So-Young Park1,2, Heewon Jung1,3, Jung-Hyun Kim4, Bomi Seo4, Oh Young Kwon1, Sungkyoung Choi5, Bermseok Oh6, Hyouk-Soo Kwon1, You Sook Cho1, Hee-Bom Moon1, Sungho Won7, Taesung Park8, Tae-Bum Kim1. 1. Division of Allergy and Clinical Immunology, Department of Internal Medicine, Asan Medical Center, Ulsan University School of Medicine, Seoul, Korea. 2. Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Konkuk University Medical Center, Seoul, Korea. 3. Department of Applied Statistics, Chung-Ang University, Seoul, Korea. 4. Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea. 5. Department of Pharmacology, Yonsei University College of Medicine, Seoul, Korea. 6. Department of Biochemistry and Molecular Biology, School of Medicine, Kyung-Hee University, Seoul, Korea. 7. Department of Public Health Science, Seoul National University, Seoul, Korea. 8. Department of Statistics, Seoul National University, Seoul, Korea.
Abstract
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 (FEV1)/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 FEV1 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.
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 (FEV1)/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 FEV1 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.
Authors: Minna Tommola; Ha-Kyeong Won; Pinja Ilmarinen; Heewon Jung; Leena E Tuomisto; Lauri Lehtimäki; Onni Niemelä; Tae-Bum Kim; Hannu Kankaanranta Journal: Respir Res Date: 2020-07-13