Blood‐based biomarker profiles of community cohort of rural‐dwelling older adults

Background Geography may influence Alzheimer’s disease risk, but there have been few prospective studies with biomarker characterization among rural‐dwelling individuals. We present preliminary biomarker data from the rural cohort followed by the Nevada Exploratory Alzheimer’s Disease Research Center, with comparisons to a harmonized urban cohort. Method Community‐dwelling adults over age 50 are enrolled and followed annually. Core assessments include medical exam, cognitive assessment, and blood‐based biomarkers of neurofilament light (NFL), phosphorylated tau (pTau181), and glial fibrillary acidic protein (GFAP) measured from plasma samples via the Quanterix Single Molecular Array (Simoa) HD‐X platform. Biomarker values exceeding 3 standard deviations from the combined sample mean were removed from analyses. Primary comparisons included ANCOVAs with main between‐group effects of cohort and cognitive status, accounting for both age and sex; interactions between cohort and impairment status were also explored. Correlations between biomarkers and cognitive screening (MoCA) were also assessed. Raw biomarker data were log transformed prior to analysis. Result NFL was associated with age (F(1,143) = 53.26, p