title: Racial differences in CT phenotypes in COPD.
abstract: BACKGROUND
  Whether African Americans (AA) are more susceptible to COPD than non-Hispanic Whites (NHW) and whether racial differences in disease phenotype exist is controversial. The objective is to determine racial differences in the extent of emphysema and airway remodeling in COPD.
  
  
  METHODS
  First, 2,500 subjects enrolled in the COPDGene study were used to evaluate racial differences in quantitative CT (QCT) parameters of% emphysema, air trapping and airway wall thickness. Independent variables studied included race, age, gender, education, BMI, pack-years, smoking status, age at smoking initiation, asthma, previous work in dusty job, CT scanner and center of recruitment.
  
  
  RESULTS
  Of the 1,063 subjects with GOLD Stage II-IV COPD, 200 self-reported as AA. AAs had a lower mean% emphysema (13.1% vs. 16.1%, p = 0.005) than NHW and proportionately less emphysema in the lower lung zones. After adjustment for covariates, there was no statistical difference by race in air trapping or airway wall thickness. Measured QCT parameters were more predictive of poor functional status in NHWs compared to AAs.
  
  
  CONCLUSIONS
  AAs have less emphysema than NHWs but the same degree of airway disease. Additional factors not easily assessed by current QCT techniques may account for the poor functional status in AAs.
authors: Johns Hopkins University, Baltimore, Maryland, USA. nhansel1@jhmi.edu
authors: Nadia N
authors: NN
authors: Hansel
authors: George R
authors: GR
authors: Washko
authors: Marilyn G
authors: MG
authors: Foreman
authors: MeiLan K
authors: MK
authors: Han
authors: Eric A
authors: EA
authors: Hoffman
authors: Dawn L
authors: DL
authors: DeMeo
authors: R Graham
authors: RG
authors: Barr
authors: Edwin J R
authors: EJ
authors: Van Beek
authors: Ella A
authors: EA
authors: Kazerooni
authors: Robert A
authors: RA
authors: Wise
authors: Robert H
authors: RH
authors: Brown
authors: Jennifer
authors: J
authors: Black-Shinn
authors: John E
authors: JE
authors: Hokanson
authors: Nicola A
authors: NA
authors: Hanania
authors: Barry
authors: B
authors: Make
authors: Edwin K
authors: EK
authors: Silverman
authors: James D
authors: JD
authors: Crapo
authors: Mark T
authors: MT
authors: Dransfield
mesh_terms: D001741:Black or African American; D000368:Aged; D056151:Airway Remodeling; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010641:Phenotype; D029424:Pulmonary Disease, Chronic Obstructive / Q000000981:diagnostic imaging / Q000208:ethnology* / Q000503:physiopathology; D011656:Pulmonary Emphysema / Q000000981:diagnostic imaging / Q000208:ethnology*; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed; D044465:White People