Comparative Analysis of Heart Rate Variability During Different Phases of Menstrual Cycle in Eumenorrhea & Dysmenorrhea Subjects

Abstract

Introduction. The reproductive system of women shows regular cyclic changes that teleologically may be regarded as periodic preparations for fertilization and pregnancy [4]. Painful menstruation otherwise called Dysmenorrhea is a common gynecological problem in females of a reproductive age group. Primary dysmenorrhea has prevalence up to 70 % of young females (3). Severe dysmenorrhea is associated with restriction of activity and absenteeism from school and work & this affects academic performance & social activities [6, 15, 23]. Few studies have reported some degree of autonomic imbalance in primary dysmenorrhea [11, 17]. Autonomic nervous system (ANS) regulates the function of various systems in human body to maintain homeostasis and adaptation to stressful situations [12]. Autonomic nervous system of the intrinsic cardiac pacemakers modulates beat to beat variability in heart’s rhythm. Analysis of HRV provides a more sensitive noninvasive measure of cardiac autonomic regulation than catecholamine levels and skin conductance [19]. Autonomic nervous system & endocrine system interact with each other to alter many physiological functions [15] but the extent to which it is related to dysmenorrhea is not yet understood. In eumenorrhea subjects significantly greater HRV and increased vagal activity in follicular phase and increased sympathetic activity during luteal phase is showed by [16, 17, 21]. Since there is paucity of information on the influence of ANS on the changes in time domain parameters of HRV, this study was intended to compare HRV changes during menstrual, follicular and luteal phases of menstrual cycle in both eumenorrhea and dysmenorrhea groups. Aim. This study had been planned to compare the autonomic activity among eumenorrhea & dysmenorrhea subjects. Materials and methods. A longitudinal observational study was conducted among 60 female volunteers aged between 18 & 25years in the department of physiology in M.S. Ramaiah Medical College Hospital & Research centre in Bangalore after obtaining Institutional Ethics Committee clearance before the commencement of the study. The subjects were explained the testing procedure and protocol. Informed consent was obtained prior to participation in this study. A detailed medical and menstrual history was obtained from all participants. Standard anthropometric measurements like height, weight, body mass index (BMI) were recorded. Inclusion criteria. Females between the age group of 18-25years having regular menstrual cycles (21-35days) were included. Females experiencing dysmenorrhea for the last three months with every menstruation & who are not on any medication were considered as cases. Females who are not suffering from dysmenorrhea were considered as eumenorrhea subjects. Exclusion criteria. Females with irregular menstrual cycles, or taking treatment for dysmenorrhea like OCPs were excluded. Females who are diag-