Comparison of Cardiovascular Disease Risk Factors Between 2 Subclinical Atherosclerosis Measures in Healthy Postmenopausal Women Carotid Artery Wall Thickness and Echogenicity

Objectives Although carotid artery intima media thickness (CIMT) is a widely used determinant of subclinical atherosclerosis, gray-scale median of the intima-media complex (IM-GSM) of the common carotid artery is a relatively novel measure of echogenicity reflecting composition of the arterial wall. It is important to compare cardiovascular disease (CVD) risk factor correlates across CIMT and IM-GSM to determine whether these measures reflect distinct aspects of atherosclerosis. Methods Baseline information from a completed randomized clinical trial of 643 healthy postmenopausal women without clinically apparent CVD was included in this cross-sectional study. The women were on average +/- SD 61 +/- 7 years old, and predominantly non-Hispanic White. CIMT and IM-GSM were measured by high-resolution B-mode ultrasonogram in the far wall of the right common carotid artery. CVD risk factors including age, race, body mass index (BMI), smoking, weekly hours of physical activity, systolic (SBP) and diastolic blood pressure (DBP), lipids, glucose, and inflammatory markers were measured at baseline. Linear regression models were used to assess associations of CVD risk factors with CIMT and IM-GSM. Multivariable models included groups of risk factors added one at a time with and withoutbasic demographic factors (age, race, BMI, physical activity) with model R-2 values compared between CIMT and IM-GSM. Results In multivariable analysis, age, Black race, BMI, SBP, and DBP were associated with CIMT (all P < .05), whereas age, Hispanic race, BMI, SBP, physical activity, LDL-cholesterol, and leptin were correlates of IM-GSM (all P < .05). Adjusted for age, race, BMI, and physical activity, the R-2 value for SBP was greater for CIMT association, whereas R-2 values for lipids, glucose, inflammatory markers, and adipokines were greater for IM-GSM associations. Conclusions CIMT and IM-GSM assess different attributes of subclinical atherosclerosis. Integrating both measures may provide improved assessment of atherosclerosis in asymptomatic individuals.