title: The chronic bronchitic phenotype of COPD: an analysis of the COPDGene Study.
abstract: BACKGROUND
  Chronic bronchitis (CB) in patients with COPD is associated with an accelerated lung function decline and an increased risk of respiratory infections. Despite its clinical significance, the chronic bronchitic phenotype in COPD remains poorly defined.
  
  
  METHODS
  We analyzed data from subjects enrolled in the Genetic Epidemiology of COPD (COPDGene) Study. A total of 1,061 subjects with GOLD (Global Initiative for Chronic Obstructive Lung Disease) stage II to IV were divided into two groups: CB (CB+) if subjects noted chronic cough and phlegm production for ≥ 3 mo/y for 2 consecutive years, and no CB (CB-) if they did not.
  
  
  RESULTS
  There were 290 and 771 subjects in the CB+ and CB- groups, respectively. Despite similar lung function, the CB+ group was younger (62.8 ± 8.4 vs 64.6 ± 8.4 years, P = .002), smoked more (57 ± 30 vs 52 ± 25 pack-years, P = .006), and had more current smokers (48% vs 27%, P < .0001). A greater percentage of the CB+ group reported nasal and ocular symptoms, wheezing, and nocturnal awakenings secondary to cough and dyspnea. History of exacerbations was higher in the CB+ group (1.21 ± 1.62 vs 0.63 ± 1.12 per patient, P < .027), and more patients in the CB+ group reported a history of severe exacerbations (26.6% vs 20.0%, P = .024). There was no difference in percent emphysema or percent gas trapping, but the CB+ group had a higher mean percent segmental airway wall area (63.2% ± 2.9% vs 62.6% ± 3.1%, P = .013).
  
  
  CONCLUSIONS
  CB in patients with COPD is associated with worse respiratory symptoms and higher risk of exacerbations. This group may need more directed therapy targeting chronic mucus production and smoking cessation not only to improve symptoms but also to reduce risk, improve quality of life, and improve outcomes.
  
  
  BACKGROUND
  ClinicalTrials.gov; No.: NCT00608764; URL: www.clinicaltrials.gov.
authors.affiliation: Temple University School of Medicine, Philadelphia, PA. Electronic address: victor.kim@tuhs.temple.edu.
authors.forename: Victor
authors.initials: V
authors.lastname: Kim
authors.affiliation: University of Michigan School of Medicine, Ann Arbor, MI.
authors.forename: MeiLan K
authors.initials: MK
authors.lastname: Han
authors.affiliation: Temple University School of Medicine, Philadelphia, PA.
authors.forename: Gwendolyn B
authors.initials: GB
authors.lastname: Vance
authors.affiliation: National Jewish Health, Denver, CO.
authors.forename: Barry J
authors.initials: BJ
authors.lastname: Make
authors.affiliation: National Jewish Health, Denver, CO.
authors.forename: John D
authors.initials: JD
authors.lastname: Newell
authors.affiliation: University of Colorado at Denver, Denver, CO.
authors.forename: John E
authors.initials: JE
authors.lastname: Hokanson
authors.affiliation: Brigham and Women's Hospital, Boston, MA.
authors.forename: Craig P
authors.initials: CP
authors.lastname: Hersh
authors.affiliation: National Jewish Health, Denver, CO.
authors.forename: Douglas
authors.initials: D
authors.lastname: Stinson
authors.affiliation: Brigham and Women's Hospital, Boston, MA.
authors.forename: Edwin K
authors.initials: EK
authors.lastname: Silverman
authors.affiliation: Temple University School of Medicine, Philadelphia, PA.
authors.forename: Gerard J
authors.initials: GJ
authors.lastname: Criner
mesh_terms: D000368:Aged; D029481:Bronchitis, Chronic / Q000453:epidemiology / Q000235:genetics / Q000503:physiopathology* / Q000628:therapy; D015897:Comorbidity; D003430:Cross-Sectional Studies; D018450:Disease Progression; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010641:Phenotype; D011788:Quality of Life; D012129:Respiratory Function Tests; D012907:Smoking / Q000453:epidemiology; D016540:Smoking Cessation