Reproductive senescence blunts response of estrogen receptor-α expression to estrogen treatment in rat post-ischemic cerebral microvessels

Sex hormones and stroke: Beyond estrogens

Stroke risk and poor stroke outcomes in postmenopausal women have usually beeen attributed to decreased levels of estrogen. However, two lines of evidence suggest that this hormone may not be solely responsible for elevated stroke risk in this population. First, the increased risk for CVD and stroke occurs much earlier than menopause at a time when estrogen levels are not yet reduced. Second, estrogen therapy has not successfully reduced stroke risk in all studies. Other sex hormones may therefore also contribute to stroke risk. Prior to menopause, levels of the gonadotrophin Follicle Stimulating Hormone (FSH) are elevated while levels of the gonadal peptide inhibin are lowered, indicating an overall decrease in ovarian reserve. Similarly, reduced estrogen levels at menopause significantly increase the ratio of androgens to estrogens. In view of the evidence that androgens may be unfavorable for CVD and stroke, this elevated ratio of testosterone to estrogen may also contribute to the postmenopause-associated stroke risk. This review synthesizes evidence from different clinical populations including natural menopause, surgical menopause, women on chemotherapy, and preclinical stroke models to dissect the role of ovarian hormones and stroke risk and outcomes.

Long-term Effects on Cognitive Trajectories of Postmenopausal Hormone Therapy in Two Age Groups

BACKGROUND

Postmenopausal hormone therapy may have long-term effects on cognitive function depending on women's age.

METHODS

Postintervention follow-up was conducted with annual cognitive assessments of two randomized controlled clinical trial cohorts, beginning an average of 6-7 years after study medications were terminated: 1,376 women who had enrolled in the Women's Health Initiative when aged 50-54 years and 2,880 who had enrolled when aged 65-79 years. Women had been randomly assigned to 0.625mg/d conjugated equine estrogens (CEE) for those with prior hysterectomy (mean 7.1 years), CEE with 2.5mg/d medroxyprogesterone acetate for those without prior hysterectomy (mean 5.4 years), or matching placebos.

RESULTS

Hormone therapy, when prescribed to women aged 50-54 years, had no significant long-term posttreatment effects on cognitive function and on changes in cognitive function. When prescribed to older women, it was associated with long-term mean (SE) relative decrements (standard deviation units) in global cognitive function of 0.081 (0.029), working memory of 0.070 (0.025), and executive function of 0.054 (0.023), all p < .05. These decrements were relatively stable over time. Findings did not vary depending on the hormone therapy regimen, prior use, or years from last menstrual period. Mean intervention effects were small; however, the largest were comparable in magnitude to those seen during the trial's active intervention phase.

CONCLUSIONS

CEE-based hormone therapy delivered near the time of menopause provides neither cognitive benefit nor detriment. If administered in older women, it results in small decrements in several cognitive domains that remain for many years.