Bone matrix insulin-like growth factor (IGF)-I, IGF-II and transforming growth factor (TGF)-beta1 levels in men and postmenopausal women with osteoporosis: lack of association with circulating growth factors and bone mineral density

Abstract

Previous clinical studies have suggested a positive correlation between serum insulin-like growth factor components and bone mass in both men and women with or without osteoporosis. The aim of the present study was to analyze the relationship between the skeletal levels of insulin-like growth factors and transforming growth factor-b1 and bone mineral density in a group of men and postmenopausal women in whom osteoporosis was diagnosed previously. Bone matrix extraction was achieved by passive dialysis against tetrasodium EDTA-guanidine-HCL. IGF's were quantified by radioimmunoassay. TGF-b1 was assessed by a specific enzyme-linked immunoassay. No correlation between BMD and the concentration of IGF-I, IGF-II and TGF-b1 in bone matrix was detected in either men or postmenopausal women with osteoporosis. In addition, circulating growth factors levels failed to be associated with the concentration of IGF-I, IGF-II and TGF-b1 in the skeleton. Thus, our study provides no evidence for a major role of bone matrix IGF's or TGF-b1 as determinants of bone mass in men or postmenopausal women with osteoporosis.