Gender differences in autonomic functional status in response to stress

Abstract

Introduction: Men and women are similar in their cognitive appraisal of a stress. But their behavior is different when exposed to stress. As stress responses and cognitive abilities are closely associated with autonomic nervous system, an attempt had been made to evaluate the behavioral pattern of autonomic functional status in males and females under stressed conditions. Methodology: 30 normal young male and female students (15 each) participated in this study. Systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR) and heart rate variation (HRV) were recorded before and after postural change, Valsalva maneuver and cold exposure. Results: SBP and DBP decreased and HR increased after standing from lying posture (p < 0.000) in both the genders. But the changes were less in males than in females (SBP and HR – non significant, DBP p < 0.008,) 30:15 ratio was higher in males (p < 0.001) upon standing. After Valsalva maneuver, SBP decreased (p < 0.05) and DBP increased (p < 0.000) with a higher Valsalva ratio (p < 0.002) in females than in males. After exposure to cold, males showed more decrease in SBP and DBP and less increase in HR (non-significant) than females. Discussion: Results reveal more sympathetic activity in males than in females when exposed to stress. This may be because of the altered baroreceptor mechanism, male-female type of fat distribution, difference in vascular bed resistance, influence of cortisol and hypothalamus-pituitary-adrenal axis. Conclusion: The fact that females have less tolerance to stress may help us in understanding the sex linked pathophysiology of cardiovascular diseases and developing a different approach in treating the similar cardiovascular disease in men and women.