Changes in weight and lean body mass during highly active antiretroviral therapy.

BACKGROUND Few studies have prospectively evaluated the impact of highly active antiretroviral therapy (HAART) on body weight and lean body mass (LBM) or explored the impact of baseline immunologic or virological changes on these parameters. METHODS Adult AIDS Clinical Trials Group (ACTG) protocol 892 was a prospective, 48-week, multisite observational study of body composition conducted during 1997-2000 among 224 antiretroviral-naive and antiretroviral-experienced subjects coenrolled into various adult ACTG antiretroviral studies. Assessments included human immunodeficiency virus type 1 (HIV-1) RNA load (by polymerase chain reaction); T lymphocyte subset analysis; Karnofsky score; height (baseline only); weight, LBM, and fat (by bioelectrical impedance analysis); and functional performance (by questionnaire). RESULTS Overall, only modest median increases in body weight (1.9 kg) and LBM (0.6 kg) occurred after 16 weeks of therapy. Significantly greater median increases in body weight (2.1 vs. 0.5 kg; P=.045) occurred in subjects who achieved virological suppression (HIV-1 RNA load, <500 copies/mL) at week 16 than in subjects who did not. Subjects who were antiretroviral naive at baseline gained more weight (median increase in body weight, 2.6 vs. 0.0 kg; P<.001) and LBM (1.0 vs. 0.1 kg; P=.002) after 16 weeks of treatment than did subjects who were antiretroviral experienced. Subjects with lower baseline CD4 cell counts (<200 cells/mm3) and subjects with higher baseline HIV-1 RNA loads (> or =100,000 copies/mL) were more likely to show increases in LBM of >1.5 kg (P=.013 and P=.005, respectively). CONCLUSIONS HAART had modestly favorable effects on body composition, particularly in patients with greater pretreatment immunocompromise and virological compromise. The difference between antiretroviral-naive and antiretroviral-experienced subjects with regard to the ability to achieve increased body weight and LBM requires more study.