May 3, 2012 -- There are countless reasons why women who smoke should kick the habit for their health, but here's one more.
Smoking women have more hot flashes as they transition through menopause, and this is especially true for women who carry certain genes, a new study finds.
Smokers Had More Hot Flashes
As expected, smokers in the study reported more hot flashes than women who did not smoke.
But smokers who also carried specific gene variations linked to estrogen metabolism and susceptibility to environmental toxins had the most hot flashes of all, says researcher and ob-gyn Samantha Butts, MD, of the University of Pennsylvania Perelman School of Medicine.
Butts says knowing that smoking increases the frequency and severity of hot flashes may convince some menopausal women to give up cigarettes once and for all, even if they have tried to quit before.
About 1 in 5 women in the U.S. -- roughly 20 million women -- smokes cigarettes.
"The reason close to 20% of women still smoke is because it is really hard to quit," Butts says. "But if you tell a woman who is having terrible hot flashes that it might be because she smokes, that could make all the difference."
Menopause, Smoking, and Genes
The study included close to 300 women followed for just over a decade as part of a larger menopause study. About half the participants were African-American and half were white.
The women were still menstruating when they entered the study, and they either entered menopause or completed it over 11 years of observation.
During this time, blood samples were taken and the women were questioned about their medical and reproductive histories, as well as their menopausal symptoms and lifestyle.
Women who had one or more of five gene variations linked to the metabolism of estrogen and susceptibility to environmental toxins, like cigarette smoke, had more hot flash symptoms than women without the variants. This was especially true for African-American women, Butts says.
After factoring in the impact of other hot flash risk factors, such as obesity and alcohol consumption, African-American smokers were 84% more likely to experience hot flashes at one point in the study than African-American nonsmokers. White smokers were 56% more likely to have hot flashes than white nonsmokers.
Message to Smokers: 'Stop'
While smokers in the study were about twice as likely as nonsmokers to experience hot flashes, the risk was as much as 21 times greater for smokers who carried specific gene variants, Butts says.
She adds that exposure to secondhand smoke and other environmental pollutants might also increase the frequency and severity of hot flashes in menopausal women who carry these variants.
Cleveland ob-gyn Margery Gass, MD, says that while the genetic aspect of the study is interesting, the basic message is simply that all women who smoke are at greater risk for hot flashes as they transition through menopause.
Gass is the executive director of the North American Menopause Society.
"I don't think most women who smoke know that they are at risk for earlier menopause and more severe menopause symptoms," she tells WebMD. "This is an important message to get out there and it is one more reason for women to avoid smoking."