Hot Flashes: 7 Years and Counting

Some women experienced hot flashes and night sweats for more than 7 years during menopausal transition, researchers reported.

Among a diverse group of women in the U.S. who reported a high frequency of symptoms, vasomotor symptoms (VMS) persisted for a median of 7.4 years, with a median of 4.5 years of symptoms after final menstrual period, according to Nancy E. Avis, PhD, of Wake Forrest School of Medicine in Winston-Salem, N.C., and colleagues.

These findings exceeded the length of VMS symptoms reported in previous research, they wrote in JAMA Internal Medicine.

Broken down by race/ethnicity, African-American women reported the longest duration of VMS at 10.1 years, and Japanese women reported the shortest duration of VMS at 4.8 years, they added.

"Despite the high prevalence of VMS among midlife women, surprisingly little research has been done on the underlying etiology, individual differences in symptom presentation, sociodemographic and clinical correlates, or duration of symptoms," wrote Gloria Richard-Davis, MD, of the University of Arkansas in Little Rock, and JoAnn E. Manson, MD, DrPH, of Harvard Medical School, in an accompanying editorial.

Richard-Davis and Manson also noted that prior research on VMS duration generally suggested symptoms didn't last longer than 2 years. "The findings from recent studies underscore the limitations of the earlier evidence base on VMS that has guided clinical practice for many decades," they pointed out.

Avis and colleagues looked at 881 women from seven U.S. sites for the Study of Women's Health Across the Nation (SWAN) who reported frequent -- at least 6 days of symptoms in the past 2 weeks -- hot flashes and night sweats associated with menopause.

The women had visited their healthcare provider a median of 13 times throughout the study years from 1996 to 2013.

The longest duration of symptoms occurred in women who reported premenopausal or early perimenopausal symptoms. These women had a median duration of VMS for 11.8 years, 9.4 years of which were after their final menstrual period.

The shortest duration of symptoms at a median of 3.4 years was found in women who were postmenopausal during the onset of symptoms.

Race/ethnicity determined the widest variation in reported duration of symptoms:

• African American: median 10.1 years
• Japanese: median 4.8 years
• Chinese: median 5.4 years
• Non-Hispanic white women: median 6.5 years
• Hispanic women: median 8.9 years

Except for Chinese versus Japanese women, all pairwise racial/ethnic differences were statistically significant (P<0.05), Avis' group reported.

Longer duration of symptoms was found in women who were younger, had lower levels of education, higher levels of perceived stress, greater sensitivity to symptoms, and higher levels of depressive and anxiety symptoms at the onset of VMS.

More than half of the women in the study had VMS for 4.5 years after their final menstrual period.

As a potential explanation for the duration disparity between this study and previous research, Avis' team suggested that prior investigations into VMS either didn't include a racially/ethnically diverse group of participants, excluded participants who reported VMS at baseline, and/or counted women who still had VMS during the last follow-up visit as no longer having VMS.

Richard-Davis and Manson noted that the onset of VMS isn't synonymous with loss of reproductive capabilities. "During the premenopause and perimenopause, some women may be appropriate candidates for treatment with a low-dose combined oral contraceptive, which could address the needs for both the management of VMS and effective contraception," they stated.

However, the editorialists cautioned against hormonal treatments, and long-term use in particular, for candidates who might be at risk for breast cancer, stroke, venous thromboembolism, and other adverse events. In such cases, they suggest low-dose paroxetine mesylate, other selective serotonin-reuptake inhibitors, selective serotonin-norepinephrine reuptake inhibitors, gabapentin, pregabalin, or clonidine hydrochloride to treat VMS. However, they stressed that "no treatment is without risks."

The study authors acknowledged several limitations, including the underestimation of VMS due to recollection bias and self-report, VMS fluctuations over time, and the potential of symptom recurrence or continuation after the end of the study.

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

The SWAN study was supported by the NIH, Department of Health and Human Services, National Institute on Aging, National Institute of Nursing Research, and the Office of Research on Women's Health.
Avis and most co-authors disclosed no relevant relationships with industry. One co-author disclosed relevant relationships with Cephalon/Teva, Noven, and Merck.
Richard-Davis and Manson disclosed no relevant relationships with industry.

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