eNOS and ACE genes influence peripheral arterial disease predisposition in smokers.

OBJECTIVE: Several biologic mediators and genetic predisposing factors may contribute to the development of peripheral arterial disease (PAD). The eNOS gene, encoding for endothelial nitric oxide synthase, has been proposed as a candidate gene in the predisposition to the disease. In this study, we evaluated the role of eNOS-786T>C, -894G>T and 4a/4b polymorphisms as markers of PAD per se and in the presence of the ACE D allele in patients previously investigated. METHODS: We analyzed 281 consecutive patients (220 men, 61 women; median age, 72 years) with PAD and 562 healthy controls, comparable for sex and age. RESULTS: eNOS-786C, but not -894T and 4a, allele frequency was significantly higher in PAD patients than in controls (P = .03). An association with the predisposition to PAD was found for the eNOS-786C allele (odds ratio [OR], 1.52; 95% confidence interval [CI], 1.11-2.09; P = .009) and the eNOS -786C/4a haplotype (OR, 1.41; 95% CI, 1.02-1.94, P = .04) at univariate analysis but not after adjustment for traditional risk factors. When smoking habit was considered, we observed that eNOS-786C/4a haplotype, but not the eNOS-786C allele, influenced PAD predisposition after adjustment for traditional risk factors in smokers (OR, 2.71; 95% CI, 1.38-5.30; P = .004). The eNOS-786C and eNOS-786C/4a haplotype did not modify the susceptibility to PAD in patients carrying the ACE D allele. Nevertheless, the presence of the eNOS-786C/4a haplotype increased PAD predisposition in smokers also carrying ACE D allele (OR, 2.71 to 3.79; P > .05 for interaction). CONCLUSIONS: This study demonstrated an association between eNOS and ACE genes in increasing PAD susceptibility in smokers, thus providing evidence for a gene-environment interaction in modulating predisposition to the disease.