Spinal bone mineral density, IGF-1 and IGFBP-3 in children with cerebral palsy.

BACKGROUND/AIMS Childhood cerebral palsy (CP) is associated with osteopenia and the GH-IGF axis plays an important role in bone metabolism. We studied the relationship between spinal bone mineral density (BMD) and serum IGF-1 and IGFBP-3 in children with CP. METHODS Cross-sectional study of 30 children (9 F and 21 M, ages 4.5-15) with CP. Subjects underwent dual-energy x-ray absorptiometry scans (spinal BMD), blood tests (IGF-1, IGFBP-3, Ca, P, PTH, vitamin D, osteocalcin) and urine tests (N-telopeptide). RESULTS Spinal BMD was decreased in children with CP (average Z-score -2.14 +/- 1.08) compared to age- and gender-matched norms. IGF-1 and IGFBP-3 were also decreased compared to age-matched norms (average IGF-1 Z-score -0.74 +/- 1.2, average IGFBP-3 Z-score -0.68 +/- 1.2). All other blood and urine tests, including measures of calcium and vitamin D status, were normal. In 25 CP children with osteopenia (Z-score >-1), there was a trend towards correlation between spinal BMD Z-score and serum IGF-1 SDS score (r = 0.328, p = 0.09). IGFBP-3 Z-scores were available in 24 of these patients and had a statistically significant correlation with spinal BMD Z-score (r = 0.386, p = 0.05). CONCLUSION Osteopenia is common in children withCP and may be associated with lower IGF-1 and IGFBP-3 levels.