Associations Between Vitamin D Receptor Gene Polymorphisms And Asthma:a Meta-analysis

ObjectiveTo evaluate the associations between Apa I (rs7975232, CIA), Fok I (rs2228570, C/T), Tag I (rs731236, T/C) and Bsm I (rsl544410, G/A) of VDR gene polymorphisms and the susceptibility to bronchial asthma.MethodsPubMed (Medline), Web of Knowledge, EMBASE, Cochrane Library, CNKI, VIP Chinese Periodical Database and WanFang Chinese Periodical Database were searched for the case-control studies on the associations of VDR gene polymorphisms with asthma (up to September2013). All articles were strictly evaluated and screened according to inclusion criteria. Sub-group analysis was performed based on the ethnic different. Stata12.0software was applied for investigating the heterogeneity among studies. The pooled odds ratios (ORs) and their95%confidence intervals (CIs) were calculated by either fixed or random effect pooled measure according to the basis of heterogeneity test. ResultsA total of10eligible studies (2161cases and2100controls) were included. For overall population, the significant associations were seen for Apa I polymorphism and asthma in dominant, recessive and allele models (A vs C, OR=0.796,95%CI:0.715-887; AA+CC vs CC, OR=0.736,95%CI:0.625-0.867; AA vs CC+AC, OR=0.769,95%CI:0.642-0.921). Subgroup analyses showed that Apa I polymorphisms were both significantly associated with asthma in Caucasian and Asian population, but not in Africans. For overall population, the significant association was seen for Bsm I polymorphism and asthma in recessive models (AA vs GG+GA, OR=2.07,95%CI:1.27,3.36, P<0.05); For overall population, no significant associations were observed between Fok I, Tag I polymorphisms and asthma. Subgroup analyses showed that Fok I was significantly associated with asthma in Africans (CC+CT vs TT, OR=0.621,95%CI:0.421-0.915).ConclusionThe results suggested that asthma was associated with Apa I and Bsm I polymorphisms in the VDR gene, but not Fok I and Tag I.