Hot flashes, night sweats 'last for at least 7 years during menopause'

Hot flashes and night sweats affect up to 75% of women in the US who are going through menopause. Though common, these symptoms can significantly impact a woman's quality of life. 

But how long do they last? According to a new study published in JAMA Internal Medicine, many women may experience these symptoms frequently for at least 7 years.

Women are likely to experience frequent hot flashes and night sweats for at least 7 years during menopause.

Collectively, hot flashes and night sweats are referred to as vasomotor symptoms (VMS). 

As well as making menopausal women feel uncomfortable, VMS can reduce energy levels, disturb sleep and affect social functioning and overall quality of life.

According to the research team at the Wake Forest School of Medicine in Winston-Salem, NC, there is a "lack of robust estimates" of how long women may experience VMS.

The North American Menopause Society (NAMS) say VMS can last between 6 months to 2 years, though they note that some studies suggest the symptoms can persist for 3-5 years, with some women experiencing them for 10 years or more.

For their study, the researchers set out to identify the average length of time women may experience frequent VMS during menopausal transition - defined as having hot flashes or night sweats over at least 6 days in the past 2 weeks. They also wanted to identify risk factors for longer VMS duration.

Premenopausal, perimenopausal women had longest VMS duration

The research team assessed 1996-2013 data of 3,302 women who were part of the Study of Women's Health Across the Nation (SWAN). Of these, 1,449 had frequent VMS during menopausal transition.

The researchers found that on average, total frequent VMS duration was 7.4 years.

Women who were premenopausal (continuing to have normal menstrual cycles) or early perimenopausal (moving toward menopausal transition) at the first report of VMS experienced the longest duration of hot flashes and night sweats, with an average of at least 11.8 years.

The shortest total duration of VMS was found among women who were postmenopausal (had experienced their last menstrual cycle) at the time of VMS onset, with an average of 3.4 years.

On analyzing the data by racial/ethnic groups, the researchers found that African American women experienced the longest duration of VMS, with an average of 10.1 years, while Japanese and Chinese women had the shortest VMS duration, with an average of 4.8 years and 5.4 years, respectively.

Non-Hispanic white women had an average VMS duration of 6.5 years, while Hispanic women experienced VMS for an average of 8.9 years.

The researchers also found that at the first report of VMS, younger age, greater perceived stress, lower educational attainment, greater symptoms of depression and anxiety and greater sensitivity to VMS symptoms was associated with longer duration of VMS.

Commenting on the results, the research team says:

"These findings can help health care professionals counsel patients about expectations regarding VMS and assist women in making treatment decisions based on the probability of their VMS persisting.

In addition, the median total VMS duration of 7.4 years highlights the limitations of guidance recommending short-term HT [hormone therapy] use and emphasizes the need to identify safe long-term therapies for the treatment of VMS."

In an editorial linked to the study, another team of researchers at the University of Arkansas Medical Sciences, and at Women's Hospital in Boston, MA, say the findings from Avis and colleagues are "highly informative" and pave the way for health care professionals to adopt a more personalized approach when it comes to counseling women about VMS.

"The good news is that women now have more options for managing VMS and more opportunities for shared decision making with their health care professionals," they add. "Continued research in this area holds promise for further advances that will guide future care of women experiencing VMS."

Earlier this month, a different team of researchers reported on a study by researchers from the Centers for Disease Control and Prevention (CDC) suggesting there may be a link between chronic fatigue syndrome and symptoms of early menopause, as well as other gynecologic conditions.

References:

1.  Duration of menopausal vasomotor symptoms over the menopause transition, Nancy E. Avis, et al., JAMA Internal Medicine, doi:10.1001/jamainternmed.2014.8063, published online 16 February 2015, abstract.
2.  Vasomotor symptom duration in midlife women - research overturns dogma, Gloria Richard-Davis, JoAnn E. Manson, JAMA Internal Medicine, doi:10.1001/jamainternmed.2014.8099, published online 16 February 2015, editorial.
3.  JAMA news release, accessed 16 February 2015.
4.  Additional source: NAMS, Hot flashes, accessed 16 February 2015.