Alzheimers disease blood-based biomarkers in the Boston Latino Aging Study (BLAST): Associations with cognition and depressive symptoms

Background: Blood-based biomarkers (BBMs) may facilitate early detection of Alzheimers disease (AD), yet data in Latino populations remain limited. We examined associations of plasma biomarkers with cognition and depressive symptoms in Spanish-speaking Latino older adults enrolled in the Boston Latino Aging Study (BLAST). Methods: Baseline data from 122 older adults without dementia were analyzed. Plasma AB42/40, brain-derived phosphorylated tau (p-tau) 217, neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAP) were measured using NULISA. Cognition was assessed with the Latin American Spanish version of the Preclinical Alzheimers Cognitive Composite (LAS-PACC5) and depressive symptoms with the Geriatric Depression Scale (GDS). Regression models were adjusted for age, sex, and education. Results: Cognitively impaired participants had higher p-tau217 and GFAP than cognitively normal participants. Higher p-tau217 and GFAP were associated with poorer LAS-PACC5 performance, while higher NfL was associated with greater depressive symptoms. AB42/40 showed no significant associations. Conclusions: Distinct biomarker associations with cognitive and emotional functioning support further longitudinal evaluation of BBMs for risk characterization in Latino older adults and potential disease monitoring applications.