A recent study has suggested that women who experience an early onset of menopausal symptoms like night sweats or hot flashes are at a higher risk of dying from heart disease.
The participants were 254 women who had the following traits:
- Over age 50
- Retained both ovaries
- Not taking hormone therapies
- Were referred for suspected myocardial ischemia (type of coronary artery disease)
The women were asked about the age at which they developed night sweats and hot flashes (“vasomotor symptoms”) and were classified as either early onset (before age 42) or late onset (at or after age 42). An unidentified subset of the women were tested for epithelial dysfunction, a type of imbalance in the lining of blood vessels that is associated with various types of disease. The women were followed for an average of six years.
Researchers discovered that women who had earlier onset of vasomotor symptoms, as well as the women who reported never having vasomotor symptoms, both had earlier cardiovascular disease mortality than those who had late onset symptoms. Women with early onset vasomotor symptoms were also more likely to show endothelial dysfunctions than those with late onset symptoms. No information is given about any dysfunction seen in the women who never experienced vasomotor symptoms, or even if they were evaluated for it.
The study concludes that women with signs of ischemia who have early vasomotor symptoms have a higher cardiovascular disease mortality and higher endothelial dysfunction when compared to women with late onset symptoms. This is a direct reporting of the results and there is no problem with it.
The issues with this study come up when the authors try and explain the results in their press release. For instance, they say that it suggests that “for some women, particularly for younger midlife women, menopausal symptoms might mark adverse changes in the blood vessels during midlife that places them at increased risk for heart disease.”
There are several things potentially wrong with this statement:
- Everyone in the study was suspected of having ischemic heart disease. By definition, this places them in a more at-risk group and are not inherently representative of the population at large
- It conveniently ignores the women who did not experience vasomotor symptoms and who also had a higher rate of cardiovascular disease deaths
- The study looked at deaths from cardiovascular disease. It did not measure risks for heart disease.
- By pushing all participants into either “early” or “late” onset groups, there was no “average” onset that could be compared to
- 254 is a very small sample, especially since hot flashes and night sweats affect around 80% of all women going through menopause
Hot flashes and night sweats are a common quality of life issue for women going through menopause. In a certain, very specific subgroup with heart disease, there might be a correlation between early death and these symptoms. However, the strength of this risk is obscured by the small sample size and trying to draw actual conclusions, rather than directions for future research, is folly.
Thurston, R., et. al., “Menopausal symptoms and cardiovascular disease mortality in the Women’s Ischemia Syndrome Evaluation (WISE),” Journal of the North American Menopause Society, 2016; 10.1097/GME.0000000000000731.
“Pitt Study of Early Onset Menopausal Symptoms Could Predict Heart Disease,” UPMC web site, September 28, 2016; http://www.upmc.com/media/NewsReleases/2016/Pages/thurston-menopausal-systems.aspx, last accessed September 29, 2016.