Gender differences in systolic, diastolic, and mean blood pressures,cardiac output, and total systemic resistance during stress and recovery in hypertensive subjects.

Abstract

Striking differences in the acquisition of high blood pressure between men and women have been observed. Men have also shown significantly higher risk of developing coronary heart disease and related deaths than women. No clear explanation exists for these gender differences. This study evaluated possible gender-related differences in cardiac reactivity to acute stress. Variables studied were cardiac output (CO), blood pressure (BP) and total systemic resistance (TSR) during two types of stress, and during each recovery period. It was hypothesized that women would evidence less reactivity than men. Sixty-nine hypertensive patients (44 men and 25 women) served as subjects. Following medication withdrawal, psychophysiologic reactivity was assessed employing cardiac impedance and automated BP measurement. Reactivity testing included: 20-minute self-relaxation baseline, serial 7's subtraction task, six-minute recovery, and 90-second cold pressor task with recovery. This study utilized a three-factor MANOVA design with repeated measures on 2 factors. No differences were seen with regard to gender for any variable. For all subjects, a highly significant difference between tasks was seen in each analysis (E < .001). A highly significant difference was observed between stressor and recovery periods in all analyses (E < .001). Interactions were significant between gender and task (E < .074), gender and period (E < .148), and task and period (E < .001). These results suggest that, among hypertensive patients, in regard to the specific tasks of mental arithmetic and cold pressor, gender related differences in cardiac reactivity are not significant. This conclusion must, however, be qualified in that (1) all subjects were referred for self-regulation training (2) the tasks selected may not be gender sensitive, (3) data on menstrual cycle phase are unavailable and (4) the homogeneity of the sample (all hypertensives) may limit the possibility of observing differences. Despite the absence of significant gender differences observed in this study, reactivity assessment appears to provide an exciting and objective foundation for further exploration into the uncharted waters of human psychophysiology.