Racial Differences in Prevalence and Clinical Characteristics of Asthma-Chronic Obstructive Pulmonary Disease Overlap

Yong Suk Jo; Yong Il Hwang; Kwang Ha Yoo; Myung Goo Lee; Ki Suck Jung; Kyeong-Cheol Shin; Hyoung Kyu Yoon; Deog Kyeom Kim; Sang Yeub Lee; Chin Kook Rhee

doi:10.3389/fmed.2021.780438

Racial Differences in Prevalence and Clinical Characteristics of Asthma-Chronic Obstructive Pulmonary Disease Overlap

Front Med (Lausanne). 2021 Nov 22:8:780438. doi: 10.3389/fmed.2021.780438. eCollection 2021.

Authors

Affiliations

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

Abstract

Background: This study examined the differences in the prevalence and clinical features of asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO) with identical diagnostic criteria by race and ethnicity in two nationwide cohorts of COPD. Methods: We used data from the Korean COPD Subgroup Study (KOCOSS) and phase I of the US Genetic Epidemiology of COPD (COPDGene) study. We defined ACO by satisfying bronchodilator response (BDR) >15% and 400 ml and/or blood eosinophil count ≥300/μl. Results: The prevalences of ACO according to ethnicity were non-Hispanic white (NHW), 21.4%; African American (AA), 17.4%; and Asian, 23.8%. Asian patients with ACO were older, predominantly male, with fewer symptoms, more severe airflow limitation, and fewer comorbidities than NHW and AA patients. During 1-year follow-up, exacerbations occurred in 28.2, 22.0, and 48.4% of NHW, AA, and Asian patients with ACO, respectively. Compared to patients with non-ACO from the same racial group, the risk for exacerbation was significantly higher in NHW and Asian patients with ACO [adjusted incident rate ratio (aIRR), 1.17; 95% CI, 1.01-1.36, and aIRR, 1.37; 95% CI, 1.09-1.71 for NHW and Asian patients with ACO, respectively]. Inhaled corticosteroid (ICS) reduced the risk for future exacerbation in total patients with ACO but the effect was not significant in each racial group. Conclusions: The prevalence of ACO was similar in the two cohorts using the same diagnostic criteria. The risk for future exacerbation was significantly higher in ACO, and the use of ICS reduced the risk for exacerbation in total patients with ACO.

Keywords: ACO; COPDGene (UA Genetic Epidemiology of COPD); KOCOSS (Korean COPD Subgroup Study); asthma–COPD overlap; exacerbation; inhaled corticosteroid (ICS); racial and ethnic differences.