The two newly published studies are among the first to show that reversible lifestyle factors play a role in one of the most bothersome symptoms associated with what is euphemistically referred to as "the change of life."
Nationally recognized menopause expert Isaac Schiff, MD, says it is not clear if lifestyle factors actually cause hot flashes or just increase a woman's sensitivity to them. Schiff is a professor of gynecology at Harvard Medical School and chief of the Women's Care Division at Massachusetts General Hospital.
"But [the findings] suggest that interventions aimed at reducing these factors could potentially lower the occurrence of hot flashes," he says.
Anxious Women Suffer Most
The studies are published in the May/June issue of the North American Menopause Society journal Menopause.
One involved a six-year follow-up of 436 white and black women who were premenopausal (had regular cycles) and between the ages of 35 and 47 at the start of the study. Tests designed to measure anxiety were conducted at the beginning of the study and six years later.
At the end of the study, about half of the women started having variable cycle lengths or skipped periods. Reports of hot flashes increased as women entered into a transitional period (menstrual irregularities) toward menopause.
Menopause is defined as the permanent ending of menstruation, occurring 12 months after the last period.
Anxiety scores were associated with the occurrence, frequency, and severity of hot flashes. Women with moderate degrees of anxiety reported three times more hot flashes than women with normal levels of anxiety. Women with the highest levels of anxiety reported nearly five times as many hot flashes.
Researcher Ellen W. Freeman, PhD, of the University of Pennsylvania, says the findings could have implications for the treatment of menopause-related hot flashes, especially among women who worry about taking hormone therapy.
She says more studies are needed for evaluating the usefulness of medications such as selective serotonin reuptake inhibitor (SSRI) antidepressants -- Prozac, Paxil, and Zoloft -- in the treatment of menopause symptoms.
"There have been a few studies, but not many," Freeman tells WebMD. "Since anxiety can play a very big role in the experience of hot flashes, it makes sense to look closer at anxiety treatments."
Impact of Smoking and Body Weight
The second study included women followed for 10 years as part of a larger investigation on bone health. The women were between the ages of 24 and 44 when they were recruited for the trial in 1992, and they were followed through the transition to menopause.
Researchers from the University of Michigan reported that current smokers and women who were overweight were far more likely to experience bothersome hot flashes as they approached menopause as nonsmoking women and women of normal weight.
Current smokers reported nearly twice as many severe hot flashes as women who did not smoke. And women who were overweight reported seven times more hot flashes that they considered "very bothersome" as women who were not overweight.
The study is not the first to link smoking and obesity to hot flashes. University of Maryland researchers reported in 2003 that women who smoked or were obese had earlier and more severe hot flashes than nonsmoking women of normal weight.
Smokers in this study typically had their first hot flashes two to five years earlier than women who never smoked. Obese women were found to be twice as likely as women of normal weight to have earlier, daily, and more severe hot flashes.
The link between hot flashes and body weight is not clear, says Schiff. "An increase in body weight can result in a higher core body temperature and, possible more hot flashes. This may be offset by increase in estrogen coming from adipose [fat] tissue which would, in turn, decrease the hot flash risk."