Independent associations of insulin resistance with high whole-body intermuscular and low leg subcutaneous adipose tissue distribution in obese HIV-infected women

Background: Obesity and insulin resistance are growing problems in HIV-positive (HIV+) women receiving highly active antiretroviral therapy (HAART). Objective: The objective was to determine the contribution of adipose tissue (AT) enlargement and distribution to the presence of insulin resistance in obese HIV+ women. Design: Whole-body intermuscular AT (IMAT), visceral AT (VAT), subcutaneous AT (SAT), and SAT distribution (leg versus upper body) were measured by whole-body magnetic resonance imaging. Insulin sensitivity (S _I) was measured with an intravenous glucose tolerance test in obese HIV+ women recruited because of their desire to lose weight (n = 17) and in obese healthy controls (n = 32). Results: The HIV+ womenhad relatively less whole-body SAT and more VAT and IMAT than did the controls (P < 0.05 for all). A significant interaction by HIV status was observed for the relation of total SAT with S_I (P < 0.001 for the regression's slope interactions after adjustment for age, height, and weight). However, relations of IMAT, VAT, and SAT distribution (leg SAT as a percentage of total SAT; leg SAT%) with SI did not differ significantly between groups. For both groups combined, the best model predicting a low S_I included significant contributions by both high IMAT and low leg SAT%, independent of age, height, and weight, and no interaction between groups was observed (overall r ² = 0.44, P = 0.0003). Conclusion: In obese HIV+ women, high whole-body IMAT and low leg SAT% distribution are independently associated with insulin resistance.