FASTING HYPERINSULINEMIA AND CARDIOVASCULAR-DISEASE RISK-FACTORS IN NONDIABETIC ADULTS - STRONGER ASSOCIATIONS IN LEAN VERSUS OBESE SUBJECTS

The association between hyperinsulinemia and atherogenic risk factors has not been well studied in blacks and may be different for obese versus lean individuals. To investigate this possibility and to confirm the associations of hyperinsulinemia with cardiovascular disease risk factors in blacks and whites, we analyzed the joint associations of fasting serum insulin and obesity with risk factors in the Atherosclerosis Risk in Communities (ARIC) Study (1,293 black men, 4,797 white men, 2,033 black women, and 5,445 white women). Insulin values greater than or equal to 90th percentile (greater than or equal to 21 mu U/mL) constituted hyperinsulinemia; body mass index (BMI) values greater than or equal to 27.3 kg/m(2) for women and greater than or equal to 27.8 for men constituted obesity. Participants with hyperinsulinemia in all four race-sex groups had more atherogenic levers of most risk factors studied than those with normoinsulinemia. Among black men and women, mean levels of triglycerides, low-density lipoprotein cholesterol (LDL-C), apolipoprotein (apo) B, glucose, and fibrinogen (men only) were higher in hyperinsulinemic lean participants as compared with the normoinsulinemic obese group. Furthermore, most associations between insulin level and risk factors were stronger among lean versus obese subjects. For example, among lean black men, the difference in mean triglyceride concentration between those with hyperinsulinemia and those with normoinsulinemia was 147 - 99 = 48 mg/dL; among obese black men, the difference was 155 - 121 = 34 mg/dL (P < .05 for the interaction). Generally, similar negative interactions between BMI and insulin concentration were also observed among whites. We conclude that the association between hyperinsulinemia and many atherogenic risk factors holds for both blacks and whites and is stronger among lean versus obese adults. Copyright (C) 1995 by W.B. Saunders Company