Growth hormone therapy in adults: rationales, results, and perspectives.
This review outlines the present knowledge of the rationales, clinical aspects, and perspectives of a therapy with recombinant human growth hormone (rhGH) in adults. In patients with hypopituitarism the effects of rhGH replacement have been extensively studied. Recent clinical trials show that rhGH treatment improves most alterations of body composition and psychological performance, but many of the metabolic actions of GH remain equivocal. Although side effects after short-term administration are usually mild, the risks of severe long-term adverse effects are still uncertain. A supplementation with rhGH is also suggestive in advanced age and obesity, but the clinical results are controversial so far. The anabolic actions of rhGH were exploited in several recent trials including patients who were severely ill, malnourished, on chronic haemodialysis, or on total parenteral nutrition. Although nitrogen-sparing effects of GH have been demonstrated in most cases, the data do not indicate a clinical benefit in terms of reduced mortality, improved outcome, or accelerated recovery. Therefore, recommendations for the use of rhGH do not have any rationale in these patients yet. The efficacy of rhGH in the treatment of reproductive or immunological disorders remains elusive and needs further investigation. In conclusion, the application of rhGH is still an experimental therapy which should be performed under close observation in well-controlled clinical studies.