title: Associations between radiographic findings and spirometry in a community exposed to Libby amphibole.
abstract: BACKGROUND
  Among asbestos-exposed individuals, abnormal spirometry is usually associated with parenchymal abnormalities or diffuse pleural thickening. Localised pleural thickening (LPT), the most common abnormality associated with asbestos exposure, is typically thought to be a marker of exposure with little clinical consequence. Our objective was to determine if abnormal spirometry is associated with LPT independent of other abnormalities, using data from community-based screening conducted in Libby, Montana.
  
  
  METHODS
  Subjects were a subset of screening participants comprising persons with interpretable spirometry and chest radiograph results (n=6475). Chest radiographs were independently evaluated by two or three B readers, and participants were classified by mutually exclusive categories of spirometry outcome: normal, restriction, obstruction or mixed defect.
  
  
  RESULTS
  Restrictive spirometry was strongly associated with parenchymal abnormalities (OR 2.9; 95% CI 1.4 to 6.0) and diffuse pleural thickening (OR 4.1; 95% CI 2.1 to 7.8). Controlling for the presence of these abnormalities as well as age, smoking status and other covariates, restrictive spirometry was also associated with LPT (OR 1.4; 95% CI 1.1 to 1.8). The risk of restrictive spirometric findings correlated with the severity of LPT.
  
  
  CONCLUSIONS
  In this large community-based screening cohort, restrictive spirometry is significantly associated with LPT, indicating that this abnormality may result in lung function impairment. Physicians treating patients exposed to Libby amphibole should be aware that LPT may have functional consequences.
authors.affiliation: Division of Health Studies, Agency for Toxic Substances and Disease Registry, Atlanta, GA 30341, USA. thl3@cdc.gov
authors.forename: Theodore C
authors.initials: TC
authors.lastname: Larson
authors.forename: Michael
authors.initials: M
authors.lastname: Lewin
authors.forename: E Brigitte
authors.initials: EB
authors.lastname: Gottschall
authors.forename: Vinicius C
authors.initials: VC
authors.lastname: Antao
authors.forename: Vikas
authors.initials: V
authors.lastname: Kapil
authors.forename: Cecile S
authors.initials: CS
authors.lastname: Rose
mesh_terms: D000293:Adolescent; D000328:Adult; D017636:Asbestos, Amphibole / Q000633:toxicity*; D001195:Asbestosis / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D010995:Pleural Diseases / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology*; D011237:Predictive Value of Tests; D011859:Radiography; D013147:Spirometry; D055815:Young Adult
chemical_list: D017636:Asbestos, Amphibole