No association between IL-1β -31 C/T polymorphism and the risk of duodenal ulcer: a meta-analysis of 3793 subjects.

The aim of this study was to perform a meta-analysis to investigate a more authentic association between IL-1β -31 C/T polymorphism and duodenal ulcer (DU). Systematic searches of electronic databases Embase, PubMed and Web of Science were performed. Study selection, data abstraction and study quality evaluation were independently conducted in duplicate. Statistical analyses were conducted using software Stata 11.0. The pooled odds ratios (ORs) with 95% confidence intervals (95%CIs) were applied. Publication bias was tested by Begg's funnel plot and Egger's regression test. A total of 12 studies including 1151 cases and 2642 controls were included in our final meta-analysis. There was no evidence of significant association between IL-1β -31 C/T polymorphism and DU (allelic model: OR=0.96, 95%CI=0.86-1.07; additive model: OR=0.85, 95%CI=0.67-1.07; dominant model: OR=0.95, 95%CI=0.81-1.13; and recessive model: OR=0.95, 95%CI=0.79-1.15). Significant association was found in additive model for PB subgroup (OR=0.65, 95%CI=0.44-0.96) and recessive model for non-Asian subgroup (OR=0.72, 95%CI=0.52-0.99). In conclusion, our meta-analysis suggested that there was no evidence of significant association between IL-1β -31 C/T polymorphism and DU with or without Helicobacter pylori infection in overall population, whereas significant association was found by subgroup analyses which showed protective effect of C/C genotype against DU risk.