Association between Arg16Gly Polymorphism in the <i>Β<sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"></i>-Adrenergic Receptor Gene and Obesity Risk in Patients with Bronchial Asthma

The objective of our study was to investigate the association between the Arg16Gly polymorphism in the β2-АR gene and body mass index (BMI) in patients with bronchial asthma (BA) with regard to the age of onset. Materials and methods: 553 patients were examined. The control group consisted of 95 apparently healthy individuals. The patients were divided into 2 groups depending on the age of BA onset: 282 patients with late onset (Group I) and 271 patients with early onset (Group II). Arg16Gly polymorphism in the β2-АR gene (rs1042713) was determined using polymerase chain reaction- restriction fragment length polymorphism analysis. Statistical analysis of obtained results was performed using SPSS–17 program. Results: There was no significant difference in the distribution of genotypes for Arg16Gly polymorphism in the β2-AR gene depending on BMI (χ2 = 5.74;р = 0.22), and no association was found with obesity risks disregarding the age of BA onset. The study on the frequency of genotypes for this polymorphism with regard to the age of asthma onset and BMI found statistically significant differences between early-onset (χ2 = 11.27;p = 0.02) and late-onset (χ2 = 10.66;p = 0.03) asthma. It was found that the risk of obesity in Group I patients was 1.57 times higher in the additive model and 2.67 times higher—in the recessive model of inheritance. In patients with late-onset asthma, Gly16 allele in the recessive model of inheritance was found to have a protective role against obesity. Conclusions: There was no significant difference in the distribution of genotypes for Arg16Gly polymorphism in the β2-AR gene with regard to BMI, and no association was found with obesity risks in BA patients disregarding the age of BA onset. The risk of obesity in patients with early-onset asthma was 1.6 times higher in the additive model and 2.7 times higher—in the recessive model of inheritance.