Q+A: Fiona Baker, PhD, on sleep disturbances in menopause and the role of vasomotor symptoms

In a discussion with Contemporary OB/GYN, Fiona Baker, PhD, director, Human Sleep Research Program, SRI International, discusses how vasomotor symptoms, including hot flashes and night sweats, play a distinct role in disrupting sleep during the menopause transition. Baker explains that hot flashes occurring at night are associated with sleep disturbance and awakenings, often leaving women unable to fall back asleep, and that sleep EEG research has helped clarify how these symptoms interact with the sleeping brain, revealing both brief arousals and longer awakenings tied directly to nighttime hot flashes.

Baker also addresses the longer-term cardiovascular and cognitive implications of sustained sleep disruption during menopause. She points to research showing that nighttime awakenings, including those triggered by hot flashes, can blunt the body's normal overnight restoration of heart rate and blood pressure, and notes that longitudinal data have linked menopausal sleep disturbance to increased long-term cognitive and cardiovascular risk.

Baker was a co-author on the abstract "Effects of elinzanetant on wakefulness after sleep onset in postmenopausal women: Post hoc analysis of NIRVANA study," which was presented at the SLEEP 2026 Annual Meeting in Baltimore, Maryland.

Read our coverage of the NIRVANA post hoc analysis presented at SLEEP 2026 here.

Contemporary OB/GYN:
Your research focuses on sleep physiology across the lifespan in women—how well does the clinical world currently understand the distinction between primary sleep disorders and sleep disruption that is directly driven by vasomotor symptoms, and does that distinction change treatment?

Fiona Baker, PhD:
A lot of my focus of my research has been on considering issues of sleep in women, whether it's across the menstrual cycle in women who have menstrual-associated disorders, and then also in the menopause transition, which is such a prime time where women are reporting that their sleep is disturbed. I think we're still, from a research perspective, building those blocks of understanding sleep disturbance that's happening in the context of menopause, and what is unique and distinct about that sleep disturbance compared to other kinds of sleep disturbance, whether we're looking at women at different times of their life, or even more broadly at everyone. Sleep disturbance for everyone is a problem that needs to be addressed. Poor sleep quality affects everybody the next day and also has long-term consequences for their health.

When we're looking at women in particular in the menopause transition and post-menopause, one of the unique factors there can be those vasomotor symptoms, or hot flashes and night sweats, because, of course, they happen during the night as well as during the day, and the majority of the hot flashes happening at night are associated with sleep disturbance and awakenings, then women can have trouble going back to sleep. So being aware of what the role is of vasomotor symptoms in the menopause transition and post-menopause is critical when understanding sleep disturbance in the context of menopause.

That said, there are other factors that happen. Sleep is sensitive to so many things. So, in the context of menopause, there's the hormone changes themselves that can be directly affecting sleep, there's the hot flashes and night sweats that can be affecting sleep, and then there are other factors that are related to stress and mood, so those are strongly linked with sleep disturbance. Then post-menopause, there's an increase in risk for sleep apnea, one of the primary sleep disorders, and so when women are postmenopausal, there is a need to also be aware of the potential for sleep apnea that could be disturbing their sleep, so there are these multifactors that need to be considered, and probably need to consider each individual as to what extent those variety of factors may be influencing her sleep.

Contemporary OB/GYN:
What does sleep EEG research tell us about the specific architecture changes that occur during menopause—and how do those changes differ from normal aging-related sleep changes in ways that are clinically relevant?

Baker:
In my research, I have relied a lot on measuring sleep EEG, and what we mean by that is really measuring the brain activity, it's measuring the sleeping brain, and so you get a lot of detailed information about the sleeping brain and the architecture across the night, so a lot more information than you can get from a wearable or from just knowing about your sleep, how you perceive your sleep. The details that you get from that have really helped advance us into understanding more the mechanisms of, for example, how hot flashes are related to awakenings or very brief arousals.

For example, with some of my research, I have been able to look at very precise timings of when there is a hot flash that's measured in the lab, and the measurement of those hot flashes is also measured along with the EEG, and so we can track these very brief arousals that can be less than 15 seconds long, can be very brief, but still impacting someone's sleep. We've shown that those hot flashes are linked both with the very brief arousals and also with longer awakenings during the night, so it's really helpful to understand more of what is happening in menopausal sleep disturbance, what makes it different from other kinds of sleep disturbances.

We can also use that, along with measurements of breathing rate, we can tease apart the contributions of, for example, obstructive sleep apnea events, hot flashes, all these factors that can be disturbing sleep, so it helps us to understand better what's going on.

Contemporary OB/GYN:
What are the longer-term cardiometabolic and cognitive consequences of sustained VMS-related sleep disruption that your research has helped characterize, and are clinicians communicating those risks adequately?

Baker:
I think it's important when we look at sleep disturbance to not only think about the next-day effect, like that somebody's tired because they didn't sleep well. There is strong evidence from a variety of different sources showing the importance for sleep in restoring the body, whether it's restoring, allowing your cardiovascular system to recover on a nightly basis, as well as supporting cognitive function in your brain, and some of my research has looked just at the immediate effects of sleep disturbance associated with menopause and shown that when women are waking up during the night, such as with hot flashes or other reasons, then they are not showing such a strong restoration of their heart rate and blood pressure across the night.

Now, with those studies, it's just looking at one night or a couple of nights in the lab, so we don't know what the long-term impact of that is, but there are some very strong longitudinal studies that have been using those large longitudinal data sets to look at what are the longer-term effects of menopausal sleep disturbances, such as those associated with vasomotor symptoms, and show that there is an increased risk of both cognitive impacts as well as cardiovascular risks in the long term in women who've got sleep disturbances during menopause.

So, I think it's always important to look not just at the immediate effect, although that's clearly important for day-to-day quality of life, but also to consider that there are health consequences for sleep disturbances. So what do we need to do when we need to be aware and know that there are options for treatment, and there is a growing list of options for treatment that people can consider, that clinicians can consider to signal the menopausal sleep disturbances and to treat them.