Vitamin D receptor genetic polymorphisms and the risk of urolithiasis: a meta-analysis.

OBJECTIVE Genetic variants of vitamin D receptor (VDR) were implicated in urolithiasis susceptibility in several case-control studies. However, these studies so far have provided conflicting results. In order to investigate the potential relationship, a meta-analysis was conducted. METHODS Eligible studies were retrieved via both computerized searches and review of references. The relation of VDR polymorphisms to urolithiasis was quantified on ApaI, BsmI, FokI and TaqI separately. Stratified analyses on regional characteristics and stone composition were also performed. Estimates of OR with 95% CI were summarized using the fixed- or random-effect models as appropriate. RESULTS A total of 17 studies were included in our analysis. There was no evidence showing significant associations between ApaI and BsmI polymorphisms and urolithiasis risk in overall estimates. However, f allele and ff+Ff genotype in the dominant model of FokI were related with an increase of urolithiasis risk. TaqI also presented with increased urolithiasis risk with t allele and tt+Tt genotype in the dominant model. CONCLUSION Our meta-analysis indicated VDR polymorphisms could be potential biomarkers for urolithiasis susceptibility.