Gillian Goddard

Are Hot Flushes Really Linked to Heart Problems?

Don’t lose sleep over the latest panic headlines

Gillian Goddard

Feb. 13, 2024 6 minute read

In the past couple of months, I have been asked one question more than any other. Patients, friends, even my mother (hi, Mom!) want to know what the deal is with hot flushes.* Are they dangerous? These women have — or used to have — hot flushes; how can they avoid having a heart attack or developing dementia?

Their concern stems from recent headlines reporting on a new study (S-12), which investigated a link between hot flushes and stroke and heart attack and was presented at the annual meeting of the North American Menopause Society (NAMS) in September 2023. Let’s talk about this particular study and how I approach this type of health news more generally.

Why are we interested in this now?

My first question when I see a story like this one is: why now? Usually the answer is one of two reasons. First, a paper was published in a “high-impact” scientific journal — these are journals with a large influence and circulation, like the New England Journal of Medicine or Science. Or second, a medical society is holding its annual meeting, where research is presented. When medical meetings occur, there is typically a flurry of news over several days all on a related topic, like menopause.

In the case of hot flushes and cardiovascular disease, it is the latter. In the study from NAMS that the popular press is reporting on, researchers presented data that showed an association between the number of hot flushes women experience and a marker of inflammation in the blood called high-sensitivity C-reactive protein (hsCRP).

The source, journal versus meeting, is important to me. If a study is in a journal like the New England Journal of Medicine, I know it has gone through a rigorous vetting process. Often the studies are large randomized controlled trials. Research presented at meetings, especially research that is presented as a poster or oral presentation, often focuses on smaller studies that may be observational, or pilot studies to prove a concept. This research is critical because it forms the basis for larger future studies, but it’s often not enough to draw strong conclusions.

In this case, what is published is an abstract, not a complete paper. We don’t have the same detailed methods and results to review. I am less likely to change my practice or treatment choices based on research that is not yet published as a full article in a journal.

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What does the abstract tell us?

When I have located the original abstract or paper, I think about how the research was conducted. Here, the researchers had 276 women wear a device that could measure how many hot flushes the study participants were having. They also measured the hsCRP in the women’s blood. They found that the women who had 14 or more measured hot flushes in a 24-hour period were more likely to have high levels of hsCRP in their blood.

Unlike research published in a paper, we don’t know many details about the study participants. They are peri- and postmenopausal and between the ages of 40 and 60. We don’t know their race, ethnicity, level of fitness, or pre-existing medical problems. In short, we can’t tell if the participants are similar in specific ways to the population we care about, in this case you and me.

What is hsCRP, anyway, and what does it have to do with heart attacks and dementia?

C-reactive protein is a protein made mostly in the liver. High levels of CRP have been associated with increased inflammation throughout the body and an increased risk for cardiovascular disease. Currently, there is no evidence that CRP causes cardiovascular disease. There is also little agreement on what a “normal” level of CRP should be. “Low” is good. “High” is bad. But we don’t actually know what “low” and “high” should be. The “hs” in hsCRP just refers to the specific lab test used in measuring CPR.

So what this research tells us is that more hot flushes are associated with increased hsCRP, which is associated with an increased risk of cardiovascular disease.

Does this change what we already know?

Finally, I consider how this fits with what we already know. Essentially, why should you and I care about this research?

Menopause and cardiovascular disease have long been linked. As early as the 1970s, studies have shown that before menopause, women have very little cardiovascular disease compared with men the same age. We think the hormone estrogen prevents plaque from building up in the arteries. When estrogen levels fall during perimenopause, plaque can begin to form. By about 10 years after menopause (in their early to mid-60s for most), women have the same risk for cardiovascular disease as men.

More recently, menopausal symptoms like hot flushes (called vasomotor symptoms in medical literature) have been associated with higher levels of inflammatory markers in the blood. And inflammation in the arteries is a key step in the path to cardiovascular disease.

So what is really new here? Not much. The new study builds on a known association. Rather than relying on women to report their vasomotor symptoms, the authors measured their hot flushes using a technology called sternal skin conductance.

Dennis Bahr, “Miniature ambulatory skin conductance monitor and algorithm for investigating hot flash events”

Should I be worried that my hot flushes are causing heart problems?

Bottom line, this new research is not keeping me up at night. Nor is it changing how I treat my patients.

Your best bet for reducing cardiovascular disease is unchanged: follow a healthy lifestyle. Adequate sleep, a diet rich in fiber and low in saturated fat, and exercise are all beneficial. Additionally, work with your physician to treat metabolic changes like high cholesterol and high blood sugar that can crop up as we move into our 40s and 50s.

And if hot flushes and night sweats are affecting your daily functioning, I urge you to discuss treatment options with your doctor — not because of cardiovascular risk, but just because it is impacting your life! There are many options available — hormonal and non-hormonal — but that is a conversation for another day.

* A quick note on vocabulary. “Hot flash” is a colloquial term (which we obviously embrace!) for the terms used in the medical literature of “hot flush” or “vasomotor symptoms.” Since we are talking about data here at Hot Flash, I will use the medical terminology.