The study, the largest to date examining the effects of hormone therapy in early post-menopausal women, involved 180 women between the ages of 45 and 55 who had finished their last menstrual cycle in the past one to three years. The women were randomly given placebo or hormone therapy consisting of daily estrogen and progesterone for four months. The women also underwent tests on memory, attention, cognitive function, emotional status, sexuality, and sleep.
The study found no significant difference in cognition among women taking hormone therapy compared to women taking placebo.
"These results are similar to previous studies suggesting hormone therapy has minimal effect on a woman's memory when taken many years after menopause," said study author Pauline Maki, PhD, with the University of Illinois in Chicago. "While our results are inconsistent with smaller studies that found improvement in verbal memory for women who only used estrogen, it may be that progesterone modifies the protective effects of estrogen on verbal memory."
The study also found an increase in sexual interest and thoughts in the women taking hormone therapy. "The level of sexual interest reported by women on hormone therapy increased 44 percent and their number of sexual thoughts increased 32 percent compared to the placebo group," said Maki.
In addition, women with vasomotor symptoms, such as hot flashes and night sweats, showed a decrease in such symptoms and an improvement in general quality of life, but no cognitive benefits over placebo.
Maki says the study is limited since it was terminated before it reached its desired sample size of 275 women due to a drop in participation over concerns about the safety of hormone therapy following publication of the Women's Health Initiative, which suggested long-term use of hormone therapy increases a women's risk for breast cancer and does not protect against cardiovascular disease.