(RxWiki News) Hot flashes may be one of the best-known symptoms of menopause — and they may also signal a heart health risk.
Two new studies have found that when hot flashes start early in life, they could be a sign of increased risk for heart disease.
Poor endothelial function is one of the earliest predictors of heart disease, according to these studies. The endothelium is the inner lining of blood vessels. Study patients whose hot flashes started earlier had signs that their blood vessels had trouble responding to stress like a hot flash.
The authors of these studies noted that although the studies were small, they indicated a way doctors could identify women who had a higher risk of heart disease. Early detection could allow women to make lifestyle changes to decrease their heart disease risk.
Rebecca C. Thurston, PhD, associate professor of psychiatry, psychology and epidemiology at the University of Pittsburgh, led both studies.
"We tend to think of hot flashes as solely a quality of life issue, but these studies — based on data from two very different samples — call that into question,” Dr. Thurston said in a press release. "Hot flashes appear to be more toxic in younger than older women … Endothelial function is very important to vascular health, and it's often the first thing to go in the atherosclerotic process, so it's an early marker of cardiovascular risk.”
Rather than relying on women’s reports of hot flashes, Dr. Thurston and team had the study subjects wear a monitor that confirmed the presence and frequency of hot flashes. Also, Dr. Thurston and team performed an ultrasound of an artery in the forearm to check for dilation of the arteries.
Flow-mediated dilation indicates how well the endothelium responds to stress, such as a hot flash. Flow-mediated dilation in the brachial artery of the forearm is a good indicator of how the arteries in the heart respond to stress as well.
The first study included 189 women who were near menopause or who had already gone through it.
Women who had more hot flashes in a 24-hour period and were younger than 52 had poor endothelial function compared to older women and those who had fewer or no hot flashes. Younger women who had any number of hot flashes in the 24-hour period had a 3 percent reduction in endothelial flow compared to women who had no hot flashes.
Endothelial function in younger women who had 10 or more hot flashes a day was reduced by half compared to women who had no hot flashes. In other words, the more hot flashes, the higher chance a younger women would have poor endothelial flow.
In the second study, 104 women with an average age of 67 were also assessed for hot flashes. These women, however, already had signs of heart disease.
None of the study subjects were on hormone therapy. These women were divided into three groups: no hot flashes, hot flashes beginning at age 42 or younger and hot flashes beginning after age 42.
Among these women, those who started having hot flashes younger had much lower flow-mediated dilation and endothelial function than those who ever had hot flashes or started having them after age 42.
"Hot flashes occur at a time in a woman's life when her risk for heart disease increases," Dr. Thurston said. "Because current cardiovascular risk algorithms do not always predict clinical cardiovascular disease well for midlife women, gaining a better understanding of the role vasomotor symptoms might play on vascular health could help identify women most at risk."
Both studies will be presented March 16 at the American College of Cardiology's 64th Annual Scientific Session in San Diego. Research presented at conferences may not have been peer-reviewed.
The National Heart, Lung and Blood Institute funded both studies. Information on conflicts of interest was not available at the time of publication.