Gender Difference in Bone Loss and Vascular Calcification Associated with Age

Background and Objectives: It is widely known that both bone loss and vascular calcification are age-related processes. The purpose of this study was to investigate the relationship between coronary artery calcium (CAC) score or bone mineral density (BMD) with age and whether there is a gender difference factoring in the two conditions among healthy subjects. Subjects and Methods: Between March 2009 and August 2011, participants included 1727 subjects (mean age: $55{\pm}10$ years, M : F=914 : 813) with routine health check-ups. After being categorized into three groups (normal, osteopenia, and osteoporosis) according to the World Health Organization (WHO) diagnostic classification, we estimated BMD by dual energy X-ray absorptiometry (DEXA) and CAC score by dual-source CT (DSCT). Results: There was a significant gender difference among the risk factors, including total-lumbar spine ($1.213{\pm}0.176g/cm^2$ : $1.087{\pm}0.168g/cm^2$, p<0.001) and femur ($1.024{\pm}0.131g/cm^2$ : $0.910{\pm}0.127g/cm^2$, p<0.001) in BMD by DEXA, and CAC score ($68{\pm}227$ : $27{\pm}116$, p<0.001) in coronary artery calcification by DSCT. Age in male [odds ratio (OR): 1.138 {95% confidence interval (CI): 1.088-1.190}, p<0.001] and menopause in female subjects {OR: 12.370 (95% CI: 3.120-49.047), p<0.001} were, respectively, independently associated with osteopenia. Conclusion: Although our results do not demonstrate a direct association between CAC score and BMD in both genders, there is a gender difference of CAC score in normal and osteopenia groups according to the WHO diagnostic classification. Additionally, we suggest that more specific therapeutic strategies be considered during any early bone loss period, especially in female subjects.