Overview
- In a Nature analysis of 11,486 HUNT cohort participants, researchers used plasma pTau217 alongside cognitive testing and found roughly 10% of people aged 70+ had dementia with Alzheimer’s pathology, with similar shares showing prodromal and preclinical biomarker positivity.
- Prevalence rose sharply with age, from under 8% abnormal biomarker findings at 65–69 to about 65% in those over 90, indicating higher-than-expected rates in the oldest groups and lower-than-expected rates in younger seniors.
- Approximately 11% of over‑70s met eligibility criteria for anti‑amyloid monoclonal antibodies such as lecanemab or donanemab, a scale that, if applied to UK criteria, would imply more than 1 million potential candidates versus the NHS estimate of about 70,000.
- Researchers and commentators cautioned that prevalence depends on assay thresholds and study selection, that biomarker positivity is not a diagnosis, and that only 60% of dementia cases in over‑70s showed Alzheimer’s‑type changes, underscoring other contributors to cognitive decline.
- The study reported higher biomarker prevalence in people with lower education and no significant sex differences, and health services are preparing evaluations, including a UK trial recruiting about 1,100 memory‑clinic patients to test blood‑based workflows with results expected in roughly three years.