Age predominates as associate than reproductive health stage for 5 min heart rate variability in middle aged women- a cross-sectional study from Gujarat, India.

Introduction: Cardiovascular health is adversely affected by menopausal transition with reduced heart rate variability (HRV) as a manifest. Electrocardiogram (ECG) based 5 min HRV has worsening trend from premenopausal to postmenopausal stage, but age is the biggest confounder. We aimed to study 5 min HRV among age-matched sample population of premenopausal, perimenopausal and postmenopausal healthy women. Methodology: A cross-sectional field study was conducted on apparently healthy women of 40-55 years of age. STRAW+10 criteria were used to stratify reproductive health stage groups. Lead II ECG-based 5 min HRV (VarioWin HR software) was recorded in supine position using standard protocol. Meticulous age matching was used to create premenopausal, perimenopausal (early and late), and postmenopausal (early and late) subgroups. Various age-matched pairs of subgroups were compared for time domain, frequency domain, and geometric HRV parameters. Results: There was a lack of significant difference among premenopausal, perimenopausal and postmenopausal subgroups. Difference of HRV was small, insignificant without any general pattern in age matched pair of: premenopausal verses early perimenopausal group ( Conclusion: Middle aged healthy women revealed lack of difference of 5 min HRV parameters between premenopausal, perimenopausal or postmenopausal women after age-matching. This lack of association indicates age and other confounders as significant attribute for HRV than the reproductive health status of women, and its calls for further study for reinforcement and causality.