Estrogen isn t quite a sleep aid

Estrogen therapy may reduce the hot flashes that so often wake menopausal women during the night but the quality of their sleep won t necessarily improve, says a new study in Obstetrics and Gynecology.

In this study, investigators looked at the effects of synthetic estrogens on a group of 145 women whose sleep was frequently interrupted by hot flashes. For three months, one third of the women took a high dose of estrogen, another third took a low dose, and the rest were given a placebo. The women tracked their sleep by keeping a diary of how often they woke during the night, the quality of their sleep, and their level of sleepiness the next day. Several times throughout the study, the women also wore an electronic bracelet that measured their limb movements during the night.

Ultimately, the women taking the high or low doses of estrogen woke up five or four fewer times per week, respectively, than the women on the placebo. Additionally, by the end of the study, a third of the women on estrogen therapy no longer were awakened by hot flashes during the night; this was true for only one-tenth of the placebo group. Unfortunately, despite these promising results for women taking estrogen, the total amount of sleep, as well as the quality of sleep and daytime sleepiness, remained the same for all of the women throughout the study.

Yet a sleep researcher at Harvard Medical School who was not involved in the study pointed out that women may still benefit from uninterrupted sleep, even if the estrogen therapy doesn t improve the overall quality and quantity of sleep. Waking up during the night can be stressful, Dr. Quentin Regestein observed, and sleeping through the night can ease some of that anxiety. I think it s not wakefulness per se, but how bothered you are by it, he said.

ACSH s Dr. Ruth Kava points out that the findings can be added to the risk/benefit assessment that any woman should think about before beginning estrogen replacement therapy. It s a little thing, she notes, but it could make a difference for some women.

ACSH s Dr. Gilbert Ross, however, feels that there needs to be a much larger randomized controlled trial in order to more precisely determine how estrogen replacement therapy affects a woman s quality of sleep.