Meta-analysis of vitamin D receptor gene polymorphisms and benign prostatic hyperplasia risk.

The association between vitamin D receptor (VDR) gene polymorphisms and risk of benign prostatic hyperplasia (BPH) has been investigated in numerous publications, but published results remain inconclusive. Hence, we conducted this meta-analysis to derive a more precise conclusion. Four polymorphisms (Taq-I, Bsm-I, Apa-I, and Fok-I) of the VDR gene with risk of BPH from six case-control studies and one cohort study involving 2,248 individuals were identified from PubMed and China National Knowledge Internet databases up to November 20, 2013 (updated on March 5, 2014). After data extraction, the meta-analysis was performed using Comprehensive Meta-Analysis software. All four VDR polymorphisms were not associated with the risk of BPH [Taq-I: OR 0.61, 95 % CI (0.38-1.24) for tt vs. TT; Bsm-I: OR 1.27, 95 % CI (0.96-1.69) for bb vs. BB; Apa-I: OR 1.26, 95 % CI (0.64-2.46) for aa vs. AA; Fok-I: OR 0.95, 95 % CI (0.60-1.50) for ff vs. FF]. Subgroup analysis according to ethnicity for Taq-I polymorphism also showed that the polymorphism was not associated with risk of BPH for either Caucasians [OR 0.74, 95 % CI (0.31-1.78) for tt vs. TT] or Asians [OR 0.35, 95 % CI (0.11-1.11) for tt vs. TT]. However, results of this meta-analysis should be treated with caution because this meta-analysis has several limitations. We propose to conduct a high-quality study with large sample size to further identify the association between VDR gene polymorphisms and BPH susceptibility.