title: Patients with Active Luminal Crohn's Disease Have Evidence of Significant Functional and Clinical Pulmonary Involvement.
abstract: BACKGROUND
  Pulmonary involvement is a recognized extraintestinal complication of inflammatory bowel disease and is associated with airway inflammation. Changes in pulmonary function were previously described as being subclinical. The purpose of this study was to compare pulmonary findings in a large case series of patients with active and quiescent Crohn's disease (CD).
  
  
  METHODS
  CD patients, prospectively enrolled between May 2011 and May 2012, completed a demographic questionnaire and Harvey-Bradshaw Index to define disease activity. Each patient also completed blood work, a chest x-ray, pulmonary function testing, respiratory symptom and dyspnea scoring, and a 6-minute walk test. Results are reported as mean ± SE or descriptively as a percent and were analyzed using t tests and chi-square or Fisher's exact tests, respectively. Multivariable linear regression models were built for continuous outcomes and logistic regression models for categorical outcomes.
  
  
  RESULTS
  Ninety-five patients (54 remission, 41 active disease), 58.9% males, with a mean age of 41 ± 1 years were enrolled. Patients with active disease compared with those in remission had lower absolute ratios of forced expiratory volume in 1 second to forced vital capacity (FEV1/FVC) (0.74 ± 0.01 versus 0.77 ± 0.01, P = 0.023), higher degrees of peripheral airway obstruction (34.1% versus 16.7%, P = 0.049), more frequent respiratory symptoms (29.3% versus 9.3%, P = 0.012) and higher Medical Research Council (MRC) dyspnea scales (MRC 2 or 3, 58.5% versus 22.2%, P = 0.001), respectively.
  
  
  CONCLUSIONS
  CD patients with active disease display clinical pulmonary dysfunction compared with those in remission.
authors.affiliation: *Department of Medicine, Division of Gastroenterology, University of Alberta, Edmonton, AB, Canada; and †Department of Medicine, Division of Pulmonary Medicine, University of Alberta, Edmonton, AB, Canada.
authors.forename: Farhad
authors.initials: F
authors.lastname: Peerani
authors.forename: May
authors.initials: M
authors.lastname: Choi
authors.forename: Justin
authors.initials: J
authors.lastname: Weinkauf
authors.forename: Richard N
authors.initials: RN
authors.lastname: Fedorak
authors.forename: Brendan
authors.initials: B
authors.lastname: Halloran
mesh_terms: D000293:Adolescent; D000328:Adult; D003424:Crohn Disease / Q000150:complications*; D005260:Female; D005500:Follow-Up Studies; D005541:Forced Expiratory Volume; D006801:Humans; D008171:Lung Diseases / Q000175:diagnosis / Q000209:etiology*; D008297:Male; D011379:Prognosis; D011446:Prospective Studies; D012129:Respiratory Function Tests; D018570:Risk Assessment; D012720:Severity of Illness Index