July 6, 2006

Women who have severe hot flashes may have more chronic sleep problems than women who do not, according to a report in the June 26 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.

Maurice M. Ohayon, MD, DSc, PhD, Stanford University School of Medicine, Palo Alto, Calif, conducted telephone interviews with 3,243 individuals in California, including 982 women ages 35 to 65 years, between June 2003 and April 2004.

About 33% of the women reported having hot flashes, including 12.5% of the premenopausal women, 79% of perimenopausal women, and 39.3% of postmenopausal women. Of those who had hot flashes, about half reported that they were typically mild, while about a third had moderate hot flashes and about 15% had severe hot flashes.

More than 81% of women with regular severe hot flashes had symptoms of chronic insomnia. These women reported difficulty falling asleep, non-restful sleep, and overall dissatisfaction with their sleep patterns on a regular basis (at least 3 nights a week for at least the past 6 months). Women with mild hot flashes did not report these problems any more frequently than did women without hot flashes. Women were also more likely to have problems staying asleep as their hot flashes became more severe.

The researchers also examined how insomnia related to women’s menopausal status and found that women in perimenopause were more likely to have difficulty falling asleep, non-restful sleep, and overall dissatisfaction with sleep. One third of perimenopausal and postmenopausal women reported that they believed insomnia was related to the development of menopause.

“This study provides evidence that severe hot flashes are associated with chronic insomnia in women aged 35 to 65 years,” the authors wrote. “The dramatic increase in insomnia in women with severe hot flashes indicates that severity of hot flashes should be routinely assessed in all studies of menopause.”

“Treating hot flashes could improve sleep quality and minimize the deleterious consequences of chronic insomnia,” the authors concluded.