Growth Hormone in Pediatric Crohn's Disease

Background: Poor growth is reported in 40% of pediatric patients with Crohn's disease (CD) resulting in short stature as adults. We determined clinical efficacy of human growth hormone (GH) in pediatric CD patients with growth failure ± steroid dependency. Methods: 6 boys and 4 girls (mean age 12.6 ± 4.5 [SD] [range 4.8-19.6] yrs) with unfused growth plates were enrolled; 4 were prepubescent. In addition to their individual therapies, all patients received open label GH 0.043 mg/kg/day SQ injection for one year. Assessments made at baseline, 2, 4, and 8 weeks, 3, 6, 9 and 12 months. Data were analyzed by paired t-tests and analysis of variance for repeated measures using STATA 7.0. Results: Mean growth velocity increased from 2.68 ± 1.47 [range 0.7-4.6] cm/yr at baseline to 8.52 ± 4.80 [range 2.4-17.4] at 6 months and 8.06 ± 3.75 [1.9-14.3] cm/yr at 1 year of GH (p = 0.004). Height Z scores increased by 0.79 ± 0.47 (p = 0.002); weight Z scores increased by 0.57 ± 0.56 (p = 0.02). DXA scans at 1 yr revealed mean increase lumbar spine T scores of 0.61 ± 0.39 (p < 0.001) above baseline. Percent body fat (by DXA scan) decreased in 8 patients, while mean BMI increased in all patients (p = 0.02), suggesting increased lean body mass. Serum alkaline phosphatase levels correspondingly increased in all subjects (p = 0.004). Levels of IGF-1 (p = 0.002) and IGF-BP3 (p = 0.007) increased. Of the 5 patients taking prednisone at the start of the study, 4 were completely weaned within the first month of treatment and did not require further prednisone during the year of GH. The Pediatric Crohn's Disease Activity Index (PCDAI) varied throughout the study period in all subjects. Conclusion: GH is beneficial in pediatric Crohn's disease patients exhibiting poor growth and poor bone mineralization. Further studies are needed to determine the ideal timing and combination of therapies for pediatric Crohn's patients exhibiting poor growth and the role for GH as a primary therapy for children and adolescents with CD. Supported in part by NIH grants DK 060617, DK 007762, and M01RR01271 and by the Genentech Center for Clinical Research in Endocrinology.