Abstract

Background: Menstruation involves a cyclic expulsion of sanguinous fluid and a sloughing of uterine wall in a female and is a typical feature of the reproductive cycle in humans and subhuman primates. The variations in radial artery distensibility are typical in the natural menstrual cycle. Respiratory function is influenced by female sexual hormones, especially progesterone, which could increase ventilator at rest and soon after exercise.

Objective: To study the cardiorespiratory changes during mid-follicular phase and early luteal phases of menstrual cycle before and soon after exercise.

Materials and Methods: The samples were collected from young unmarried and nonpregnant women of age group 17 and 25 years from Government General Hospital, Madras Medical College. Blood was drawn during the mid-follicular phase and early luteal phase of menstrual cycle; the serum was separated and stored at 20C. The separated serum was used for quantitative determination of estradiol (E2) concentration by SMAR Test diagnostics and for progesterone determination using hormone kit. Cardiac output, peripheral blood flow, expiratory blast test, performance of isotonic exercise, and cardiac output measurement were performed, and the comparison was made between the different phases of parameters.

Result: Cardiac output, peripheral blood flow, and expiratory blast test were performed, and the comparison was made between the parameters. Female subjects show higher ventilatory responses in the luteal phases than in the follicular phase without a change in VO2. Progesterone stimulates respiration and the alveolar PCO2 in women during the luteal phase of menstrual cycle, which is lower than that in men. During exercise, the muscle blood flow can increase a maximum of about 25-fold, the value being 90 mL/100g muscle/min from resting blood flow of 3.6 mL/100 g. In expiratory blast test, a normal subject can increase the mercury column to 55–100 mm or more during a single forceful expiration.

Conclusion: The result suggests that cardiovascular parameters were more affected in follicular phase after exercise. Respiratory parameters were more affected in luteal phase after exercise. Change in peripheral blood flow was found to show marked effect than in cardiac output.

Key words: Mid-follicular phase, early luteal phase, cardiac output, expiratory blast test