Impact of Age at Menopause on Autonomic Cardiovascular Function

Following menopause, cardiovascular disease and hypertension risk increases in females potentially due to impaired autonomic cardiovascular control. However, age at menopause varies, with earlier menopausal onset being associated with higher blood pressure (BP). Thus, it may be important to understand the effect of the timing of menopause onset on autonomic cardiovascular control measures such as baroreflex sensitivity (BRS) and heart rate variability (HRV). This study aimed to examine the impact of age at menopause onset on autonomic cardiovascular control measures. We hypothesized that females with early menopausal onset would have lower BRS and lower HRV compared with females who experienced menopause at a later age. Forty-six postmenopausal females (56-66 years) were categorized into early (≤49 years; n=26) or late (≥53 years; n=20) menopause onset groups. Heart rate (HR) and R-R intervals (RRI) were measured via 3-lead ECG, and beat-to-beat BP was measured using finger plethysmography. Cardiovagal BRS (cvBRS) was measured during phase IV of the Valsalva maneuver using the slope of the relationship between RRI and systolic BP (SBP). HRV was measured during a 5-minute rest and reported as the standard deviation of RRI (SDRR), root mean square of successive differences (RMSSD), low frequency (LF) power, high frequency (HF) power, and LF/HF ratio. Independent sample t-tests were used to compare demographics and autonomic cardiovascular variables. Data are presented as mean ± SD. At baseline, there were no differences between early versus late menopause groups in HR (62±7 bpm vs. 61±9 bpm; P=0.625), SBP (134±14 mmHg vs.124±19 mmHg; P=0.066), or diastolic BP (79±7 mmHg vs. 75±9 mmHg; P=0.083). For cvBRS in early (n=21) versus late onset (n=15) groups, the early onset group had lower cvBRS compared to the late onset group (6.30±2.76 ms/mmHg vs. 9.42±4.68 ms/mmHg; P< 0.05). Regarding HRV, there were no differences observed for SDRR (47.8±25.0 ms vs. 42.0±18.6 ms; P=0.368) and RMSSD (41.4±35.5 ms vs. 31.4±19.0 ms; P=0.230) between early versus late menopause groups. In the early onset group, there was a lower LF (43.2±22.6 nu, 66.6±21.0 nu; P< 0.05), higher HF (55.7±21.1 nu, 32.6±19.9 nu; P< 0.05), and a lower LF/HF ratio (1.32 ± 1.71; 4.48 ± 5.69; P< 0.05) compared to the late onset group. In summary, early menopausal onset females had lower BRS, lower LF, higher HF, and a lower LF/HF ratio compared to late menopausal onset females, which suggests that the age of onset of menopause has complex physiological implications for autonomic cardiovascular control. Future work should examine the mechanisms underlying these differences to clarify how age at menopause influences long-term cardiovascular risk. Funding: AHA (191PLOI34680015) and NIH (T32HL007936) 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.