title: COPD phenotypes in a lung cancer screening population.
abstract: OBJECTIVE
  COPD (chronic obstructive pulmonary disease) is a very heterogeneous disease, and phenotypic categorization of a high-risk population has many potential benefits. The present study uses a symptom questionnaire, low-dose computed tomography (LDCT) and pulmonary function tests (PFT) to phenotypically subgroup a high-risk population.
  
  
  METHODS
  Study group consisted of current or former smokers who underwent lung cancer screening with LDCT as a subgroup of Pittsburgh Lung Screening Study. In addition to LDCT, PFT and a symptom query questionnaire were obtained from each patient.
  
  
  RESULTS
  The study group consisted of 3183 subjects (age 50-79) subdivided into eight groups according to presence of symptoms, obstruction on PFT and presence of emphysema on LDCT. A total of 501 (15.7%) subjects were asymptomatic, with no airflow obstruction or evidence of emphysema. There were 866 (27.2%) subjects with both obstruction on PFT and emphysema on LDCT, but only 660 (20.7%) had symptoms. Five hundred thirty (16.6%) of the subjects had no emphysema on LDCT but had obstruction on PFT, although only 370 (11.6%) had symptoms. Four hundred seventy-four (14.9%) of subjects had emphysema on LDCT, but no airflow obstruction, with 312 (9.8%) symptomatic. Finally, 812 (25.5%) of subjects had no evidence of airflow obstruction on PFT or emphysema on LDCT, but had symptoms.
  
  
  CONCLUSIONS
  Combining LDCT with PFT and a comprehensive questionnaire allows subgroup classification of COPD phenotypes in a high-risk population and may lead to earlier intervention and an improved framework for future studies.
authors.affiliation: Department of Medical Education, Baskent University Faculty of Medicine, Ankara, Turkey.
authors.forename: Arzu
authors.initials: A
authors.lastname: Balkan
authors.affiliation: Department of Pediatrics, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.
authors.forename: Yonca
authors.initials: Y
authors.lastname: Bulut
authors.affiliation: Department of Radiology, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
authors.forename: Carl R
authors.initials: CR
authors.lastname: Fuhrman
authors.affiliation: Department of Radiology, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
authors.forename: Stephen N
authors.initials: SN
authors.lastname: Fisher
authors.affiliation: Department of Pulmonary and Critical Care Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
authors.forename: David O
authors.initials: DO
authors.lastname: Wilson
authors.affiliation: Department of Epidemiology, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
authors.forename: Joel L
authors.initials: JL
authors.lastname: Weissfeld
authors.affiliation: Department of Pulmonary and Critical Care Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
authors.forename: Frank C
authors.initials: FC
authors.lastname: Sciurba
mesh_terms: D000368:Aged; D055088:Early Detection of Cancer / Q000379:methods; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D010414:Pennsylvania / Q000453:epidemiology; D010641:Phenotype; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000453:epidemiology; D011656:Pulmonary Emphysema / Q000175:diagnosis / Q000000981:diagnostic imaging; D012129:Respiratory Function Tests / Q000379:methods; D012907:Smoking / Q000453:epidemiology; D011795:Surveys and Questionnaires; D014057:Tomography, X-Ray Computed / Q000379:methods
keywords: chronic obstructive pulmonary disease; computed tomography; pulmonary function tests