LOW INSULIN SENSITIVITY IS ASSOCIATED WITH CLUSTERING OF CARDIOVASCULAR-DISEASE RISK-FACTORS

Hyperinsulinemia is associated with multiple metabolic disorders inclu ding high triglyceride level, low high density lipoprotein (HDL) chole sterol level, hypertension, and impaired glucose tolerance (IGT). This metabolic constellation is also called the insulin resistance syndrom e. All previous data on clustering of these risk factors are, however, based on insulin levels. Therefore, the authors examined the associat ion of insulin sensitivity estimated by means of a frequently sampled intravenous glucose tolerance test and the minimal model with the numb er of metabolic disorders (dyslipidemia [high triglyceride level or lo w HDL cholesterol level or both], hypertension, and IGT according to t he World Health Organization criteria). Of 153 nondiabetic subjects ag ed 53-61 years who had participated in a previous population-based stu dy, 79 had no disorders, 55 had one disorder, 16 had two disorders, an d 3 had three disorders. Insulin sensitivity index (S-1) decreased wit h the increasing number of disorders (4.1, 3.5, 1.8, and 1,4 x 10(-4) min(-1) mu U-1 mL(-1), in subjects with 0, 1, 2, and 3 disorders, resp ectively; p < 0.001 for trend). Similarly, fasting (7.5, 7.8, 15.3, an d 22.0 mu U/mL; p < 0.001) and 2-hour insulin levels (39.9, 49.0, 98.7 , and 149.6 mu U/mL; p < 0.001) increased by the increasing number of disorders. The relations of S, and fasting and 2-hour insulin levels w ith multiple metabolic disorders were independent of sex, obesity, and body fat distribution, Furthermore, these associations were similar i n men and women and in lean and obese subjects. The authors conclude t hat a clustering of cardiovascular disease risk factors in nondiabetic subjects is not only associated with hyperinsulinemia but also with i nsulin resistance.