title: African ancestry, early life exposures, and respiratory morbidity in early childhood.
abstract: BACKGROUND
  Racial disparities persist in early childhood wheezing and cannot be completely explained by known risk factors.
  
  
  OBJECTIVE
  To evaluate the associations of genetic ancestry and self-identified race with early childhood recurrent wheezing, accounting for socio-economic status (SES) and early life exposures.
  
  
  METHODS
  We studied 1034 children in an urban, multi-racial, prospective birth cohort. Multivariate logistic regression was used to evaluate the association of genetic ancestry as opposed to self-identified race with recurrent wheezing (>3 episodes). Sequential models accounted for demographic, socio-economic factors and early life risk factors. Genetic ancestry, estimated using 150 ancestry informative markers, was expressed in deciles.
  
  
  RESULTS
  Approximately 6.1% of subjects (mean age 3.1 years) experienced recurrent wheezing. After accounting for SES and demographic factors, African ancestry (OR: 1.16, 95% CI: 1.02-1.31) was significantly associated with recurrent wheezing. By self-reported race, hispanic subjects had a borderline decrease in risk of wheeze compared with African Americans (OR: 0.44, 95% CI: 0.19-1.00), whereas white subjects (OR: 0.46, 95% CI: 0.14-1.57) did not have. After further adjustment for known confounders and early life exposures, both African (OR: 1.19, 95% CI: 1.05-1.34) and European ancestry (OR: 0.84, 95% CI: 0.74-0.94) retained a significant association with recurrent wheezing, as compared with self-identified race (OR(whites) : 0.31, 95% CI: 0.09-1.14; OR(hispanic) : 0.47, 95% CI: 0.20-1.08). There were no significant interactions between ancestry and early life factors on recurrent wheezing.
  
  
  CONCLUSIONS
  In contrast to self-identified race, African ancestry remained a significant, independent predictor of early childhood wheezing after accounting for early life and other known risk factors associated with lung function changes and asthma. Genetic ancestry may be a powerful way to evaluate wheezing disparities and a proxy for differentially distributed genetic and early life risk factors associated with childhood recurrent wheezing.
authors.affiliation: Division of Allergy and Immunology, Children's Memorial Hospital, Chicago, IL 60614, USA. rkumar@childrensmemorial.org
authors.forename: R
authors.initials: R
authors.lastname: Kumar
authors.forename: H-J
authors.initials: HJ
authors.lastname: Tsai
authors.forename: X
authors.initials: X
authors.lastname: Hong
authors.forename: C
authors.initials: C
authors.lastname: Gignoux
authors.forename: C
authors.initials: C
authors.lastname: Pearson
authors.forename: K
authors.initials: K
authors.lastname: Ortiz
authors.forename: M
authors.initials: M
authors.lastname: Fu
authors.forename: J A
authors.initials: JA
authors.lastname: Pongracic
authors.forename: E G
authors.initials: EG
authors.lastname: Burchard
authors.forename: H
authors.initials: H
authors.lastname: Bauchner
authors.forename: X
authors.initials: X
authors.lastname: Wang
mesh_terms: D001741:Black or African American / Q000235:genetics*; D001900:Boston / Q000453:epidemiology / Q000208:ethnology; D002648:Child; D002675:Child, Preschool; D004781:Environmental Exposure / Q000009:adverse effects*; D005260:Female; D005819:Genetic Markers; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D011446:Prospective Studies; D012135:Respiratory Sounds / Q000235:genetics* / Q000276:immunology*; D012307:Risk Factors; D012923:Social Class; D044465:White People / Q000235:genetics
chemical_list: D005819:Genetic Markers
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