title: Asthma-like Features and Clinical Course of Chronic Obstructive Pulmonary Disease. An Analysis from the Hokkaido COPD Cohort Study.
abstract: Some patients with chronic obstructive pulmonary disease (COPD) have asthma-like features, such as significant bronchodilator reversibility, blood eosinophilia, and/or atopy, even if they are not clinically diagnosed as having asthma. However, the clinical significance of asthma-like features overlapping with COPD remains unclear.
  
  
  
  The aim of this study was to assess the effect of asthma-like features on the clinical course of patients with COPD who were adequately treated and followed-up over 10 years.
  
  
  
  A total of 268 patients with COPD who had been clinically considered as not having asthma by respiratory specialists were included in this study. The asthma-like features included in this study were bronchodilator reversibility (ΔFEV1, ≥12% and ≥200 ml), blood eosinophilia (≥300 cells/μl), and atopy (positive specific IgE for any inhaled antigen). The annual changes in post-bronchodilator FEV1and COPD exacerbations were monitored during the first 5 years, and mortality was followed during the entire 10 years of the study.
  
  
  
  Fifty-seven subjects (21%) had bronchodilator reversibility, 52 (19%) had blood eosinophilia, and 67 (25%) had atopy. Subjects with blood eosinophilia had significantly slower annual post-bronchodilator FEV1decline; bronchodilator reversibility and atopy did not affect the annual post-bronchodilator FEV1decline, and none of the asthma-like features was associated with development of COPD exacerbation. Even if subjects had two or more asthma-like features, they displayed annual post-bronchodilator FEV1declines and exacerbation rates similar to those of subjects with one or zero asthma-like features, as well as a lower 10-year mortality rate (P = 0.02).
  
  
  
  The presence of asthma-like features was associated with better clinical course in patients with COPD receiving appropriate treatment.
authors.affiliation: First Department of Medicine, Hokkaido University School of Medicine, Sapporo, Japan.
authors.forename: Masaru
authors.initials: M
authors.lastname: Suzuki
authors.affiliation: First Department of Medicine, Hokkaido University School of Medicine, Sapporo, Japan.
authors.forename: Hironi
authors.initials: H
authors.lastname: Makita
authors.affiliation: First Department of Medicine, Hokkaido University School of Medicine, Sapporo, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Konno
authors.affiliation: First Department of Medicine, Hokkaido University School of Medicine, Sapporo, Japan.
authors.forename: Kaoruko
authors.initials: K
authors.lastname: Shimizu
authors.affiliation: First Department of Medicine, Hokkaido University School of Medicine, Sapporo, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Kimura
authors.affiliation: First Department of Medicine, Hokkaido University School of Medicine, Sapporo, Japan.
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Kimura
authors.affiliation: First Department of Medicine, Hokkaido University School of Medicine, Sapporo, Japan.
authors.forename: Masaharu
authors.initials: M
authors.lastname: Nishimura
mesh_terms: D000368:Aged; D001249:Asthma / Q000150:complications* / Q000503:physiopathology*; D015331:Cohort Studies; D004802:Eosinophilia / Q000097:blood / Q000503:physiopathology; D005260:Female; D005500:Follow-Up Studies; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D007564:Japan; D008297:Male; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications* / Q000503:physiopathology*; D013577:Syndrome
keywords: asthma–COPD overlap syndrome; atopy; blood eosinophilia; bronchodilator reversibility