Adipocyte-derived hormone levels in HIV lipodystrophy

Abstract

Objective: Despite evidence for the role of adipocyte-derived hormones in insulin resistance, little is known about their levels in human lipodystrophic states. We examined the relationships of plasma leptin and adiponectin levels to fat distribution and insulin sensitivity in the HIV lipodystrophy syndrome. Design: Cross-sectional study. Setting: HIV primary care practices. Patients: HIV-infected men with (n=13) and without (12) lipodystrophy and healthy uninfected controls (12). Main outcome measures: Plasma adiponectin and leptin levels were measured in the fasting state. Body composition was assessed by physical examination, dual-energy x-ray absorptiometry and computed tomography. Insulin sensitivity (SI) was measured using the insulin-modified frequently sampled intravenous glucose tolerance test. Results: Leptin levels were significantly higher in HIV-infected men with lipodystrophy as compared to HIV-infected controls (5.2 vs 3.0 ng/ml, P=0.01). Across the entire study population, leptin levels were positively correlated with measures of general adiposity. In the HIV-infected patients, leptin levels were negatively correlated with SI after adjustment for fat mass (r=-0.38, P=0.07). Adiponectin levels were significantly lower in HIV-infected men with lipodystrophy as compared to both HIV-infected and healthy controls (1.6 vs 3.4 μg/ml, P<0.05 and 1.6 vs 6.7 μg/ml, P<0.001, respectively). Adiponectin levels, after adjustment for fat mass, were correlated with measures of fat distribution. Finally, in the HIV-infected patients, adiponectin levels were significantly and positively correlated with SI after adjustment for fat mass (r=0.75, P≤0.001), and adiponectin level was also an independent determinant of SI. Conclusions: Plasma leptin and adiponectin levels are altered in the HIV lipodystrophy syndrome. Adiponectin deficiency may play a role in the insulin resistance associated with HIV lipodystrophy.