Maurice Ohayon, MD, PhD, DSc, associate professor of psychiatry and behavioral sciences and director of sleep epidemiology at the Stanford University School of Medicine, recently sought to determine the factors that contribute to insomnia among these midlife women. Below is a snapshot of his research findings, which will appear in the July 26 issue of the Archives of Internal Medicine.
To what extent can hot flashes in midlife women be considered a cause of chronic insomnia?
Because hot flashes may occur during the night, their presence has been frequently associated with insomnia; however, many other factors can be responsible for insomnia. These include anxiety and depression, which often occur during menopause, and sleep apnea or other sleep disorders, which become more common with age.
Researchers conducted telephone interviews with 982 women, ages 35 to 65, about their sleep history, hot flashes and overall health status. Chronic insomnia was defined as having difficulty getting to sleep or staying asleep at least three nights a week for the past six months or more. Hot flashes were evaluated on their frequency, severity and daytime functioning. The results were controlled for the presence of variables generally associated with insomnia.
The overall prevalence of hot flashes was 79 percent in perimenopausal women (having at least one menstrual cycle in the past 12 months) and 51 percent in postmenopausal women (no menstrual cycles in the past year) - figures that are consistent with those from previous studies. The prevalence of insomnia was 57 percent in perimenopausal women and 51 percent in postmenopausal women. While insomnia was influenced by several factors, such as poor health and sleep apnea, hot flashes seemed to play the largest role. In particular, chronic insomnia dramatically increased among women with severe hot flashes: 81 percent of women experiencing them had symptoms of insomnia. The temporal relationship between symptoms of insomnia and menopause shows that insomnia is more likely to occur around or after the beginning of menopause.
What the researcher says:
"In this paper, we have observed without any doubt and in a significant way that hot flashes are associated with insomnia. This is the first observational study showing the link between insomnia and hot flashes while controlling for other factors that could account for insomnia in women."
Why it matters:
Physicians can help improve sleep quality and minimize consequences of insomnia among certain patients by focusing on treating hot flashes, rather than pursuing other avenues.
Stanford University Medical Center integrates research, medical education and patient care at its three institutions - Stanford University School of Medicine, Stanford Hospital & Clinics and Lucile Packard Children's Hospital at Stanford. For more information, please visit the Web site of the medical center's Office of Communication & Public Affairs at http://mednews.stanford.edu.
Michelle Brandt at (650) 723-0272
Last reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
Published on PsychCentral.com. All rights reserved.