TY - JOUR

T1 - Incident dementia and long-term exposure to constituents of fine particle air pollution

T2 - A national cohort study in the United States

AU - Shi, Liuhua

AU - Zhu, Qiao

AU - Wang, Yifan

AU - Hao, Hua

AU - Zhang, Haisu

AU - Schwartz, Joel

AU - Amini, Heresh

AU - van Donkelaar, Aaron

AU - Martin, Randall V.

AU - Steenland, Kyle

AU - Sarnat, Jeremy A.

AU - Caudle, W. Michael

AU - Ma, Tszshan

AU - Li, Haomin

AU - Chang, Howard H.

AU - Liu, Jeremiah Z.

AU - Wingo, Thomas

AU - Mao, Xiaobo

AU - Russell, Armistead G.

AU - Weber, Rodney J.

AU - Liu, Pengfei

N1 - Publisher Copyright: © 2022 the Author(s).

PY - 2023

Y1 - 2023

N2 - Growing evidence suggests that fine particulate matter (PM2.5) likely increases the risks of dementia, yet little is known about the relative contributions of different constituents. Here, we conducted a nationwide population-based cohort study (2000 to 2017) by integrating the Medicare Chronic Conditions Warehouse database and two independently sourced datasets of high-resolution PM2.5 major chemical composition, including black carbon (BC), organic matter (OM), nitrate (NO3 -), sulfate (SO4 2-), ammonium (NH4 +), and soil dust (DUST). To investigate the impact of long-term exposure to PM2.5 constituents on incident all-cause dementia and Alzheimer's disease (AD), hazard ratios for dementia and AD were estimated using Cox proportional hazards models, and penalized splines were used to evaluate potential nonlinear concentration-response (C-R) relationships. Results using two exposure datasets consistently indicated higher rates of incident dementia and AD for an increased exposure to PM2.5 and its major constituents. An interquartile range increase in PM2.5 mass was associated with a 6 to 7% increase in dementia incidence and a 9% increase in AD incidence. For different PM2.5 constituents, associations remained significant for BC, OM, SO4 2-, and NH4 + for both end points (even after adjustments of other constituents), among which BC and SO4 2- showed the strongest associations. All constituents had largely linear C-R relationships in the low exposure range, but most tailed off at higher exposure concentrations. Our findings suggest that long-term exposure to PM2.5 is significantly associated with higher rates of incident dementia and AD and that SO4 2-, BC, and OM related to traffic and fossil fuel combustion might drive the observed associations.

AB - Growing evidence suggests that fine particulate matter (PM2.5) likely increases the risks of dementia, yet little is known about the relative contributions of different constituents. Here, we conducted a nationwide population-based cohort study (2000 to 2017) by integrating the Medicare Chronic Conditions Warehouse database and two independently sourced datasets of high-resolution PM2.5 major chemical composition, including black carbon (BC), organic matter (OM), nitrate (NO3 -), sulfate (SO4 2-), ammonium (NH4 +), and soil dust (DUST). To investigate the impact of long-term exposure to PM2.5 constituents on incident all-cause dementia and Alzheimer's disease (AD), hazard ratios for dementia and AD were estimated using Cox proportional hazards models, and penalized splines were used to evaluate potential nonlinear concentration-response (C-R) relationships. Results using two exposure datasets consistently indicated higher rates of incident dementia and AD for an increased exposure to PM2.5 and its major constituents. An interquartile range increase in PM2.5 mass was associated with a 6 to 7% increase in dementia incidence and a 9% increase in AD incidence. For different PM2.5 constituents, associations remained significant for BC, OM, SO4 2-, and NH4 + for both end points (even after adjustments of other constituents), among which BC and SO4 2- showed the strongest associations. All constituents had largely linear C-R relationships in the low exposure range, but most tailed off at higher exposure concentrations. Our findings suggest that long-term exposure to PM2.5 is significantly associated with higher rates of incident dementia and AD and that SO4 2-, BC, and OM related to traffic and fossil fuel combustion might drive the observed associations.

KW - air pollution

KW - Alzheimer's disease

KW - dementia

KW - epidemiology

KW - PM2.5 constituents

U2 - 10.1073/pnas.2211282119

DO - 10.1073/pnas.2211282119

M3 - Journal article

C2 - 36574646

AN - SCOPUS:85144806400

VL - 120

JO - Proceedings of the National Academy of Sciences of the United States of America

JF - Proceedings of the National Academy of Sciences of the United States of America

SN - 0027-8424

IS - 1

M1 - e2211282119

ER -