Differences in allergic sensitization by self-reported race and genetic ancestry.
BACKGROUND
Many allergic conditions occur more frequently in African American patients when compared with white patients; however, it is not known whether this represents genetic predisposition or disparate environmental exposures.


OBJECTIVE
We sought to assess the relationship of self-reported race and genetic ancestry to allergic sensitization.


METHODS
We included 601 women enrolled in a population-based cohort study whose self-reported race was African American or white. Genetic ancestry was estimated by using markers that differentiate West African and European ancestry. We assessed the relationship between allergic sensitization (defined as > or =1 allergen-specific IgE results) and both self-reported race and genetic ancestry. Regression models adjusted for sociodemographic variables, environmental exposures, and location of residence.


RESULTS
The average proportion of West African ancestry in African American participants was 0.69, whereas the mean proportion of European ancestry in white participants was 0.79. Self-reported African American race was associated with allergic sensitization when compared with those who reported being white (adjusted odds ratio, 2.19; 95% CI, 1.22-3.93), even after adjusting for other variables. Genetic ancestry was not significantly associated with allergic sensitization after accounting for location of residence (adjusted odds ratio, 2.09 for urban vs suburban residence; 95% CI, 1.32-3.31).


CONCLUSIONS
Self-reported race and location of residence appeared to be more important predictors of allergic sensitization when compared with genetic ancestry, suggesting that the disparity in allergic sensitization by race might be primarily a result of environmental factors rather than genetic differences.
Yang
James J
JJ
Department of Biostatistics and Research Epidemiology, Henry Ford Health System, Detroit, Mich.
Burchard
Esteban G
EG
Department of Medicine, University of California San Francisco, San Francisco, Calif; Department of Biopharmaceutical Sciences, University of California San Francisco, San Francisco, Calif.
Choudhry
Shweta
S
Department of Medicine, University of California San Francisco, San Francisco, Calif.
Johnson
Christine C
CC
Department of Biostatistics and Research Epidemiology, Henry Ford Health System, Detroit, Mich.
Ownby
Dennis R
DR
Department of Pediatrics, Medical College of Georgia, Augusta, Ga.
Favro
David
D
Center for Health Services Research, Henry Ford Health System, Detroit, Mich.
Chen
Justin
J
Cardiovascular Research Institute, University of California San Francisco, San Francisco, Calif.
Akana
Matthew
M
Cardiovascular Research Institute, University of California San Francisco, San Francisco, Calif.
Ha
Connie
C
Cardiovascular Research Institute, University of California San Francisco, San Francisco, Calif.
Kwok
Pui-Yan
PY
Cardiovascular Research Institute, University of California San Francisco, San Francisco, Calif.
Krajenta
Richard
R
Department of Biostatistics and Research Epidemiology, Henry Ford Health System, Detroit, Mich.
Havstad
Suzanne L
SL
Department of Biostatistics and Research Epidemiology, Henry Ford Health System, Detroit, Mich.
Joseph
Christine L
CL
Department of Biostatistics and Research Epidemiology, Henry Ford Health System, Detroit, Mich.
Seibold
Max A
MA
Department of Medicine, University of California San Francisco, San Francisco, Calif; Department of Biopharmaceutical Sciences, University of California San Francisco, San Francisco, Calif.
Shriver
Mark D
MD
Department of Anthropology, Pennsylvania State University, University Park, Pa.
Williams
L Keoki
LK
Department of Biostatistics and Research Epidemiology, Henry Ford Health System, Detroit, Mich; Center for Health Services Research, Henry Ford Health System, Detroit, Mich; Department of Medicine, Henry Ford Health System, Detroit, Mich. Electronic address: kwillia5@hfhs.org.
D000328:Adult; D001741:Black or African American; D000485:Allergens; D002675:Child, Preschool; D015331:Cohort Studies; D004781:Environmental Exposure; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000208:ethnology* / Q000235:genetics* / Q000276:immunology; D007073:Immunoglobulin E / Q000276:immunology; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008824:Michigan / Q000208:ethnology; D011247:Pregnancy; D012959:Socioeconomic Factors; D013383:Suburban Population; D014505:Urban Population; D044465:White People
D000485:Allergens; D007073:Immunoglobulin E