Effects of Muscle Strength Training and Testosterone in Frail Elderly Males

• Autores: Osama Bishara, William J. Evans, Larry E. Johnson, Paula K. Roberson, Dennis H. Sullivan
• Localización: Medicine & Science in Sports & exercise: Official Journal of the American College of Sports Medicine, ISSN 0195-9131, Vol. 37, Nº. 10 (Octubre), 2005, págs. 1664-1672
• Idioma: inglés
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• Resumen

  • Purpose: 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.

    Methods: 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 (>=80% 1RM) and weekly injections), each subject received training and injections for 12 wk.

    Results: 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.

    Conclusion: 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