A Prospective Study of Vitamin E and Coronary Heart Disease Among Men:
Is benefit restricted only to Primary Prevention?
A growing body of evidence suggests that oxidative modification of LDL-cholesterol is important in the early development of atherosclerotic lesions. Although past observational epidemiologic evidence suggests CHD benefit for long term vitamin E supplement use, two recent large secondary prevention trials have not found a lower risk of CVD among patients randomized to vitamin E. Data comparing the benefits of vitmain E between populations with and without prior CVD have not been adequately explored. We examined prospectively the association between vitamin E supplements (>100 IU/day for 2 or more years) and risk of coronary heart disease among 38,884 U.S. male health professionals, 40 to 75 years of age at baseline (1986) and who were free of diagnosed CVD, diabetes, and cancer. During ten years of follow-up, we documented 1145 incident cases of fatal and non-fatal myocardial infarction (MI). After controlling for several known coronary risk factors, we observed a lower risk of coronary disease among men with use of vitamin E supplements. As compared with men who did not take vitamin E supplements, men who took at least 100 IU per day for at least two years had a multivariate relative risk of MI of 0.78 (95 percent confidence interval, 0.65 to 0.95). The benefits of vitamin E were substantially greater among populations free of CVD-related conditions. Among men without self-reported physician-diagnosed hypercholesterolmia, the RR of MI for vitamin E was 0.74 (95% CI 0.60,0.93). Men with hypercholesterolemia did not show appreciable benefit from vitamin E (RR=0.93;95% CI 0.63, 1.37). Men without hypertension had a lower risk of MI associated with vitamin E use (RR=0.74;95% CI 0.58, 0.94) than men with hypertension (RR=0.88;95% CI0.63, 1.22). Men free of either condition showed a significantly greater benefit from taking vitamin E (RR=0.71; 95% CI 0.54, 0.92) than men with either of these two conditions (RR=0.88; 0.67, 1.17). These data suggest a reduced risk of CHD for long term vitamin E supplement use among an otherwise healthy population and are consistent with the recent null findings from secondary prevention trials.