Comparison of cardiac autonomic functions among postmenopausal women with and without hormone replacement therapy, and premenopausal women.

The aim of present study was comparison of cardiac autonomic status during different phases of reproductive life in women - in premenopausal women between proliferative and secretory phase, in postmenopausal women and in postmenopausal women receiving hormone replacement therapy (HRT). The study included 30 premenopausal women (Group 1) who were assessed in both proliferative (Group 1A) and secretory phase (Group 1B) of menstrual cycle, 30 postmenopausal women (Group 2) and 30 postmenopausal women on HRT (Group 3). Various autonomic function tests were done to assess parasympathetic and sympathetic functions. Results were obtained by ANOVA followed by Tukey test. The postmenopausal women (Group 2) showed increased sympathetic and decreased parasympathetic tone compared to premenopausal women (Group1). The women on HRT (Group 3) showed parasympathetic dominance and decrease in sympathetic activity compared to postmenopausal women (Group 2). Across the menstrual cycle, increased parasympathetic activity was seen in secretory phase while no change was observed in the sympathetic activity in the two phases.