Vasomotor symptoms may persist more than five years in menopausal women

Issue: June 2009

The duration of vasomotor symptoms in middle-aged women may continue for more than five years, according to a reanalysis of data from the Melbourne Women’s Midlife Health Project.

“The estimate of symptom duration varied substantially according to the duration of follow-up,” the researchers wrote. “When we examined those women after seven years of follow-up who did not report flushing at baseline or in the eighth year of follow-up, the estimated duration of symptoms was only 2.4 years as compared with 5.2 years when the 13-year follow-up period was used.”

Col et al reanalyzed primary data for 438 Australian women included in the longitudinal cohort of the population-based Melbourne Women’s Midlife Health Project. The researchers estimated the average duration of hot flashes and identified factors that may affect vasomotor symptom duration in this population. Follow-up was 13 years.

The age range of women during the study period was 45 to 69 years. At baseline, none were using hormone therapy and all had menstruated within the last three months.

Participants were interviewed annually, until the ninth year when only women still menstruating were interviewed. Participants were asked to complete general health questionnaires and underwent cognitive function testing at years 11 and 13. At year 12, participants were examined for osteoarthritis and were also asked to complete questionnaires. Retention was 67% at year 13 of follow-up.

Vasomotor symptoms

Data on the duration of hot flashes were examined for 381 women from baseline to eight years and for 205 women from baseline to 13 years. The mean duration of menopausal symptoms for the women who completed 13 years of follow-up and never used HT was 5.2 years; when women who used HT were included, the mean duration was 5.5 years. Researchers reported that exercise was the only factor associated with hot flashes with more exercise associated with shorter duration of symptoms.

Twenty-three percent of women reported hot flashes at the 13-year follow-up. Although there were no significant differences between women who used HT and those who did not at year 13 of follow-up, women who used HT were more likely to exercise (P<.05).

Researchers reported several limitations of this study, including high use of HT (47% in the 13-year follow-up), and because all participants were white, the findings may have been limited for other racial groups. – by Jennifer Southall

Col N. Menopause. 2009;6:453-457.

Multiple studies have shown that these symptoms begin to increase before menopause, peak within two to three years of menopause and then gradually taper off for most women. In the Kronenberg et al study on hot flashes (Ann NY Acad Sci. 1990;592:52-86), data demonstrated that although hot flashes peaked around the time of menopause a small percentage of women continued to have hot flashes for more than 20 years past menopause. Research is beginning to show that women with hot flashes, even those with premenopausal hot flashes, may be different from those who do not have hot flashes - with regard to increased bone loss and adverse lipid profiles. In addition, there are observational data to suggest a critical window when hormone therapy may be of preventive value for both cognition and heart disease. For women who have mild hot flashes, menopause may be easier to navigate and be associated with less risk than those with moderate to severe or persistent hot flashes.

– JoAnn V. Pinkerton, MD

Director, Midlife Health Center and Division, University of Virginia