March 17, 2000 (New York) -- Estrogen replacement therapy (ERT) appeared to bring sleep patterns closer to normal and improve sleep quality in a group of postmenopausal women, according to a report in the February issue of the American Journal of Obstetrics and Gynecology.
"Sleep disorders become more common in women as they progress past menopause. Women have more trouble falling asleep and staying asleep. When they do sleep, it has been documented that they spend less time in rapid eye movement (REM) sleep and, therefore, when they wake up, they report that they feel less rested," Suzanne Trupin, MD, tells WebMD. Trupin is a clinical professor of obstetrics and gynecology at the University of Illinois College of Medicine at Urbana.
"When we look at studies of estrogen on sleep in menopausal women, estrogen usually improves the quality of sleep, reduces time to fall asleep, and increases the amount of REM sleep. Sleep lab studies also indicate estrogen reduces the number of times a patient awakens and may improve cognitive function," says Trupin.
A recent study cowritten by Irina A. Antonijevic, MD, PhD, of the department of psychiatry at the Max Planck Institute of Psychiatry in Munich, Germany, used advanced technology available in a sleep laboratory to help clarify some of the subtle effects of estrogen on the electrical activity of the brain during various stages of sleep and wakefulness.
The authors used a device called an electroencephalogram (EEG) to record the electrical activity of the brain while a group of women on ERT slept. They then compared those EEG recordings to others taken while the women were sleeping and off ERT therapy.
The group comprised women ages 46 to 62 years old who had gone through menopause, either naturally or surgically, and had been postmenopausal for at least one year. Five of the women were on ERT before the study and had their ERT sleep evaluation first and the non-ERT evaluation two weeks after a washout period. The rest of the group had the non-ERT evaluation, then began ERT treatment, and had a second sleep evaluation during the last two days of estrogen treatment.
Patients were either already on a patch that delivers estrogen through the skin before the study began or were prescribed one. Patches were changed twice weekly and released daily doses of estrogen.
The study confirmed that ERT had subtle but specific effects on sleep. For instance, ERT significantly increased the amount of time patients had REM sleep and reduced the time spent awake from 20 to 12 minutes during the first two sleep cycles of the night. A sleep cycle is a period of non-REM sleep followed by a minimum of five minutes of REM sleep. A sleep cycle can last approximately 70 to 120 minutes and be repeated four to six times a night.
The authors noted changes in deep sleep that mimicked the deep sleep patterns seen in younger, healthy individuals. People with sleep difficulties and depressed people do not have such patterns. They also found evidence that ERT appeared to play a role in the improvement of cognitive functioning, according to Antonijevic.
Without ERT, 10 of the 11 women rated their sleep as dissatisfying and reported three to five awakenings per night. That ratio changed dramatically after ERT, as 10 of the 11 women rated the quality of their sleep as very or quite satisfying, with only one or two awakenings per night.
"The improvement of sleep with ERT in menopausal women was documented in the late 1970s in England and we documented it in 1980," Quentin Regestein, MD, of the psychiatry department at Harvard Medical School, tells WebMD. "We also found the women got to sleep faster and had more REM -- but we didn't show some of the details, like the decrease in [deep] sleep these people have found." Regestein, however, was quite impressed with the reported change in sleep satisfaction after ERT, a finding he says is "extremely telling."
Menopausal patients with sleep problems should keep track of their sleep with a sleep diary, Trupin says. Then "they should have a general evaluation with a health care provider to rule out other medical causes of insomnia. If the patient is postmenopausal and a candidate for estrogen, most physicians would then probably recommend ERT as the next step."
If patients are menopausal and not having symptoms like hot flashes and are not that interested in hormone replacement therapy, Trupin would "probably prescribe a nonaddicting, short-acting sleep medicine. However, I find my patients do better by placing them on estrogen than going with strictly traditional sleeping medications. I believe that if a patient's sleep disruption is due to [hot flashes], 95% to 98% ... can be cured with ERT," she says.