Diagnostic Utility of Osteocalcin, Undercarboxylated Osteocalcin, and Alkaline Phosphatase for Osteoporosis in Premenopausal and Postmenopausal Women

2 , Acibadem Background: We aimed to investigate the diagnostic utility of osteocalcin (OC), undercar- boxylated osteocalcin (ucOC), and alkaline phosphatase (ALP) in pre- and postmenopausal women for femoral neck, L1-4, and L2-4 bone mineral density (BMD) values by taking into consideration their age, body mass index (BMI), and menopausal status. Methods: Premenopausal (N= 40) and postmenopausal cases (N= 42) were classifi ed as 25-34 or 35-45 yr of age and within the fi rst 5 yr or 5 yr or more after the onset of meno- pause, respectively. Results: Among the groups, statistical differences were found for age, BMI, OC, ucOC, ALP, femoral neck BMD, L1-4 BMD, and L2-4 BMD. The highest serum OC, ucOC, and ALP levels were observed in cases within the fi rst 5 yr after the onset of menopause, prob- ably due to a more rapid bone turnover rate. The best predictors for the femoral neck os- teoporosis were ALP, OC, and calcium (areas under the ROC curve (AUC)= 0.882, 0.829, and 0.761, respectively), and those for L1-4 and L2-4 osteoporosis were OC, ALP, and ucOC (AUC= 0.949, 0.873, and 0.845; and 0.866, 0.819, and 0.814, respectively). Multiple logis- tic regression analysis revealed that the most discriminative parameter for osteoporosis was OC. Conclusions: These results indicate that serum OC levels, with or without ucOC and ALP, may be useful to monitor follow-up changes that currently cannot be assessed with BMD and to diagnose femoral neck, L1-4 spine, and L2-4 spine osteoporosis.