Favorable longitudinal change of lung function in patients with asthma-COPD overlap from a COPD cohort

• Published in: Respiratory research 2018-03, Vol.19 (1), p.36-36, Article 36
• Main Authors: Park, Hye Yun, Lee, Suh-Young, Kang, Danbee, Cho, Juhee, Lee, Hyun, Lim, Seong Yong, Yoon, Ho Il, Ra, Seung Won, Kim, Ki Uk, Oh, Yeon-Mok, Sin, Don D, Lee, Sang-Do, Park, Yong Bum
• Format: Article
• Language: English
• Subjects: Asthma; Care and treatment; Chronic obstructive lung disease; Chronic obstructive pulmonary disease; Diagnosis; Lung function; Pulmonary function tests; Risk factors
• ISSN: 1465-993X; 1465-9921; 1465-993X
• DOI: 10.1186/s12931-018-0737-8

The recognition of asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO) as a distinct phenotype of COPD or asthma has increased. Although ACO has worse clinical features than non-ACO COPD, limited information is available on long-term outcomes of lung function decline for ACO and non-ACO COPD. COPD patients with at least 3 years of follow-up were selected from the Korean Obstructive Lung Disease cohort. ACO was defined based on 3 major criteria: 1) airflow limitation in individuals 40 years of age and older, 2) ≥10 pack-years of smoking history, and 3) a history of asthma or bronchodilator response of > 400 mL in forced expiratory volume in 1 s (FEV ) at baseline; and at least 1 minor criterion: 1) history of atopy or allergic rhinitis, 2) two separated bronchodilator responses of ≥12% and 200 mL in FEV , or 3) peripheral blood eosinophils ≥300 cells/μL. Lung function decline was compared using a linear mixed effects model for longitudinal data with random intercept and random slope. Among 239 patients, 47 were diagnosed with ACO (19.7%). During the follow-up period, change in smoking status, use of inhaled corticosteroids (ICS) and long-acting β2-agonists or ICS and at least 2 exacerbations per year were similar between patients with non-ACO COPD and ACO. Over a median follow-up duration of 5.8 years, patients with non-ACO COPD experienced a faster annual decline in pre-bronchodilator FEV than patients with ACO (- 29.3 ml/year vs. -13.9 ml/year, P = 0.042), which was persistent after adjustment for confounders affecting lung function decline. Patients with ACO showed favorable longitudinal changes in lung function compared to COPD patients over a median follow-up of 5.8 years.