Age-related differences in cardiovascular reactivity during acute psychological stress in men and women.
We examined potential age and gender differences in cardiovascular reactivity during acute psychosocial stress in 133 normotensive 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 of myocardial 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.