The Paradoxical Response To Short-Acting Bronchodilator Administration In Patients With Chronic Obstructive Pulmonary Disease

Background: There are a few studies about paradoxical bronchodilator response (BDR), which means a decrease in forced expiratory volume in 1 second (FEV1) or forced vital capacity (FVC) after short-acting bronchodilator administration in patients with chronic obstructive pulmonary disease (COPD). We evaluated the effect of paradoxical BDR on the clinical outcomes of COPD patients in South Korea.Methods: We analyzed the KOrea COpd Subgroup Study team (KOCOSS) cohort data in South Korea between January 2012 and December 2017. BDR was defined as at least a 12% and 200-mL reduction in FEV1 or FVC after bronchodilator administration.Results: A total of 1,991 patients were included in this study. A paradoxical BDR was noted in 57 (2.9%) patients and was independently associated with worse dyspnea and poor quality of life. High C-reactive protein (CRP) levels were associated with a paradoxical BDR (OR, 1.05; 95% CI, 1.01-1.09; P=0.003). However, paradoxical BDR was not associated with severe acute exacerbations. Pre-bronchodilator FEV1 (L) showed a higher area under the curve (AUC) for predicting severe acute exacerbations than the postbronchodilator FEV1 (L) in the paradoxical BDR group (0.788 vs. 0.752).Conclusion: A paradoxical reduction of FEV1 or FVC after bronchodilator administration may be associated with chronic inflammation in the airway and independently associated with worse respiratory symptoms and poor quality of life.