Sociodemographic correlates of cognition and Alzheimer's disease and vascular biomarkers among middle to older age participants in the Healthy Brain Initiative

Background Key sociodemographics (e.g., nativity) plausibly related to Alzheimer's disease and related dementia (ADRD) risk have been investigated less frequently in relation to cognitive function, brain imaging, and blood-based biomarkers. Objective To examine associations between multiple sociodemographics and ADRD/vascular outcomes among middle- to older-age adults. Methods We used cross-sectional data on 341 Healthy Brain Initiative participants. Outcomes included cognitive domain scores (e.g., episodic memory, language), magnetic resonance imaging (MRI) (e.g., hippocampal and white matter hyperintensity volume), and blood-based biomarkers (e.g., Aβ 42/40 , pTau-217, NfL, GFAP). Sociodemographics included age, sex, racial group, Hispanic ethnicity, primary language, nativity, socioeconomic position, area deprivation, and living alone. Multivariable linear regression examined associations between sociodemographics and brain health outcomes. Results Mean age was 69 ± 9 and 71% were women. Older individuals, women, Black and Hispanic individuals, those of lower socioeconomic position, and those born outside the US performed worse across various cognitive domains, while those who primarily spoke Spanish (versus English) scored better on episodic memory. Older individuals, women, and Hispanic individuals had worse brain health, and those identifying as other racial group and born outside of the US had better brain health measured via MRI. Older and Hispanic individuals had worse brain health and Black individuals and women had better brain health as measured via blood-based biomarkers. Conclusions This study contributes to the growing number of studies identifying differences in ADRD/vascular biomarkers by sociodemographics. Additional studies are needed to assess whether social and economic determinants of health are associated with longitudinal change in ADRD/vascular biomarkers.