A national cohort study (2000-2018) of long-term air pollution exposure and incident dementia in older adults in the United States

• Type of Material: Article
• Authors: Liuhua Shi, Emory University; Kyle Steenland, Emory University; Robert Lyles, Emory University; Haomin Li, Emory University; Pengfei Liu, Georgia Institute of Technology; Yuhan Zhang, Emory University; Weeberb J Requia, Fundação Getúlio Vargas; Sindana D Ilango, University of Washington; Howard Chang, Emory University; Thomas Wingo, Emory University; Rodney J Weber, Georgia Institute of Technology; Joel Schwartz, Harvard T.H. Chan School of Public Health
• Language: English
• Date: 2021-11-19
• Publisher: NATURE PORTFOLIO
• Publication Version: Final Published Version
• Copyright Statement: © The Author(s) 2021
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1038/s41467-021-27049-2
• Title of Journal or Parent Work: NATURE COMMUNICATIONS
• Volume: 12
• Issue: 1
• Start Page: 6754
• End Page: 6754
• Grant/Funding Information: This study was supported by the National Institute on Aging (NIA/NIH R01 AG074357, L.S.), the HERCULES Center P30 ES019776 (L.S.), and the Goizueta Alzheimer’s Disease Research Center (ADRC) of Emory University (P50 AG025688, L.S.). The views expressed in this article are those of the authors, and do not necessarily represent the views of the funding Agencies. The authors acknowledge Dr. Joel Schwartz’s lab for providing us with access to their estimated air pollution data, and acknowledge Kimberly Lochner for fruitful discussion.
• Keywords: POPULATION; MEDICARE CLAIMS; ALZHEIMERS-DISEASE; NEUROLOGICAL DISORDERS; ERROR; ACCURACY; Science & Technology - Other Topics; Science & Technology; OZONE; MODEL; Multidisciplinary Sciences
• Research Categories: Environmental Sciences; Public Administration; Health Sciences, Epidemiology

Abstract

Air pollution may increase risk of Alzheimer’s disease and related dementias (ADRD) in the U.S., but the extent of this relationship is unclear. Here, we constructed two national U.S. population-based cohorts of those aged ≥65 from the Medicare Chronic Conditions Warehouse (2000–2018), combined with high-resolution air pollution datasets, to investigate the association of long-term exposure to ambient fine particulate matter (PM2.5), nitrogen dioxide (NO2), and ozone (O3) with dementia and AD incidence, respectively. We identified ~2.0 million incident dementia cases (N = 12,233,371; dementia cohort) and ~0.8 million incident AD cases (N = 12,456,447; AD cohort). Per interquartile range (IQR) increase in the 5-year average PM2.5 (3.2 µg/m3), NO2 (11.6 ppb), and warm-season O3 (5.3 ppb) over the past 5 years prior to diagnosis, the hazard ratios (HRs) were 1.060 (95% confidence interval [CI]: 1.054, 1.066), 1.019 (95% CI: 1.012, 1.026), and 0.990 (95% CI: 0.987, 0.993) for incident dementias, and 1.078 (95% CI: 1.070, 1.086), 1.031 (95% CI: 1.023, 1.039), and 0.982 (95%CI: 0.977, 0.986) for incident AD, respectively, for the three pollutants. For both outcomes, concentration-response relationships for PM2.5 and NO2 were approximately linear. Our study suggests that exposures to PM2.5 and NO2 are associated with incidence of dementia and AD.