Growth hormone for the treatment of growth failure in children

The etiology, diagnosis, and clinical features of growth failure in children are presented, with discussion of exogenous growth hormone (GH) replacement, its indications, efficacy, and adverse effects. Causes of growth delay include malnutrition, systemic illness, emotional deprivation, deficiency of endogenous growth hormone, thyroid hormone deficiency, and cortisol excess. Growth hormone (somatotropin) is secreted by the anterior pituitary gland in response to various stimuli, including exercise, hypoglycemia, and arginine. This hormone stimulates growth of skeletal muscle and connective tissue, increases rate of protein synthesis, and decreases rate of glucose use. Diagnosis of GH deficiency usually relies upon detection of adequate GH release in response to two stimuli. However, because patients with adequate endogenous GH release (determined by testing) may also grow when given exogenous GH, other methods are being evaluated for diagnosis of GH-dependent states. In many children, exogenous GH replacement produces increased rates of growth within 6 to 12 months; subsequently, growth rates decline. Distribution of the pituitary-derived GH product somatotropin was halted because of reports of Creutzfeldt-Jakob disease in some patients receiving it. Somatrem, a biosynthetic GH produced by recombinant DNA technology, has shown efficacy similar to somatotropin in clinical studies and is currently available to pediatric endocrinologists. Growth hormone replacement is beneficial in idiopathic and acquired GH deficiency, including partial GH deficiency. Further testing is needed to determine the usefulness and cost-benefit of somatrem therapy in GH-dependent and other types of growth failure.