Ambulatory Blood Pressure Reactivity as a Moderator in the Association Between Daily Life Psychosocial Stress and Carotid Artery Atherosclerosis

OBJECTIVE: We examined whether associations between daily psychosocial stressor exposures and carotid artery intima-medial thickness (IMT) may be stronger among those showing larger stress-related cardiovascular reactivity (CVR) during the course of daily living. METHODS: A total of 474 healthy working adults (ages 30-54 years) collected ambulatory blood pressure and recorded their daily experiences, using electronic diaries, during two 2-day periods for a week. Measures of mean momentary task strain and social conflict were used as indices of stressor exposure, and partial regression coefficients linking momentary strain and conflict with ambulatory blood pressure fluctuations were used as measures of CVR. IMT was assessed in the carotid arteries using B-mode ultrasound. RESULTS: After covariate adjustment, associations between mean task strain exposure and IMT were significant among those high in CVR to strain (for systolic blood pressure, p = .006, for diastolic blood pressure, p = .011) but not among those low in strain CVR. Similarly, associations involving mean conflict exposure were significant among those high in CVR to social conflict (p < .001 for systolic blood pressure, p = .001 for diastolic blood pressure) but not among low social conflict reactors. Significant moderation effects were more consistently shown for task strain than for social conflict, but the overall pattern of results was robust across two different types of statistical modeling procedures. CONCLUSIONS: Individual differences in CVR may moderate the effects of daily psychosocial stress on subclinical CVD among healthy employed adults. Using ecological momentary assessment to measure stress exposure as well as stress reactivity may facilitate our ability to detect these effects.