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A1425 - The Indoor Environment and Bronchodilator Response in Urban Minority Youth: The Study of African -Americans, Asthma, Genes, and Environments (SAGE-II)
Author Block: T. Elliott1, E. Burchard2, K. Meade3, A. M. Davis3, E. Brigino-Buenaventura4, L. N. Borrell5, M. Lenoir6; 1Pulmonary and Critical Care Medicine, University of California, San Francisco, San Francisco, CA, United States, 2University of California, San Francisco, San Francisco, CA, United States, 3Children's Hospital and Research Center Oakland, Oakland, CA, United States, 4Kaiser Permanente Vallejo Medical Center, Vallejo, CA, United States, 5Graduate School of Public Health Lehman College, Bronx, NY, United States, 6Bay Area Pediatrics, Oakland, CA, United States.
RATIONALE
Approximately 9% of US children have asthma; there is a disproportionate disease burden borne by minority children. African American children with asthma have greater asthma severity, greater health care use, and mortality compared to their European American counterparts. Albuterol is the first-line treatment for asthma, regardless of severity, worldwide. Bronchodilator response (BDR) is the quantification of albuterol drug response and is defined as a change in forced expiratory volume in one second (FEV1) ≥ 12% after drug administration. BDR has been shown to vary between racial/ethnic populations; specifically, African American children display decreased BDR compared to European American children. The disparity in asthma morbidity and mortality may be explained, in part, by this disparity. BDR is a complex phenotype that is likely affected by several genetic and environmental factors. Previous studies have shown that inner city children with asthma who are sensitized and exposed to multiple indoor allergens have increased asthma morbidity. The impact of indoor allergen exposure on variation in BDR has yet to be fully defined. Defining the relationship between exposure to indoor allergens and BDR in African American children with asthma is essential to improving patient care in this “at risk” population.
METHODS
We evaluated the impact of early-life exposure to several indoor allergens (pet dander, mold, cockroaches, etc.) on BDR (responders vs non-responders) using logistic regression in 871 African American children with asthma. BDR response was defined according to ATS criteria for clinical response to albuterol. Allergen exposure information was obtained from questionnaires administered to the parents of the participants to collect demographic, medical histories, and environmental exposure-related information. Regression models were adjusted for age, sex, and composite socioeconomic status (SES).
RESULTS
Logistic regression was utilized to assess the association between indoor allergen exposure, asthma, and BDR. Preliminary results indicate a suggestive association between exposure to dog dander and variation in BDR in African American children with asthma with a positive BDR (p=0.06). This trend was not seen between BDR and exposure to cats, birds, mold, or cockroaches.
CONCLUSION
Early- life exposures to indoor allergens may represent a modifiable risk factor affecting BDR in children with asthma. Our results indicate that exposure to these modifiable risk factors results in a variable BDR. Our study warrants validation in a larger population of African American children with asthma. Future directions include an investigation to identify susceptibility loci for BDR based on exposures using a genome-wide association study.