Six-week improvements in muscle mass and strength during androgen therapy in older men

Background. The purpose of our study was to assess the early effects of a potent anabolic androgen on muscle mass and strength, lower extremity power, and functional performance in older men. Methods. Thirty-two men 72 [+ or -] 6 years of age were randomized to receive oxandrolone (10 mg twice daily) or matching placebo in a 2:1 manner for 12 weeks. Total and appendicular lean body mass (LBM) were assessed by dual-energy x-ray absorptiometry (DEXA). Lower extremity muscle volume was determined by magnetic resonance imaging to validate DEXA changes. Results. Total LBM increased by 2.7 [+ or -] 1.6 kg after 6 weeks with oxandrolone (p < .00l), which was greater (p < .001) than the decline in LBM (-0.5 [+ or -] 0.9 kg) with placebo. Appendicular LBM increased by 1.2 [+ or -] 0.9 kg after just 6 weeks with oxandrolone (p < .001), which was greater (p < .001) than the decline in LBM (-0.4 [+ or -] 0.5 kg) with placebo. These changes were >90% of the gains in total and appendicular LBM (3.0 [+ or -] 1.5 kg and 1.3 [+ or -] 0.9 kg, respectively) after 12 weeks. Total thigh and hamstring muscle volume increased by 111 [+ or -] 29 [mm.sup.3] (p = .001) and 75 [+ or -] 18 [mm.sup.3] (p .001), respectively, after 12 weeks. Maximal strength increased for the leg press 6.3 [+ or -] 5.6% (p = .003), leg curl 6.7 [+ or -] 8.6% (p = .01), chest press 6.9 [+ or -] 6.5% (p = .001), and latissimus pull-down 4.8 [+ or -] 6.3% (p = .009) with oxandrolone after 6 weeks; these increases were different than those with placebo (p < .001) and were 93%, 96%, 74%, and 94% of the respective gains at week 12. There were no improvements in functional measures. Conclusion. Treatment with a potent anabolic androgen may produce significant increases in muscle mass and strength after only 6 weeks in healthy older men. However, such treatment did not improve leg muscle power or walking speed.