Health & Aging Brain Study - Health Disparities (HABS-HD)-RF00283

This work describes an ongoing prospective investigation into brain health and aging with explicit attention to health disparities across racial and ethnic groups. The current manuscript provides a comprehensive description of baseline cohort characteristics and outlines the study methodology used to evaluate demographic, medical, biomarker, neuroimaging, cognitive, and social determinant variables. HABS-HD includes substantial enrollment across three key groups: 1,066 non-Hispanic Black (NHB) partners, 1,425 Hispanic partners, and 1,349 non-Hispanic White (NHW) partners who were actively enrolled and for whom baseline data were analyzed. The study emphasizes comparative, groupwise analyses to elucidate differences that may underpin disparities in cognitive impairment and dementia risk.

Methods described in the report include descriptive statistical analyses across demographic and medical measures, cognitive diagnostic classification, and evaluation of select biomarkers consistent with the A/T/(N) framework, amyloid (A), tau (T), and neurodegenerative (N) markers, spanning both proteomic assays and neuroimaging measures. Groupwise differences in cognitive test performance and select social determinants of health (SDoH) factors were also examined to contextualize biological findings within broader psychosocial and health contexts. The manuscript reports differences in age, education, sex distribution, and cognitive diagnosis across the three racial/ethnic groups, highlighting that NHB and Hispanic partners exhibited higher rates of cognitive impairment, including mild cognitive impairment (MCI) and dementia, compared with NHW partners despite the NHW group being older on average.

Medical comorbidity patterns differed across groups, with NHB and Hispanic partners showing higher rates of hypertension and diabetes relative to NHW partners. Biomarker analyses revealed differences across multiple plasma A/T(N) measures and select neuroimaging outcomes, including measures derived from a meta-region of interest and white matter hyperintensity burden. These findings underscore a multidimensional pattern in which clinical, vascular, proteomic, and neuroimaging indicators of brain aging and pathology vary by race and ethnicity within the HABS-HD cohort.

By providing detailed baseline characterization and methodological transparency, the HABS-HD report aims to support ongoing and future analyses that will interrogate pathways contributing to observed disparities in cognitive impairment and dementia. The scope, encompassing diverse populations, proteomic and imaging biomarkers, cognitive assessment, and SDoH measures, positions the study to explore interactions among biological risk markers and social determinants that may differentially affect brain aging across groups. As an ongoing prospective study, HABS-HD establishes a foundation for longitudinal follow-up to determine how baseline differences translate into divergent trajectories of cognitive decline, neurodegeneration, and clinical outcomes. The present manuscript offers a resource describing participant composition and the analytic approach, and it frames subsequent work that will leverage these data to identify mechanisms and potential targets for intervention to reduce health disparities in brain aging and dementia.