Blood pressure and pulse responses to three stressors: associations with sociodemographic characteristics and cardiovascular risk factors.

ABSTRACT

Cardiovascular reactivity is hypothesized to increase the risk of hypertension and other CVD-related conditions. However, studies to date are inconclusive. We compared the association of blood pressure and pulse responses to three stressors (postural challenge, handgrip test, mental arithmetic) with sociodemographic characteristics and CVD risk factors. We included 782 participants from the Hypertension Genetic Epidemiology Study. Blood pressure and pulse responses to stressors were defined as the difference between post- and pre-stress measurements. Stepwise regression analyses examined change in SBP and pulse in response to stressors as a function of sociodemographic and CVD risk factors. Age, race, and gender were forced into models and other variables (education, BMI, waist circumference, resting SBP and DBP, cigarette smoking, LDL and HDL cholesterol, glucose, and antihypertensive medications (beta-blockers, calcium channel blockers, diuretics, ace inhibitors)) were retained if P<0.10. Age was a significant predictor of SBP response to all stressors. The SBP response to a change in posture was not related to other variables. The SBP response to mental arithmetic was significantly higher among men, those with larger waists, higher SBP, beta-blocker users, and lower among smokers. SBP response to the handgrip was significantly higher among those with higher SBP and beta-blocker users. Similarly, the association of the pulse response to the risk factors varied considerably across the stressors. Overall, the socio-demographic and CVD risk factors accounted for between 9 and 14% of the variance in the SBP response to the stressors and from between 4 and 12% of the variance in the pulse response to the three stressors. The associations between sociodemographic and CVD risk factors and the SBP and pulse response to stress were modest and inconsistent across stressors. The findings suggest that cardiovascular reactivity is a concept that needs to be defined in reference to specific stressors so that mechanisms leading to responses can be better understood.