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What's New - Hormone Therapy Risks

Hundreds of Portland-area women involved in studies At Kaiser Permanente's Center for Health Research

Combination Hormone Therapy Doubles Risk of Dementia, Does Not Improve Cognitive Function, and Raises Risk of Stroke

(PORTLAND, Ore.) - Three new studies from the Women's Health Initiative (WHI), appearing in the May 28 issue of the Journal of the American Medical Association, raise new questions about the value and safety of long-term use of estrogen and progestin to prevent disease. One study found that postmenopausal women age 65-79 who took estrogen plus progestin (E+P) developed dementia at slightly more than twice the rate of similar women who took placebos. The study also found that the two groups of women developed mild cognitive impairment at the same rates. A second study, which looked at global cognitive function (concentration, language, memory, and abstract reasoning) among the same two groups of women, found that women taking E+P had slightly lower cognitive function scores than women on placebo. The third study found that postmenopausal women aged 50-79 taking E+P had a 31 percent greater risk of stroke than similar women who took placebos and that women in all age groups and health categories taking E+P were at increased risk.

"These new findings strengthen the view that women should not take the estrogen plus progestin combination long-term to prevent diseases," says Cheryl Ritenbaugh, PhD, MPH, principal investigator for the WHI clinical center at Kaiser Permanente's Center for Health Research. "At this point, the benefits of the hormone combination for osteoporosis and colon cancer are far outweighed by the increased risks of breast cancer, heart disease, stroke, and dementia, and by the lack of benefit for maintaining or improving cognitive function."

Women in these new studies stopped taking estrogen plus progestin in July 2002 when it was found that the risks of breast cancer, heart disease, and stroke outweighed the benefits. At that time, not all the cognitive data had been analyzed and the dementia risk had not been established. Since then, WHI researchers have also reanalyzed the stroke data to find out if there were any groups of women who did not have an increased risk of stroke.

The two new cognition studies are part of a WHI sub-study called WHIMS (Women's Health Initiative Memory Study). Both studies involved 5,532 postmenopausal women age 65 and older (118 in the Northwest, including 85 in the Portland area, 17 in Clark County, 13 in the Salem area, and three in Longview, Wash.) who were followed for an average of 4.2 years at 39 of the 40 WHI clinical centers. Almost half of the women (2,229) received a daily tablet of the combination estrogen plus progestin, marketed as PremproTM, and the other women (2,303) received a placebo or "inactive" drug. The risk for dementia, primarily Alzheimer's disease, among women taking the hormone combination was 2.05 times that of women taking the placebo. Sixty-one cases of dementia were diagnosed among all the women, 40 of them among women on hormone combination and 21 on placebo. Translated to a population of 10,000 women taking the combined hormone therapy, there would be an additional 23 cases of dementia per year. The WHIMS study also found that the combined hormone therapy did not prevent mild cognitive impairment nor did it improve women's general cognitive abilities.

Stroke risk affected all women

Participants were randomly assigned to one of three groups - Advice-Only, Established, and Established Plus DASH. Everyone received printed materials about blood pressure and lifestyle. Those in the Advice-Only group also received a 30-minute individual session with a nutritionist that did not include counseling on how to make behavior changes. Those in the Established group had 18 counseling sessions over six months (14 group meetings and four individual sessions). They kept track of their diet, including calorie and sodium consumption, and their physical activity. Those in the Established Plus DASH group had the same intervention program as those in the Established group but were also taught to follow the DASH diet and to record their daily servings of fruits, vegetables, dairy products, and fat.

The new WHI stroke study provides additional information about stroke risk that was not available in July 2002. This study involved 16,608 postmenopausal women (346 in the Northwest) age 50-79 who were followed for an average of 5.6 years. The study showed that women taking the combined hormone therapy had a 31 percent greater risk of all strokes than women who received placebos (rising to 44 percent greater risk of ischemic stroke). This increased stroke risk occurred in all age groups, all categories of stroke risk at baseline, and in women with and without high blood pressure, prior history of heart disease, and prior use of hormones, statins, or aspirin. Known risk factors for stroke (smoking, blood pressure, diabetes, lower use of vitamin C supplements, blood-based biomarkers of inflammation, higher white cell blood count, and higher hemocrit) did not change the effect of combined hormone therapy on stroke risk.

The estrogen-only arm of WHI (for women who have had a hysterectomy) is still continuing. This arm of the study, scheduled to end in 2005, is looking at the effects of estrogen-alone in preventing breast cancer, colon cancer, heart disease, stroke, osteoporosis, dementia, and cognitive function. The study results released in July 2002 and this week about estrogen plus progestin do not apply to women who are taking estrogen alone.

"Women who are taking the combined hormone therapy for short-term relief of menopausal symptoms can probably continue to do so," says Ritenbaugh. "How long is it safe for women to do this? We can't identify a completely risk-free period for a woman to take them. However, I think a woman who is taking the hormone combination for symptom relief should consult her physician to get a good assessment of her individual risks for these diseases. I think she should also consider taking the lowest dose that works for her, tapering down, or even stopping if her individual risks or her worries about them outweigh the benefits of symptom relief. Symptom relief is a large issue for some women, but most women who stop taking combined hormone therapy after several years of use discover that their menopausal symptoms are far less severe than when they started."

The WHI trials are supported by the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health. The WHIMS sub-study is funded by Wyeth Pharmaceuticals, which manufactures PremproTM, which it provided for use in the WHI trials. The National Institute of Aging has been involved in reviewing the current WHIMS findings as the National Institute of Health's lead institute on age-related memory change and dementia.

Kaiser Permanente's Center for Health Research, founded in 1964, is a not-for-profit research institute whose mission is to advance knowledge to improve health.

Kaiser Permanente Northwest is a prepaid, group practice health care organization serving the medical care needs of more than 450,000 people in Oregon and Southwest Washington.

For more infomation contact:
Terry Fitzpatrick (503) 335-6602 or
Jim Gersbach (503) 831-4820

Released: May 27, 2003