HRT Increases The Risk Of Dementia

Most of the news about the Women's Health Initiative (WHI) initially focused on the findings that combination estrogen and progesterone therapy (HRT) increased the risk of heart attacks, stroke, blood clots and invasive breast cancer in postmenopausal women who took HRT for more than five years.   Further analysis of the WHI data revealed another surprise:  menopausal women in the combination HRT group also had an increased risk of cognitive impairment (brain function) and of ischemic stroke. 

This information came from an two separate arms of the WHI called the "Women's Health Initiative Memory Study" (WHIMS) which were both double-blind and placebo controlled.  Over 4,000 women over age 65 were studied.  In the first study, the risk of dementia in the women who took combined HRT was nearly twice that of women who took placebo.  What does this mean?  The study authors figured that this would account for 23 additional cases of dementia for every 10,000 women over age 65 on HRT per year. The second study group did not show similar effects of HRT on dementia.  However, in this study, more women in the combination HRT group experienced a substantial and clinically relevant decline in their cognitive function compared to women taking placebo.  This information counters a previously popular hypothesis that HRT might actually reduce or delay the onset of certain types of dementia, particularly Alzheimer's disease.

Created: 10/15/2003  -  Donnica Moore, M.D.