Growth hormone therapy improves bone mineral density in children with cerebral palsy: a preliminary pilot study

Abstract

Context: Cerebral palsy is associated with osteopenia, increased fracture risk, short stature, and decreased muscle mass, whereas GH therapy is associated with increased bone mineral density (BMD) and linear growth and improvement in body composition.

Objective: We conducted a pilot study to evaluate the effect of 18 months of GH therapy on spinal BMD, linear growth, biochemical markers, and functional measures in children with cerebral palsy.

Design and setting: The study was a randomized control trial, conducted from 2002-2005 at the University of California, Los Angeles, Orthopedic Hospital's Center for Cerebral Palsy.

Patients: Patients included 12 males with cerebral palsy, ages 4.5-15.4 yr.

Intervention: We compared 18 months of GH (50 microg daily) vs. no treatment.

Primary outcome measures: Spinal BMD (dual-energy x-ray absorptiometry scan), height, growth factors, and bone markers were assessed.

Results: Ten subjects (five in each group) completed the study. Pre- and post-average height z-scores were -1.47 +/- 0.23 and 0.8 +/- 0.2 (GH-treated group) vs. -1.35 +/- 1.26 and -1.36 +/- 1.27 (control group) (Delta SD score, 0.67 vs. -0.01; P = 0.01). Average change in spinal BMD z-score (Delta SD score corrected for height) was 1.169 +/- 0.614 vs. 0.24 +/- 0.25 in the treated and control groups, respectively (P = 0.03). Osteocalcin, IGF-I, and IGF-binding protein 3 levels increased during GH therapy. There was no change in quality of life scores as measured by the Pediatric Orthopedic Disability Inventory.

Conclusions: This small pilot study suggests that 18 months of GH therapy is associated with statistically significant improvement in spinal BMD and linear growth.