Current indications for growth hormone therapy for children and adolescents.

Growth hormone (GH) therapy has been appropriate for severely GH-deficient children and adolescents since the 1960s. Use for other conditions for which short stature was a component could not be seriously considered because of the small supply of human pituitary-derived hormone. That state changed remarkably in the mid-1980s because of Creutzfeldt-Jakob disease associated with human pituitary tissue-derived hGH and the development of a (nearly) unlimited supply of recombinant, 22 kDa (r)hGH. The latter permitted all GH-deficient children to have access to treatment and one could design trials using rhGH to increase adult height in infants, children and adolescents with causes of short stature other than GH deficiency, as well as trials in adult GH-deficient men and women. Approved indications (US Food and Drug Administration) include: GH deficiency, chronic kidney disease, Turner syndrome, small-for-gestational age with failure to catch up to the normal height percentiles, Prader-Willi syndrome, idiopathic short stature, SHOX gene haploinsufficiency and Noonan syndrome (current to October 2008). The most common efficacy outcome in children is an increase in height velocity, although rhGH may prevent hypoglycemia in some infants with congenital hypopituitarism and increase the lean/fat ratio in most children - especially those with severe GH deficiency or Prader-Willi syndrome. Doses for adults, which affect body composition and health-related quality of life, are much lower than those for children, per kilogram of lean body mass. The safety profile is quite favorable with a small, but significant, incidence of raised intracranial pressure, scoliosis, muscle and joint discomfort, including slipped capital femoral epiphysis. The approval of rhGH therapy for short, non-GH-deficient children has validated the notion of GH sensitivity, which gives the opportunity to some children with significant short stature, but with normal stimulated GH test results, to benefit from rhGH therapy and perhaps attain an adult height within the normal range and appropriate for their mid-parental target height (genetic potential).