Associations between eNOS polymorphisms and susceptibility to Behcet's disease: A meta-analysis

Objective To determine whether endothelial nitric oxide synthase (eNOS) polymorphisms confer susceptibility to Behcet's disease (BD). Methods A meta-analysis was conducted on the associations between the G894T and 4b/a polymorphisms of eNOS and BD using: (i) the allele contrast, (ii) the recessive model, (iii) the dominant model and (iv) the additive model. Results A total of eight studies, which included 841 cases and 866 controls, were included in the meta-analysis. Meta-analysis of the G894T polymorphism revealed no association with BD in all study subjects or in Turkish and Asian populations. However, one Tunisian study of the T allele showed a significant association with BD (OR = 0.707, 95% CI = 0.510-0.980, P = 0.038), but the OR of the T allele among Tunisians was lower, whereas it was higher in Europeans (OR = 2.129, 95% CI = 1.407-3.220, P = 0.0003). Meta-analysis showed no association between BD and the 4b/a polymorphism in all study subjects. Stratification by ethnicity indicated no significant association between the a allele of the 4b/a polymorphism and BD in Turkish and Asian populations. Conclusions This meta-analysis shows that the eNOS G894T and the 4b/a polymorphisms are not associated with BD in the Turkish and Asian populations. These data suggest that the G894T and the 4b/a polymorphisms may not confer susceptibility to BD in the Turkish and Asian populations.