Rheumatoid arthritis increases the risk of chronic obstructive pulmonary disease: a nationwide retrospective cohort study.

BACKGROUND: Most reports of pulmonary manifestations in rheumatoid arthritis (RA) have been related to interstitial lung diseases. RA and chronic obstructive pulmonary disease (COPD) are both chronic inflammatory systemic diseases.

RESEARCH QUESTION: Does RA increase the risk of developing COPD? Is there a difference between seropositive and seronegative RA in the risk of COPD?

STUDY DESIGN AND METHODS: Using the Korean National Health Insurance Database, we screened individuals diagnosed with RA between 2010 and 2017. We identified 46,030 patients with RA (32,608 seropositive RA and 13,422 seronegative RA) and 276,180 matched control individuals, and monitored them until December 2019. We used multivariate Cox proportional hazard models to estimate the adjusted hazard ratio (aHR) of risk factors for the development of COPD.

RESULTS: The incidence of COPD among patients with RA was 5.04/1,000 person-year and 2.23/1,000 person-year in the control group. Patients with RA showed a higher risk of developing COPD (aHR 2.11, 95% confidence interval [CI] 1.96-2.28) compared with the control group. While both seropositive RA and seronegative RA were associated with an increased risk of COPD, patients with seropositive RA had a higher risk for the development of COPD (aHR 1.26, 95% CI 1.09-1.46) compared with patients with seronegative RA. In the subgroup analyses, smoking history did not demonstrate significant interactions between RA and COPD development.

INTERPRETATION: RA is associated with an increased risk of COPD development, augmented by seropositivity. Clinicians should monitor respiratory symptoms and pulmonary function carefully in patients with RA.