A new study finds a link between the common hot flashes experienced by most women around the time of their menopause, and vascular health. The study suggests that hot flashes may indicate a higher risk of heart disease.
As many as 70 percent of women experience hot flashes, and around a third of these women say that the hot flashes are frequent or severe.
Recent research suggests that hot flashes actually occur earlier than previously believed. It is now thought that they may begin to occur during the late reproductive years and not necessarily in the perimenopausal period. Some studies have also shown that hot flashes can persist for over a decade.
The new research, published in the journal Menopause, examines the link between hot flashes and the risk of cardiovascular disease (CVD). More specifically, it looks at the association between hot flashes and endothelial function. The endothelium is a layer of cells that line the inside of the blood vessels.
The assessment of endothelial function is considered a key factor in predicting atherosclerosis - a form of CVD that affects the blood vessels' ability to dilate and contract. If left untreated, atherosclerosis can lead to more serious cardiovascular problems, such as heart attack, stroke, or heart failure.
According to the Centers for Disease Control and Prevention (CDC), heart disease accounts for 1 in 4 yearly deaths in the United States. Approximately 610,000 U.S. individuals die of CVD each year; heart disease is the leading cause of death in both men and women.
Analyzing the link between hot flashes and vascular health
The new study examined 272 women aged between 40 and 60 years who reported having hot flashes either daily or not at all. The women did not smoke and had no history of CVD.
The researchers monitored the women for physiologic signs of hot flashes in ambulatory care, as well as using diary monitoring. The participants had their blood tested, and their endothelial function was evaluated by performing an ultrasound measurement of the flow-mediated dilation of their brachial artery.
Flow-mediated dilation (FMD) is a process that helps the arteries to relax in response to shear stress, such as vasodilation.
The associations between hot flashes and FMD were calculated using linear regression models, and the researchers adjusted for factors such as demographics, CVD factors, estradiol (a female sex hormone released from the ovaries and adrenal glands), and lumen diameters (which relates to the size of the inside of a tubular organ, such as a blood vessel).
Younger midlife women with hot flashes may be at risk of CVD
The authors found no association between hot flashes and vascular dysfunction in older women - that is, in participants aged between 54 and 60.
However, they did find that hot flashes were associated with endothelial dysfunction in women in the younger tertile of the study - or those women aged between 40 and 53 years. The correlations found did not depend on other CVD risk factors.
This suggests that younger women with hot flashes may have poor vascular function.
The authors conclude that:
"Among younger midlife women, frequent hot flashes were associated with poorer endothelial function and may provide information about women's vascular status beyond cardiovascular disease risk factors and estradiol."
Dr. JoAnn Pinkerton, executive director of the North American Menopause Society, weighs in on the findings:
"Hot flashes are not just a nuisance," she says. "They have been linked to cardiovascular, bone, and brain health. In this study, physiologically measured hot flashes appear linked to cardiovascular changes occurring early during the menopause transition."