Age-related differences in cardiovascular reactivity during acute psychological stress

We examined potential age and gender differences in cardiovascular reactivity during acute psychosocial stress in 133 nor-motensive participants using a cross-sectional design. Results revealed that age predicted increased systolic blood pressure (SBP) reactivity during stress (p<.001). The greater SBP reactivity found in older individuals appeared due to an age-associated increase in both cardiac output and total peripheral resistance during stress as statistically controlling for these changes rendered the age and SBP reactivity effect nonsignificant. Similar analyses revealed that the age-related increase in cardiac output reactivity appeared to be driven by increased cardiac sympathetic control ofmyocardial contractility as measured by pre-ejection period. Older individuals also had greater vagal withdrawal during stress compared to younger individuals as indexed by respiratory sinus arrhythmia (p <.01). These results were comparable for men and women, and could not be explained by task-specific affective responses, task performance, or demographic factors. Implications for the study of age, cardiovascular reactivity, and health are discussed. AGING is associated with changes in physiological function l \ that confer increased vulnerability to physical health prob-lems (Kart, Metress, & Metress, 1992; Timiras, 1994). There are well-documented age-related differences in resting cardio-vascular function (e.g., increased blood pressure) that may in-fluence cardiovascular disease risk (Timiras, 1994). However, much less is known about the influence of age on cardiovascu-lar reactivity during psychosocial stress (Boutcher & Stocker, 1996; Jennings et al., 1997). According to the reactivity hypoth-esis, stress-induced changes in cardiovascular function may be independent predictors of the development and expression of cardiovascular disease (Kamarck et al., 1997; Krantz et al.