Coronary artery disease (CAD), the leading cause of death worldwide, is a multifactorial disease arising from the complex interplay of genetic and environmental factors. Paraoxonase 1 (PON1) polymorphisms have been implicated as risk factors for CAD, but the results of genetic association studies on the related phenotype of CAD are inconclusive. The aim of the present study was to investigate the association between the PON1 promoter –108 C>T (rs705381) and the coding region Gln192Arg (Q192R, rs662) and Leu55Met (L55M, rs854560) variants with myocardial infarction (MI) in a sample of the Tunisian population.

A total of 382 unrelated MI patients and 380 healthy controls were enrolled in this study. Genotyping was performed by the polymerase chain reaction and restriction fragment length polymorphism method (PCRRFLP). The frequencies of the alleles and genotypes between MI patients and controls were compared by the chi-square test.

Genotype distribution and allele frequencies of L55M were similar among the control and MI groups. The PON1-Q192R and –108 C>T genotypes exhibited significant differences in allele and genotype frequencies among the MI and control groups. At PON1-192 locus, there were significant differences between patients and controls (p<0.05), leading to significant odds ratios for RR genotype (OR=1.89, CI: 1.21 – 2.94) and R allele (OR=1.37, CI: 1.11 – 1.69). Binary logistic regression analysis also confirmed that RR genotypes have a higher risk of MI (OR=1.75, CI: 1.03 – 2.98). The T allele of –108C>T polymorphism was found to be a risk marker for MI (OR=1.29, CI: 1.05 – 1.58; p=0.011).

The present study showed a significant and independent association between the PON1 Q192R and – 108 C>T polymorphisms and MI in the Tunisian male population.