Hot flashes are the bane of many menopausal womens' lives, but they may have an upside, say US researchers.
Hot flashes, also known as hot flushes or night sweats, at the onset of menopause may be linked to a reduced risk of having a heart attacks or stroke, according to a new study published in the online edition of Menopause.
"While they are certainly bothersome, hot flashes may not be all bad," says Dr Emily Szmuilowicz, the paper's lead author.
The researchers followed over 60,000 women with an average age of 63 who were enrolled in the Women's Health Observational Study for 10 years, to determine the relationship between menopause symptoms and vascular disease.
The women were grouped into four categories - women who experienced hot flashes and night sweats at the onset of menopause, later in menopause, during both time periods and not at all.
"We found that women who experienced symptoms when they began menopause had fewer cardiovascular events than those who experienced hot flashes late in menopause, or not at all," says Szmuilowicz, an endocrinologist at the Northwestern Memorial Hospital in Chicago.
Hot flashes are caused by the dilation of blood vessels in the skin in response to perceived body temperature changes. Around 40 per cent of Australian women experience some symptoms during menopause and between 20 - 25 per cent experience severe symptoms.
While the mechanism is unclear, research over the last decade has linked hot flashes to an increased risk of heart attacks and strokes.
"It is reassuring that these symptoms, which are experienced by so many women [at the time of menopause], do not seem to correlate with increased risk of cardiovascular disease," says Szmuilowicz.
Late menopause symptoms up risk
Women who develop hot flashes in late menopause, however, may be at greater risk of cardiovascular disease and death, the research shows.
The ability to predict the risk of heart attack and stroke may vary with the onset of hot flashes at different stages of menopause, say the researchers, but more research is needed to understand the relationship between hot flashes and late menopause.
The authors add that the study is limited by the retrospective self-reporting of symptoms, and some of the women may have been taking hormone replacement therapy, which may mask the symptoms and is also linked to a greater cardiovascular risk for women over 70.
Professor Henry Burger a consultant endocrinologist to the Jean Hailes Foundation says the US study "adds to the information base" but is limited by its design.
"The relationship between heart disease and symptoms remains somewhat confusing."
One practical implication of the late symptom risk is that it should make women who experience late menopausal symptoms, and their doctors, more alert to taking preventative measures to stop them having heart attacks, he says.