Association between the different phases of menstrual cycle and time domain analysis of heart rate variability in young adult and older adult in Indian Women's

The menstrual cycle is associated with corresponding significant changes in multiple neurohumoral homeostatic mechanisms regulating the cardiovascular system. Heart rate variability [HRV] has proved to be a more sensitive tool for the detection of autonomic balance than mean heart rate [HR]. HRV refers to the beat-to-beat alterations in heart rate. Hence, the present study was undertaken to assess the HRV in different phases of menstrual cycle in young adult and older adult women's. The present study was conducted after the institutional ethical clearance. About 90 subjects were recruited and are divided into 2 groups as young adult and older adult subjects. The influence of menstrual cycle on the HRV was investigated in 3 different phases and compared between young adults and older adult women. The HRV evaluation was done in the time domain in accordance to the task force. Analysis of HRV in the time domain was done using the software Version1.1, AIIMS, New-Delhi. The data obtained was analyzed using student's't' test followed by Mann Whitney-U test and P< 0.05 was considered the level of significance. The mean value of SDANN in Group-1 showed non significantly higher values in the follicular phase whereas, when the SDANN values among the phases of menstrual cycle in the Group-2, there was no significant difference, but the values were high for luteal phase. Time domain analysis of these two groups in Luteal phase showed that SDANN of Group-2 was significantly higher [p<0.05] than Group-1 during normal breathing. This study concludes a slow and steady decline in autonomic modulation with age, which may have a close interaction with hormonal activity.