Carey Gleason of the University of Wisconsin and colleagues analyzed data from 275 participants in the KEEPS clinical trial and found that four years of different types of hormone replacement therapy at menopause was not associated with the risk of cognitive decline 10 years later. In the trial, participants received either 0.45 milligrams of conjugated estrogens orally, 50 micrograms of estradiol transdermal patches (both combined with 200 milligrams of micronized progesterone) per day, or a placebo for 48 months within three years of their last menstrual period. They completed a battery of cognitive tests before starting therapy, after stopping it, and about 10 years later. The results are published in the journal PLoS Medicine.
It turned out that the most reliable long-term predictors of cognitive indicators were their initial level and dynamics during the trials. The intake of hormone replacement therapy and its type did not have a significant effect on them.