Associations of fire smoke and other pollutants with incident rheumatoid arthritis and rheumatoid arthritis-associated interstitial lung disease

Vanessa L Kronzer; Yangyuna Yang; Punyasha Roul; James L Crooks; Cynthia S Crowson; John M Davis 3rd; Jeffrey A Sparks; Jeffrey R Pierce; Katelyn O'Dell; Brian C Sauer; Grant W Cannon; Joshua F Baker; Ted R Mikuls; Bryant R England

doi:10.1002/art.43113

Associations of fire smoke and other pollutants with incident rheumatoid arthritis and rheumatoid arthritis-associated interstitial lung disease

Arthritis Rheumatol. 2025 Jan 12. doi: 10.1002/art.43113. Online ahead of print.

Authors

Vanessa L Kronzer¹, Yangyuna Yang^{2

3}, Punyasha Roul^{2

3}, James L Crooks⁴, Cynthia S Crowson^{1

5}, John M Davis 3rd¹, Jeffrey A Sparks⁶, Jeffrey R Pierce⁷, Katelyn O'Dell⁸, Brian C Sauer⁹, Grant W Cannon⁹, Joshua F Baker¹⁰, Ted R Mikuls^{2

3}, Bryant R England^{2

3}

Affiliations

¹ Division of Rheumatology, Mayo Clinic, Rochester, MN.
² Medicine & Research Service, VA Nebraska-Western Iowa Health Care System, Omaha, NE.
³ Division of Rheumatology & Immunology, University of Nebraska Medical Center, Omaha, NE.
⁴ National Jewish Health, Denver, CO.
⁵ Department of Quantitative Health Sciences, Mayo Clinic, Rochester, MN.
⁶ Division of Rheumatology, Inflammation, and Immunity; Brigham and Women's Hospital & Harvard Medical School, Boston, MA.
⁷ Department of Atmospheric Science, Colorado State University, Fort Collins, CO.
⁸ Dept of Environmental and Occupational Health, George Washington University, Washington, DC.
⁹ Salt Lake City VA & University of Utah, Salt Lake City, UT.
¹⁰ Corporal Michael J. Crescenz VA & University of Pennsylvania, Philadelphia, PA.

PMID: 39800945
DOI: 10.1002/art.43113

Abstract

Objective: Determine whether pollutants such as fire smoke-related particulate matter smaller than 2.5 microns (PM_2.5) are associated with incident rheumatoid arthritis (RA) and RA-associated interstitial lung disease (RA-ILD).

Methods: This case-control study used Veterans Affairs data 10/1/2009-12/31/2018. We identified incident RA and RA-ILD cases using validated algorithms, matching each case to up to 10 controls on age, gender, and VA enrollment year. We obtained pollutants including fire smoke PM_2.5, carbon monoxide, nitrogen oxides (NOx), ozone_, overall PM_2.5, PM₁₀, and sulfur dioxide (SO₂) at least one year before index date. We fit conditional logistic regression models to estimate adjusted odds ratios (aOR) with 95% confidence intervals (CI) for incident RA and RA-ILD, adjusted for confounders.

Results: We identified 9,701 incident RA cases (mean age 65, 86% male), including 531 RA-ILD cases (mean age 69, 91% male), and 68,852 matched controls. Fire smoke PM_2.5 was not associated with RA (aOR 1.07, 95% CI 0.92-1.23), but was associated with RA-ILD (aOR 1.98, 95% CI 1.08-3.62, per 1 μg/m³). Increased levels of NOx were associated with RA (aOR 1.16, 95% CI 1.06-1.27, highest vs. lowest quartile). The highest quartiles of ozone (aOR 1.19, 95% CI 1.06-1.34) and PM₁₀ (aOR 1.25, 95% CI 1.10-1.43) were associated with seronegative RA. Carbon monoxide, overall PM_2.5, and SO₂ were not, or negatively, associated with RA and RA-ILD.

Conclusion: Increased fire smoke PM_2.5 was associated with RA-ILD, while NOx, ozone, and PM₁₀ were associated with RA risk. Thus, air pollution may increase the risk of RA and RA-ILD.