Association of residential road proximity with cognitive decline and dementia: The Atherosclerosis Risk in Communities (ARIC) Study

Abstract

BACKGROUND AND AIM: Increasing evidence links higher air pollution exposures to increased risk of cognitive impairment, and there is growing interest in the role of noise in cognitive aging. Although risk factor associations with incident dementia are often strongest when midlife values of risk factors are considered, few studies have considered associations between midlife exposures to traffic-related air pollution or road noise and late life cognition. Our aim was to determine if midlife residential proximity to major roads, a proxy for traffic-related air pollution exposure and road noise, is associated with increased risk of incident dementia in the Atherosclerosis Risk in Communities (ARIC) study. METHODS: ARIC participants were enrolled from 4 US sites in 1987-1989 at ages 45 to 65. We considered data from 12,135 participants of ARIC Visit 2 (1990-1992, study baseline). We calculated midlife residential Euclidean distance to a major (A1, A2, or A3) road based on geocoded residential addresses at Visit 2. We ascertained dementia status through 2019 via in-person study visits with neurocognitive assessment, telephone cognitive interview, informant interview, and access to hospitalization and death records. We estimated the association between midlife residential road proximity and incident dementia using adjusted Weibull models. RESULTS: At study baseline, the mean age of participants was 57 years, 22% were black, 56% were female. 48% lived within 200m and 36% lived within 200 to 500m of a major road. 20% developed dementia during follow-up. While residing closer to major roads in midlife was associated with increased risk of incident dementia in unadjusted models, this association did not persist in adjusted analyses. CONCLUSIONS: Residence near a major road in midlife, a proxy for higher exposure to traffic-related air pollution and noise, does not appear to increase risk of dementia. KEYWORDS: dementia, air pollution, roadway, roads, particulate matter, cognition, aging, epidemiology