Increased Risk of Exacerbation in Asthma Predominant Asthma-Chronic Obstructive Pulmonary Disease Overlap Syndrome

Jisoo Park; Eun Kyung Kim; Mi Ae Kim; Tae Hyung Kim; Jung Hyun Chang; Yon Ju Ryu; Sei Won Lee; Yeon Mok Oh; Suk Joong Yong; Won Il Choi; Kwang Ha Yoo; Ji Hyun Lee

doi:10.4046/trd.2017.0064

Increased Risk of Exacerbation in Asthma Predominant Asthma-Chronic Obstructive Pulmonary Disease Overlap Syndrome

Tuberc Respir Dis (Seoul). 2018 Oct;81(4):289-298. doi: 10.4046/trd.2017.0064. Epub 2018 Mar 7.

Authors

Jisoo Park¹, Eun Kyung Kim¹, Mi Ae Kim¹, Tae Hyung Kim², Jung Hyun Chang³, Yon Ju Ryu³, Sei Won Lee⁴, Yeon Mok Oh⁴, Suk Joong Yong⁵, Won Il Choi⁶, Kwang Ha Yoo⁷, Ji Hyun Lee⁸

Affiliations

¹ Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, CHA Bundang Medical Center, CHA University, Seongnam, Korea.
² Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Hanyang University Guri Hospital, Guri, Korea.
³ Division of Pulmonary and Critical Care Medicine, Department of Medicine, Ewha Womans University College of Medicine, Seoul, Korea.
⁴ Department of Pulmonary and Critical Care Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
⁵ Department of Internal Medicine, Wonju Severance Christian Hospital, Yonsei University Wonju College of Medicine, Wonju, Korea.
⁶ Department of Internal Medicine, Keimyung University Dongsan Medical Center, Keimyung University School of Medicine, Daegu, Korea.
⁷ Department of Pulmonary and Critical Care Medicine, Konkuk University School of Medicine, Seoul, Korea.
⁸ Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, CHA Bundang Medical Center, CHA University, Seongnam, Korea. plmjhlee@cha.ac.kr.

Abstract

Background: Obstructive airway disease patients with increased variability of airflow and incompletely reversible airflow obstruction are often categorized as having asthma-chronic obstructive pulmonary disease (COPD) overlap syndrome (ACOS). ACOS is heterogeneous with two sub-phenotypes: asthma-ACOS and COPD-ACOS. The objective of this study was to determine the difference in risk of exacerbation between the two sub-phenotypes of ACOS.

Methods: A total of 223 patients exhibiting incompletely reversible airflow obstruction with increased variability (spirometrically defined ACOS) were enrolled. These patients were divided into asthma-ACOS and COPD-ACOS according to their physician's diagnosis and smoking history of 10 pack-years. Within-group comparisons were made for asthma-ACOS versus COPD-ACOS and light smokers versus heavy smokers.

Results: Compared to patients with COPD-ACOS, patients with asthma-ACOS experienced exacerbation more often despite their younger age, history of light smoking, and better lung function. While the light-smoking group showed better lung function, they made unscheduled outpatient clinic visits more frequently. On multivariate analysis, asthma-ACOS and poor inhaler compliance were significantly associated with more than two unscheduled clinic visits during the previous year.

Conclusion: Spirometrically defined ACOS includes heterogeneous subgroups with different clinical features. Phenotyping of ACOS by physician's diagnosis could be significant in predicting future risk of exacerbation.

Keywords: Asthma; Phenotype; Pulmonary Disease, Chronic Obstructive.