Study Links Blood ptau217 to Dementia Risk 25 Years Early

A new study of thousands of postmenopausal women has found that elevated levels of a protein called phosphorylated tau 217, or ptau217, in the blood can signal an increased risk of mild cognitive impairment or dementia up to 25 years before symptoms appear. Researchers analyzed blood samples collected in the late 1990s from 2,766 participants in the Women's Health Initiative Memory Study, a long-term project tracking the health of women aged 65 to 79 at enrollment. Over a median follow-up of 14 years, extending to 2021, 1,311 women developed cognitive issues, with higher ptau217 levels strongly linked to these outcomes.

The study, led by Aladdin Shadyab, an associate professor of public health and medicine at the University of California, San Diego, measured ptau217 using a sensitive assay on fasting blood samples taken at baseline. Participants, who were cognitively healthy at the start, included about 74 percent White women, 18 percent Black and 7 percent Latino or Hispanic, with an average age of nearly 70. Those with higher ptau217 were often older, White, nonsmokers and carriers of the APOE ε4 gene variant, a known risk factor for Alzheimer's disease, the leading cause of...