Visceral obesity is associated with
insulin resistance, but the association of other regional adipose depots with
insulin resistance is not understood. In
HIV infection, buffalo hump (upper trunk fat) is associated, but the association of upper trunk fat with
insulin resistance has not been examined in controls. To determine the independent association of adipose depots other than visceral with
insulin resistance, we performed a cross-sectional analysis of controls and HIV-infected subjects in the Fat Redistribution and Metabolic Change in
HIV Infection (FRAM) study, who had measurements of
glucose,
insulin, and adipose tissue volumes by whole-body magnetic resonance imaging. We studied 926 HIV-positive persons from 16 academic medical center clinics and trials units with demographic characteristics representative of US patients with
HIV infection and 258 FRAM controls from the population-based Coronary Artery Risk Development in Young Adults study. We measured visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) volume in the legs, arms, lower trunk (back and abdomen), and upper trunk (back and chest) and assessed their association with the homeostasis model of assessment (HOMA) and HOMA >4 by stepwise multivariable analysis. The prevalence of HOMA >4 as a marker of
insulin resistance was 28% among controls compared with 37% among HIV-infected subjects (P = 0.005). Among controls, those in the highest tertile of upper trunk SAT volume had an odds ratio (OR) of 9.0 (95% confidence interval [CI]: 2.4 to 34; P = 0.001) for having HOMA >4 compared with the lowest tertile, whereas in HIV-positive subjects, the OR was lower (OR = 2.09, 95% CI: 1.36 to 3.19; P = 0.001). Among controls, the highest tertile of VAT volume had an OR of 12.1 (95% CI: 3.2 to 46; P = 0.0002) of having HOMA >4 compared with the lowest tertile, whereas in HIV-positive subjects, the OR was 3.12 (95% CI: 2.0 to 4.8; P < 0.0001). After adjusting for VAT and upper trunk SAT, the association of other SAT depots with HOMA >4 did not reach statistical significance. Thus, VAT and upper trunk SAT are independently associated with
insulin resistance in controls and in HIV-infected persons.