Women who wake up at least three times during the night from bothersome hot flashes wake up less when they take estrogen, but the quality of their sleep remains the same, according to a new study.
"There may be a benefit for treating with estrogen, but in no way does it show that you can use estrogens as a general sleep aid," said lead author Dr. Kathleen Reape, the vice president for medical affairs and women's health at Watson Pharmaceuticals.
Estrogen is already known to reduce hot flashes in women going through menopause, Reape told Reuters Health.
In her study, funded by Duramed Research, now Teva Women's Health R&D, Reape and her colleagues tested the effect of a mix of synthetic estrogens on 145 women whose hot flashes woke them up at night. The results are published in the journal Obstetrics and Gynecology.
One third of the women took a high dose of the estrogen therapy - 0.625 milligrams per day - another third took a low dose - 0.3 milligrams daily - and another third took a fake pill that resembled the estrogen tablet but had no hormones in it.
The estrogen mix goes by the brand name Enjuvia, marketed by Teva Women's Health, and costs a little more than US$2 (S$2.6) a tablet through online pharmacies.
The study lasted for nearly three months, and the women kept a diary of how many times they woke up, how well they slept, and their sleepiness during the day.
The women also wore an electronic bracelet several times throughout the study that measured their limb movements during sleep.
Although all the women woke up fewer times at the end of the study than at the beginning, the high dose group woke up five fewer times per week and the low dose group woke up about four fewer times per week, on average, than the women who took the fake pill.
Additionally, by the end of the study, about a third of the women who took estrogen no longer had any nighttime hot flashes rousing them, compared to a tenth of the women in the other group.
The total amount of sleep as measured by the monitoring bracelet, and the quality of sleep and daytime sleepiness that the women reported, however, remained the same throughout the study.
Menopause linked to broken sleep
Menopause linked to broken sleep
Reape said that sleep disturbances are likely caused by a number of factors, and not just the hot flashes.
Dr. Quentin Regestein, a professor at Harvard Medical School who was not involved in this study, said sleep quality declines as we age, and many older people struggle with broken sleep.
"Menopause superimposes a deterioration of sleep that varies highly among women," he told Reuters Health.
Waking up during the night can be stressful to people, Regestein said, and helping people stay asleep can help the anxiety.
"I think it's not wakefulness per se, but how bothered you are by it," Regestein. "So for those who are, and who had the wakefulness eliminated, that's a good thing."
The study did not measure whether the women's mood was affected by the treatment, and more research is necessary to determine whether estrogen therapy could be used to help women sleep better during the sometimes slumber-disturbing process of menopause.
Reape noted that the women in the study didn't necessarily have sleep problems or daytime sleepiness concerns before the study began, and studying women with sleep problems could be useful.
There are a variety of estrogen products that are prescribed to treat hot flashes.
Reape said it's important that women discuss the benefits and risks associated with estrogen therapy to treat their hot flashes.
Studies have found that certain kinds of hormone therapy might increase the risk of stroke and other health problems.
Estrogen can also carry side effects, such as weight gain, breast tenderness and an upset stomach.
SOURCE: Obstetrics and Gynecology, January 2012.