Long Bone Fracture Healing: IGF-I Concentrations and Specific Binding to Erythrocytes

Abstract

Animal experiments suggested a possible interaction between GH or GH-dependent growth factors and bone healing. The aim of this study was to determine whether there were any significant changes in serum levels of IGF-I and/ or the activity of its receptors while a fractured bone was healing. Serum concentrations of IGF-I and its specific binding to erythrocyte receptors (IGF-I SB) were determined in a group of 12 prepubertal children treated for long bone fractures. Results were compared to those obtained from a group of age- and sex-matched controls. Blood samples were taken from all patients two weeks following the fractures, when bone formation rate should have been maximal. We found no difference in IGF-I SB between the two groups. However, serum IGF-I levels were increased in the group of children with fractures compared to controls. Results are suggestive of a possible interaction between IGF-I and bone repair processes as other investigators have suggested on the basis of animal experiments.