Implications of GLI spirometry reference equations in Northeast Asian patients with COPD

Joon Young Choi; Chang-Hoon Lee; Hyonsoo Joo; Yun Su Sim; Jaechun Lee; Hyun Lee; Kwang Ha Yoo; Seoung Ju Park; Ju Ock Na; Yet Hong Khor

doi:10.1016/j.chest.2024.08.048

Implications of GLI spirometry reference equations in Northeast Asian patients with COPD

Chest. 2024 Sep 12:S0012-3692(24)05150-X. doi: 10.1016/j.chest.2024.08.048. Online ahead of print.

Authors

Joon Young Choi¹, Chang-Hoon Lee², Hyonsoo Joo³, Yun Su Sim⁴, Jaechun Lee⁵, Hyun Lee⁶, Kwang Ha Yoo⁷, Seoung Ju Park⁸, Ju Ock Na⁹, Yet Hong Khor¹⁰

Affiliations

¹ Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea. Electronic address: tawoe@naver.com.
² Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul National University Hospital, Seoul, Republic of Korea.
³ Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Uijeongbu St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
⁴ Division of Pulmonary, Allergy and Critical Care Medicine, Hallym University Kangnam Sacred Heart Hospital, Seoul, Republic of Korea.
⁵ Department of Internal Medicine, Jeju National University Hospital, Jeju National University School of Medicine, Jeju, Republic of Korea.
⁶ Department of Internal Medicine, Hanyang University Hospital, Hanyang University College of Medicine, Seoul, Republic of Korea.
⁷ Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, Republic of Korea.
⁸ Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Internal Medicine, Jeonbuk National University Hospital, Jeonbuk National University Medical School, Jeonju, Republic of Korea.
⁹ University of Soonchunhyang College of Medicine, University Hospital for Pulmonary Diseases, Cheonan, Republic of Korea.
¹⁰ Respiratory Research@Alfred, School of Translational Medicine, Monash University, Melbourne, Victoria, Australia; Department of Respiratory and Sleep Medicine, Austin Health, Heidelberg, Victoria, Australia; Institute for Breathing and Sleep, Heidelberg, Victoria, Australia; Faculty of Medicine, University of Melbourne, Melbourne, Victoria, Australia.

PMID: 39276977
DOI: 10.1016/j.chest.2024.08.048

Abstract

Background: Accurate spirometry interpretation is critical in the diagnosis and management of chronic obstructive pulmonary disease (COPD). With increasing efforts for a unified approach by the Global Lung Function Initiative (GLI), this study evaluated the application of race-specific 2012-GLI and race-neutral 2022-GLI reference equations compared to Choi's reference equations, which is derived and widely used in South Korea, for spirometry interpretation in Northeast Asian patients with COPD.

Research question: What are the effects of applying race-specific 2012-GLI, race-neutral 2022-GLI, and Choi's reference equations on the diagnosis, severity grade, and clinical outcome associations of COPD STUDY DESIGN AND METHODS: Serial spirometry data from the Korea COPD Subgroup Study (KOCOSS) consisting of 3,477 patients were utilized for re-analyses using 2012-GLI, 2022-GLI, and Choi's reference equations. The COPD diagnosis and severity categorization, associations with disease manifestations and health outcomes, and longitudinal trajectories of lung function were determined.

Results: Although there was strong concordance in COPD diagnosis comparing 2012-GLI, and 2022-GLI reference equations to Choi's reference equations, a notable portion of patients were reclassified to milder disease severity (17.0% and 23.4% for 2012-GLI and 2022-GLI reference equations, respectively). Relationships between FEV₁ percent-predicted values calculated using 2012-GLI, 2022-GLI, and Choi's equations with clinical outcomes including dyspnea severity, exercise capacity, health-related quality of life, and frequency of exacerbations remain consistently significant. Similar annual decline rates of FEV₁ and FVC percent-predicted were observed among the reference equations used, except for slower annual decline rate of FEV₁ in Choi's equation compared to 2022-GLI race-neutral equation.

Interpretation: Application of GLI reference equations for spirometry interpretation in Northeast Asian patients with COPD has potential implications on disease severity grade for clinical management and trial participation, and maintains consistent significant relationships with key disease outcomes.

Keywords: GLI reference equation; KOCOSS; chronic obstructive pulmonary disease; cohort; spirometry.