Effects of Muscle Strength Training and Testosterone in Frail Elderly Males

Abstract

Determine the independent and combined effects of progressive resistance muscle strength training (PRMST) and testosterone on strength, muscle mass, and function in hypogonadal elderly male recuperative care patients. Between 1999 and 2004, 71 subjects (mean age 78.2 +/- 6.4 yr, 86% white) were enrolled. After baseline one-repetition maximum (1RM) strength testing and then randomization to one of four treatment groups (low-resistance (20% of the 1RM) exercises and weekly injections of either 100 mg of testosterone enanthate or placebo or high-intensity PRMST (> or =80% 1RM) and weekly injections), each subject received training and injections for 12 wk. Ten subjects withdrew from the study before its completion. Based on intent-to-treat analyses, strength improved in all groups, but was greater with high-intensity PRMST compared with low-resistance exercise (e.g., leg press, (mean +/- SE), 28 +/- 4 vs 13 +/- 4%, P = 0.009). Although testosterone led to significantly greater increases in midthigh cross-sectional muscle area compared with placebo (7.9 +/- 1.3 vs 2.4 +/- 1.4%, P = 0.005), it produced only a nonsignificant trend toward greater strength gains (e.g., leg press 25 +/- 4 vs 16 +/- 4%, P = 0.144). Change in aggregate functional performance score (the sum of 4 functional performance test scores) did not differ between the four intervention groups nor with high-intensity PRMST compared with low-resistance exercise (7 +/- 5 vs 15 +/- 5%, P = 0.263). There was not a significant interaction between exercise and testosterone for any outcome. High-intensity PRMST is as safe and well tolerated as a similarly structured low-resistance exercise regimen for very frail elderly patients, but produces greater muscle strength improvements. The addition of testosterone leads to greater muscle size and a trend toward greater strength but did not produce a synergistic interaction with exercise. Neither intervention had a significant effect on functional performance.