Serum Insulin-like Growth Factors IGF-I and IGFBP-3 in Children With Slipped Capital Femoral Epiphysis

Abstract

Hormonal imbalance in puberty and biomechanical overload due to obesity have been implied in the still unknown cause of slipped capital femoral epiphysis (SCFE). Local mediators of growth hormone (GH) action, such as insulin-like growth factor I (IGF-I), play a crucial role in the development of the growth plate cartilage. Concentrations of IGF-I and its binding protein 3 (IGFBP-3) were measured in the serum of 19 SCFE children without endocrine disorders. Standing height and body weight were determined. The results were related to the bone age. Concentrations for IGF-I and IGFBP-3 were predominantly within the normal ranges for chronologic age and bone age. The correlation of IGF-I and IGFBP-3 serum levels was high. Standing height and body weight showed a tendency toward the higher percentile ranges. Ten of 19 patients were above the 97th percentile concerning their weight for height. Bone age did not differ significantly from chronologic age. Serum concentrations of IGF-I and IGFBP-3 provided no evidence of a disturbance of the somatotropic axis in SCFE children. Increased body weight associated with normal skeletal maturation implies a mechanical stress factor in the cause of SCFE in these children.