HYPERINSULINEMIA AS AN INDEPENDENT RISK FACTOR FOR ISCHEMIC-HEART-DISEASE

Background. Prospective studies suggest that hyperinsulinemia may be a n important risk factor for ischemic heart disease. However, it has no t been determined whether plasma insulin levels are independently rela ted to ischemic heart disease after adjustment for other risk factors, including plasma lipoprotein levels. Methods. In 1985 we collected bl ood samples from 2103 men from suburbs of Quebec City, Canada, who wer e 45 to 75 years of age and who did not have ischemic heart disease. A first ischemic event (angina pectoris, acute myocardial infarction, o r death from coronary heart disease) occurred in 114 men (case patient s) between 1985 and 1990. Each case patient was matched for age, body- mass index, smoking habits, and alcohol consumption with a control sel ected from among the 1989 men who remained free of ischemic heart dise ase during follow-up. After excluding men with diabetes, we compared f asting plasma insulin and lipoprotein concentrations at base line in 9 1 case patients and 105 controls. Results. Pasting insulin concentrati ons at base line were 18 percent higher in the case patients than in t he controls (P<0.001). Logistic-regression analysis showed that the in sulin concentration remained associated with ischemic heart disease (o dds ratio for ischemic heart disease with each increase of 1 SD in the insulin concentration, 1.7; 95 percent confidence interval, 1.3 to 2. 4) after adjustment for systolic blood pressure, use of medications, a nd family history of ischemic heart disease. Further adjustment by mul tivariate analysis for plasma triglyceride, apolipoprotein B, low-dens ity lipoprotein cholesterol, and high-density lipoprotein cholesterol concentrations did not significantly diminish the association between the insulin concentration and the risk of ischemic heart disease (odds ratio, 1.6; 95 percent confidence interval, 1.1 to 2.3). Conclusions. High fasting insulin concentrations appear to be an independent predi ctor of ischemic heart disease in men. (C) 1996, Massachusetts Medical Society.