Estrogen & Dementia, No Significant Link
We received a press release (see below) from the National Institutes of Health (NIH) headed "Estrogen-Alone Hormone Therapy Could Increase Risk of Dementia in Older Women."
Our Comment: We think this is a very misleading headline. In the study, 47 women were diagnosed with "probable dementia " -- 28 of them had taken estrogen only and 19 of them had taken a placebo. This is NOT a significant difference. It is a difference that could easily have occurred by chance alone.
The headline might better have read: "Estrogen-Alone Therapy Does Not Reduce the Risk of Dementia." That is accurate. But that is really nothing more than the recommendation that hormone therapy should not be used to prevent dementia in older women after the menopause, and that recommendation was made last year.
Estrogen-Alone Hormone Therapy Could Increase Risk of Dementia in Older Women
Older women using estrogen-alone hormone therapy could be at a slightly greater risk of developing dementia, including Alzheimer's disease (AD), than women who do not use any menopausal hormone therapy, according to a new report by scientists with the Women's Health Initiative Memory Study (WHIMS). The scientists also found that estrogen alone did not prevent cognitive decline in these older women. These findings from WHIMS appear in the June 23/30, 2004, Journal of the American Medical Association.
"These studies further support last year's recommendations that menopausal hormone therapy should not be used to prevent cognitive decline or dementia in older postmenopausal women," stated Judith A. Salerno, MD, MS, Deputy Director of the National Institute on Aging (NIA). "Women should follow the Food and Drug Administration's recommendation that those who want to use menopausal hormone therapy to control their menopausal symptoms should use it at the lowest effective dose for the shortest time necessary."
The latest findings were reported by WHIMS Principal Investigator Sally A. Shumaker, PhD, Wake Forest University School of Medicine, and her colleagues at the 39 study sites. This research was funded by Wyeth Pharmaceuticals, which manufactures Premarin™, the conjugated equine estrogens used in this trial, and Wake Forest University Baptist Medical Center. WHIMS is a substudy of the Women's Health Initiative (WHI) Hormone Trial, which is funded by the National Institutes of Health (NIH) at the Department of Health and Human Services (DHHS). The National Institute on Aging (NIA), a component of NIH, has been involved in reviewing the current findings as the lead NIH institute on age-related cognitive change and dementia.
The WHI Hormone Trial using estrogen plus progestin was stopped early in July 2002 when researchers found an increased risk of breast cancer, along with greater risks of heart disease, stroke, and blood clots, and determined that these risks outweighed the benefits of reduced risks of hip fracture and colorectal cancer. In May 2003, WHIMS investigators reported the results of the estrogen plus progestin part of their memory substudy. They found that estrogen plus progestin increased the risk of probable dementia in women 65 and older and did not preserve cognitive function. This part of WHIMS was also stopped in July 2002.
At the end of February 2004, the remaining parts of the WHI Hormone Trial and WHIMS, the estrogen-alone components, were halted because results were showing an increased risk of stroke and no reduction in the risk of heart disease in the women using estrogen alone. Scientists further believed that continuing the study until its planned conclusion next year would probably not add new information. In April 2004, the WHI investigators reported that they found an increased risk of blood clots, but no significant effect on breast or colorectal cancer and also a reduced risk of fractures in those women using estrogen alone.