Greater intima–media thickness in the carotid bulb is associated with reduced baroreflex sensitivity

The aim of this study was to evaluate the association between resting baroreflex sensitivity (BRS) and carotid intima–media thickness (IMT), a putative marker of subclinical atherosclerosis. Participants were 64 men and 18 women (median age, 57 years; range, 40 to 70 years), who did not have a previous history of coronary artery disease or treatment for hypertension. Resting BRS was measured during a 9-min baseline period using the noninvasive sequence technique; carotid IMT was subsequently determined using ultrasonography. Hierarchical multiple regression analyses showed that greater IMT in the carotid bulb (an area with a high density of baroreceptors) was associated with reduced BRS. These findings remained after adjusting BRS for resting mean arterial pressure, age, body mass index, gender, and smoking history, R2 = 0.06, P = .03. In contrast, IMT in the common and internal carotid regions (areas with presumably lower baroreceptor densities) did not account for a significant proportion of the variance in BRS. These results suggest that subclinical atherosclerosis, specifically in a region with high baroreceptor density, is associated with a reduced sensitivity of the baroreflex.