Assessing the impact of menstrual cycle phase on respiration rate, resting heart rate, heart rate variability, nocturnal oxygenation and sleep time using wearable devices
Conor Heneghan, Belen Lafon, Logan Schneider, Nichole Young-LinBackground
Prior studies have observed changes in parameters such as respiration rate, heart rate variability, and resting heart rate over the course of the menstrual cycle. However, prior studies have been limited in scale and have not considered concurrent variations in sleep duration or nocturnal oxygenation.
Objectives
To determine the variations in nocturnal respiration rate, heart rate variability, resting heart, main sleep duration and average nocturnal SpO 2 , associated with underlying menstrual cycle timing.
Design
This was a retrospective observational study based on wearable data and self-reported menstrual cycle timing and birth control usage.
Methods
Data was collected over 24 months in women using wearable devices (Fitbit and Pixel Watch) who also self-recorded their menstrual cycles and birth control usage. The study considered 1754 women on hormonal birth control (HBC) pills, and 7279 naturally cycling (NC) women. Self-reported menstrual cycle parameters were consistent with normal physiology, and participants recorded wearable data on greater than 70% of the nights.
Results
By averaging parameters relative to their day within a menstrual cycle, variations were seen in respiration rate (RR), resting heart rate (RHR) and heart rate variability (HRV), dependent on cycle phase. For the NC cohort, RR varied between the assumed follicular and luteal phase by approximately 0.6 breaths/min (∼4% variation,
Conclusion
The menstrual cycle has a small but statistically significant effect on a number of cardiorespiratory variables over a typical cycle. The effect size is largest for changes in resting heart rate, followed by HRV and respiration rate, with effects on main sleep time and SpO 2 being negligible.