Risk association between the NF-κB1 -94ins/delATTG promoter polymorphism and inflammatory bowel diseases: a meta-analysis.

BACKGROUND: Extensive investigation of the NF-κB1 -94ins/delATTG promoter polymorphism for risk association with ulcerative colitis (UC) and Crohn's disease (CD) risk has yielded conflicting results. AIMS: The objective of this meta-analysis was to evaluate the risk association between the NF-κB1 -94ins/delATTG promoter polymorphism and UC and CD. METHODS: All eligible case-control studies of the association of NF-κB1 -94ins/delATTG promoter polymorphism with UC and CD were identified in the Pubmed and Embase databases. From these data, odds ratios (OR) with 95 % confidence intervals (CI) were calculated. Meta-analysis was performed for alleles (D vs. W) and genotypes (DD + WD vs. WW, DD vs. WW + WD, DD vs. WW, WD vs. WW) in a fixed/random effects model. RESULTS: Nine case-control studies that included 4,447 cases (2,631 UC and 1,816 CD) and 2,195 controls were identified. Results indicated increased risk association of D allele carriers with UC (D vs. W: OR = 1.08, 95 % CI = 1.01-1.17, P = 0.03; DD vs. WW + WD: OR = 1.16, 95 % CI = 1.01-1.32, P = 0.04 and DD vs. WW: OR = 1.20, 95 % CI = 1.03-1.39, P = 0.02). No risk association was identified with CD. CONCLUSION: This meta-analysis indicated that the NF-κB1 -94ins/delATTG promoter polymorphism is a risk factor for UC but not CD.