Racial Residential Segregation in Young Adulthood and Brain Integrity in Middle Age: Can We Learn From Small Samples?

Abstract

Racial residential segregation is associated with multiple adverse health outcomes in Black individuals. Yet, the influence of structural racism and racial residential segregation on brain aging is less understood. In this study, we investigate the association between cumulative exposure to racial residential segregation over 25 years (1985-2010) of young adulthood, measured by the Getis-Ord Gi*-statistic, and year 25 measures of brain volume in midlife (cerebral, gray matter, white matter, and hippocampal volumes). We studied 290 Black participants with available brain imaging data who were enrolled in the Coronary Artery Risk Development in Young Adults (CARDIA) prospective cohort study. CARDIA originally recruited 2637 Black participants aged 18 to 30 years old from 4 field centers across the United States. We conducted analyses using marginal structural models, incorporating inverse probability weighting and inverse censoring weighting. We found that compared to low/medium segregation, greater cumulative exposure to residential segregation throughout young adulthood was associated with smaller brain volumes in general (e.g. β for cerebral volume: -0.08 [95% CI]: [-0.15, -0.02]) and with a more pronounced reduction in hippocampal volume, though results were not statistically significant. Our findings suggest that exposure to segregated neighborhoods may be associated with worse brain aging.

Promoting diverse perspectives: Addressing health disparities related to Alzheimer's and all dementias

“…This tool has helped reveal associations between living in a disadvantaged neighborhood and cognitive decline and cortical thinning 15 as well as AD neuropathology 16 . These factors can have lasting effects; for example, living in racially segregated neighborhoods as young adults has been associated with worse processing speed and smaller brain volumes in midlife among African American adults 17,18 . Among women, any time spent in the paid workforce has been associated with slower memory declines 19 …”

A practitioner's guide to geospatial analysis in a neuroimaging context

“…Now is the opportune time to link spatial analysis approaches from public health applications with richly characterized neuroimaging phenotypes. 11 To support other researchers, we present an analytical approach to evaluating sample, as well as a brief introduction to point pattern analysis. Complete example code is available at https://github.com/jwisch/PractitionersGuideSpatAnalysis or in the supplemental materials.…”

“…Given the sensitivity of BAG to quantify structural changes in the brain and the role the environment plays in health disparities, 2 we will assess the association between BAG and the environment in St. Louis, Missouri. Now is the opportune time to link spatial analysis approaches from public health applications with richly characterized neuroimaging phenotypes 11 . To support other researchers, we present an analytical approach to evaluating sample, as well as a brief introduction to point pattern analysis.…”

Race, community disadvantage, and cognitive decline: Findings from KHANDLE and STAR

“…Lifecourse community SES may therefore be an important explanatory factor for racial disparities in late‐life cognition. A handful of studies have considered lifecourse community exposures for later‐life outcomes using additive approaches, which precludes testing for sensitive periods 19,32,33,39 . Disentangling the effects of individual SES from community SES at different stages of the lifecourse may point to the causal pathways that shape susceptibility/resistance to the embodiment of contextual exposures (i.e., the social exposome) that produces disparities 40–42 .…”

“…26,27 Structural racism underpins racialized health inequities through multiple mechanisms, including residential segregation. [28][29][30][31][32][33][34][35] Residential segregation has systematically deprived minoritized communities of individual and community social and material resources that have been directly associated with lowering dementia risk, including clean air, access to healthy food, and access to quality health care. [36][37][38] Lifecourse community SES may therefore be an important explanatory factor for racial disparities in late-life cognition.…”