The Role of Oral Growth Hormone Secretagogues in Anti-Aging Therapy

BACKGROUND Based on the increasing body of evidence that adults with human growth hormone (hGH) deficiency exhibit signs of impaired health, many countries have approved the use of hGH (somatotropin) as a replacement therapy in deficient adults. The results and efficacy of hGH therapy are strikingly consistent. Untreated hGH deficient adults are shown to have increased cardiovascular mortality, reduced skeletal muscle strength, reduced exercise capacity, reduced glomerular filtration and renal plasma flow, defective thermo-regulation and sweat secretion, reduced energy expenditure and basal metabolic rate, reduced myocardial function, clinical signs of premature atherosclerosis, and abnormal thyroid metabolism. Body composition has been found to be abnormal in these patients, as evidenced by decreased lean body mass, increased fat mass, visceral obesity, reduced bone mineral content, and reduced extracellular fluid volume, while independent groups have reported impaired psychological well being. Somatotropin deficiency has distinct clinical consequences, all of which can be totally or partially alleviated by rhGH replacement therapy.