Indicators for Risk of Hip Fracture in Elderly Women Without Osteoporosis

Purpose: Fracture prediction in non-osteoporotic elderly women is often neglected due to their relatively normal bone mineral density (BMD). This study aimed to identify key risk factors and develop a predictive model for hip fracture risk in this particular population. Methods : The study included 125 patients in the experimental group and 109 in the control group. Data of BMD, 25-hydroxyvitamin D (25(OH)D), C-terminal telopeptide of type I collagen (β-CTX), N-terminal mid-fragment of osteocalcin (N-MID), and demographic characteristics were collected for analysis. Univariate and multivariate logistic regression analyses were performed to identify independent risk factors, and prediction models were developed and assessed using the Receiver Operating Characteristic (ROC) curve and DeLong test. Results: After adjusting all covariates and confounders, β-CTX (adjusted-OR 1.004 [1.002-1.006], P<0.01), N-MID (adjusted-OR=0.816 [0.743-0.897], P<0.01), 25(OH)D (adjusted-OR=0.884 [0.841-0.928], P<0.01) and height (adjusted-OR=1.245 [1.058-1.487], P<0.01) persisted as risk factors in the multivariate regression model. Among these, 25(OH)D exhibited the highest predict value (AUC=0.85), with an optimal cutoff value established at 24.07 ng/ml. The AUC value of predictive model including height, β-CTX, N-MID and 25(OH)D was significantly greater (AUC=0.902, P<0.05) than that of other combinations. Conclusion: In non-osteoporotic elderly women, 25(OH)D demonstrates a higher predictive capability than BMD, with levels below 24.07 ng/mL significantly increasing hip fracture risk. The proposed predictive model, composed of height, β-CTX, N-MID, and 25(OH)D, offers excellent predictive value, evidenced by an AUC of 0.902. Trial registration: The study protocol was reviewed by the Ethics Committee of Shanghai Sixth People’s Hospital (Shanghai, China; approval number, 2017-152), and successfully registered with the China Clinical Trial Center, clinical trial registration number ChiCTR-ONC-17013389 (registered in November 15, 2017).