Risk of dementia due to Co-exposure to air pollution and neighborhood disadvantage

Seth Frndak; Zhengyi Deng; Cavin K Ward-Caviness; Irena Gorski-Steiner; Roland J Thorpe; Aisha S Dickerson

doi:10.1016/j.envres.2024.118709

Risk of dementia due to Co-exposure to air pollution and neighborhood disadvantage

Environ Res. 2024 Mar 15;251(Pt 2):118709. doi: 10.1016/j.envres.2024.118709. Online ahead of print.

Authors

Seth Frndak¹, Zhengyi Deng², Cavin K Ward-Caviness³, Irena Gorski-Steiner⁴, Roland J Thorpe⁵, Aisha S Dickerson⁶

Affiliations

¹ Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, USA. Electronic address: sfrndak1@jhu.edu.
² Department of Urology, Stanford School of Medicine, USA.
³ Center for Public Health and Environmental Assessment, US Environmental Protection Agency, USA.
⁴ Department of Mental Health, Johns Hopkins Bloomberg School of Public Health, USA.
⁵ Department of Health, Behavior and Society, Johns Hopkins Bloomberg School of Public Health, USA; Hopkins Center for Health Disparities Solutions, Johns Hopkins Bloomberg School of Public Health, USA; Johns Hopkins Alzheimer's Disease Resource Center for Minority Aging Research, USA.
⁶ Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, USA; Hopkins Center for Health Disparities Solutions, Johns Hopkins Bloomberg School of Public Health, USA.

PMID: 38493859
DOI: 10.1016/j.envres.2024.118709

Abstract

Background: Co-exposure to air pollution and neighborhood disadvantage may influence cognition decline. We tested these associations in the context of dementia risk.

Methods: We leveraged a cohort of adults ≥65 years (n = 5397) enrolled from 2011 to 2018 in the National Health and Aging Trends Study (NHATS). Particulate matter (PM) ≤ 10 μm in diameter, PM ≤ 2.5 μm in diameter, carbon monoxide, nitric oxide, and nitrogen dioxide - and neighborhood disadvantage were tested for joint associations with dementia risk. Pollutant concentrations at the 2010 census tract level were assigned using the US Environmental Protection Agency's Community Multiscale Air Quality Modeling System. Neighborhood disadvantage was defined using the tract Social Deprivation Index (SDI). Dementia was determined through self- or proxy-report or scores indicative of "probable dementia" according to NHATS screening tools. Joint effects of air pollutants and SDI were tested using quantile g-computation Cox proportional hazards models. We also stratified joint air pollution effects across SDI tertiles. Analyses adjusted for age at enrollment, sex, education, partner status, urbanicity, income, race and ethnicity, years at residence, census segregation, and census region.

Results: SDI score (aHR = 1.08; 95% CI 0.96, 1.22), joint air pollution (aHR = 1.03, 95% CI 0.92, 1.16) and joint SDI with air pollution (aHR = 1.04, 95% CI 0.89, 1.22) were not associated with dementia risk. After accounting for competing risk of death, joint SDI with air pollution was not associated with dementia risk (aHR = 1.06; 95% CI 0.87, 1.29). In stratified models, joint air pollution was associated with greater risk of dementia at high (aHR = 1.19; 95% CI 0.87, 1.63), but not at medium or low SDI.

Conclusion: Air pollution was associated with greater dementia risk in disadvantaged areas after accounting for competing risks. Air pollution associations with dementia incidence may be attenuated when other risk factors are more prominent in disadvantaged neighborhoods.

Keywords: Air pollution mixtures; Dementia; Effect modification; Joint effects; Neighborhood disadvantage.

Abstract

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