title: Childhood-onset asthma in smokers. association between CT measures of airway size, lung function, and chronic airflow obstruction.
abstract: OBJECTIVE
  Asthma is associated with chronic airflow obstruction. Our goal was to assess the association of computed tomographic measures of airway wall volume and lumen volume with the FEV1 and chronic airflow obstruction in smokers with childhood-onset asthma.
  
  
  METHODS
  We analyzed clinical, lung function, and volumetric computed tomographic airway volume data from 7,266 smokers, including 590 with childhood-onset asthma. Small wall volume and small lumen volume of segmental airways were defined as measures 1 SD below the mean. We assessed the association between small wall volume, small lumen volume, FEV1, and chronic airflow obstruction (post-bronchodilator FEV1/FVC ratio < 0.7) using linear and logistic models.
  
  
  RESULTS
  Compared with subjects without childhood-onset asthma, those with childhood-onset asthma had smaller wall volume and lumen volume (P < 0.0001) of segmental airways. Among subjects with childhood-onset asthma, those with the smallest wall volume and lumen volume had the lowest FEV1 and greatest odds of chronic airflow obstruction. A similar tendency was seen in those without childhood-onset asthma. When comparing these two groups, both small wall volume and small lumen volume were more strongly associated with FEV1 and chronic airflow obstruction among subjects with childhood-asthma in multivariate models.
  
  
  CONCLUSIONS
  In smokers with childhood-onset asthma, smaller airways are associated with reduced lung function and chronic airflow obstruction. Clinical trial registered with www.clinicaltrials.gov (NCT00608764).
authors.affiliation: 1 Division of Pulmonary and Critical Care Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
authors.forename: Alejandro A
authors.initials: AA
authors.lastname: Diaz
authors.forename: Megan E
authors.initials: ME
authors.lastname: Hardin
authors.forename: Carolyn E
authors.initials: CE
authors.lastname: Come
authors.forename: Raúl
authors.initials: R
authors.lastname: San José Estépar
authors.forename: James C
authors.initials: JC
authors.lastname: Ross
authors.forename: Sila
authors.initials: S
authors.lastname: Kurugol
authors.forename: Yuka
authors.initials: Y
authors.lastname: Okajima
authors.forename: MeiLan K
authors.initials: MK
authors.lastname: Han
authors.forename: Victor
authors.initials: V
authors.lastname: Kim
authors.forename: Joe
authors.initials: J
authors.lastname: Ramsdell
authors.forename: Edwin K
authors.initials: EK
authors.lastname: Silverman
authors.forename: James D
authors.initials: JD
authors.lastname: Crapo
authors.forename: David A
authors.initials: DA
authors.lastname: Lynch
authors.forename: Barry
authors.initials: B
authors.lastname: Make
authors.forename: R Graham
authors.initials: RG
authors.lastname: Barr
authors.forename: Craig P
authors.initials: CP
authors.lastname: Hersh
authors.forename: George R
authors.initials: GR
authors.lastname: Washko
mesh_terms: D017668:Age of Onset; D000368:Aged; D001249:Asthma / Q000453:epidemiology / Q000503:physiopathology*; D002648:Child; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology*; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology*; D012907:Smoking / Q000503:physiopathology*; D014057:Tomography, X-Ray Computed; D014797:Vital Capacity / Q000502:physiology*
keywords: airway lumen volume; airway wall volume; wall area percent