The association of coronary artery calcification and carotid artery intima-media thickness with distinct, traditional coronary artery disease risk factors in asymptomatic adults

Abstract

Coronary artery calcification (CAC) and common carotid artery intima-media thickness (CIMT) are measures of subclinical vascular disease. This 2000-2006 study aimed to characterize the associations among coronary artery disease risk factors, CAC quantity, and CIMT and to estimate shared genetic and environmental contributions to both CAC and CIMT among 478 asymptomatic Amish adults in Lancaster County, Pennsylvania. Heritability for CAC quantity and CIMT, adjusted for age and sex, was 0.42 (P = 0.0001) and 0.29 (P = 0.003), respectively. CAC quantity and CIMT were modestly correlated (adjusted r = 0.14, P = 0.003) but showed little evidence of shared genetic or environmental factors. However, significant genetic correlations were found for CAC quantity and total cholesterol (0.44 (standard error, 0.19); P = 0.03), for CAC quantity and low density lipoprotein cholesterol (0.55 (standard error, 0.17); P = 0.005), and for CIMT and waist circumference (0.58 (standard error, 0.25); P = 0.046), suggesting shared genes for these risk factors and measures of subclinical disease. Results suggest that some of the same genes influence variation in CAC and low density lipoprotein cholesterol, whereas a different set of genes influences variation in CIMT and waist circumference.

Figure 1.

Heritability of quantity of coronary artery calcification (ln(CAC score + 1)), adjusted for age, age², age × sex, and age² × sex, with further adjustment for other coronary artery disease risk factors, among Old Order Amish study subjects from Lancaster County, Pennsylvania, 2000–2006. BMI, body mass index; CHOL, total cholesterol; DBP, diastolic blood pressure; HDL-C, high density lipoprotein cholesterol; LDL-C, low density lipoprotein cholesterol; PP, pulse pressure; SBP, systolic blood pressure; TG, triglycerides; Waist, waist circumference. Each vertical line and centered box represents heritability (standard error).

Figure 2.

Heritability of common carotid artery intima-media thickness (lnCIMT), adjusted for age, age², age × sex, and age² × sex, with further adjustment for other coronary artery disease risk factors, among Old Order Amish study subjects from Lancaster County, Pennsylvania, 2000–2006. BMI, body mass index; CHOL, total cholesterol; DBP, diastolic blood pressure; HDL-C, high density lipoprotein cholesterol; LDL-C, low density lipoprotein cholesterol; PP, pulse pressure; SBP, systolic blood pressure; TG, triglycerides; Waist, waist circumference. Each vertical line and centered box represents heritability (standard error).