Linear growth in children suffering from juvenile idiopathic arthritis requiring steroid therapy: natural history and effects of growth hormone treatment on linear growth.

We assessed linear growth and final height retrospectively in a group of 24 patients suffering from juvenile idiopathic arthritis (JIA) during childhood who had received steroid therapy. In these patients, there was a significant loss of height of more than 2 standard deviations during the first years of the disease, which correlated positively with the duration of prednisone therapy. After remission of the disease and discontinuation of prednisone treatment, 70% of the patients achieved catch-up growth, although 30% showed a persistent loss of height. Their mean final height was strongly correlated with their mean height at the end of steroid therapy and was significantly different between the group of patients with catch-up growth and the group without catch-up growth. This pattern of growth observed in patients with JIA should help us to define strategies of growth hormone (GH) treatment in these patients in order to improve their final height. We have previously reported the beneficial effects on growth and body composition of 1 year of GH treatment in a group of 14 growth-retarded patients suffering from JIA who received glucocorticoid therapy. These patients (n = 13) were treated again with GH at the same dosage (0.46 mg/kg/week [0.07 mg/kg/day]) for another 3-year period. GH treatment markedly increased growth velocity in these patients, but had a minor effect on height SDS, suggesting that these children will remain short when adults. Starting GH therapy in these patients earlier after the onset of the disease may prevent growth deterioration and metabolic complications induced by chronic inflammation and long-term steroid therapy.