Introduction
The menopausal transition is accompanied by hormonal and functional changes that influence cardiovascular and autonomic health. Heart rate variability (HRV) and aerobic capacity are established markers of autonomic and cardiorespiratory function respectively.
Methodology
Study design
A cross-sectional, correlational study recruited 100 women aged 45 to 60 years, equally divided between perimenopausal and postmenopausal groups using stratified random sampling.
Outcome measures
BMI was calculated using the standard formula. Aerobic capacity was assessed with the 6-minute walk test. HRV was recorded with a chest-strap monitor, using the standard deviation of normal-to-normal intervals (SDNN) as the primary metric.
Results
The mean HRV was significantly higher in perimenopausal women (51.5 ms) than in postmenopausal women (44.8 ms), with P = 0.003, indicating a decline in autonomic function as menopause advances. A weak negative correlation was observed between BMI and aerobic capacity, while HRV and the 6-minute walk test were not significantly correlated.
| Variable | Perimenopausal | Postmenopausal | P value |
|---|---|---|---|
| HRV / SDNN (ms) | 51.5 | 44.8 | 0.003 |
| 6-MWT distance (m) | 483 | 470 | 0.247 |
Discussion
The pronounced decline in HRV after menopause is consistent with reduced parasympathetic tone associated with falling oestrogen. The minimal correlation between aerobic capacity and HRV suggests each reflects a distinct dimension of health.
Conclusion
Higher BMI and reduced aerobic capacity are moderately associated, whereas HRV declines independently after menopause. Tailored interventions targeting weight, fitness, and autonomic regulation are recommended.