Third study to conclude that risks of combination hormone therapy may outweigh benefits

May 28, 2003

WORCESTER, Mass.—Older postmenopausal women taking combination hormone replacement therapy may face twice the risk of developing dementia as women taking a placebo, according to a report by the Women’s Health Initiative Memory Study.  Researchers with the multi-site Women’s Health Initiative estrogen plus progestin trials released two papers today in the Journal of the American Medical Association focusing on the effect of estrogen plus progestin on cognitive function in older women. 

Judith K. Ockene, PhD, the Barbara Helen Smith Chair in Preventive and Behavioral Medicine, professor of medicine and chief of the Division of Preventive and Behavioral Medicine, co-authored the paper, “Estrogen Plus Progestin and the Incidence of Dementia and Mild Cognitive Impairment in Postmenopausal Women.”

As part of the WHIMS study, 4500 postmenopausal women between the ages of 65 and 79 who were taking the combination hormone or placebo daily were evaluated annually in areas of cognitive function such as attention, concentration, language, abstract reasoning and calculation. The tests measured whether the participants’ cognitive function had declined abnormally or whether mild cognitive impairment or dementia were present.

The study found that over a five-year period the risk for dementia among women taking the hormones was more than double: an increase from 22 per 10,000 to 45 per 10,000. Among the 4,500 women in the WHIMS study, 61 were diagnosed with dementia; 40 were taking the hormones and 21 were taking the placebo.  The study supports the conclusion of reports published previously, in July 2002 and March 2003, that the risks associated with the combination hormone therapy outweigh the benefits.

“This is yet one more piece of the puzzle regarding the effects of the estrogen plus progestin combination,” said Dr. Ockene.  “The recent findings in JAMA underscore that the risks outweigh the benefits. There remains very little reason for women to continue to take the combination hormone therapy other than for the potential of handling menopausal symptoms short-term.  However, even this may not be reason enough to take it due to the harmful short-term cerebrovascular effects.  This study is a wonderful example of how important medical research is and how it can affect the practice of medicine."

The larger EplusP component of the WHI studies enrolled between 1993 and 1998 more than 16,600 menopausal women, aged 50 to 79 who had not had a hysterectomy.  The study was abruptly halted in July 2002 when researchers reported an unexpected increased risk of invasive breast cancer, coronary heart disease, stroke, and pulmonary embolism among postmenopausal women using the combination hormone replacement therapy. An additional WHI study in March 2003 further indicated that the hormones provided no significant improvement of quality of life, contradicting a long-held belief that the hormones were beneficial to postmenopausal women’s quality of life.

The second study released today, “Effect of Estrogen Plus Progestin on Global Cognitive Function in Postmenopausal Women” indicates that among postmenopausal women 65 or older, the hormones did not improve cognitive function when compared to the placebo.

The WHI involves over 161,000 women who are participating in a set of clinical trials or an observational study at more than 40 sites across the country. Clinical trials in Massachusetts are based at UMass Medical School in conjunction with Fallon Clinic, and at the Brigham and Women’s Hospital. The clinical trials are designed to test promising but unproven treatments for heart disease, breast and colorectal cancer, and osteoporosis. WHI is sponsored by NHLBI in collaboration with four other components of the NIH: the National Cancer Institute; the National Institute of Arthritis and Musculoskeletal and Skin Diseases; the National Institute on Aging; and the Office of Research on Women’s Health.

The JAMA studies can be found at www.jama.ama-assn.org . Information about the WHI is available on the NHLBI website at: www.nhlbi.nih.gov, and information about these findings can also be found on the study website at: www.whi.org .

Contact: Alison Duffy, 508-856-2000