Racial disparities persist in early childhood wheezing and cannot be completely explained by known risk factors.
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.
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.
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 (ORwhites: 0.31, 95% CI: 0.09–1.14; ORhispanic: 0.47, 95% CI: 0.20–1.08). There were no significant interactions between ancestry and early life factors on recurrent wheezing.
Conclusions and Clinical Relevance
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.