Polymorphisms in the paraoxonase and endothelial nitric oxide synthase genes and the risk of early-onset myocardial infarction.

In young patients, the accumulative burden of traditional cardiovascular risk factors may not be as significant as in an older population. Genetic risk factors were suggested to have a role in the early development of myocardial infarction (MI). However, data about the association between polymorphisms in heart disease-related genes and the early onset of a first MI are limited. In the present study, age at onset of a first MI was related to individual single-nucleotide polymorphisms in each of 18 prespecified candidate genes in a cohort of 814 patients enrolled in the Thrombogenic Factors and Recurrent Coronary Events (THROMBO) Study. Multivariate regression analysis showed in patients who had the high-risk genotypes of paraoxonase 1 (PON1) Q192R and endothelial nitric oxide synthase (eNOS) E298D that ages at onset of a first MI were 1.8 (p = 0.02) and 3.5 years (p = 0.02) earlier than in noncarriers of the genotypes, respectively. Consistently, high-risk genotypes of the PON1 Q192R and eNOS E298D polymorphisms were significantly associated with onset of a first MI at age <50 years (adjusted odds ratio 1.70, p = 0.005, adjusted odds ratio 2.15, p = 0.01, respectively). In conclusion, our findings suggest that high-risk genotypes of the PON1 Q192R and eNOS E298D polymorphisms are independently associated with a significantly earlier occurrence of coronary events.