Fat distribution and metabolic changes are strongly correlated and energy expenditure is increased in the HIV lipodystrophy syndrome

Abstract

Objective: To examine the relationships between protease inhibitor (PI) therapy, body fat distribution and metabolic disturbances in the HIV lipodystrophy syndrome.

Design: Cross-sectional study.

Setting: HIV primary care practices.

Patients: PI-treated patients with lipodystrophy (n= 14) and PI-treated (n= 13) and PI-naive (n= 5) patients without lipodystrophy.

Main outcome measures: 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. Lipid profiles, other metabolic parameters, duration of HIV infection, CD4 lymphocyte counts, HIV-1 RNA load and resting energy expenditure (REE) were also assessed.

Results: PI-treated patients with lipodystrophy were significantly less insulin sensitive than PI-treated patients and PI-naive patients without any changes in fat distribution (SI(22) x 10(-4) (min(-1)/microU/ml) versus 3.2 x 10(-4) and 4.6 x 10(-4) (min(-1)/microU/ml), respectively; P < 0.001). Visceral adipose tissue area and other measures of central adiposity correlated strongly with metabolic disturbances as did the percent of total body fat present in the extremities; visceral adipose tissue was an independent predictor of insulin sensitivity and high density lipoprotein cholesterol levels. REE per kg lean body mass was significantly higher in the group with lipodystrophy compared to the groups without lipodystrophy (36.9 versus 31.5 and 29.4 kcal/kg lean body mass; P < 0.001), and SI was strongly correlated with and was an independent predictor of REE in this population.

Conclusions: Body fat distribution and metabolic disturbances are strongly correlated in the HIV lipodystrophy syndrome and REE is increased.