Estrogen therapy and risk of cognitive decline: Results from the Womenʹs Estrogen for Stroke Trial (WEST)

Objective This study was undertaken to assess whether estrogen therapy (ET) reduces the risk of cognitive decline in women with cerebrovascular disease. Study design We conducted a randomized, double-blind trial of estradiol 17β versus placebo for secondary stroke prevention in 664 postmenopausal women with a recent stroke or transient ischemic attack. The Mini-Mental State Examination (MMSE) and 5 domain measures were obtained at baseline and exit. Results Among 461 women withdrawn alive without stroke, ET did not have a significant effect on cognitive measures after an average of 3 years (relative risk of MMSE decline: 0.74, 95% CI, 0.49-1.13). In women with normal MMSE at entry, estrogen was associated with less decline (relative risk, 0.46, 95% CI, 0.24-0.87). Conclusion In this study, estradiol did not have significant effects on cognitive measures. However, in women with normal function at baseline, there may be a benefit for ET in reducing the risk for cognitive decline