The role of bone turnover markers in screening low bone mineral density and their relationship with fracture risk in the postmenopausal period

BACKGROUND: Using bone turnover marker (BTM) monitoring to identify “quick losers” who may develop osteoporosis in the coming years is one of the main challenges in clinical practice. This study was implemented to examine the association of BTMs with bone mineral density (BMD) as well as to determine their relationship with the fracture risk assessment tool (FRAX) in women in the postmenopausal period. MATERIALS AND METHODS: This study was observational cross-sectional research that was done on women between the ages of 50 and 65 who were in the postmenopausal period. A dual-energy X-ray absorptiometry was applied to select 120 eligible women with normal BMD and 120 women without normal BMD. BTMs were assessed using enzyme-linked immunosorbent assay. Osteoporosis's Odds Ratio (OR) was estimated using a confounder-adjusted logistic regression model. The area under curve was calculated for the differentiation of low BMD in the postmenopausal period through receiver-operator characteristic (ROC) curves. To assess the probability of major osteoporotic fracture and hip fracture for the future 10 years, FRAX was applied. RESULTS: Higher serum osteocalcin (OC) (OR: 1.134, 95% confidence interval [CI]: 1.086–1.184), osteopontin (OP) (OR: 1.180; 95%CI: 1.105–1.261), and alkaline phosphatase (ALP) (OR: 1.007; 95%CI: 1.001–1.144) concentrations were potential risk factors for developing low BMD in women after menopause. The area under curve (AUC) (95%CI) for OC, OP, and ALP was 0.75 (0.668–0.8130), 0.75 (0.685–0.812), and 0.602 (0.524–0.670), respectively. ROC analysis indicated that at the cut-off point of 16.28 ng/mL, sensitivity and specificity were 70.3% and 70.9%, respectively, for OC. Furthermore, at the cut-off point of 28.85 ng/mL, the sensitivity of 70.3% and specificity of 66.6% were obtained for OP. The serum OC and OP were significantly related to hip and major osteoporotic fractures (P < 0.05). CONCLUSION: The higher serum concentration of OC, OP, and ALP had significant associations with lower BMD. These BTMs can be complementary tools and helpful in the postmenopausal period as measures for screening of bone loss and possible bone fracture.