Effects of in utero and childhood tobacco smoke exposure and β2-adrenergic receptor genotype on childhood asthma and wheezing

Department of Preventive Medicine, Keck School of Medicine, University of Southern California, 1540 Alcazar St, CHP 236, Los Angeles, CA 90033, USA.
PEDIATRICS (Impact Factor: 5.3). 08/2008; 122(1):e107-14. DOI: 10.1542/peds.2007-3370
Source: PubMed

ABSTRACT Associations between single-nucleotide polymorphisms in the beta2-adrenergic receptor gene and asthma and wheeze have been inconsistent. Recent studies indicated that tobacco smoke affects beta2-adrenergic receptor gene expression and associations of beta2-adrenergic receptor gene variants with asthma in adults. We aimed to investigate the joint effects of in utero and childhood secondhand tobacco smoke exposure and 2 well-characterized functional single-nucleotide polymorphisms (Arg16Gly and Glu27Gln) of beta2-adrenergic receptor gene on asthma and wheezing in 3128 non-Hispanic and Hispanic white children of the Children's Health Study.
We fitted logistic regression models to estimate odds ratios and 95% confidence intervals for the independent and joint effects of these single-nucleotide polymorphisms and in utero and secondhand tobacco smoke exposure on asthma and wheeze outcomes.
Exposures to in utero maternal smoking and secondhand tobacco smoke were associated with wheezing. Children who were homozygous for the Arg16 allele and were exposed to maternal smoking in utero were at a threefold increased risk for lifetime wheeze compared with children who were unexposed and had at least 1 Gly16 allele. We found similar joint effects of secondhand tobacco smoke and Arg16Gly with wheezing. The risk for lifetime, current, and nocturnal wheeze increased with the number of smokers at home among Arg16 homozygous children. The results were consistent in 2 cohorts of children recruited in 1993 and 1996. Diplotype-based analyses were consistent with the single-nucleotide polymorphism-specific results. No associations were found for Glu27Gln.
Both in utero and childhood exposure to tobacco smoke were associated with an increased risk for wheeze in children, and the risks were greater for children with the Arg16Arg genotype or 2 copies of the Arg16-Gln27 diplotype. Exposures to smoking need to be taken into account when evaluating the effects of beta2-adrenergic receptor gene variants on respiratory health outcomes.

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Available from: Muhammad T Salam, Dec 25, 2013
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    • "It has been shown that polymorphisms in this gene interact with environmental tobacco smoke in children (Wang et al. 2008; Zhang et al. 2007) and cigarette smoke in adults (Joos et al. 2003; Litonjua et al. 2004; Wang et al. 2001). However, a previous study evaluating the combined effects of air pollutants and ADRB2 in children did not report significant findings (Melén et al. 2008). "
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    ABSTRACT: Copyright (C) 2011 by the American Thoracic Society.
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