Fine particulate matter and neuroanatomic risk for Alzheimer’s disease in older women

Objective: To examine whether late-life exposure to PM2.5 (particulate matter with aerodynamic diameters <2.5-µm) contributes to progressive brain atrophy predictive of Alzheimer’s disease (AD) using a community-dwelling cohort of women (aged 71-89) with up to two brain MRI scans (MRI-1: 2005-6; MRI-2: 2010-11).

Methods: AD pattern similarity (AD-PS) scores, developed by supervised machine learning and validated with MRI data from the AD Neuroimaging Initiative, was used to capture high-dimensional gray matter atrophy in brain areas vulnerable to AD (e.g., amygdala, hippocampus, parahippocampal gyrus, thalamus, inferior temporal lobe areas and midbrain). Based on participants’ addresses and air monitoring data, we employed a spatiotemporal model to estimate 3-year average exposure to PM2.5 preceding MRI-1. General linear models were used to examine the association between PM2.5 and AD-PS scores (baseline [n=1365] and 5-year standardized change [n=712]), accounting for potentia...