Hormone therapy does not prevent dementia and may even raise the risk in older, postmenopausal women, new research says.
“We did not find any protective effect of hormone therapy, and there was a trend towards an increased risk of dementia,” said Claudine Legault, an author of the study and director of the Women’s Health Center of Excellence at Wake Forest University in Winston-Salem, N.C.
The findings, from the Women’s Health Initiative Memory Study, appear in the June 23/30 issue of the Journal of the American Medical Association.
The memory study was established to look at whether hormone therapy, either estrogen alone or estrogen plus progestin could reduce the risk of dementia in women ages 65 to 79. The memory study is part of the larger Women’s Health Initiative, which looked at the effect of hormone therapy on a variety of health outcomes. The estrogen plus progestin arm of the study ended in July 2002 when it became clear that women taking hormones were having more serious side effects. The estrogen-only arm was terminated on Feb. 29, 2004, because of an excess risk of stroke in women taking active hormones.
This study looked at the effects of estrogen alone (Premarin) or estrogen plus progestin (Prempro) in 7,479 women, all of whom had had a hysterectomy. The women were divided into those with probable dementia, those with mild cognitive impairment, and those with no dementia.
Compared with the placebo group, women in the estrogen group had a 34 percent higher risk of being diagnosed with mild cognitive impairment. This increased risk was not considered to be significant. Women on estrogen had a 38 percent greater risk of having either mild cognitive impairment or probable dementia, compared with women in the placebo group.
Outside experts are careful to point out that this study does not pertain to all women or to all hormones.
“This is not a study about women. This is about older women, so this cannot be extrapolated to women who have recently undergone menopause who want to go on hormone therapy,” said Dr. Alan M. Altman, an assistant professor of obstetrics, gynecology, and reproductive biology at Harvard Medical School. Altman was not involved in the research.
This also does not mean that hormone therapy doesn’t have a place. “It’s clear that use of hormones to prevent dementia or cognitive decline in women 65 or older is not recommended,” Dr. Gary Stiles, executive vice president and chief medical officer at Wyeth Pharmaceuticals, said during a teleconference Monday. Wyeth makes Premarin and Prempro.
“The most appropriate reason that women initiate the therapy is for symptomatic relief of menopausal symptoms, and that was not studied in this study,” Stiles said. “We believe that these drugs have their appropriate use.”