Growth hormone treatment in children on chronic glucorticoid therapy

Growth failure is common in paediatric disorders associated with inflammation and nutritional deficiency. Examples are Crohn's disease (CD), juvenile idiopathic arthritis (JIA) and cystic fibrosis. Several factors contribute to the abnormal growth, notably excess pro-inflammatory cytokine production and nutritional deficiency, both of which can disturb the GH-IGF- I axis. Typically, growth hormone (GH) secretion is normal, whereas IGF-I production is compromised. Against this background of a disturbed IGF system, glucorticoid therapy, particularly in JIA, and to some extent in CD is frequently initiated to suppress inflammation and provide symptomatic relief. The availability of GH therapy and its efficacy in non-GH- deficient disorders has led to a number of trials in children with glucocorticoid-dependent diseases. In JIA, GH in pharmacological dosages of 0.066 and 0.047 mg/kg/day was effective in preventing the rapid decrease in height SDS values in the acute phase of the disease and in increasing adult height after long-term therapy respectively. In CD, fewer children are steroid-dependent because of widespread use of enteral nutrition, non-steroidal immunosuppressive agents and anti-tumour necrosis factor therapy. However, two trials of GH, using similar doses to those above, have demonstrated anabolic effects with increase in height velocity, bone mineral density and fat free mass compared to untreated controls. Collaboration between paediatric endocrinologists and other subspecialists will improve the opportunity for successful GH therapy. Treatment should be initiated before or during early puberty.