LAUSR

Sleep is an essential part of women’s health and well-being. Hormonal fluctuations that occur across the menstrual cycle or when approaching menopause might affect sleep quality. Most studies rely on self-reported data, or laboratory measures in small samples, to examine changes in sleep across the menstrual cycle. Here, we investigated sleep quality, as measured continuously with a wearable device, across the menstrual cycle in different reproductive stages (reproductive, menopausal transition). 56 women participated, with 31 in the reproductive stage (age: 24.65 +/- 6.09 years) and 25 in the early menopausal transition (47.36 +/- 2.78 years). Participants were healthy, without sleep disorders, and free of premenstrual and mood complaints, as well as not using hormonal contraceptives. Sleep was tracked with the Oura ring across an entire menstrual cycle – confirmed as ovulatory using ovulation tests. Participants also completed a sleep diary each morning, rating sleep quality and how refreshed they felt. Measures were averaged for four phases: menses, ovulation, mid-luteal, late-luteal. Participants were assessed for mood symptoms (DASS-21) once during each of these phases. Objective measures of sleep quality (Total Sleep Time, Efficiency, and Wake After Sleep Onset) did not change across the menstrual cycle in either group or differ between groups. Similarly, self-reported sleep and mood symptoms remained stable across the menstrual cycle, although women in the menopausal transition reported poorer sleep quality and felt less refreshed than reproductive stage women, overall. Physiological measures (Temperature, Heart Rate, and Heart Rate Variability) during sleep reflected the well-known fluctuations across the menstrual cycle (e.g., increased temperature in the luteal phase vs. menses) in both groups of women. Objective, wearable-derived measures indicate sleep quality remains stable across the menstrual cycle during reproductive and early-menopausal transition stages, at least in healthy women without mood or premenstrual complaints. While women in the menopausal transition reported a poorer sleep quality, there was no difference in objective sleep continuity measures between groups. Future studies are needed to better understand sleep across the reproductive lifespan, considering cycle-related (e.g., premenstrual syndrome) and other factors that could make some women sensitive to menstrual cycle effects on sleep. NIH, RF1AG061355 (BAKER/MEDNICK)