title: Effects of allergic phenotype on respiratory symptoms and exacerbations in patients with chronic obstructive pulmonary disease.
abstract: BACKGROUND
  Chronic obstructive pulmonary disease (COPD) guidelines make no recommendations for allergy diagnosis or treatment.
  
  
  OBJECTIVE
  To determine whether an allergic phenotype contributes to respiratory symptoms and exacerbations in patients with COPD.
  
  
  METHODS
  Two separate cohorts were analyzed: National Health and Nutrition Survey III (NHANES III) and the COPD and domestic endotoxin (CODE) cohort. Subjects from NHANES III with COPD (n = 1,381) defined as age > 40 years, history of smoking, FEV1/FVC < 0.70, and no diagnosis of asthma were identified. The presence of an allergic phenotype (n = 296) was defined as self-reported doctor diagnosed hay fever or allergic upper respiratory symptoms. In CODE, former smokers with COPD (n = 77) were evaluated for allergic sensitization defined as a detectable specific IgE to perennial allergens. Bivariate and multivariate models were used to determine whether an allergic phenotype was associated with respiratory symptoms and exacerbations.
  
  
  RESULTS
  In NHANES III, multivariate analysis revealed that individuals with allergic phenotype were more likely to wheeze (odds ratio [OR], 2.1; P < 0.01), to have chronic cough (OR, 1.9; P = 0.01) and chronic phlegm (OR, 1.5; P < 0.05), and to have increased risk of COPD exacerbation requiring an acute doctor visit (OR, 1.7; P = 0.04). In the CODE cohort, multivariate analysis revealed that sensitized subjects reported more wheeze (OR, 5.91; P < 0.01), more nighttime awakening due to cough (OR, 4.20; P = 0.03), increased risk of COPD exacerbations requiring treatment with antibiotics (OR, 3.79; P = 0.02), and acute health visits (OR, 11.05; P < 0.01). An increasing number of sensitizations was associated with a higher risk for adverse health outcomes.
  
  
  CONCLUSIONS
  Among individuals with COPD, evidence of an allergic phenotype is associated with increased respiratory symptoms and risk of COPD exacerbations.
authors.affiliation: Department of Medicine, School of Medicine, Johns Hopkins University, Baltimore, MD, USA.
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Jamieson
authors.forename: Elizabeth C
authors.initials: EC
authors.lastname: Matsui
authors.forename: Andrew
authors.initials: A
authors.lastname: Belli
authors.forename: Meredith C
authors.initials: MC
authors.lastname: McCormack
authors.forename: Eric
authors.initials: E
authors.lastname: Peng
authors.forename: Simon
authors.initials: S
authors.lastname: Pierre-Louis
authors.forename: Jean
authors.initials: J
authors.lastname: Curtin-Brosnan
authors.forename: Patrick N
authors.initials: PN
authors.lastname: Breysse
authors.forename: Gregory B
authors.initials: GB
authors.lastname: Diette
authors.forename: Nadia N
authors.initials: NN
authors.lastname: Hansel
mesh_terms: D000368:Aged; D018450:Disease Progression; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009749:Nutrition Surveys; D010641:Phenotype; D029424:Pulmonary Disease, Chronic Obstructive / Q000235:genetics* / Q000276:immunology*; D012135:Respiratory Sounds / Q000235:genetics