Aortic calcification and bone metabolism: the relationship between aortic calcification, BMD, vertebral fracture, 25-hydroxyvitamin D, and osteocalcin.

The aim of this study was to investigate the relationship between aortic calcification (AC) and low bone mineral density (BMD), 25(OH)D, C-terminal telopeptide (CTx), and osteocalcin levels in Asian women. We also tried to find the association between AC and the risk of vertebral fracture. We included 769 patients in this study. All patients underwent QCT. Aortic calcium score (ACS) was quantified by the Agatston scoring method. Spinal fracture was defined by lumbar spine radiography. Among 769 subjects, 96 had at least one vertebral fracture and 345 had AC. ACS positively correlated with age. Osteocalcin, CTx, 25(OH)D, total-hip trabecular BMD (tBMD), femoral neck tBMD, and vertebral tBMD were inversely related with ACS. However, cortical BMD (cBMD) did not correlate with ACS. Among these parameters, only osteocalcin significantly correlated with ACS, even after adjusting for age. We divided the subjects into two groups based on the presence of AC to determine the association between AC and vertebral fracture. Multivariate logistic regression analysis showed that age, tBMD of each site, and AC were associated with vertebral fractures. After adjusting for confounding factors, patients with AC had more than a threefold increased risk of vertebral fracture (OR = 3.29-3.57, P < 0.05 according to site). This study suggests that high ACS is related to low tBMD but not cBMD. Furthermore, our findings indicate that this relationship is definitely age-dependent. Finally, we found that AC is significantly associated with the prevalence of vertebral fracture in Asian women.