The relationship between fibroblast growth factor 23 and osteoporosis in postmenopausal women

Abstract

Aim. A lack of estrogen in postmenopausal women is an important factor causing the development of osteoporosis. Our purpose is to investigate the effects of Fibroblast Growth Factor 23 (FGF-23) on bone mineral metabolism and bone turnover. Methods. Twenty-eight patients with postmenopausal osteoporosis (PMO), 32 patients with postmenopausal osteopenia and 30 healthy control subjects (postmenopausal non-osteoporosis) were included in this study. In order to assess the bone mineral metabolism; FGF 23, parathyroid hormone, vitamin D, calcium, phosphate, osteocalcin, alkaline phosphatase and hydroxyproline levels were measured. Results. FGF 23 levels were found significantly higher in PMO group compared with postmenopausal osteopenia and control groups (P<0.01 and P<0.05 respectively). Urine hydroxyproline level was detected to be significantly lower in PMO patients compared with control group (P<0.01). Lomber and femur BMD levels were found to be significantly lower in PMO patients compared with postmenopausal osteopenia and control groups (P<0.001, P<0.001; P<0.001, P<0.001 respectively). On the other hand, when we categorized the PMO group subjects according to the age of menopause, the FGF 23 levels were found to be significantly higher in the group of menopausal age <5 years compared to the group of menopausal age >10 and to the group of menopausal age 5-10 years (P<0.05, P<0.05). Conclusion. We think our findings indicate that serum FGF 23 level is a significant determinant of increased bone turnover at early periods in PMO patients.