Fetuin-A in postmenopausal women with osteoporosis: Active player in the field

Background: Fetuin-A is a glycoprotein formed by liver cells and is secreted into the serum in high concentration. It regulates the process of osteogenesis by inhibiting transforming growth factor-? (TGF-?) and bone morphogenic protein. Fetuin-A plays a role in bone metabolism and it has various functions such as ectopic calcification inhibition. One of the functions of fetuin-A is the restriction of formation and expansion of extra osseous hydroxyapatite crystals. The exact correlation of fetuin-A with bone mineral density (BMD) has not been clearly elucidated. In this study, we aimed to assess the relationship between BMD and fetuin-A in postmenopausal women. Materials and Methods: Forty postmenopausal women (20 with osteoporosis, 20 healthy controls) were included in the study. All participants were comparable for age and body mass index. None of the osteoporotic patients had received any medical treatment for osteoporosis. Serum fetuin-A levels were measured by ELISA method. Results: BMD scores of the groups were statistically significant (P < 0.001). Serum fetuin-A levels of the osteoporosis group were significantly lower compared to the control group (P < 0.001). Additionally, there was a mild to moderate positive correlation between fetuin-A and lumbar BMD (r = 0.407, P = 0.054) in the osteoporotic group, though it did not reach statistical significance. Conclusion: Decreased fetuin-A levels in women with postmenopausal osteoporosis suggest that fetuin-A may have a role in the development of osteoporosis. Further studies are required to define the exact role of fetuin-A in bone metabolism.