Hot Flashes and Your Heart: What's the Connection?

One of the most surprising findings of this study was that older women who still have significant hot flashes turned out to be the hormone-therapy users who were at greater risk for heart disease. Can you explain this?
This was an unexpected finding. We knew that there were increased risks for older women using hormone therapy from the original WHI studies, but when we did a sub-analysis of the older women who were still getting hot flashes and night sweats, we were rather surprised to find that they had an increased risk of heart disease. When we looked at that in more detail, they had more risk factors of cardiovascular disease. They were more likely to have high blood pressure, high blood cholesterol, diabetes and to be overweight. We weren't sure that those things totally explained the increased risk of taking hormones, because when we did an adjusted analysis, we found the increased risk was still there. In other words, being an older woman who has severe hot flashes seems to be a marker of something gone wrong.

We think persisting menopausal symptoms (hot flashes or night sweats) in older women may signal the presence of increased risk factors for heart disease or diseased arteries. But it's just an association at this point [i.e. not proof of cause and effect]. As a result of those findings, our advice to older women who have persisting hot flashes and night sweats, is that they try to get off of hormone therapy, and have themselves checked and treated for cardiovascular risk factors.

Women often joke that no one ever died of a hot flash, but you seem to be saying that severe flashes and night sweats may be a warning that your health isn't as good as you think it is.
We're saying this is a potentially important marker. These findings suggest that women with hot flashes and night sweats may have more risk factors that should be measured and monitored, and more risk factors are associated with a higher risk of heart disease.

How common is it for women to continue to experience severe hot flashes into their 60s and 70s?
In our study, overall, 12 to 17 percent of the postmenopausal women aged 50-79 experienced moderate to severe hot flashes. Usually, they end a few years after the menopause. But for some women, they persist into their 70s. Specifically, we found that about 8.6 percent of women in the estrogen trial and about 4.8 percent of women in the estrogen with progestin trial had moderate to severe hot flashes, the kind that interfere with your life, into their 70s. This study reinforces the conclusion that these women need to get off of hormones if they can.

You've been discouraging older women from taking hormone therapy since the WHI studies came out in 2002. But now, you're emphasizing it even more?
Yes. Hormone therapy was an approved indication for all women with moderate to severe hot flashes or night sweats  in the past. But these new findings sharpen the focus. Hormone therapy can be started during the first five or 10 years after menopause, but after that, we think women—even those with severe symptoms—should avoid it. That's one of the new contributions made by this study.

But older women who have been using hormones for decades are usually the women most resistant to stopping, aren't they? Many say it's very hard for them to get off hormones, because their symptoms are so disruptive to their lives?
That is so. But they need to understand that having these [menopausal] symptoms indicates that they are more likely to have risk factors. Luckily, most risk factors are treatable, and presumably, you can lower your risk of heart disease by taking action. If you look at it that way, these symptoms could be seen as a useful clue.