Growth hormone increases final height in patients with juvenile idiopathic arthritis: data from a randomized controlled study.

BACKGROUND: GH treatment stimulates growth in short children with juvenile idiopathic arthritis (JIA). The extent to which this therapy increases final height is not known. METHODS: Thirty-one growth-retarded children with systemic and polyarticular idiopathic arthritis were enrolled in this controlled study. After a mean observational time of 8.4 yr, final height was reached in 13 patients (seven females and six males) treated with GH for a mean of 6.7 yr in a dose of 0.33 mg/kg body weight per week. Eighteen patients (12 females and six males) served as an untreated control group. RESULTS: Mean increment in height in the treatment group was 1.6 +/- 0.8 SD, whereas the patients of the control group lost 0.7 +/- 1.8 SD. Overall, mean final height in the treatment group was -1.6 SD and in the control group -3.4 SD. More GH-treated patients reached a final height within target height than untreated patients (11 of 13 vs. four of 18). Disease activity markers had a significant influence on height outcome. After adjustment for baseline and average disease activity, the difference between treatment and control group was still significant (mean 1.5 SD). Patients with a moderate overall disease activity profited most from GH treatment. No adverse events were noted throughout the study. CONCLUSION: Our data suggest that long-term GH therapy has a beneficial effect on growth and final height in the majority of growth retarded children with severe forms of JIA.

Dynamics of body composition and bone in patients with juvenile idiopathic arthritis treated with growth hormone.

INTRODUCTION: GH has a positive impact on growth, bone, and muscle development. The objectives of this study were to demonstrate the effects of GH treatment on regional body composition and bone geometry at final height in patients with juvenile idiopathic arthritis (JIA). PATIENTS AND METHODS: In this longitudinal study, parameters of bone mineral density and geometry as well as muscle and fat cross-sectional area (CSA) in the nondominant forearm were recorded using peripheral quantitative computed tomography at yearly intervals until final height in 12 patients (seven females) receiving GH treatment. Data at final height were compared with 13 patients (nine females) with JIA not treated with GH. RESULTS: Patients were treated with GH for a mean of 5.35 +/- 0.7 yr. Correcting for height, total bone CSA (+0.89 +/- 0.5 sd) and muscle CSA (+1.14 +/- 0.6 sd) increased significantly and normalized at final height. Compared with JIA patients without GH at final height, there was a significantly higher muscle CSA and a lower fat CSA in GH-treated patients. Additionally, in relation to total bone CSA, there was significantly more cortical and less marrow CSA in boys with GH treatment. CONCLUSION: During GH treatment, there was a significant increase and normalization of total bone and muscle CSA at final height. In accordance with an anabolic effect of GH, fat mass stabilized at the lower limit of healthy children. At final height, cortical and marrow CSA, relative to total bone CSA, were normalized in GH-treated patients.

Bone mass development and bone metabolism in juvenile idiopathic arthritis: treatment with growth hormone for 4 years.

OBJECTIVE: To study the acquisition of bone mass and changes in bone mineral density (BMD) related to age, bone age, pubertal status, and growth hormone (GH) therapy in 11 children with juvenile idiopathic arthritis (JIA) longitudinally over 4 years, in comparison to healthy children. METHODS: Bone mineral content (BMC), BMD, and vertebral area were measured by dual energy x-ray absorptiometry. Since BMC and BMD increase with size, BMD was converted to volumetric BMD (vBMD) after adjustment for vertebral size. RESULTS: At inclusion all patients (7 female, 4 male, mean age 10.3 +/- 2.1 yrs) had low BMD, with a mean z-score for area BMD (aBMD) of -2.04 +/- 0.8 SD. After adjustment for size, vBMD was 0.198 g/cm3, and after 4 years of GH treatment it increased significantly to 0.232 g/cm3 (p < 0.03), expressed as SD scores that increased from -2.97 +/- 0.81 SD to -2.83 +/- 0.67 SD. In relation to bone age, vBMD SD increased from -2.53 +/- 0.85 to -2.41 +/- 0.79. Compared to pretreatment values, bone formation and resorption markers increased significantly during treatment. CONCLUSION: Our results reflect an increase in bone turnover under GH therapy in these patients. Despite biochemical changes there was a stabilization of vBMD for age and bone age, with a percentage increase comparable to healthy children. Longterm GH treatment will be necessary to evaluate a potential positive effect of GH on bone density and metabolism in patients with JIA.