• Posted September 27, 2023

Timing of Hot Flashes Could Give Clues to Alzheimer's Risk

Hot flashes and night sweats top the list of bothersome symptoms for women going through menopause.

Now, a new study suggests that hot flashes, especially during sleep, may be more than a nuisance: They may foreshadow Alzheimer's disease.

And the more hot flashes a woman experiences during sleep, the greater her risk for developing Alzheimer's disease, the most common type of dementia.

"Women with nighttime hot flashes should see them as a wake-up call to do what they can to take care of their health,"said study author Rebecca Thurston, director of the Women's Biobehavioral Health Laboratory at the University of Pittsburgh. "[This includes] adequate sleep, diet, physical activity, moderating alcohol use, treatment of any [high blood pressure] and diabetes, and taking care of any mental health conditions."

Previous research has shown that hot flashes -- particularly those that occur during sleep -- may travel with poorer memory and small vessel disease in the brain, which has been linked to risk for future problems with memory and thinking, Thurston said.

The new research connects the dots even further by linking hot flashes to blood biomarkers of Alzheimer's disease: "We found that women with more hot flashes [during sleep] had greater markers of amyloid, a component of the biology of Alzheimer's disease,"she added.

For the study, close to 250 older women were monitored for hot flashes during the day and while asleep. The researchers also analyzed blood samples for certain markers of Alzheimer's disease including amyloid β (Aβ) 42/40 ratio.

Women who had more hot flashes during sleep were more likely to be in the low/abnormal Aβ 42/40 range, the study showed.

"Decreased ratio of beta-amyloid 42/40 is a strong marker of Alzheimer's disease and can be detected early in the disease progression," Thurston said.

These findings held even after the researchers controlled for other factors that could affect risk for Alzheimer's disease, including levels of the female sex hormone estrogen and sleep.

Exactly how hot flashes during sleep may increase the risk for Alzheimer's disease is not fully understood yet. "There may be something particularly important about these nocturnal hot flashes that we have not appreciated up to this point,"Thurston suggested.

The findings were presented Wednesday during the Menopause Society annual meeting in Philadelphia. Findings presented at medical meetings should be considered preliminary until they are published in a peer-reviewed journal.

It's too early to say whether treating hot flashes with hormone replacement therapy would lower the risk for dementia, but what's good for the heart is good for the brain, said Dr. Stephanie Faubion, director of women's health at the Mayo Clinic in Jacksonville, Fla., and medical director for the North American Menopause Society.

The best way to lower the risk for Alzheimer's disease is to manage heart disease risk factors, including high blood pressure, high cholesterol and diabetes. One can also stop tobacco use, eat healthy, exercise regularly and maintain a healthy weight, Faubion added.

"Staying socially connected and keeping your brain stimulated are good strategies to maintain brain health,"said Faubion, who has no ties to the research.

More information

HealthDay has more on how to treat hot flashes.

SOURCES: Rebecca Thurston, PhD, director, Women's Biobehavioral Health Laboratory, University of Pittsburgh; Stephanie Faubion, MD, director, women's health, Mayo Clinic, Jacksonville, Fla., and medical director, North American Menopause Society, Philadelphia; Sept. 27, 2023, presentation, The Menopause Society annual meeting, Philadelphia