A meta-analysis: association between Beta-2 adrenergic receptor Arg16Gly polymorphism and asthma in China
Asthma is a kind of allergic disease of the respiratory tract, and has become a global public health problem in recent years (To et al., 2012). The prevalence of asthma is 0.2-21.0% wordwide, which is still increased, especially in developing countries such as China (To et al., 2012; Pearce et al., 2007; Yangzong et al., 2012). So far, numerous reports demonstrated that multiple genetic variations are involved in asthma. Among these genetic variations, the polymorphisms in beta-2 adrenergic receptor (ADRB2) have been most evaluated in asthma. For instance, single nucleotide polymorphisms of ADRB2 in the coding gene region including Arg16Gly (A46G, rs1042713), Gln27Glu (C79G, rs1042714), Thr164Ile (C491T, rs1800888) and Arg19Cys (T-47C, rs1042711) have proven the influence of ADRB2 activation on the small airways, suggesting the effective therapy of ADRB2 agonists in asthma (Pignatti 2004; Gao et al., 2004). Notably, the mutation of the Arg16Gly located at the ADRB2 gene has been extensively examined in studies on ADRB2 polymorphisms in asthma. The potential relationships on ADRB2 Arg16Gly polymorphism and asthma risk among Chinese people being remain conflicting. To our knowledge, it had lower statistical effect on the result than using a meta-analysis while the sample sizes in the individual studies are small. Therefore, this meta-analysis was performed to understand the importance of ADRB2 Arg16Gly polymorphism for asthma risk in Chinese population.