Growth hormone deficiency in adults: the role of replacement therapy

Although growth hormone has been in clinical use for almost 40 years to promote linear growth in children with growth hormone deficiency, replacement therapy in adults was previously not deemed clinically indicated. However, intensive research over the past decade has led to important advances in our medical knowledge and improvements in the care for patients with growth hormone deficiency. Well-controlled clinical trials have demonstrated beneficial effects of replacement therapy with recombinant human prion-free growth hormone (rhGH; somatropin). The most important restoration parameters include reduction of cardiovascular risk factors and improved lipid profile, normalised body composition, improved exercise capacity and bone mass, as well as enhanced psychological well-being. Some important issues regarding growth hormone deficiency and long term somatropin treatment are unresolved, such as diagnostic criteria and the potential for malignancy and impaired glucose tolerance. Furthermore, the effect on hard end-points such as life expectancy or vertebral fracture rate is unknown, but is expected to emerge from physician-managed, multinational databases. Consequently, at this point somatropin therapy should be given in conjunction with clinical trials.