Background: It has been reported that the presence of high levels of fibroblast growth factor 23 (FGF23) is a risk factor for osteoporotic fracture in elderly men. The aim of the present study was to elucidate the association between FGF23 and osteoporotic fracture in postmenopausal women.
Methods: We enrolled 190 postmenopausal women who were undergoing examination for osteoporosis. Serum levels of Ca, P, Cr, PTH, 25-hydroxy vitamin D [25(OH)D], FGF23, PINP and CTX were measured. The BMD of the lumbar spine (L2-4) and femoral neck (FN) was measured using dual-energy X-ray absorptiometry, the presence or absence of morphological vertebral fracture was determined, and the presence or absence of existing non-vertebral fracture was determined through physician interviews.
Results: Mean values of age were 63.4±7.5 years. Mean serum levels of Cr, 25(OH)D, FGF23, PINP and CTX were 0.58±0.10 mg/dL, 16.0±4.2 ng/mL, 33.9±9.1 pg/mL, 53.9±16.6 ng/mL and 0.401±0.149 ng/mL, respectively. Mean BMD value were 0.839±0.149 g/cm2 (T score −1.6±1.3) at L2-4, and 0.621±0.090 (−1.5±0.8) at FN. FGF23 was not significantly different between subjects with and without vertebral fractures and between subjects with and without nonvertebral fractures. Since FGF23 is linked to renal function, further analysis was conducted by the patients chronic kidney disease (CKD) stage. In the group of subjects with Stage 2 CKD (eGFR: 6089 mL/min/1.73 m2), FGF23 was significantly elevated in subjects with nonvertebral fractures (p<0.05), but not in those with vertebral fractures. Logistic regression analysis identified FGF23 as a significant risk factor for nonvertebral fracture, even after adjusted for age, BMI, grip strength, Ca, P, Cr, PTH, 25(OH)D, CTX and BMD [odds ratio: 1.96(95%CI:1.113.46), p<0.05].
Conclusion: This study showed that FGF23 is a risk factor for nonvertebral fracture in postmenopausal women with mild renal dysfunction.
Disclosure: The authors declared no competing interests.