No association between IL-1β -511 C/T polymorphism and the risk of duodenal ulcer: a meta-analysis of 4667 subjects.

Epidemiological studies have evaluated the association between IL-1β -511 C/T polymorphism and duodenal ulcer (DU) risk. However, the results remain conflicting. The aim of this study was to perform a meta-analysis to investigate a more authentic association between IL-1β -511 C/T polymorphism and DU. Systematic searches of electronic databases Embase, PubMed and Web of Science as well as hand searching of the references of identified articles and the meeting abstracts were performed. Study selection, data abstraction and study quality evaluation were independently conducted in duplicate. Statistical analyses were performed using software Stata 11.0. The pooled odds ratios (ORs) with 95% confidence intervals (95% CIs) were performed. Publication bias was tested by Begg's funnel plot and Egger's regression test. A total of 14 studies including 1887 cases and 2780 controls were included in our final meta-analysis. There was no evidence of significant association between IL-1β -511 C/T polymorphism and DU (for T allele vs. C allele: OR=0.93, 95% CI=0.82-1.06; for T/T vs. C/C: OR=0.83, 95% CI=0.64-1.08; for dominant model: OR=0.93, 95% CI=0.80-1.07; and for recessive model: OR=0.87, 95% CI=0.69-1.11). Significant association was found in all genetic models for the PB subgroup and sensitivity analyses. In conclusion, our meta-analysis suggests that there was no evidence of a significant association between IL-1β -511 C/T polymorphism and DU with or without Helicobacter pylori infection, whereas a significant association was found by sensitivity analyses which showed a protective effect of the T allele against DU risk.