The modulatory influence of different phases of menstrual cycle on the parasympathetic tone in sedentary females-A cross-sectional study

Introduction: The cyclical fluctuating gonadal hormones in a female affect the functioning of the autonomic nervous system & a decline in parasympathetic neural activity is a forerunner to multiple cardiac conditions like MI, angina etc hence its detection at its inception is primary to institute remedial measures. Aim: The aim of the present study was to examine whether the cardiac parasympathetic status of a healthy eumenorrhic female is altered during different phases of menstrual cycle. Materials and Methods- Thirty eumenorrhic females were recruited during the follicular and luteal phases of menstrual cycle & subjected to battery of parasympathetic autonomic tests. Statistical Analysis: Data was analyzed statistically using student’s paired t-test. Results: The results from 30:15 ratio in follicular phase was (1.19 ±0.05) while in luteal (1.08 ±0.05 ), E:I ratio in follicular ( 1.58 ±0.15 ) while in luteal phase was (1.29 ±0.25), Valsalva ratio in follicular (1.89 ±0.32 ) while in luteal phase was (1.73 ±0.34 )while the values of DBD and Tachycardia ratio were insignificant statistically. Conclusion: We hence conclude that there is an obvious interaction between the gonadal hormones and autonomic nervous system which is reflected by a reduced vagal outflow during luteal phase.