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Longitudinal analysis to better characterize Asthma‐COPD overlap syndrome: Findings from an adult asthma cohort in Korea (COREA)
Author(s) -
Park SoYoung,
Jung Heewon,
Kim JungHyun,
Seo Bomi,
Kwon Oh Young,
Choi Sungkyoung,
Oh Bermseok,
Kwon HyoukSoo,
Cho You Sook,
Moon HeeBom,
Won Sungho,
Park Taesung,
Kim TaeBum
Publication year - 2019
Publication title -
clinical and experimental allergy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.462
H-Index - 154
eISSN - 1365-2222
pISSN - 0954-7894
DOI - 10.1111/cea.13339
Subject(s) - medicine , asthma , copd , cohort , methacholine , bronchodilator , overlap syndrome , pulmonary function testing , vital capacity , provocation test , respiratory disease , lung function , lung , pathology , diffusing capacity , alternative medicine
Summary Background Asthma‐chronic obstructive pulmonary disease ( COPD ) overlap syndrome ( ACOS ), which has received much attention, has not been unanimously defined. Objective In this study, we tried to demonstrate that longitudinally defined ACOS is more useful in the real world than blending patients with asthma and COPD . Methods The study patients had undergone two consecutive pulmonary function tests measured at least 3 months apart (n = 1889). We selected the patients who had positive bronchodilator response or methacholine provocation tests (n = 959). Next, we defined ACOS as a patient with a persistent airflow obstruction [forced expiratory volume in 1 second ( FEV 1)/forced vital capacity <0.7] that was identified twice consecutively by an interval of at least 3 months (n = 228). Results The proportions of patients who were older, male and smokers were significantly higher, and baseline lung function was lower in patients with ACOS . In the longitudinal analysis, the mean change in lung function was high, and a greater decline in FEV 1 was observed in patients with ACOS . In addition, we compared ACOS and severe asthma, and we also performed a cluster analysis and compared the results with our definition of ACOS . According to our definition, ACOS is an independent subtype with distinctive characteristics. Finally, a genome‐wide association study ( GWAS ) was performed to identify genetic variations associated with ACOS , but no significant single nucleotide polymorphisms were identified. Conclusion Our findings suggest that ACOS should be defined longitudinally and considered as an independent subgroup distinguished by inherited environmental factors rather than as a genetically distinct independent group.