The heat comes out of nowhere, so intense for some that their faces burn and sweat oozes from every pore of their bodies. Welcome to the hot flushes and other symptoms of the menopause – an experience that experts say about 75% of women will experience if they live long enough.
Even if menopause is years or decades away, it’s time to pay attention – because according to new science, the menopause experience may be damaging to future health.
Unpublished studies presented Wednesday at the annual meeting of the Menopause Society in Philadelphia found that severe hot flashes are linked to an increase in C-reactive protein, a marker for future heart disease, and to a blood biomarker that may predict a later diagnosis of Alzheimer’s disease.
“This is the first time science has shown that hot flashes are associated with blood biomarkers of Alzheimer’s disease,” said Dr Stephanie Faubion, director of the Mayo Clinic’s Women’s Health Specialty Clinic in Jacksonville, Florida, and medical director of The Menopause Society.
“This is more evidence that hot flashes and night sweats may not be as benign as we thought in the past,” said Faubion, who was not involved in the studies.
Alzheimer’s risk
Nearly 250 women between the ages of 45 and 67 who were experiencing menopausal symptoms wore a device for three nights to objectively measure their sleep quality. The women were also fitted with sweat monitors to record their hot flushes on one of these nights. The researchers then took blood samples from the study participants and tested them for a specific protein biomarker of Alzheimer’s disease called beta-amyloid 42/40.
“Beta-amyloid 42/40 is thought to be a marker of amyloid plaques in the brain, which is one of the components of the pathophysiology of Alzheimer’s disease dementia,” said lead study author Dr Rebecca Thurston.
“We found that night sweats were associated with adverse beta-amyloid 42/40 profiles, suggesting that hot flashes during sleep may be a marker for women at risk for Alzheimer’s disease dementia,” said Thurston, a professor of psychiatry, epidemiology and psychology who directs the Women’s Biobehavioral Health Laboratory at the University of Pittsburgh’s Pitt Public Health.
The biomarker does not identify whether a person has clinical Alzheimer’s disease, Thurston said, only the possibility of developing the disease in the future.
“In other words, hot flashes at night don’t cause this risk. They’re just a marker for people who are at increased risk,” Faubion said. “Similarly, we don’t know if treating night sweats would reduce the risk. We don’t know that.”
The study also looked at two biomarkers for tau protein, the other hallmark of Alzheimer’s disease, but found no association, Thurston said. “These biomarkers are still developing rapidly, and although they’ve been validated at this point, there’s still more to learn.”
The objective sleep measures allowed the researchers to rule out the role of poor sleep, a known risk factor for dementia, in the findings. Previous research that also controlled for sleep found that hot flushes and night sweats were associated with poor memory performance and changes in brain structure, function and connectivity.
“All the evidence is converging to underline that there’s something about these nocturnal vasomotor symptoms, apart from sleep itself, that affects the brain,” she said.
Heart disease
Another study presented by Thurston’s team at the conference looked at inflammatory markers of heart disease. Previous research by Thurston found that women who reported frequent or persistent hot flashes during early menopause had a 50% to 80% increased risk of cardiovascular events such as heart attack, stroke and heart failure.
Frequent moderate to severe hot flashes can often last an average of seven to 10 years, and less frequent or severe hot flashes can last even longer, according to experts.
In this new research, scientists used sweat monitors on 276 women who were part of the MSHeart study to more objectively measure the frequency and intensity of hot flashes during the day and at night.
“A lot of people actually underreport their hot flashes, saying they don’t have many when they really do,” Faubion said. “Using this monitor is an objective way to quantify them.”
The researchers compared the frequency and intensity of hot flashes with blood measurements of C-reactive protein, a protein that indicates the level of inflammation in the body and is used to determine the risk of heart disease and stroke in people who don’t already have heart disease.
The results showed that daytime hot flashes were associated with higher levels of C-reactive protein, even after adjusting for other potential causes such as age, body mass index (BMI), education, ethnicity, the hormone estradiol and race.
“This is the first study to examine physiologically measured hot flashes in the context of inflammation and adds to a growing body of literature suggesting that hot flashes may signal underlying vascular risk,” said lead author Mary Carson, a clinical and bio-health doctoral student in the University of Pittsburgh’s department of psychology, in a statement.
What you can do
Since heart disease is the leading cause of death for women worldwide, doctors should start asking patients about their experience with hot flashes as a risk factor for future disease, Faubion said.
“Women who have night sweats in particular may need to have their cardiovascular risk assessed in general,” she said.
“As for what to do, the recommendations will be the same as for heart and brain health: get better sleep, eat right, exercise regularly, reduce stress, stay socially connected and do something that stimulates your brain.”
