Long-Term Exposure to PM10 and in vivo Alzheimer’s Disease Pathologies

Abstract

Background:

Previous studies indicated an association between Alzheimer’s disease (AD) dementia and air particulate matter (PM) with aerodynamic diameter <10μm (PM10), as well as smaller PM. Limited information, however, is available for the neuropathological links underlying such association.

Objective:

This study aimed to investigate the relationship between long-term PM10 exposure and in vivo pathologies of AD using multimodal neuroimaging.

Methods:

The study population consisted of 309 older adults without dementia (191 cognitively normal and 118 mild cognitive impairment individuals), who lived in Republic of Korea. Participants underwent comprehensive clinical assessments, ¹¹C-Pittsburg compound B (PiB) positron emission tomography (PET), and magnetic resonance imaging scans. A subset of 78 participants also underwent ¹⁸F-AV-1451 tau PET evaluation. The mean concentration of PM with aerodynamic diameter <10μm over the past 5 years (PM10_mean) collected from air pollution surveillance stations were matched to each participant’s residence.

Results:

In this non-demented study population, of which 62% were cognitively normal and 38% were in mild cognitive impairment state, exposure to the highest tertile of PM10_mean was associated with increased risk of amyloid-β (Aβ) positivity (odds ratio 2.19, 95% confidence interval 1.13 to 4.26) even after controlling all potential confounders. In contrast, there was no significant associations between PM10_mean exposure and tau accumulation. AD signature cortical thickness and white matter hyperintensity volume were also not associated with PM10_mean exposure.

Conclusion:

The findings suggest that long-term exposure to PM10 may contribute to pathological Aβ deposition.