FokI polymorphism of the vitamin D receptor (VDR) gene and susceptibility to tuberculosis: Evidence through a meta-analysis

Background Tuberculosis is one of the top ten causes of deaths worldwide. The deficiency of vitamin D was reported to be associated with the increased susceptibility of tuberculosis. Various previous reports were published to check the association of FokI polymorphism of the vitamin D receptor gene with tuberculosis risk. But their results were inconsistent so, we performed a meta-analysis to know the exact relation of the two. Methods Different databases were screened up to November 2020 with the keywords "Vitamin D receptor", "VDR", and "FokI", along with "Tuberculosis" and "TB" to find the suitable articles. All the statistical analyses were performed by the Open Meta-Analyst program and all p-values were two-tailed with a significance level of 0.05. Results No statistically significant association was observed in the allele contrast model (OR fvs.F = 1.11, 95%CI = 0.99-1.24, p = 0.05, I 2 = 73.46%), in the dominant model (OR ff+Ffvs.FF = 1.11, 95%CI = 0.96-1.28, p = 0.14, I 2 = 71.39%), and in the co-dominant model (OR Ffvs.FF = 1.05, 95%CI = 0.92-1.21, p = 0.41, I 2 = 65.97%). However, a significant association was found in the homozygote model (OR ffvs.FF = 1.32, 95%CI = 1.03-1.69, p = 0.02, I 2 = 67.02%) and in the recessive model (OR FF+Ff vs.ff = 1.26, 95%CI = 1.03-1.54, p = 0.02, I 2 = 58.01%). Further analysis was performed on the bases of the ethnicity. In Asian population a significant association was found in the homozygote model (OR ffvs.FF = 1.57, 95%CI = 1.12-2.21, p = 0.008, I 2 = 70.37%) and in the recessive model (OR FF+Ff vs.ff = 1.43, 95%CI = 1.08-1.89, p = 0.01, I 2 = 63.13%). Conclusion In conclusion, a significant association of FokI with tuberculosis susceptibility was found in the overall analysis and in the Asian population.