Body-composition measurements as predictors of glucose and insulin abnormalities in HIV-positive men

Background: Fat redistribution and metabolic abnormalities are seen increasingly in HIV-positive patients. However, the degree to which abnormalities in fat distribution predict glucose and insulin concentrations in these patients remains unknown. Objective: We determined how well measurements of fat distribution derived from anthropometry, dual-energy X-ray absorptiometry, and computed tomography predicted hyperinsulinemia in HIV-positive men. Design: Body-composition data were analyzed in 41 HIV-positive men (21 with fat redistribution and 20 without) and 20 HIV-negative control subjects matched for age and body mass index (BMI). Multivariate modeling was performed to determine the effects of body composition on fasting insulin and insulin area under the curve (AUC) during standard glucose tolerance testing. Results: WHR was superior to other body-composition measures in predicting fasting hyperinsulinemia and was a strong predictor of insulin AUC in HIV-positive men. Fasting insulin increased by 77.4 pmol/L for each 0.1-unit change in WHR (95% CI: 18.6, 136.1; P = 0.011), overall r(2) = 0.415 in a model also including age, BMI, and protease inhibitor use. Measures of intraabdominal and subcutaneous fat did not predict fasting hyperinsulinemia but were independent predictors of insulin AUC in multivariate modeling. The ratio of visceral to subcutaneous abdominal fat predicted the largest degree of variance in insulin AUC. Conclusions: Fat redistribution contributes to hyperinsulinemia in HIV-positive men, independent of BMI and protease inhibitor use. WHR is an integrated index of body-composition changes and strongly predicts both fasting hyperinsulinemia and insulin AUC in HIV-positive men.