Women who start having hot flashes in their 40s and early 50s may be at a higher risk of cardiovascular disease later on, researchers say.
In a study of 272 women aged 40 to 60, the researchers found a connection between hot flashes at younger ages and endothelial dysfunction.
“Hot flashes were considered solely quality of life issues. Few investigators have considered their links with women’s heart health,” lead author Rebecca Thurston of the Women's Biobehavioral Health Laboratory at the University of Pittsburgh told Reuters Health by email.
In women who were having hot flashes at ages 40 to 53, the researchers observed lower brachial artery flow-mediated dilation, an indication of increased risk for cardiovascular disease later in life.
This was not true for women of the same age who were not having hot flashes. Nor was the link between hot flashes and endothelial dysfunction seen among older women, ages 54 to 60 years, they report in the journal Menopause, April 10.
None of the women were smokers, and none of them had been diagnosed with cardiovascular disease.
For reasons as yet unknown, waking hot flashes may indicate a higher risk than hot flashes during sleep, the researchers found.
Whereas previous studies regarding hot flashes and cardiovascular risk were observational and based on reports by the women themselves, this new study involved real-time hot flash monitoring, blood tests, and ultrasound measurement of brachial artery flow-mediated dilation. For this reason, the researchers say, their results are superior to previous studies.
The researchers also took into account other cardiovascular risk factors and the lower levels of estrogen found in older women, which itself can cause poorer blood vessel function.
A weakness of the study was that the average participant was white and college educated, which might mean the results don’t apply to other types of women.
Dr JoAnn Manson of Brigham and Women’s Hospital and Harvard Medical School in Boston was one of the lead investigators on a 2011 study of participants in the large-scale Women’s Health Initiative which found a similar connection between hot flashes and impaired blood vessel dilation – but in women ages 54 to 60.
“The relationship between menopausal hot flashes and cardiovascular risk remains controversial, and this paper does not provide a definitive answer,” Manson told Reuters Health by email.
“In the present study, an association between hot flashes and impaired blood vessel dilation was found in the youngest women, but not in women aged 54-60 (who were in early-to-middle stages of menopause),” said Manson. “In the Women’s Health Initiative, the largest study to date, the opposite was found: hot flashes in late, but not early menopause, were linked to increased cardiovascular risk. Thus, the hot flashes-cardiovascular disease puzzle continues to be incomplete, with many missing pieces.”