Context: Long-term glucocorticoid therapy adversely affects growth and body composition in children with juvenile idiopathic arthritis (JIA). In previous studies, recombinant human growth hormone (rhGH) halted the progression of these complications without inducing catch-up growth.

Objectives: The objective of the study was to evaluate the impact on growth and body composition of rhGH started early after glucocorticoid initiation and to record adverse effects, in children with JIA.

Design: This is a 3-year randomized controlled study.

Setting: This study was conducted in a teaching hospital.

Patients: 30 children, 12-15 months into glucocorticoid therapy for severe JIA, were enrolled.

Intervention: Patients received rhGH (0.46 mg/kg/week) in daily subcutaneous injections (n = 15) or no rhGH therapy (n = 15) for 3 years.

Main Outcome Measure: Difference in height standard deviation score (SDS) change between the two groups was assessed. Height velocity, body composition and oral glucose tolerance were evaluated yearly.

Results: Mean height SDS increase was larger with rhGH (+0.37 ± 1.5 SDS) than without (-0.96 ± 1.2 SDS) (P = 0.04). Mean height velocity returned to normal within the first year of rhGH treatment and remained normal thereafter. Mean lean mass increase was greater with rhGH-treatment (+7.3 ± 2.9 kg vs. +4.4 ± 2.8 kg; P = 0.03). Fat mass and bone mineralization were not significantly different in the two groups. Fasting serum insulin increased significantly in rhGH-treated patients (5.2 ± 16 mIU/L) compared to untreated controls (-2.3 ± 5 mIU/L) (P = 0.04); fasting glycemia was unchanged.

Conclusions: rhGH started early in the course of JIA preserved normal growth velocity and height. Although rhGH was well tolerated, carbohydrate metabolism should be monitored closely.