Fat distribution is strongly tied to metabolic disturbances in HIV lipodystrophy

In HIV-infected patients with lipodystrophy, body fat distribution is strongly associated with the metabolic disturbances that accompany this disorder, according to a recent report. In addition, resting energy expenditure (REE) is increased in these patients.

Dr Lisa A. Kosmiski, from the University of Colorado Health Sciences Center in Denver, and colleagues assessed the body fat composition, metabolic profile, and REE of 32 HIV-infected patients. The study group included 14 protease inhibitor (PI)-treated patients with lipodystrophy, 13 PI-treated patients without lipodystrophy, and 5 PI-naïve patients without lipodystrophy.

Lipodystrophy patients were significantly less sensitive to insulin than other patients, the authors note. Among patients without lipodystrophy, PI-treated patients tended to be less insulin sensitive than PI-naïve subjects.

In lipodystrophy patients, measures of central obesity correlated strongly with metabolic disturbances. The percent of total body fat present in extremities also correlated strongly with metabolic changes, but it appeared to be protective against metabolic abnormalities.

Multivariate analysis revealed that the amount of visceral adipose tissue independently predicted insulin sensitivity and HDL-cholesterol levels, the investigators state in the October 19th issue of AIDS.

REE was significantly higher in the lipodystrophy group than in the other groups, the researchers state. In addition, insulin sensitivity was a strong independent predictor of REE in the lipodystrophy patients.

In a related editorial, Dr David Nolan and Dr Simon Mallal from the Royal Perth Hospital in Western Australia comment that -there is now abundant evidence that HIV PIs as a class make a powerful independent contribution to the ‘metabolic syndrome’ that accompanies the long-term use of highly active antiretroviral therapy regimens. –

Drs Nolan and Mallal note that the current findings -move us one step closer to elucidating the proximal pathogenic mechanisms of the metabolic syndrome induced by the PI class, which in turn will clarify the relationship between nucleoside analogue reverse transcriptase inhibitors and PIs in the pathogenesis of the lipodystrophy syndrome as a whole. –