Bronchodilator Responsiveness in Tobacco-Exposed Persons with or without COPD

Abstract

Background

Bronchodilator responsiveness (BDR), in obstructive lung disease varies over time and may be associated with distinct clinical features.

Research question

Is consistent BDR over time (always present) differentially associated with obstructive lung disease features relative to inconsistent (sometimes present) or never (never present) BDR in tobacco-exposed people with or without COPD.

Study Design and Methods

We retrospectively analyzed data of 2,269 tobacco-exposed participants in SPIROMICS with or without COPD. We used various BDR definitions: change ≥200ml and ≥12% in FEV₁ (FEV₁-BDR), in FVC (FVC-BDR), and in FEV₁ and/or FVC (ATS-BDR). Using generalized linear models adjusted for demographics, smoking history, post-bronchodilator FEV₁ %predicted, and number of visits that the participant completed, we assess the association of BDR group: i) consistent BDR, ii) inconsistent BDR, and iii) never BDR with asthma, CT features, blood eosinophils, and FEV₁ decline in participants without COPD (GOLD0) and the entire cohort (participants with or without COPD).

Results

Both consistent and inconsistent ATS-BDR were associated with asthma history and greater small airway disease (%PRM^fSAD) relative to never ATS-BDR in GOLD0 participants and the entire cohort. We observed similar findings using FEV₁-BDR and FVC-BDR definitions. Eosinophils did not consistently vary between BDR groups. Consistent BDR was associated with FEV1 decline over time relative to never BDR in the entire cohort. In GOLD0, both inconsistent (OR=3.20;95%CI 2.21 to 4.66;P<0.001) and consistent ATS-BDR group (OR=9.48;95%CI 3.77 to 29.12;P<0.001) were associated with progression to COPD relative to never ATS-BDR group.

Interpretation

Demonstration of BDR, even once, describes an obstructive lung disease phenotype with history of asthma, and greater small airway disease. Consistent demonstration of BDR indicates a high risk for lung function decline over time in the entire cohort and was associated with higher risk for progression to COPD in GOLD0