GENERALIZED OSTEOARTHRITIS ASSOCIATED WITH INCREASED INSULIN-LIKE GROWTH-FACTOR TYPE-I AND TYPE-II AND TRANSFORMING GROWTH-FACTOR-BETA IN CORTICAL BONE FROM THE ILIAC CREST - POSSIBLE MECHANISM OF INCREASED BONE-DENSITY AND PROTECTION AGAINST OSTEOPOROSIS

Objective. To investigate whether growth factors stored in bone might explain the increased bone density and resistance to osteoporosis in generalized osteoarthritis. Methods. Levels of insulin-like growth factor (IGF) types I and II and transforming growth factor beta (TGFbeta) were measured in extracts of cortical bone from the iliac crest obtained at necropsy from subjects with or without osteoarthritis of the hands. Results. Concentrations of IGF-I, IGF-II, and TGFbeta were significantly higher in extracts of bone powder from subjects in the osteoarthritis group than in extracts from subjects in the control group. Conclusion. The results suggest that the increased bone density and resistance to osteoporosis in patients with osteoarthritis may be associated with increased skeletal concentrations of IGF-I, IGF-II, and TGFbeta and may reflect a generally increased biosynthetic activity of osteoblasts in these patients.