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Estrogen replacement therapy fails to protect against dementia, may lower cognitive function
Two studies that appeared in the June 23/30 issue of the Journal of the American Medical Association (http://jama.ama-assn.org/) found that conjugated equine estrogens (CEE) used alone failed to reduce the risk of dementia or mild cognitive impairment in women, and lowered cognitive function. The findings of the studies refute previous research that suggested that estrogen replacement therapy helped protect brain function in older women.
The studies analyzed data from the Women’s Health Initiative Memory Study (WHIMS), an ancillary study to the Women’s Health Initiative which examined the role of hormone replacement therapy on approximately 27,000 women aged 65 to 79. Both the estrogen combined with medroxyprogesterone acetate (MPA) and estrogen alone arms of the trial were terminated early because of increased adverse health risks experienced by both groups who received the hormones.
In the first study, Sally A. Shumaker, PhD, of the Wake Forest University School of Medicine and colleagues sought to find out whether conjugated estrogens alone lowered the risk of dementia and mild cognitive impairment in women who received them compared to those who received placebos. They found that the hormones increased the combined risk of dementia and mild cognitive impairment and recommended against using hormone therapy in to prevent either condition.
In the second study, Mark A. Espeland, PhD, also of Wake Forest University School of Medicine, and colleagues from the WHIMS investigated cognitive function in the conjugated equine estrogens alone group and in the combined estrogen alone and estrogen plus progestin groups. They concluded, "Our results suggest that neither CEE nor CEE plus MPA should be initiated in older women for the purpose of protecting cognitive function. Furthermore, at least 1 subgroup of women was at particularly high risk for the adverse effects of hormone therapy on cognition--women with relatively low baseline cognitive function."
In an accompanying editorial, Lon S. Schneider, MD of the University of Southern California, Los Angeles, asks whether short-term estrogen use in early post menopause could be effective to reduce dementia two to three decades later. He concludes that, "The WHIMS results do not prove that estrogen therapy has no effect on AD or dementia, but they do clearly indicate that women older than 65 years should not be treated with CEE with or without MPA to attempt to prevent dementia or enhance cognition.”