Women who wake up at least three times during the night from hot flashes wake up less when they take oestrogen, but the quality of their sleep remains the same, according to a new study.
"There may be a benefit for treating with oestrogen, 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.
In her study, funded by Duramed Research, now Teva Women's Health R&D, Dr Reape and her colleagues tested the effect of a mix of synthetic estrogens (Enjuvia, Teva) on 145 women whose hot flashes woke them up at night. The results are published in the January issue of Obstetrics and Gynaecology.
One third of the women took a high dose of the oestrogen therapy (0.625 mg per day), another third took a low dose (0.3 mg daily), and the rest took a placebo.
Night time hot flashes disappear
Over the course of the three-month study, 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 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 oestrogen no longer had any night-time hot flashes rousing them, compared to 10% of the women in the control group.
Sleep quality declines with age
The total amount of sleep, the quality of sleep, and daytime sleepiness, however, remained the same throughout the study.
Dr 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 with age, and many older people struggle with broken sleep.
"Menopause superimposes a deterioration of sleep that varies highly among women," he told Reuters Health.
Hot flashes are stressful
Waking up during the night can be stressful to people, Dr 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," he said "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 oestrogen therapy could be used to help women sleep better during menopause.
Dr 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.
(Reuters Health, December 2011)