A blood test measuring a specific protein may identify dementia risk in women as early as 25 years before symptoms appear, according to findings published in the Journal of the American Medical Association. The study examined associations between levels of plasma phosphorylated tau 217 (p-tau217) in blood and the development of mild cognitive impairment (MCI) or dementia.
Study Details and Findings
Researchers evaluated 2,766 U.S. women ages 65 to 79 without cognitive impairment at baseline. Participants were recruited between 1996 and 1999 and assessed for up to 25 years, through 2021. By the study’s conclusion, 1,311 women had developed either MCI or dementia. Those with higher baseline p-tau217 levels were more likely to develop dementia or MCI over the follow-up period.
The study also examined hormone therapy’s role. Participants were randomized into groups receiving estrogen therapy versus placebo, or estrogen plus progestin therapy versus placebo. Researchers found stronger p-tau217 associations with dementia in women assigned to estrogen plus progestin therapy compared to placebo. The estrogen-only group showed no significant variation in associations.
Larger associations between p-tau217 and dementia or MCI appeared in women older than 70 and those carrying the APOE ε4 gene. According to the Cleveland Clinic, “Having at least one copy of the APOE-ε4 gene increases your risk of developing Alzheimer’s disease.”
Important Limitations
The study examined only older women, and dementia was not analyzed by subtype. The sample included fewer Black women than white women, affecting results. Researchers found p-tau217 associations with MCI or dementia were greater in white women than Black women, and p-tau217 “was not associated with incident MCI in Black women.”
Aladdin H. Shadyab, the study’s lead author from UC San Diego, stated: “Our study suggests it may be possible to detect risk of dementia two decades in advance using a simple blood test in older women.” However, Ian McDonough from the State University of New York at Binghamton cautioned that “plasma biomarkers are not going to be a one-size-fits-all forecasting solution,” noting the need to identify subgroups for whom these markers might be misleading.
This article is an AI-assisted summary. All facts and figures are drawn from the original report: https://www.huffpost.com/entry/dementia-risk-women-blood-test_n_69b42dd7e4b0676e64bf39b9