Hormone therapy
raises dementia riskResearch finds more bad news
for women taking a dual regimen
A national study that included Hawaii participants shows the risk of developing dementia may be doubled in older women who take hormone replacement therapy combining estrogen and progestin, researchers reported today.
The Women's Health Initiative Memory Study, appearing in this week's Journal of the American Medical Association, involved 4,532 postmenopausal women 65 and older who were followed an average of 4.2 years at 39 of 40 Women's Health Initiative centers.
About half of the women received a daily tablet of the combination estrogen plus progestin, marketed as Prempro, and the other women received a substitute, or placebo.
The study found an additional 23 cases of dementia per year could occur for every 10,000 women taking O.65 milligrams daily of conjugated equine estrogen plus 2.5 milligrams daily of medroxyprogesterone acetate.
Dementia involves a significant decline in memory, judgment and ability to think. Alzheimer's disease was the most common form among the study participants.
"The overall individual risk to women is low, although there is reason for concern," said Sally A. Shumaker, national principal investigator for the study at Wake Forest University Baptist Medical Center.
"Because of the potential harm and lack of benefit found, we recommend that older postmenopausal women not take the combination hormone therapy to prevent dementia, and we hope that doctors will incorporate what we've learned in their recommendations to women," she said.
The memory study was part of a large national Women's Health Initiative study that was halted in last July after findings that the combination of hormones might increase the risk of breast cancer, strokes and cardiovascular disease.
In Hawaii, 265 women participated.
All were taken off the estrogen plus progestin therapy but the dementia risk hadn't been determined because all the memory data hadn't been analyzed.
Researchers evaluated effects of the combined hormones on dementia, mild cognitive impairment and functions such as concentration, language, memory and abstract reasoning.
Women taking the combined hormone therapy performed slightly worse than those getting the placebos, they reported.
Hawaii investigators in the Women's Health Initiative study at the Pacific Health Research Center include: Drs. J. David Curb and Helen Petrovitch, co-principal investigators, and Drs. Beatriz Rodriguez, Kamal Masaki and Santosh Sharma, co-investigators. In the memory study portion, Masaki is principal investigator and Curb and Dr. G. Webster Ross are co-investigators.