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

Background: Increasing evidence links higher midlife air pollution exposures to increased risk of cognitive impairment, and there is growing interest in the role of noise in cognitive aging. Although associations of incident dementia with risk factors are often strongest when values of risk factors in midlife are considered, few studies have considered such associations with mid‐life exposures to traffic‐related air pollution or road noise. Thus, our objective 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. Method: ARIC participants were enrolled from 4 US sites in 1987‐1989 at ages 45 to 65. We considered data from 12,135 participants who participated in 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 residential road proximity in midlife and incident dementia using adjusted Weibull models. Result: At study baseline, the mean age of participants was 57 years, 22% were black, 56% were female, 48% lived within 200m of a major road, 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. Conclusion: Residence near a major road in midlife, which may lead to higher exposure to traffic‐related air pollution and noise, does not appear to increase risk of dementia. [ABSTRACT FROM AUTHOR]