(Ivanhoe Newswire) It's not just aging that causes sleep problems for women; hormones are partly to blame.

According to research from the Rush University Medical Center, approximately 16 percent of postmenopausal women say they have trouble falling asleep. Forty-one percent report waking up several times during the night.

The study looked at women from several ethnic groups. Caucasians were more likely to have trouble staying asleep. Hispanic women were least likely to wake up repeatedly. Among Hispanic, Caucasian, African American and Japanese women, Chinese women were more likely to report waking up earlier than planned.

The research revealed that changing hormones were partly to blame. Drops in levels of estradiol, the major form of estrogen, were associated with falling and staying asleep. While women on hormone therapy had less trouble falling asleep and didn't wake up as often, it did not influence hot flashes, cold and night sweats.

"Although we found some evidence that hormonal therapy could benefit these menopausal sleep related symptoms, this was not a consistent finding across all groups compared," said Dr. Howard Kravitz, one of the principal investigators. "So the role for this particular treatment needs more study."

Women who became menopausal because of surgery and were not on hormone therapy were most likely to have these sleep issues.

SOURCE: SLEEP, July 1, 2008
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