Coronary Calcification and Osteoporosis in Men and Postmenopausal Women Are Independent Processes Associated with Aging

Abstract
The objective of this study was to investigate whether low bone mass is directly associated with the severity of coronary atherosclerosis in men and postmenopausal women self-referred for evaluation of coronary atherosclerosis and osteoporosis. Low bone mass was evaluated by measurement of bone mineral density (BMD) using quantitative computerized tomography (QCT). Coronary atherosclerosis was evaluated by measurement of coronary calcium (CC) burden using electron beam computerized tomography (EBCT). Using a cross-sectional design, we tested the hypothesis that osteoporosis and coronary atherosclerosis are correlated, age-dependent processes. Study variables were BMD, CC scores, and other known risk factors for osteoporosis and atherosclerosis. Qualifying for the study were 313 postmenopausal women and 167 men. Men had higher baseline CC scores and higher body mass indexes compared to women. In females, those patients with coronary calcification were older and had significantly lower BMD compared to those without calcification. In males, those patients with coronary calcification were older. By univariate correlation analysis, the degree of coronary calcification was inversely associated with BMD in postmenopausal women (P < 0.0001) but not in men. However, after controlling for age, this association was absent for both men and postmenopausal women. Using multivariate logistic regression analysis in women and men separately, age was the only significant predictor of positive CC status and low BMD. Our study suggests that in postmenopausal women and in men, after controlling for age, osteoporosis and coronary atherosclerosis are independent processes.