For that reason, many medical scientists began recommending against the combined therapy in the absence of such symptoms, saying the risks of estrogen plus progestin outweighed the benefits.
The latest findings from Women's Health Initiative studies provide new evidence that the combined hormone therapy significantly boosts the risks of dementia and strokes in postmenopausal women while not improving what scientists call "global cognitive function" -- how the brain works.
"The strength of the findings last year, as well as the new ones, is not only the large number of study participants, but also that they were randomly assigned to receive daily estrogen plus progestin or placebo," said Dr. Gerardo Heiss, professor of epidemiology at the University of North Carolina at Chapel Hill School of Public Health.
The Women's Health Initiative Memory Study (WHIMS), which showed roughly a doubling of dementia among those in the treatment group, involved 4,532 women, while the new stroke investigation involved 16,608.
As a member of its steering committee, Heiss helped design the overall Women's Health Initiative study, which is producing useful data for numerous ancillary studies. He is co-author of the stroke report, whose lead author is Dr. Sylvia Wasserthiel-Smoller of the Albert Einstein College of Medicine. Drs. Sally A. Shumaker and Stephen R. Rapp of Wake Forest University are first authors of the WHIMS dementia and global cognitive function studies, respectively.
"What is new in the WHI paper on stroke is that we now include all the strokes with 5.6 years follow-up, adjudicated by neurologists wi
Contact: David Williamson
University of North Carolina at Chapel Hill