A study of more than 17,000 participants drawn from five major aging and Alzheimer's disease studies found that Hispanic participants generally had lower levels of brain amyloid than non-Hispanic white participants who shared the same characteristics, including cognitive impairment or carrying the APOE e4 gene variant. The work, from the USC Mark and Mary Stevens Neuroimaging and Informatics Institute at the Keck School of Medicine of USC, was published in Alzheimer's & Dementia: The Journal of the Alzheimer's Association.
Amyloid is the protein that clumps into plaques in the brain, one of the defining biological signatures of Alzheimer's disease. APOE e4 is the strongest common genetic risk factor for late-onset Alzheimer's, and it has long been tied to heavier amyloid accumulation. That link held in both groups in this analysis - more amyloid tracked with cognitive impairment and with e4 status - but the amount of amyloid at any given risk profile differed by population.
The practical implication is that a single interpretive yardstick may not fit every patient. If a Hispanic patient with the same genetic risk and the same degree of cognitive difficulty carries less amyloid than a non-Hispanic white patient, then amyloid readings, genetic counseling, and eligibility thresholds for amyloid-targeting therapies could all mean something slightly different depending on who is being assessed. The researchers frame the APOE e4 to amyloid relationship as more nuanced in Hispanic populations, with consequences for how risk is interpreted and how treatments are designed and applied across diverse communities.
The scale of the analysis was possible in part through the Global Alzheimer's Association Interactive Network, a data-sharing platform built at the Stevens INI with Alzheimer's Association funding that connects researchers to large aging and dementia datasets worldwide. Pooling cohorts this way is one of the few practical routes to studying populations that have historically been underrepresented in Alzheimer's research.