Home dampness, beta-2 adrenergic receptor genetic polymorphisms, and asthma phenotypes in children

BackgroundDampness in the home is a strong risk factor for respiratory symptoms and constitutes a significant public health issue in subtropical areas. However, little is known about the effects of dampness and genetic polymorphisms on asthma.MethodsIn 2007, 6078 schoolchildren were evaluated using a standard questionnaire with regard to information about respiratory symptoms and environmental exposure. Multiple logistic regression analyses were performed to assess the effects of home dampness and beta-2-adrenergic receptor (ADRB2) gene polymorphisms on the prevalence of asthma and selected indicators of severity of asthma.ResultsThe frequency of mildewy odor, the number of walls with water stamp, and the duration of water damage were all associated with being awakened at night due to wheezing. However, no other clear-cut associations were found for any of the other indicators of asthma. Children exposed to mildewy odor with ADRB2 Arg/Arg genotype were associated with being awakened at night due to wheezing (OR=1.95, 95% CI, 1.14–3.36), compared to those without exposure and with the ADRB2 Gly allele. ADRB2 Arg16Gly showed a significant interactive effect with home dampness on being awakened at night due to wheezing and current wheezing, but no significant effect on active asthma and medication use. Frequency and degree of home dampness were also associated with the prevalence of asthma and selected indicators of severity of asthma, in an exposure–response manner among children with ADRB2 Arg/Arg genotype.ConclusionsHome dampness prevention is one of the important steps of asthma control, especially in children carrying ADRB2 Arg/Arg genotypes.

► We study the effect of home dampness and beta-2 adrenergic receptor polymorphisms on asthma phenotypes.
► Exposure to home dampness may increase the risk of asthma phenotypes in children.
► Beta-2 adrenergic receptor Arg/Arg genotype showed an interactive effect with home dampness on wheezing.
► Dampness prevention is important for asthma control in susceptible individuals.