Studies of body composition and fat distribution in HIV-infected and control subjects

Objective: Recent studies have documented alterations in body fat distribution that have been associated with protease inhibitor therapy. We compared body composition, including measurements of fat distribution, in 96 HIV-infected subjects studied since January 1996 (current HIV), subjects seen prior to January 1996 (previous HIV), and healthy controls. Design: Retrospective cross-sectional studies of subjects matched by gender, race, age, and height. Methods: Body weight, height, body cell mass by whale-body counting of K-40 plus fat, fat-free mass, and body fat distribution by anthropometry were measured. Results: Current HIV men weighed more (p = .025) and had more body cell mass than previous HN men, but less than controls (p < .001). In women, the between group differences in fat were greater than the differences in body cell mass. Current and previous HIV study subjects had lower indices of subcutaneous and higher indices of visceral fat than controls. In current HIV subjects, body fat distribution was significantly associated with log plasma HIV RNA content but not with antiretroviral or protease inhibitor usage, nor with CD4(+) lymphocyte counts. In 7 of 9 current HIV subjects studied, 24-hour urinary free cortisol excretion was abnormally high. Conclusions: Alterations in body fat distribution are a characteristic feature in HIV infection. The occurrence of increased visceral fat content and decreased subcutaneous fat content preceded the era of combination antiretroviral therapy. The alteration in fat distribution may be affected by plasma HIV RNA content rather than antiretroviral or protease-inhibitor therapy. The body composition alterations might be associated with endogenous hypercortisolism.