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 various types of hormone replacement therapy during menopause was not associated with the risk of cognitive impairment 10 years later. In the trial, participants received either 0.45 milligrams of conjugated estrogens orally, 50 micrograms of estradiol transdermally via patch (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 and after therapy, and approximately 10 years later. The results were published in the journal PLoS Medicine.
It turned out that the most reliable long-term predictors of cognitive outcomes were their baseline levels and changes over the course of the trial. Hormone replacement therapy and its type had no significant impact.
