Iron-Binding Capacit as a Risk Factor for Myocardial Infarction

Background In a recent Finnish study, ferritin was suggested to be an independent risk factor for acute myocardial infarction. This study suggested that high levels of iron stores might thus be atherogenic and possibly explain partly the sex difference in the incidence of ischemic heart disease. Methods and Results A randomly selected group (n=2036), men and women aged 25 to 74 years, were examined between June and September 1983. All classic risk factors for coronary artery disease were measured as well as basic hematologic parameters and the parameters of iron metabolism, ie, iron, total iron-binding capacity (TIBC), and ferritin. During the follow-up for 8.5 years, 81 subjects experienced acute myocardial infarction (63 men and 18 women). The differences in the iron parameters between men and women were almost exclusively seen in ferritin values (198 ug/L in men and 91 ,ug/L in women), whereas small differences were seen in TIBC. The Cox proportional hazards model was used to estimate the contribution of independent variables to the risk of myocardial infarction. TIBC was found to be a strong independent negative risk factor in men (RR=0.95; 95% CI, 0.92 to 0.98),