Coronary calcification detected by electron-beam computed tomography and non-coronary measures of atherosclerosis:
the Rotterdam study.
Coronary calcification as detected by electron-beam tomography (EBT) is a measure of coronary atherosclerosis. We investigated whether coronary artery calcium is associated with non-coronary measures of atherosclerosis, using data from the population-based Rotterdam Study. Participants in the third phase of the study were invited to undergo EBT scanning for detection of coronary calcifications. EBT scans were obtained from 2263 participants (47% men, mean age (SD), 71.3 (5.7)). Quantification of coronary calcifications was performed using Agatston’s method, and resulted in a calcium score. Calcium scores were available for 1874 subjects. Measures of non-coronary atherosclerosis included presence of aorta calcification detected by X-ray, presence of plaques in carotid arteries and intima-media thickness of the common carotid artery, both detected by ultrasonography, and ankle to brachial blood pressure index as a measure of peripheral arterial disease. Three calcium score categories were considered: 0 - 100, 101 - 500, and >500. The calcium score showed a graded association with the measures of non-coronary atherosclerosis. Using logistic regression analysis, age and sex adjusted odds ratios for aorta calcification were 3.2 (95% confidence interval, 2.0 - 5.2) in subjects with calcium score 101 - 500 and 12.0 (7.6 - 18.9) in subjects with calcium score > 500, when compared to subjects in the lowest calcium score category. The corresponding odds ratios for carotid plaques were 2.4 (1.6 - 3.5) and 5.8 (3.9 - 8.6). In a general linear model adjusted for age and sex, mean intima-media thickness increased with increasing calcium score category, while mean ankle to brachial blood pressure index decreased. These results indicate that known measures of non-coronary atherosclerosis are strongly related to coronary atherosclerosis, as measured by EBT calcium.