Vitamin D Receptor ApaI (rs7975232) polymorphism confers decreased risk of pulmonary tuberculosis in overall and African population, but not in Asians: Evidence from a meta-analysis

The involvement of the VDR ApaI gene polymorphism in the development of pulmonary tuberculosis (PTB) has been reported by numerous published studies and yielded inconsistent results.The present meta-analysis evaluated the association of VDR ApaI polymorphism and risk of PTB occurrence. Procedures. PubMed (Medline), EMBASE and Google Scholar web-databases were searched and a metaanalysis was performed by calculating the pooled odds ratios (ORs) and 95% confidence intervals (95% CIs). Results.This meta-analysis included a total of 14 eligible studies comprising of 1958 confirmed PTB cases and 2938 controls. We observed decreased risk of PTB in allelic (a vs. A: p = 0.003; OR = 0.873, 95% CI = 0.798 to 0.955), homozygous (aa vs. AA: p = 0.006; OR = 0.761, 95% CI=0.626 to 0.924), dominant (aa+Aa vs. AA: p= 0.039; OR = 0 .874, 95% CI = 0.769 to 0.993) and recessive (aa vs. AA+Aa: p = 0.025; OR = 0.819, 95% CI = 0.688 to 0.975) genetic models. During subgroup analysis, allele (a vs. A: p = 0.005; OR = 0.846, 95% CI = 0.753 to 0.951), homozygous (aa vs. AA: p = 0.002; OR = 0.662, 95% CI = 0.513 to 0.854) and recessive genetic models (aa vs. AA+Aa: p=0.003; OR=0.709, 95% CI = 0.566 to 0.889) demonstrated decreased PTB risk in African population. However, no significant association was observed in Asian population. Conclusion. In conclusion, VDR ApaI polymorphism is significantly associated with decreased risk of PTB for in overall and African population, but not in Asians.