Cardiovagal Baroreflex Sensitivity in Pre- and Perimenopausal Women

Reductions in cardiovagal baroreflex sensitivity (cBRS) with aging are well established. While postmenopausal women have lower cBRS than premenopausal women (PRE), it has yet to be determined if reductions in cBRS occur during the menopausal transition (i.e., perimenopause) when sex hormones, which influence autonomic function, are altered. Therefore, the purpose of this study was to investigate the hypothesis that cBRS would be attenuated in PERI compared to PRE. cBRS was assessed using a Valsalva maneuver in twenty-three healthy, normotensive women (PRE: n=14, 26±7yrs, BMI:22±3kg/m 2 ; PERI: n=9, 51±3yrs, BMI:24±3kg/m 2 ). Subjects were instructed to forcefully exhale into a pressure-gauge mouthpiece for 15 seconds at 40 mmHg. Heart rate was measured via ECG and beat-by-beat blood pressure (BP) was measured via finger photoplethysmography (Finapres Medical Systems, Amsterdam, The Netherlands). The slope of the relation between changes in systolic BP and R-R interval during phase II (pressure decline) and phase IV (pressure increase) of the Valsalva were assessed as the index of cBRS. Resting systolic BP (PRE: 107±7mmHg vs. PERI: 114±10mmHg, p>0.05) and diastolic BP (PRE: 67±7mmHg vs. PERI: 69±6mmHg, p>0.1) were not different between groups. cBRS was not different between groups during phase II (PRE: 7.1±3.6ms/mmHg vs. PERI 5.1±4.1ms/mmHg, P=0.24), but was significantly lower in PERI during phase IV (PRE: 15.6±8.0ms/mmHg vs. PERI 6.3±4.6ms/mmHg, P=0.008). There was no significant correlation between cBRS and estradiol (r=0.23; P=0.51) or progesterone (r=0.12; P=0.73), however cBRS was inversely correlated with follicle stimulating hormone (FSH) (r=-0.68; P=0.02) and luteinizing hormone (LH) (r=-0.67; P=0.02). These preliminary data indicate that cBRS is attenuated in PERI relative to PRE, suggesting a decline in cBRS during the menopausal transition. Continued investigation is needed to understand the impact of the menopausal transition, sex hormones, and aging on autonomic function. Supported by NIH R01 HL 146558 This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.