Air Trapping and the Risk of COPD Exacerbation: Analysis From Prospective KOCOSS Cohort

Youlim Kim; Sang Hyuk Kim; Chin Kook Rhee; Jae Seung Lee; Chang Youl Lee; Deog Kyeom Kim; Kyeong-Cheol Shin; Ki Suck Jung; Kwang Ha Yoo; Yong Bum Park

doi:10.3389/fmed.2022.835069

Air Trapping and the Risk of COPD Exacerbation: Analysis From Prospective KOCOSS Cohort

Front Med (Lausanne). 2022 Mar 11:9:835069. doi: 10.3389/fmed.2022.835069. eCollection 2022.

Authors

Youlim Kim¹, Sang Hyuk Kim^{2

3}, Chin Kook Rhee⁴, Jae Seung Lee⁵, Chang Youl Lee⁶, Deog Kyeom Kim⁷, Kyeong-Cheol Shin⁸, Ki Suck Jung⁹, Kwang Ha Yoo¹, Yong Bum Park¹⁰

Affiliations

¹ Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Konkuk University Hospital, School of Medicine, Konkuk University, Seoul, South Korea.
² Division of Pulmonology and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
³ Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Hallym University Kangnam Sacred Heart Hospital, Hallym University College of Medicine, Seoul, South Korea.
⁴ Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea.
⁵ Department of Pulmonary and Critical Care Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
⁶ Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Hallym University Chuncheon Sacred Heart Hospital, Chuncheon, South Korea.
⁷ Department of Pulmonary, Allergy and Critical Care Medicine, Seoul Metropolitan Government Seoul National University Boramae Medical Center, Seoul, South Korea.
⁸ Division of Pulmonology and Allergy, Regional Center for Respiratory Disease, Yeungnam University Medical Center, Daegu, South Korea.
⁹ Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Hallym University Sacred Heart Hospital, Anyang, South Korea.
¹⁰ Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Hallym Univeristy Kangdong Sacred Heart Hospital, Seoul, South Korea.

Abstract

Background and aims: Air trapping is a predictive index for a decline in lung function and mortality in patients with chronic obstructive pulmonary disease (COPD). However, the role of air trapping in COPD exacerbation has rarely been studied. Therefore, this study aimed to investigate the impact of air trapping as a continuous parameter on COPD exacerbation.

Materials and methods: To evaluate air trapping, we identified the ratio of residual volume (RV) to total lung capacity (TLC) of patients with COPD from the Korean COPD Subgroup Study (KOCOSS) cohort, which is a multicenter-based, prospective, consecutive cohort in Korea. The primary outcome was a development of COPD exacerbation during 3 years of follow-up.

Results: Of 2,181 participants, 902 patients measured the RV/TLC ratio in the baseline enrollment, and 410 were evaluated for assessing the development of COPD exacerbation. Of 410 patients, the rate of moderate to severe exacerbation and severe exacerbation was 70.7% and 25.9%. A 10% increase of RV/TLC ratio increased the risk of the moderate to severe exacerbation by 35% and severe exacerbation by 36%. In subgroup analysis, an interaction effect between triple inhaled therapy and the RV/TLC ratio for severe exacerbation nullified the association between the RV/TLC ratio and severe exacerbation (p for interaction = 0.002).

Conclusions: In this prospective cohort study, we found that air trapping (representing RV/TLC ratio as a continuous parameter) showed an association with an increased risk of COPD exacerbation, particularly in patients who have not undergone triple inhaler therapy.

Keywords: air trapping; chronic obstructive pulmonary disease; exacerbation; lung volume measurements; total lung capacity.