Potential of quantity of coronary artery calcification to identify new risk factors for asymptomatic atherosclerosis

The goals of this study of adults asymptomatic for coronary artery disease (CAD) were to examine the relations between established CAD risk factors and quantity of coronary artery calcification (CAC) in three arterial locations using generalized linear mixed models and to estimate the variability in quantity of CAC explained by established CAD risk factors and the variability due to noise or artifact in the measure. The community-based sample included 740 asymptomatic adults (378 women) aged 20-59 years without hypertension or diabetes. Participants were recruited from Rochester, Minnesota, between 1990 and 1994. Quantity of CAC in three arterial locations was detected noninvasively by electron beam computed tomography. Sex, arterial location, age, body size, blood pressure, lipid metabolism, and smoking were significantly (p < 0.05) associated with quantity of CAC. Age was more strongly associated with quantity of CAC in the left than in the right coronary or circumflex arterial locations (p < 0.005). In each sex, risk factors together explained less than 40% of the variability in quantity of CAC. Noise or artifact in the measure accounted for only a small proportion of unexplained variability. Future studies of new risk factors for artery-specific quantity of CAC and its progression could provide additional etiologic insights into the atherosclerotic process.