Sex Differences in Longitudinal Determinants of Carotid Intima Medial Thickening With Aging in a Community-Dwelling Population: The Baltimore Longitudinal Study on Aging

Abstract

Background Common carotid intima medial thickness (IMT) increases with aging. However, the longitudinal association between IMT and other age-associated hemodynamic alterations in men and in women are not fully explored. Methods and Results We analyzed repeated measures of IMT, blood pressure, and carotid-femoral pulse wave velocity over a 20-year period in 1067 men and women of the Baltimore Longitudinal Study on Aging; participants were ages 20 to 92 years at entry and free of overt cardiovascular disease. Linear mixed-effects models were used to calculate the individual rates of change (_Change) of IMT, pulse pressure, mean arterial pressure, and pulse wave velocity, among other covariates. Multivariate regression analysis was used to examine the association of IMT_Change with baseline and rates of change of hemodynamic parameters and cardiovascular risk factors. IMT increased at accelerating rates from 0.02 mm/decade at age 50 years to 0.05 mm/decade at age 80 years greater rates in men than in women. IMT_Change was positively associated with baseline low-density lipoprotein, low-density lipoprotein_Change, and baseline systolic blood pressure and systolic blood pressure_Change, but inversely with baseline diastolic blood pressure and diastolic blood pressure_Change. When blood pressure was expressed as pulse pressure and MAP, IMT_Change was positively associated with baseline pulse pressure and pulse pressure_Change and inversely with baseline mean arterial pressure and mean arterial pressure_Change. In sex-specific analysis, these associations were observed in women, but not in men. Conclusions In summary, our analyses showed that IMT increases at accelerating rates with aging. Age-associated changes in IMT were modulated by concurrent changes of low-density lipoprotein in both sexes, and of pulsatile and mean blood pressure in women but not men.

Keywords: aging; hypertension; intima‐medial thickness; longitudinal.

Figure 1. Cross‐sectional differences and longitudinal changes of IMT in men and women.

Cross‐sectional differences and longitudinal changes of IMT in men and women across decades, from age 50 to 90 years. IMT increases cross‐sectionally across decades as indicated by the higher starting point for each decade. The slopes for each decade indicate the rate of increase of IMT in that decade, and the slope is steeper in the older decades. This indicates that IMT increases at higher rates in the older age groups. In summary, IMT starts higher and increases faster in the older decades. IMT indicates intima medial thickness.