Increased baseline sympathetic baroreflex sensitivity was associated with increased muscle sympathetic nerve activity during mental stress in postmenopausal females (-3.3 vs -1.9, p=0.02).
Observational (n=25)
In healthy postmenopausal females, increased baseline sympathetic baroreflex sensitivity is associated with increased muscle sympathetic nerve activity during cognitive stress.
Absolute Event Rate: -3.3% vs -1.9%
p-value: p=0.02
Introduction: Literature suggests that while young females experience similar changes in blood pressure (BP) and heart rate during the Stroop Color Word Test (SCWT), a lower sympathetic baroreflex sensitivity (sBRS) corresponded to an increase in muscle sympathetic nerve activity burst frequency (MSNA), while a higher BRS corresponded with a decrease in MSNA BF. However, how postmenopausal females—who have reduced estrogen levels and altered autonomic regulation—respond to the SCWT remains unknown. The purpose of this study was to test the hypothesis that postmenopausal females would exhibit impaired sBRS modulation of MSNA during the SCWT. Methods: Twenty-five healthy postmenopausal females completed two study visits. Visit 1: Informed consent, medical questionnaire and State-Trait Anxiety questionnaires. Visit 2: blood draw to measure sex hormones, heart rate (electrocardiography), BP (finger plethysmography) and MSNA BF (microneurography) were recorded during a 10-min resting baseline, a 3-min pre-stress baseline, and a 3-min SCWT. Participants were divided into groups based on whether MSNA BF increased (Increased response, IR, n=12) or decreased (Diminished response, DR, n=13) during SCWT. Sympathetic transduction during the SCWT was calculated using the delta-delta method (∆MAP/∆MSNA) from baseline to the last 30 sec of the SCWT. Sympathetic BRS was quantified using 3-mmHg bins of diastolic BP and MSNA burst incidence from the 10-min baseline. Results: Age (IR: 58 ± 5; DR: 60 ± 6yrs, p=0.28), BMI (IR: 26 ± 4; DR: 24 ± 34kg/m2, p=0.16), estradiol IR: 23± 11; DR:27 ± 24pg/mL, p=0.61), testosterone (IR: 21 ± 10: DR: 20 ± 9ng/dL, p=0.38), state-anxiety (IR: 29 ± 6; DR: 32 ± 10a.u., p=0.40), and trait-anxiety (IR: 29 ± 6; DR: 29 ± 8a.u., p=0.99) were similar between groups. Further, baseline MAP (IR: 93±7; DR: 93± 9mmHg, p=0.83), heart rate (IR: 62± 6; DR: 61± 7bpm, p=0.90), MSNA (IR: 32 ± 7; DR: 33 ± 11bursts/min, p=0.61), and sympathetic transduction (IR: 1 ± 7; DR: -1 ± 2∆mmHg/∆bursts/min., p=0.27) were similar between groups. However, sBRS was steeper in the IR group (-3.3 ± 1.5) compared to the DR group (-1.9 ± 1.2bursts/100 hb/mmHg, p=0.02). There were no associations between BP, HR, MSNA, sympathetic transduction, sBRS, anxiety or sex hormones (p >0.05). Conclusion: In postmenopausal females, MSNA responses to cognitive stress were heterogeneous, with approximately half experiencing decreases and half experiencing increases in MSNA, despite similar changes in MAP. Increased baseline sBRS was associated with increased MSNA during stress, suggesting a role for the sympathetic baroreflex within IR postmenopausal women. The cardiovascular health implications of this relationship remain unclear, but warrant further assessment. This abstract was presented at the American Physiology Summit 2026 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.
Kapeller et al. (Fri,) conducted a observational in Healthy postmenopausal females (n=25). Stroop Color Word Test (mental stress) vs. Diminished MSNA response group was evaluated on Sympathetic baroreflex sensitivity (sBRS) (p=0.02). Increased baseline sympathetic baroreflex sensitivity was associated with increased muscle sympathetic nerve activity during mental stress in postmenopausal females (-3.3 vs -1.9, p=0.02).