Can Frequent Overnight Hot Flashes Change The Brain?

Women who experience more hot flashes, particularly while sleeping, during the menopause transition have a higher likelihood of having brain changes reflecting a higher risk for cerebrovascular disease, according to a pilot study.

Cerebrovascular diseases include stroke, aneurysms and other brain blood flow problems.

Over 70 percent of women have hot flashes, a sudden feeling of intense warmth and sweatiness, while transitioning into menopause, said principal investigator Rebecca Thurston, Ph.D., associate professor of psychiatry, University of Pittsburgh School of Medicine.

It might be particularly important for women who are experiencing numerous hot flashes to consider modifying cardiovascular risk factors by quitting smoking and treating high blood pressure, Thurston said.

Although recent research has shown that hot flashes can be linked to signs of subclinical heart disease, such as changes in the blood vessels, as well as high blood pressure and elevated cholesterol levels, Thurston and colleagues examined the possible connection between hot flashes and brain health.

The work was led by researchers at the University of Pittsburgh School of Medicine, published online in Menopause and funded by the National Institutes of Health.

The research team recruited 20 women in midlife who were not taking hormone therapy and, using a device that measures skin conductance, biologically monitored their hot flashes for 24 hours.

They also conducted MRI brain imaging on participants to detect white matter hyperintensities, which are bright spots on the scan that are thought to develop due to disease of the brain’s small blood vessels. Participants also kept electronic hot flash diaries.

The women reported an average of three hot flashes per day, but the monitoring showed greater frequency, at an average of eight per day as some were likely not self-reported because they occurred during sleep, Thurston said.

Women who had more monitor-detected hot flashes, particularly during sleep, also had a greater number of white matter hyperintensities on their brain scans.

“Other factors like age and cardiovascular risk factors did not explain this effect, so these findings suggest there is a relationship between menopausal hot flashes and blood vessel changes in the brain,” Thurston said. “Further work is needed to understand whether one causes the other, or if hot flashers are a signal of some other vascular process that impacts brain health.”

Reference:

Rebecca C. Thurston, Howard J. Aizenstein, Carol A. Derby, Ervin Sejdić, Pauline M. Maki.
Menopausal hot flashes and white matter hyperintensities.
Menopause, 2015; 1 DOI: 10.1097/GME.0000000000000481

Abstract:

“Objective: Hot flashes are classic symptoms of menopause. Emerging data link hot flashes to cardiovascular disease (CVD) risk, yet whether hot flashes are related to brain health is poorly understood. We examined the relationship between hot flashes (measured via physiologic monitor and self-report) and white matter hyperintensities (WMH) among midlife women.

Methods: Twenty midlife women (aged 40-60 y) without clinical CVD, with an intact uterus and ovaries, and not taking hormone therapy were recruited. Women underwent 24 hours of ambulatory physiologic and diary hot flash monitoring to quantify hot flashes; magnetic resonance imaging to assess WMH burden; 72 hours of actigraphy to quantify sleep; and a blood draw, questionnaires, and physical measures to quantify demographics and CVD risk factors. Tests of a priori hypotheses regarding relationships between physiologically monitored and self-reported wake and sleep hot flashes and WMH were conducted in linear regression models.

Results: More physiologically monitored hot flashes during sleep were associated with greater WMH, controlling for age, race, and body mass index ([beta] [SE] = 0.0002 [0.0001], P = 0.03]. Findings persisted after controlling for sleep characteristics and additional CVD risk factors. No relationships were observed for self-reported hot flashes.

Conclusions: More physiologically monitored hot flashes during sleep are associated with greater WMH burden among midlife women without clinical CVD. Results suggest that the relationship between hot flashes and CVD risk observed in the periphery may extend to the brain. Future work should consider the unique role of sleep hot flashes in brain health.”

Photo: Angus MacAskill/flickr