Meta-analysis of the urokinase gene 3'-UTR T/C polymorphism and susceptibility to urolithiasis

Urokinase is involved in the processes of initiating urinary stones. Several published case-control studies have examined the relationship of urokinase gene 3' -untranslated region (3'-UTR) T/C polymorphism and urolithiasis, but yielded inconsistent findings. In this study, a comprehensive meta-analysis was conducted by pooling relevant studies to obtain reliable conclusions. Studies focusing on the association between urokinase gene 3' -UTR T/C polymorphism and urolithiasis were retrieved through PubMed, Medline, Web of Science and the China National Knowledge Infrastructure platform without any limit on language, until October 2012. Four independent articles were eventually identified as eligible for the final meta-analysis, involving 1,195 subjects. Crude odds ratios (ORs), as well as 95% confidence intervals (CIs), were assessed for the association by either fixed-or random-effects models using RevMan 5.0 software. Significant associations were noted in the 'TC vs. CC' codominant model for total population (OR=2.53; 95% CI, 1.43-4.46; P=0.001), Asian population (OR=2.46; 95% CI, 1.38-4.40; P=0.002), male (OR=2.98; 95% CI, 1.43-6.21; P=0.004), Hardy-Weinberg equilibrium (HWE) (OR=2.46; 95% CI, 1.38-4.40; P=0.002) and recurrence (OR=2.66; 95% CI, 1.51-4.67; P=0.00). Statistically significant associations were also observed in the 'TT+ TC vs. CC' dominant model for the Asian, male, HWE and recurrence population (P< 0.05). Additionally, a significant difference was detected in the 'T vs. C' allele model for HWE. However, there were no associations in either the 'TT vs. CC' codominant model or 'TT vs. TC+ CC' recessive model. In conclusion, the present meta-analysis suggests that urokinase gene T allele may increase the susceptibility of urolithiasis.