SWAN Study Finds Hot Flashes Last Up To 14 Years

The label “hot flash” is really a misnomer. Not only does the blazing bout of misery take longer than a flash to course through a woman’s body, the chunk of her life she can expect to suffer them has been found by the latest research to last for up to 14 years.

That’s a 40 percent increase over what was previously thought to be the top end of the spectrum at one decade. The Study of Women’s Health Across the Nation (SWAN) published its findings in JAMA Internal Medicine in April 2015.

Now in its 22nd year, the study began in 1994, following 3,302 women in seven cities through their middle years with the goal of determining how midlife experiences affect health and quality of life during aging. “The SWAN Study is strong because women were asked about hot flashes at every visit over the time of the study,” says Cynthia Stuenkel, M.D. clinical professor of medicine, endocrinology, and metabolism at the University of California, San Diego, School of Medicine in La Jolla, California.

The study found that the earlier women began experiencing hot flashes, the longer they would continue to have them. Of the women who began hot flashes before menopause, 70 percent still experienced them 13 years later. Less than 20 percent of women who begin experiencing hot flashes after menopause continued to have them for that long.

“It seems kind of ironic that the women who start early would also go later,” Stuenkel said.

“If they’re bad, if they’re severe, that’s a long time,” sympathized Nanette Santoro, M.D., a member of the North American Menopause Society Board of Trustees and professor and E. Stewart Taylor Chair of Obstetrics/Gynecology at the University of Colorado School of Medicine in Aurora, Colorado.

Race can have a significant impact on the vasomotor symptoms a woman suffers, according to Stuenkel. Black women have the most vasomotor miseries and Asian women the fewest, Stuenkel said, with whites and Latinas falling in the middle.

Santoro says hot flashes tend to peak around the time of the last menstrual period but fall into two main patterns: Women who start getting hot flashes very early (sometimes, as stated above, even before menopause) may have a longer, more difficult menopause; and women who don’t get them until the end of the menopause transition which then tends to be shorter and easier.

“The SWAN Study so far is the best thing we’ve got going,” Stuenkel said of the valuable information it’s revealing. “In any individual practice you probably have a few outliers [with unusual hot flash durations], but the number would be so small, I don’t know that an individual practitioner could sort them all out.”

Sources:

Avis NE et al. Duration of menopausal vasomotor symptoms over the menopause transition. JAMA Intern Med. 2015 Apr; 175(4):531-9. doi: 10.1001/jamainternmed.2014.8063. Retrieved October 20, 2015. http://www.ncbi.nlm.nih.gov/pubmed/25686030

Cynthia Stuenkel, M.D., via phone conversation October 20, 2015. http://answers.webmd.com/expert/39928/cynthia-stuenkel-north-american-menopause-society

Nanette Santoro, M.D., via phone conversation July 6, 2015. http://www.ucdenver.edu/academics/colleges/medicalschool/centers/SurgicalInnovation/about-us/faculty-members/Pages/Nanette-Santoro.aspx

Reviewed October 28, 2015 by Michele Blacksberg RN