Parasympathetic Nerve Function Status During Different Phases Of Menstrual Cycle In Healthy Young Women

Background: Autonomic nerve function status may be changed during follicular and late lutealphases of menstrual cycle due to fluctuations of serum estrogen and progesterone levels. Thisalteration in autonomic nerve functions may affect cardiovagal control and usually associated withdecreased parasympathetic activity in late luteal phase. Objective: To observe the parasympatheticnerve function status during follicular and late luteal phases of menstrual cycle and also theirrelationships with serum estrogen and progesterone levels in healthy young women. Methods: Thiscross-sectional study was carried out in the Department of Physiology, Sir Salimullah Medical College(SSMC), Dhaka from 1st January 2009 to 31st December 2009. A total number of thirty (30) apparentlyhealthy unmarried women age ranged from 20-25 years were studied in both follicular (phase A,control) and late luteal (phase B, study) phases of menstrual cycle. Simple autonomic nerve functiontests like heart rate (HR) response to valsalva maneuver (valsalva ratio), HR response to deep breathing,HR response to standing (30th:15th ratio) were done to assess parasympathetic activity and serumestrogen and progesterone levels were also measured by AxSYM method. All these tests were performedin both follicular and late luteal phases of menstrual cycle of the same subject. Data were analysed bypaired student’s ‘t’ test and Pearson’s correlation coefficient test as applicable. Results: Mean valuesof both HR response to valsalva ratio and HR response to standing (30th:15 th ) were non-significantlydecreased but HR response to deep breathing was significantly (p<0.05) decreased in late luteal phasethan those of follicular phase. Conclusion: From this study it can be concluded that parasympatheticactivity is decreased in late luteal phase of menstrual cycle.