Sex Differences in Predictors of Longitudinal Changes in Carotid Artery Stiffness

OBJECTIVE: To identify sex differences in predictors of longitudinal changes in carotid arterial stiffness in a multiethnic cohort. APPROACH AND RESULTS: Carotid artery distensibility coefficient (DC) and Young's elastic modulus (YEM) were measured in 2650 Multi-Ethnic Study of Atherosclerosis participants (45-84 years old and free of cardiovascular disease) at baseline and after a mean of 9.4 years. Predictors of changes in DC and YEM for each sex were evaluated using multivariable linear regression models. The 1236 men (46.6%) were 60.0 (SD, 9.3) years: 40% were white, 22% black, 16% Chinese, and 22% Hispanic. The 1414 (53.4%) women were 59.8 (9.4) years old with a similar race distribution. Despite similar rates of change in DC and YEM, predictors of changes in distensibility markers differed by sex. In men, Chinese (P=0.002) and black (P=0.003) race/ethnicity, systolic blood pressure (P=0.012), and diabetes mellitus (P=0.05) were associated with more rapidly decreasing DC (accelerated stiffening). Starting antihypertensive medication was associated with improved DC (P=0.03); stopping antihypertensives was associated with more rapid stiffening (increased YEM, P=0.05). In women, higher education was associated with slower stiffening (DC, P=0.041; YEM, P<0.001) as was use of lipid-lowering medication (P=0.03), whereas baseline use of antihypertensive medications (YEM, P=0.01) and systolic blood pressure (DC, P=0.02; P=0.04) predicted increasing stiffening in women. CONCLUSIONS: Longitudinal changes in carotid artery stiffness are associated with systolic blood pressure and antihypertensive therapy in both sexes; however, race/ethnicity (in men) and level of education (in women) may have different contributions between the sexes.