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

• Published in: Nature communications Vol. 12; no. 1; pp. 6754 - 9
• Main Authors: Shi, Liuhua, Steenland, Kyle, Li, Haomin, Liu, Pengfei, Zhang, Yuhan, Lyles, Robert H., Requia, Weeberb J., Ilango, Sindana D., Chang, Howard H., Wingo, Thomas, Weber, Rodney J., Schwartz, Joel
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 19.11.2021; Nature Publishing Group; Nature Portfolio
• Subjects: 692/617/375/132/1283; 704/844/4081; Aged; Aged, 80 and over; Air Pollutants - adverse effects; Air pollution; Air Pollution - adverse effects; Air Pollution - statistics & numerical data; Alzheimer's disease; Chronic conditions; Cohort analysis; Confidence intervals; Dementia; Dementia - epidemiology; Dementia - etiology; Dementia disorders; Environmental Exposure - adverse effects; Environmental Exposure - statistics & numerical data; Environmental Monitoring - statistics & numerical data; Exposure; Female; Follow-Up Studies; Humanities and Social Sciences; Humans; Incidence; Male; multidisciplinary; Neurodegenerative diseases; Nitrogen dioxide; Older people; Particulate matter; Particulate Matter - adverse effects; Pollutants; Population studies; Risk Factors; Science; Science (multidisciplinary); United States - epidemiology; United States; United States > US
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-021-27049-2

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 (PM 2.5 ), nitrogen dioxide (NO 2 ), and ozone (O 3 ) 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 PM 2.5 (3.2 µg/m 3 ), NO 2 (11.6 ppb), and warm-season O 3 (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 PM 2.5 and NO 2 were approximately linear. Our study suggests that exposures to PM 2.5 and NO 2 are associated with incidence of dementia and AD. Air pollution has been linked to neurodegenerative disease. Here the authors carried out a population-based cohort study to investigate the association between long-term exposure to PM 2.5 , NO 2 , and warm-season O 3 on dementia and Alzheimer’s disease incidence in the United States.