RELATIONSHIP OF INSULIN-RESISTANCE TO WEIGHT-GAIN IN NONDIABETIC ASIAN INDIAN, CREOLE, AND CHINESE MAURITIANS

There is evidence from animal models that postprandial insulin hyperse cretion may precede the development of obesity and insulin resistance, but it is not clear if this is the case in humans. Recently, two long itudinal studies have suggested that insulin resistance acts to limit further weight gain rather than to promote it. The relationship of mar kers of insulin sensitivity and secretion to changes in weight and the waist to hip ratio (WHR) was therefore examined in nondiabetic Asian Indian (n = 2,169), Creole (n = 798), and Chinese (n = 189) Mauritians over a 5-year follow-up period. Younger age and lower initial body ma ss index (BMI) were consistent independent predictors of increase in w eight in all sex-ethnic subgroups, and older age, higher BMI, and lowe r WHR were associated with change in WHR. Insulin sensitivity was asse ssed by homeostatic model assessment (HOMAS), as well as by fasting in sulin and the ratio of fasting insulin to glucose. Insulin resistance predicted weight gain in Chinese men independently of baseline age and BMI. In Asian Indian and Creole men and women, these correlations wer e in the opposite direction (ie, insulin sensitivity predicted weight gain) but became nonsignificant when age and BMI were controlled. Ther e was little relationship of insulin resistance/sensitivity to the cha nge in WHR once baseline BMI was controlled. These data provide sugges tive but not convincing evidence that insulin resistance may limit wei ght gain, and contradictory evidence in one ethnic group that insulin resistance promotes weight gain. (C) 1996 by W.B. Saunders Company.