ABSTRACT
Aging in man is associated with a progressive loss of function, leading to decreased homeostasic capacity, initially in response to various stressors, and subsequently under baseline conditions. Both aging and growth hormone (GH) deficiency are associated with decreased skeletal muscle, bone mass, strength, increased total and intra-abdominal fat, dyslipidemia, glucose intolerance, reduced cardiac endurance and immunologic function, and altered quality of life.1,2 Recent studies suggest that administration of recombinant GH to non-elderly GHdeficient men ameliorates or attenuates these abnormalities.1,2 Because normal aging in men is associated with a decline in GH secretion and serum insulin-like growth factor I (IGF-I) levels,1,2
it has been hypothesized that the above-noted alterations in body composition and function in older persons may be due in part to decrements in the function of the GH-IGF-I axis. To assess this possibility, the effects of different hormone replacement paradigms are being investigated in selected populations of elderly men. A major goal of this research effort is to assess whether tropic factors such as GH, GH-releasing hormone (GHRH), or other GHreleasing peptides or non-peptide mimetics can be used effectively, safely, ethically, and economically to prolong physical and functional independence, and to reduce morbidity and frailty in aged men.
