Sleep disruption during menopause has been thought to be associated with factors like depression, hot flashes, and fluctuating hormone levels, but a new study finds one of those factors—hormones—actually can’t predict insomnia in menopausal women. 

The study, published in Journal of Women’s Health and carried out by researchers at Carl R. Woese Institute for Genomic Biology at University of Illinois at Urbana-Champaign, used data from the Midlife Women’s Health Study, designed to identify which risk factors can cause menopausal symptoms among midlife women. Over 700 women participated in the four-year study.

In the initial clinic visits, they completed questionnaires regarding their medical history and submitted blood and urine samples. For the next three years, they returned to the clinic once a year and completed follow-up questionnaires regarding their menstrual cycles, health status, lifestyle, depressive symptoms, and sleep and submitted blood and urine samples.

The researchers then used a Bayesian network analysis to model the most likely reason for self-reported insomnia in midlife women. They tested several factors, including hormone concentrations and hot flashes, to see how these may be interacting to influence sleep disruption.

“Surprisingly, we did not find that hormone levels can predict sleep disruption. We did, however, find that women who have hot flashes at night also have insomnia. Moreover, women who had insomnia in the fourth year of the study also had it in the first year. The same was true for depression,” says Megan Mahoney, an associate professor of psychology, in a press release. “The bottom line is that some of these symptoms don’t necessarily go away over the course of menopause. When women go to the doctor, if they address these problems in the early phase of their menopause, they can address long-term problems.”

The study concludes that hot flashes at night, previous insomnia, and depression are stronger predictors of how women will self-report the frequency of sleep disruptions, and treatment may reduce menopausal sleep complaints.

The researchers would like to understand if there are lifestyle factors, such as high cholesterol, that can predict insomnia in menopausal women. If so, exercise and diet could go a long way to help. They are also interested in learning the extent to which exposure to environmental chemicals leads to sleep disruption.

Photo caption: Illinois professors, from left, Jodi Flaws, Megan Mahoney, and Rebecca Smith found that nocturnal hot flashes can serve as a predictor of insomnia in menopausal women.

Photo credit: L. Brian Stauffer