Serum 25-hydroxyvitamin D, bone turnover markers and bone mineral density in postmenopausal women with hip fractures

Background: Vitamin D and bone turnover markers (BTMs) might have an effect on the occurrence of acute hip fracture, while the current results are conflicting. The purpose of this study is to explore the relationship between serum 25(OH)D, bone turnover markers and bone mineral density in Chinese postmenopausal women with hip fracture. Methods: A total of 277 patients with hip fractures and 272 patients without fractures were included in this study. The serum 25(OH)D, bone formation markers, including N-terminal extension propeptide of type-I collagen (P1NP), alkaline phosphatase (ALP) and osteocalcin(OC), bone resorption markers, including C-terminal telopeptide of type-I collagen (CTX-1), and bone mineral density were collected and analyzed. Results: Women with hip fractures had significantly lower concentrations of serum 25(OH)D, higher concentrations of serum CTX-1, P1NP and OC, lower concentrations of femoral neck and total hip bone mineral density (P < 0.05). After adjustment for age and other confounding factors, multiple logistic regression analysis showed that serum 25(OH)D (OR = 0.878, 95%CI = 0.855-0.902, P < 0.001), CTX-1 (OR = 4.884, 95%CI = 2.419-9.861, P < 0.001)and total hip BMD (OR = 0.141, 95%CI = 0.034-0.577, P = 0.006) were independent risk factors for hip fractures in postmenopausal women. The receiver operating characteristics curves showed that serum 25(OH)D had a good AUC value (0.830). Conclusions: In this study, lower concentrations of serum 25(OH)D and total hip bone mineral density were widely existed in Chinese postmenopausal women with hip fractures. Furthermore, bone resorption was more active than bone formation in senile postmenopausal women. Therefore, monitoring the alteration of serum CTX-1 in clinically might be useful for fracture prevention.