Hot Flashes: Do They Predict CVD and Dementia?

Hello. This is Dr JoAnn Manson, professor of medicine at Harvard Medical School and Brigham and Women’s Hospital. I’d like to talk with you about a recent report in the journal Menopause linking menopausal symptoms to increased risk for cognitive impairment. I’d also like to discuss some of the recent studies that have addressed whether hot flashes are linked to increased risk for heart disease and other forms of cardiovascular disease (CVD). 
Given that 75%-80% of perimenopausal and postmenopausal women have hot flashes and vasomotor symptoms, it’s undoubtedly a more complex relationship between hot flashes and these outcomes than a simple one-size-fits-all, yes-or-no question. 
Increasing evidence shows that several additional factors are important, including the age at which the symptoms are occurring, the time since menopause, the severity of the symptoms, whether they co-occur with night sweats and sleep disruption, and the cardiovascular status of the woman.
Several studies suggest that women who have more severe hot flashes and vasomotor symptoms are more likely to have prevalent cardiovascular risk factors — hypertension, dyslipidemia, high body mass index, endothelial dysfunction — as measured by flow-mediated vasodilation and other measures.
It is quite plausible that hot flashes could be a marker for increased risk for cognitive impairment. But the question remains, are hot flashes associated with cognitive impairment independent of these other risk factors? It appears that the associations between hot flashes, vasomotor symptoms, and CVD, and other adverse outcomes, may be more likely when hot flashes persist after age 60 or are newly occurring in later menopause. In the Women’s Health Initiative observational study, the presence of hot flashes and vasomotor symptoms in early menopause was not linked to any increased risk for heart attack, stroke, total CVD, or all-cause mortality.
However, the onset of these symptoms, especially new onset of these symptoms after age 60 or in later menopause, was in fact linked to increased risk for CVD and all-cause mortality. With respect to cognitive impairment, if a woman is having hot flashes and night sweats with regular sleep disruption, performance on cognitive testing would not be as favorable as it would be in the absence of these symptoms.
This brings us to the new study in Menopause that included approximately 1300 Latino women in nine Latin American countries, with an average age of 55 years. Looking at the association between severe menopausal symptoms and cognitive impairment, researchers found that women with severe symptoms were more likely to have cognitive impairment. 
Conversely, they found that the women who had a favorable CVD risk factor status (physically active, lower BMI, healthier) and were ever users of estrogen were less likely to have cognitive impairment.
Clearly, for estrogen therapy, we need randomized clinical trials of the presence or absence of vasomotor symptoms and cognitive and CVD outcomes. Such analyses are ongoing, and new randomized trials focused specifically on women in early menopause would be very beneficial.
At the present time, it’s important that we not alarm women about the associations seen in some of these studies because often they are not independent associations; they aren’t independent of other risk factors that are commonly linked to hot flashes and night sweats. There are many other complexities in the relationship between hot flashes and cognitive impairment.
We need to appreciate that women who have moderate to severe hot flashes (especially when associated with disrupted sleep) do have impaired quality of life. It’s important to treat these symptoms, especially in early menopause, and very effective hormonal and nonhormonal treatments are available.
For women with symptoms that persist into later menopause or who have new onset of symptoms in later menopause, it’s important to prioritize cardiovascular health. For example, be more vigilant about behavioral lifestyle counseling to lower risk, and be even more aggressive in treating dyslipidemia and diabetes.
Thank you so much for your attention. This is JoAnn Manson.