 28, 2005, issue of the Journal of the American Medical Association contains an evaluation of pooled human data on fibrinogen and various diseases. A total of 154,211 study subjects were analyzed. Based on age and sex alone, the findings show that for each 100-mg/dL increase in fibrinogen over the initial baseline level, there was a 2.4-fold greater likelihood of contracting coronary heart disease.13
After adjusting for other risk factors such as diabetes, blood pressure, body mass index, and LDL, the coronary heart disease risk was 1.8-fold greater for each 100-mg/dL increase in fibrinogen levels.13 These findings corroborate previous studies suggesting that fibrinogen is a significant risk factor for heart attack and stroke!14-21
In those with fibrinogen in-creases of 100-mg/dL over baseline, deaths from cancers of the digestive tract, smoking-related cancers, and hormone-related cancers were also greater.13
What These Studies Tell Us
In the United States, fibrinogen is typically measured in milligrams per deciliter (mg/dL) of blood. Today’s standard laboratory reference range for fibrinogen is 193-423 mg/dL. Thus, according to conventional standards, fibrinogen levels as high as 423 mg/dL are acceptable.
Previous studies have indicated higher risks of heart attack, stroke, and other vascular diseases as fibrinogen levels rise above 300 mg/dL.22-26
The doctors who authored this study published in the American Medical Association’s own journal found that regardless of one’s fibrinogen level at baseline (levels evaluated at baseline were between 250 and 562 mg/dL), any increase of 100 mg/dL over baseline is associated with a significantly increased risk of heart attack, stroke, other vascular diseases, and cancer.13
Based on data from dozens of published studies, it would appear that aging adults should strive for a fibrinogen level of 200-300 mg/dL.