Simon D et al. (2007) Early recombinant human growth hormone treatment in glucocorticoid-treated children with juvenile idiopathic arthritis: a 3-year randomized study. J Clin Endocrinol Metab 92: 2567–2573

Glucocorticoids are the main treatment for juvenile idiopathic arthritis (JIA), but long-term glucocorticoid therapy has adverse effects on growth and muscle and bone development. Recombinant human growth hormone (rhGH) prevents progression of these complications but, after long-term glucocorticoid treatment, does not induce catch-up growth. Simon et al., therefore, evaluated the effect on children with JIA of rhGH therapy commencing soon (12–15 months) after initiation of glucocorticoid treatment.

Of the 30 participants (mean age 5.7 years), 15 were randomly allocated to receive rhGH (0.46 mg/kg per week); the control group continued to take prednisone alone. Although patients were still within the normal height range, growth velocity had decreased consistently in the year before study entry. The mean change in height standard deviation score over the 3-year study period was significantly better in the rhGH group than in the controls. Mean height velocity returned to normal within the first year of rhGH treatment and remained normal for the remainder of the study. Patients taking rhGH also had a significantly greater increase in lean mass than the control group. At study end, fasting hyperinsulinemia was found in seven of the rhGH group and one control patient.

The authors conclude that rhGH therapy, started soon after disease onset, preserves growth velocity in patients with JIA. Carbohydrate metabolism should, however, be closely monitored during treatment.