Effects of testosterone and exercise on muscle leanness in eugonadal men with AIDS wasting

Loss of lean body and muscle mass characterizes the acquired immunodeficien cy syndrome (AIDS) wasting syndrome (AWS). Testosterone and exercise increa se muscle mass in men with AWS, with unclear effects on muscle composition. We examined muscle composition in 54 eugonadal men with AWS who were rando mized to 1) testosterone (200 mg im weekly) or placebo and simultaneously t o 2) resistance training or no training in a 2 x 2 factorial design. At bas eline and after 12 wk, we performed assessments of whole body composition b y dual-energy X-ray absorptiometry and single-slice computed tomography for midthigh cross-sectional area and muscle composition. Leaner muscle has gr eater attenuation. Baseline muscle attenuation correlated inversely with wh ole body fat mass (r = -0.52, P = 0.0001). This relationship persisted in a model including age, body mass index, testosterone level, viral load, lean body mass, and thigh muscle cross-sectional area (P = 0.02). Testosterone (P = 0.03) and training (P = 0.03) increased muscle attenuation. These data demonstrate that thigh muscle attenuation by computed tomography varies in versely with whole body fat and increases with testosterone and training. A nabolic therapy in these patients increases muscle leanness.