Effects on bone metabolism of one year recombinant human growth hormone administration to children with juvenile chronic arthritis undergoing chronicsteroid therapy

Objective. To study the effects on bone metabolism of treatment with recomb inant human growth hormone (rhGH) in children with juvenile chronic arthrit is (JCA) who are undergoing treatment with glucocorticoids (GC) and have se vere bone lesions. Methods. We assessed the effects of rhGH treatment (1.4 U/kg/week) on bone metabolism markers and bone density measured during a one year treatment co urse in 14 patients with systemic forms of JCA undergoing longterm GC treat ment. Results. All patients at inclusion showed severe bone demineralization (mea n bone density: -3.7 standard deviation score for chronological age). Compa red to pretreatment values, bone formation markers (blood levels of osteoca lcin and C-terminal propeptide of type 1 procollagen) and bone resorption m arkers (urinary hydroxyproline, pyridinoline, and deoxypyridinoline levels) increased significantly during treatment and returned to pretreatment valu es after discontinuation of rhGH. We observed that plasma level of osteocal cin was the best predictive variable of growth response to rhGH treatment i n these patients. Conclusion. The results reflect an increase in bone turnover in these patie nts. Despite these biochemical changes no improvement of bone density was o bserved during the one year treatment. Treatment of longer duration is nece ssary to evaluate the curative effects of GH.