The Effects of Menstrual Cycle Phase on Cardiovascular and Pulmonary Responses to Behavioral and Exercise Stress

The present study was designed to compare the differential cardiopulmonary and hemodynamic responses of Type A and B women to an exercise and a psychological stressor. In addition, the effects of menstrual cycle phase on the resting and response levels of a wide range of physiological variables were explored. Thirty-two women participated in a progressive exercise stress test and a threat of shock video game during both the luteal and follicular phases of the menstrual cycle. Half of these subjects expressed the coronary-prone behavior pattern referred to as Type A, as assessed by the Jenkins Activity Survey. The remaining women were relatively free of these behaviors (Type B). Heart rate, oxygen consumption, carbon dioxide production, minute ventilation, and end-tidal carbon dioxide were monitored and recorded on a breath-by-breath basis. Systolic and diastolic blood pressure measures were taken at 2-min intervals. Results indicated similar baseline, exercise, and behavioral stress responses among Type A and B women. The stress responses were also the same between the follicular and luteal phases for all measured physiological variables. However, resting levels of heart rate, metabolism, and ventilation were all elevated at rest during the luteal phase. A regression analysis based on the exercise heart rate and oxygen consumption data demonstrated that a majority of subjects exhibited heart rate responses in excess of that expected during the psychological stressor. These data are discussed with special reference to possible mechanisms of the pathophysiology of cardiovascular disease.