Vitamin D receptor gene polymorphisms and asthma: a meta-analysis

Abstract

Objective To explore the association of vitamin D receptor (VDR) gene polymorphisms with asthma. Methods The published studies both at home and abroad on the association between VDR genes and asthma were collected.Their qualities were evaluated and the related data of the included studies were extracted.The gene analyses were made by means of allele gene model, dominant gene model and recessive gene model, and the pooled odds ratios (OR) and their 95% confidence intervals (95%CI) were calculated.Sub-group analyses for race, age and sex, the heterogeneity analysis, the sensitivity analysis and the evaluation of publication bias were performed. Results A total of 2 823 cases and 3 184 controls from 16 case-control studies were included.The results of the study showed that there was a statistically significant association between Taq Ⅰ gene polymorphism and asthma in dominant model (CC+ CT vs TT, OR=1.23, 95%CI: 1.05-1.44) and allele model (C vs T, OR=1.23, 95%CI: 1.10-1.38). In contrast, no statistical significance was found between Apa Ⅰ, Bsm Ⅰ, Fok Ⅰ gene polymorphism and asthma.Subgroup analysis for Taq Ⅰ gene showed that in the White or Black race, >20 years and male <50% groups C gene carriers could increase the risk of asthma, however no statistically significant association was found in those subgroups of Yellow race, ≤20 years, male≥50% group. Conclusions Taq Ⅰ gene polymorphism has the association with asthma and C gene carriers can increase the risk of asthma, but this effect is modified by race, age and sex. Key words: Asthma; Vitamin D receptor; Meta-analysis; Gene polym orphism