MONDAY, Sept. 24, 2007 (HealthDay News) -- Giving hormone therapy to women in the first few years after menopause doesn't improve memory, although it does seem to increase sexual interest, a new study found.
The study looked specifically at combined hormone therapy, meaning estrogen plus progesterone, suggesting that progesterone could be the active factor.
"It's saying the progesterone is good for sexuality but probably not so good for cognition," said Pauline Maki, lead author of the study and associate professor of psychiatry and psychology at the University of Illinois at Chicago. "But that's not to say that other progestins wouldn't be good for cognition."
The study was funded by Wyeth, which makes the hormone formulation Prempro. The results are published in the Sept. 25 issue of the journal Neurology.
Experts have long suspected that the natural hormonal changes associated with menopause may contribute to memory problems.
Several trials have reported that estrogen therapy might help alleviate these problems in younger postmenopausal women. And trials in older women -- 65 and over -- found negative or neutral effects, but these trials looked at combined estrogen and progesterone therapy.
Only one study has looked at combined hormone therapy on women under the age of 65. It found a beneficial effect on memory, but in a small sample of women.
The landmark Women's Health Initiative (WHI) Memory Study, released in 2004, found that estrogen on its own did not protect women from normal declines in cognitive function.
"There are a number of studies suggesting that estrogen alone improves memory functioning in women who are surgically menopausal," Maki said. "The question is what does estrogen plus progesterone do for women who are not surgically menopausal?"
"I wanted to know the effect of estrogen plus progestin in younger women," she continued.
For this study, 180 healthy postmenopausal women aged 45 to 55 were randomly assigned to receive either estrogen plus progesterone or a placebo for four months.
Although the number of women involved may seem small, this was the largest study to look at the effects of hormone therapy on early postmenopausal women. The authors had originally intended to look at 275 women, but enrollment coincided with the release of the results of the original Women's Health Initiative, which found various negative health effects from hormone therapy. As a result, fewer women were willing to participate in this study.
The study authors found no significant differences in cognition between the two groups, although there was a non-statistically significant trend toward a decrease in memory among the women taking hormones.
This finding fits with previous research suggesting that hormone therapy has little effect on memory when taken many years after menopause. It is in contrast to smaller studies that showed an improvement in verbal memory among women taking only estrogen, but it could be that progesterone neutralizes this protective effect of estrogen, the study authors said.
The study did, however, find an increase in sexual interest and thoughts in women taking hormone therapy. Women taking hormones had a 44 percent increase in sexual interest and their number of sexual thoughts increased 32 percent, compared to the placebo group.
The combination of estrogen plus progesterone also relieved some of the hallmark symptoms of menopause, such as hot flashes and night sweats.
"Surprisingly little is known about sexuality and hormone therapy in menopausal women despite the fact that vaginal dryness and sexual-desire losses are symptomatic at that time," Maki said. "We found these pretty interesting effects, which says that this could be a benefit for women who are seeking hormone therapy and that maybe we ought to study sexuality and hormones a little bit more and not disregard sexuality."
At the same time, women considering hormone therapy should talk to their doctor about the risks and benefits.
"In the last year, we've had a number of publications showing that when you separate out younger postmenopausal women, they don't have the same health risks that women who are older have," Maki said. "In fact, the overall risk-benefit ratio in younger women is for a benefit. I'm hoping that there's a growing appreciation for considering the age of the woman and how the health benefits and risks of hormone therapy need to be considered in light of that."
Dr. Jennifer Wu, an obstetrician/gynecologist at Lenox Hill Hospital in New York City, said, "It is an added bonus of hormone therapy that not only will it help menopausal symptoms like hot flashes and night sweats, it can also help libido changes. "But in terms of purely treating libido, that has to be carefully considered. I think patients need to carefully weigh the risks and benefits of hormone therapy when they're considering it solely for the purpose of libido."
More information
Learn more about hormone therapy at the Women's Health Initiative.
