The relationship between aortic calcification, BMD, vertebral fracture, 25-hydroxy-vitamin D, and osteocalcin

Abstract

Background: Aortic calcification (AC) and low bone mineral density (BMD) are associated in postmenopausal women. However, which BMD (trabecular or cortical) is related to AC and the age dependence are still unclear. The association between AC and the risk of vertebral fracture is also controversial. Furthermore, no studies have assessed the relationship between AC, 25-hydroxy-vitamin D (25(OH)D) and osteocalcin (OC) level in Asian women. Objective: The aim of this study is to investigate the relationship between AC, volumetric bone mineral density (vBMD), OC, 25(OH)D and vertebral fracture in Asian women. Design: A total of 769 patients were included in this study. All patients underwent quantitiative computed tomography(QCT). Aortic calcium score (ACS) was quantified by the Agatston scoring method. Spinal fracture was defined by lumbar spine radiography. Subjects: Among 769 subjects, 96 had at least one vertebral fracture, and 345 subjects had AC. Results: ACS correlated with: age, serum OC and 25(OH)D, total hip trabecular BMD (tBMD), femur neck tBMD, and vertebral tBMD. Cortical BMD did not correlate with ACS. After adjusting for age, ACS did not correlate with vBMD, 25(OH)D. However, serum OC level was related with ACS even after age-adjustment. We divided the subjects into 2 groups based on the presence of AC. 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 3-fold increased risk of vertebral fracture. (OR 3.29-3.57; P < 0.05 according to the site)Conclusion: This study suggests that high ACS is related to low trabecular BMD, not cortical BMD. Furthermore, our findings support that this relationship is definitely age-dependent. We also found that serum 25(OH)D and OC level inversely correlated with ACS.

Finally, we found that AC is significantly associated with the prevalence of vertebral fracture in Asian women.