A small pilot study has found that giving recently postmenopausal women estrogen via a patch is associated with reduced depositions of amyloid in the brain (a hallmark of Alzheimer’s disease) relative to women who received estrogen orally or who took a placebo. Additionally, the study found that the association was strongest among women with a greater genetic risk of Alzheimer’s disease.
The study was carefully done, and the news release offers some useful details about the study’s methods. However, the study included just 68 women, too few to make the patterns found reliable. To its credit, the release quotes the lead author about the need for larger replications. But that begs the question of why the Mayo Clinic seeks to publicize this work at all, particularly with a news release headline that emphasizes disease reduction potential, when the study only looked at amyloid levels, a risk marker. There is very active debate as to whether lowering amyloid will have any impact on actual symptoms or rates of Alzheimer’s disease. A better headline might have been: “Pilot Study Suggests Estrogen Patch in Newly Postmenopausal Women Reduces Amyloid, Marker of Alzheimer’s Risk.” Journalists certainly deserve to know about this study, but they need to keep it in their back pockets until more rigorous clinical studies have been done.
Whether estrogen replacement therapy is of value to postmenopausal women is contested territory, and researchers, including those in the Kronos Early Estrogen Prevention Study from which this research stems, are trying to explore the contingencies, if any, that distinguish women who could benefit from estrogen supplementation from those who may not.
This study adds to a body of work looking at the “timing hypothesis,” that is, the notion that estrogen has different effects in the heart and brain when given to younger postmenopausal woman compared to women in their 60s or 70s. Studies of effects on the heart using intermediate disease markers (carotid artery thickness, analogous to heart disease in the way that amyloid deposition is to Alzheimer disease) in lieu of clinical outcomes (heart attacks, cognitive impairment) have been appearing in journals over the past two years. Considered in this context, the research is of interest but needs to be shared with a strong dose of qualifiers.
Costs for hormone therapy are readily available but they are not broached in this release.
Although the news release summarizes the pattern of results—that recently postmenopausal women who received estrogen via a skin patch were found to have “lower” amyloid depositions in their brains relative to those who took estrogen by mouth or who were in the placebo group—that pattern is not explained in any numerical or statistical way. Is it a strong association? A weak one? We have no idea from the release.
According to the published report, the benefits were statistically significant but the sample size was too small to be meaningful. Just 21 of the enrolled women received the patch, 30 received a placebo and 17 received estrogen orally.
Early in the text, the writer notes that one large, older study—the Women’s Health Initiative at NIH—has found an association between use of estrogen and an increased risk of dementia among women 65 or older. The study highlighted here, in contrast, focuses on women five to 36 months past menopause, individuals predominantly in their 50s. The potential long-term effects of estrogen use by these younger women is not mentioned in the release.
Estrogen carries a well-known small increase in risk for breast cancer and blood clots, which could have been briefly acknowledged. In addition, the National Library of Medicine states that estradiol, the form of estrogen used in transdermal patches, “increases the risk that you will develop endometrial cancer (cancer of the lining of the uterus [womb]). The longer you use estradiol, the greater the risk that you will develop endometrial cancer.” Other minor side effects include head ache, breast pain and nausea, among others.
The release offers some specifics about the study design, but it doesn’t highlight the randomized, blinded nature of the study. That said, it describes the study framework:
“Of the 68 women, 21 received estrogen via a skin patch, 17 received estrogen orally and 30 received a placebo. Amyloid deposition was lower in women who received the patch, compared to the placebo, and the effect was most apparent in women with the APOE e4 genotype. The oral treatment was not associated with lower amyloid deposition.”
The release includes a comment from the lead study author regarding the need to confirm the findings by replicating the study with larger samples. But even that comment neglects the larger question of whether reducing amyloid has any effect at all on Alzheimer’s symptoms or risk. The overall implication that there’s a causal relationship, strongly inferred in the headline, earns this a not satisfactory rating.
The release doesn’t exaggerate a condition. It states that declines in estrogen associated with menopause “may” be associated with an increased risk of dementia. Unfortunately, that doesn’t give readers a feel for the robustness of the relationship, or for the evidence supporting it.
Funders are identified, and the single scientist in the release is clearly identified as the study’s lead author.
The release offers no other approaches available to postmenopausal women for reducing Alzheimer’s disease risk and that’s appropriate in this case. It would be an over-reach to try and name the many other Alzheimer’s disease prevention options being studied.
In addition, the findings address an intermediate endpoint, i.e. amyloid deposition as a disease marker, not the disease itself.
It’s common knowledge that numerous estrogen supplements — including those delivered via patch — are readily available.
The lead author makes a priority claim in the release, which seems to be justified.
Words employed by both the text and the researchers, the latter via quotes, are straightforward.