Blood Test May Predict Dementia Risk in Women 25 Years Ahead

A JAMA study followed 2,766 U.S. women aged 65–79 for up to 25 years and found higher baseline blood levels of p-tau217 were linked with later mild cognitive impairment or dementia.

A study published in the Journal of the American Medical Association reports an association between the blood protein p-tau217 and later cognitive decline in older women. Researchers followed 2,766 U.S. women aged 65 to 79 who were free of cognitive impairment at enrollment for up to 25 years. The analysis looked at baseline p-tau217 in relation to later mild cognitive impairment (MCI) or dementia and considered hormone therapy assignments and genetic factors. Key findings: - Higher baseline p-tau217 levels were associated with greater risk of MCI or dementia; 1,311 participants developed MCI or dementia during follow-up. - The p-tau217 association with dementia was larger among women randomized to estrogen plus progestin compared with placebo; the estrogen-alone comparison did not show a significant difference. - Associations were stronger for women older than 70 and for those with at least one copy of the APOE ε4 gene. - Study limitations included analysis only in older women, no examination of dementia subtypes, and a smaller sample of Black women, which may affect generalizability. Summary: The authors report that p-tau217 in blood could potentially identify elevated dementia risk many years before symptoms in older women. Undetermined at this time.