This symptom is common in menopause, but frequent or persistent episodes could be a sign of higher risk for heart attack or stroke.
Researchers have begun to pay more attention to cardiovascular risk factors that are unique to women, such as early menopause (before age 40) and certain pregnancy complications. Recently they turned their attention to a common menopausal symptom that affects up to 85% of women: hot flashes.
Study results presented in September 2019 to the North American Menopause Society from the Study of Women’s Health Across the Nation (SWAN) found that women who experience frequent or persistent hot flashes may be more likely than women who don’t to experience a heart attack or stroke or other serious cardiovascular problems. (Researchers defined “frequent” hot flashes as having them six or more days in the previous two-week period. Women with “persistent” hot flashes reported those frequent hot flashes at 25% or more of study visits.)
“The majority of women, but not all of them, get hot flashes. That in itself is not an abnormal phenomenon,” says Dr. Kathryn M. Rexrode, associate professor of medicine and chief of the Division of Women’s Health at Harvard Medical School. “On the other hand, it does seem, particularly if hot flashes are persistent over time, that it may indicate some increased cardiovascular risk.”
But if that sounds like you, don’t panic. Even among women who had more hot flashes, the overall chance of having a cardiovascular event — meaning a heart attack, stroke, heart failure, or arterial blockage — was still low, says Dr. Rexrode. “This also doesn’t mean that all women with hot flashes have, or are going to get, cardiovascular disease,” she says.
Rather, hot flashes represent an emerging area that researchers are working to better understand. One day, frequent or persistent hot flashes may join other risk factors specific to women that may prompt your doctor to treat you more aggressively to prevent cardiovascular disease.
An indicator of underlying problems
Hot flashes are brief episodes in which your body feels like it’s overheating. They can last for a few seconds or minutes. During a hot flash, your skin may flush and you may start to sweat. Afterward, you might feel cold and clammy.
Hot flashes usually occur in the months leading up to and for a few months after menopause. However, in some women, they persist for years. But their frequency varies greatly. Some women may have only a few hot flashes in a year; other women have dozens each day. It’s not clear what causes hot flashes, but some experts believe that declines in the hormone estrogen affect a part of the brain known as the hypothalamus, which acts as your body’s thermostat. When the hypothalamus senses that your body is too hot, it triggers cooling actions inside your body. As part of this process, blood vessels dilate to get rid of that extra heat. “Is there something different about women who have more frequent hot flashes with regard to how their blood vessels respond?” asks Dr. Rexrode.
Should you treat hot flashes?
While there is some evidence that frequent or persistent hot flashes may increase the risk of cardiovascular disease, there’s no evidence that reducing hot flashes will reduce that risk. So, relieving symptoms remains the only reason for treating hot flashes. Treatment options include short-term low-dose hormone therapy, with either estrogen or estrogen and progesterone combination therapy, or non-hormonal medications such as clonidine (Catapres); gabapentin (Neurontin); or antidepressants such as venlafaxine (Effexor), paroxetine (Paxil), fluoxetine (Prozac), and sertraline (Zoloft).
Triggering an underlying defect
A 2017 study hinted that this could indeed be the case. The study, published in Menopause, found that women ages 40 to 53 who experienced frequent or bothersome hot flashes showed certain characteristics in their blood vessel response that were also recognized as being linked with cardiovascular disease. Dr. Rexrode says that it’s possible that the linings of their blood vessels do not respond well to stress brought on by hormone changes at menopause.
While the 2017 study found differences in the underlying behavior of blood vessels that could potentially raise cardiovascular risks, the SWAN study took that idea a step further and actually linked hot flashes to cardiovascular events.
The SWAN study had an advantage over past studies. It didn’t have to rely on women’s recollections of hot flash severity and frequency; rather, it used data from SWAN, a large cohort study which tracked women for 20 years. The study authors were also able to track cardiovascular disease events.
The analysis found that women who had frequent hot flashes had double the risk of having a cardiovascular disease event, such as a heart attack, arterial blockage, or stroke during the study period compared with women who did not have hot flashes in the most recent two-week period. Women who had hot flashes that researchers defined as persistent were 80% more likely to go on to have a cardiovascular disease event in the next 20 years compared with women who did not have persistent hot flashes. These associations were not explained by standard cardiovascular disease risk factors (such as diabetes, obesity, or high blood pressure or cholesterol), said the study authors.
Interpreting the results
While this study provides an interesting clue about potential heart risks, it’s important to keep these numbers in perspective, says Dr. Rexrode. While “double the risk” sounds scary, the overall heart risk increase in these women associated with hot flashes remained relatively low.
So, what message should women draw from this finding? To take heart health seriously and use menopause as a time to reassess risks, says Dr. Rexrode. She recommends these important steps:
Identify your risk factors. It’s always important to reassess your cardiovascular disease risk factors as you go through midlife, says Dr. Rexrode. The chances of having a heart attack or stroke rises for women at and following menopause. While researchers found a link between hot flashes and heart risks, it’s far too soon to do anything with that information. Instead, women should still focus on established risk factors for cardiovascular disease, such as high cholesterol, high blood pressure, and diabetes, among others. The American Heart Association and the American College of Cardiology have developed a risk calculator that allows you to assess your personal risk. You can find it at www.health.harvard.edu/heartrisk.
Consider some women-only risk factors. While risk calculators don’t take into account female-specific risk factors, your doctor should consider at least two well-established ones in your assessment, says Dr. Rexrode. These are an early menopause (before age 40) or a past episode of pre-eclampsia (a potentially life-threatening pregnancy complication marked by high blood pressure and often protein in the urine). Those are considered risk enhancers, says Dr. Rexrode.
If you otherwise aren’t considered at high risk for cardiovascular disease but have one or both of those risk factors, it could push your risk level up, she says. This might prompt your doctor to address your cardiovascular health more aggressively. “Things that aren’t on that risk enhancer list yet are some other pregnancy complications, gestational diabetes, and hot flashes,” she notes. One day, if more evidence comes forth, they could be added to that list. “You could describe these as emerging areas,” she adds.
Stay tuned. Female-specific risk factors for cardiovascular disease are getting more attention from researchers, and more will be known about how these factors may influence your health in coming years.Image: JimVallee/Getty Images