Lean Tissue Mass And Fat Mass Changes In HIV-infected Persons Following Moderate Intensity Exercise Training

Abstract

BACKGROUND HIV-infected persons experience decreases in lean tissue mass (LTM), which are associated with increased morbidity and mortality. Persons infected with HIV also experience lipodystrophy, which is a combination of fat accumulation in the trunk with a loss of fat from the arms, legs, and face. PURPOSE Determine if exercise training, which has increased LTM and decreased fat stores in healthy and clinical populations, is effective in treating both of these body composition conditions. METHODS Thirty-nine HIV-infected individuals, who were medically cleared for study participation, were randomized to an exercise group (EX) who completed 6 weeks of moderate intensity exercise training, or to a control group (CON) that did not receive the exercise intervention. Twice a week, the exercise group completed 30 minutes of moderate intensity aerobic training followed by moderate intensity upper body and lower body resistance training. Each subject before and following the 6-week training period received a DEXA scan for determination of body composition. RESULTS The EX (N=21) had a significant increase in LTM (P=0.006) following the intervention, while the CON (N=18) had no significant changes in body composition. Both groups were then divided into those above 20% body fat (BF) and those below 20% BF prior to the intervention. The EX below 20% BF group had significantly more LTM than the EX above 20% BF group. Analysis of the EX then revealed that those below 20% BF increased lean tissue mass (P=0.03) only, while those above 20% BF decreased weight (P=0.03), fat mass (P=0.03) and total fat % (P=0.05) while showing a trend for decreased trunk fat % (P=0.09). There were no changes observed in the CON. Nutritional status was unchanged during the intervention. CONCLUSIONS These data indicate that 6 weeks of combined moderate intensity aerobic and resistance training in HIV-infected individuals benefits lean persons by increasing lean tissue mass and benefits overweight persons by decreasing total body weight and fat mass while retaining lean tissue mass. Results suggest that combined aerobic and resistance exercise training may have differential effects on HIV-infected persons based on body composition. This work is supported by the NINR/NIH-funded Center for Health Promotion and Risk Reduction in Special Populations and the Arnold School of Public Health.