The endothelial nitric oxide synthase gene is associated with coronary artery disease: a meta-analysis.

INTRODUCTION

Previous case-control studies have suggested that the endothelial nitric oxide synthase (eNOS) gene polymorphisms (G894T, 4b/a, T-786C) are associated with coronary artery disease (CAD). However, other studies do not confirm these relationships. The objective was to assess these relationships using meta-analysis.

METHODS

Databases, including Pubmed and Embase, were searched to access the relevant genetic association studies up to July 2009.

RESULTS

The meta-analysis included 56 studies, consisting of 23 studies for G894T, 19 for 4b/a and 14 for T-786C. For the allelic analysis of the G894T variant, all studies showed a positively significant association (OR = 0.83, p = 0.004). For the genotypic analysis, the combined studies of the T allele showed significance (OR = 1.57, p = 0.003). For the allelic analysis of the T-786C variant, all studies showed an obviously significant association (OR = 0.79, p = 0.0007), reflected in both non-Asian and Asian studies. For the genotype analysis, combined studies of the C allele showed significance (OR = 0.72, p = 0.0001). Moreover, non-Asian studies showed significant results. For the analysis of the 4b/a variant, none of the studies showed significant results. No publication bias was found in the meta-analysis.

CONCLUSION

The synthesis of available evidence supports the fact that eNOS G894T andT-786C are associated with CAD.