Alzheimer's disease-like cortical atrophy mediates the effect of air pollution on global cognitive function. (January 2023)

• Record Type: Journal Article
• Authors: Cho, Jaelim; Jang, Heeseon; Park, Hyunji; Noh, Young; Sohn, Jungwoo; Koh, Sang-Baek; Lee, Seung-Koo; Kim, Sun-Young; Kim, Changsoo
• Is Part Of: Environment international. Volume 171(2023)
• Publication Date: 2023-01
• Subjects: Epidemiology -- Air pollution -- Alzheimer's disease -- Cortical atrophy -- Cognitive function -- Mediation analysis; Environmental protection -- Periodicals; Environmental health -- Periodicals; Environmental monitoring -- Periodicals; Environmental Monitoring -- Periodicals; Environnement -- Protection -- Périodiques; Hygiène du milieu -- Périodiques; Environnement -- Surveillance -- Périodiques; Environmental health; Environmental monitoring; Environmental protection; Periodicals; 333.705
• DOI: 10.1016/j.envint.2022.107703
• Languages: English
• ISSNs: 0160-4120

Abstract

Highlights: Air pollution exposures induce Alzheimer's disease-like brain shrinkage. Air pollution exposures impair cognitive function in dementia-free adults. Brain shrinkage due to air pollution exposures leads to cognitive impairment. Abstract: Little is known about the effect of air pollution on Alzheimer's disease (AD)-specific brain structural pathologies. There is also a lack of evidence on whether this effect leads to poorer cognitive function. We investigated whether, and the extent to which, AD-like cortical atrophy mediated the association between air pollution exposures and cognitive function in dementia-free adults. We used cross-sectional data from 640 participants who underwent brain magnetic resonance imaging and the Montreal Cognitive Assessment (MoCA). Mean cortical thickness (as the measure of global cortical atrophy) and machine learning-based AD-like cortical atrophy score were estimated from brain images. Concentrations of particulate matter with diameters ≤ 10 μm (PM10 ) and ≤ 2.5 μm (PM2.5 ) and nitrogen dioxide (NO2 ) were estimated based on each participant's residential address. Following the product method, a mediation effect was tested by conducting a series of three regression analyses (exposure to outcome; exposure to mediator; and exposure and mediator to outcome). A 10 μg/m 3 increase in PM10 (β = -1.13; 95 % CI, −1.73 to −0.53) and a 10 ppb increase in NO2 (β = -1.09; 95 % CI, −1.40 to −0.78) were significantly associated with a lower MoCA score. PM10 (β = 0.27; 95 % CI, 0.06 to 0.48) and NO2 (β = 0.35; 95 % CI, 0.25 to 0.45) were significantly associated with an increased AD-like cortical atrophy score. Effects of PM10 and NO2 on MoCA scores were significantly mediated by mean cortical thickness (proportions mediated: 25 %–28 %) and AD-like cortical atrophy scores (13 %–16 %). The findings suggest that air pollution exposures may induce AD-like cortical atrophy, and that this effect may lead to poorer cognitive function in dementia-free adults.