Does Growth Hormone Therapy in Conjunction With Resistance Exercise Increase Muscle Force Production and Muscle Mass in Men and Women Aged 60 Years or Older?

Abstract

Improved muscle protein mass and increments in maximum voluntary muscle force have rarely been observed in men and women aged 60 years and older who were treated with rhGH. Although rhGH administration has been reported to increase lean body mass in older men and women, it is doubtful that this increase is localized to skeletal muscle contractile proteins. When rhGH administration was combined with 16 weeks of resistance exercises, increases in muscle mass, muscle protein synthesis, and muscle force were not greater in the rhGH-treated group than in a weight training group that received placebo injections. Side effects of rhGH treatment in elderly people are prevalent, not trivial, and further limit its usefulness as an effective anabolic agent for promoting muscle protein accretion in men and women. In particular, the induction of insulin resistance and carpal tunnel compression reduces the efficacy of rhGH replacement therapy in elderly individuals. The evidence for a GH-induced increase in human skeletal muscle protein and maximum voluntary muscle force is weak. The optimum dose and GH-replacement paradigm (GHRH, GH-secretagogues) have not been identified. Whether rhGH therapy improves muscle protein mass and force in individuals with severe cachexia associated with major trauma, burns, surgery, or muscular dystrophy is controversial and under investigation.