Blood donations and risk of coronary heart disease in men

Background-In experimental animals, iron overload appears to promote athero sclerosis and ischemic myocardial damage, but the results of epidemiologica l studies that relate iron stores to risk of coronary heart disease (CHD) h ave been inconsistent. Methods and Results-We prospectively studied blood donations, which effecti vely reduce body iron stores, in relation to the risk of CHD among particip ants in the Health Professionals Follow-up Study. The lifetime history of b lood donation was assessed with a questionnaire in 1992. The 38 244 men who were free of diagnosed cardiovascular disease at that time were included i n the analyses. During 4 years of follow-up, we documented 328 nonfatal myo cardial infarctions and 131 coronary deaths. Although the number of lifetim e blood donations was strongly associated with lower plasma ferritin levels in a subsample, the blood donation was not associated with risk of myocard ial infarction or fatal CHD. The age-adjusted relative risk (RR) of myocard ial infarction for men in the highest category of blood donations (greater than or equal to 30) compared with never donors was 1.2 (95% CI 0.8 to 1.8) , and this RR was not materially changed after adjustment for several coron ary risk factors. No significant associations were found between blood dona tion and the risk of myocardial infarction in analyses restricted to men wi th hypercholesterolemia or those who never used antioxidant supplements or aspirin. Conclusions-The study results do not support the hypothesis that reduced bo dy iron stores lower CHD risk.