gms | German Medical Science

Objectives: Serum paraoxonase (PON1) is an esterase involved in atherosclerotic events. This study was designed to analyze PON1 192 Q/R polymorphism and the enzyme activities in ischemic stroke. The polymorphism as the most common polymorphism in PON1 gene coding sequence is associated with variation in the enzyme activity and vascular disease.

Methods: One hundred and fifty-six subjects including 85 stroke patients and 71 controls were enrolled. PON1 192 polymorphism was genotyped using PCR protocol and restriction digestion. Paraoxonase activity (Para) and arylesterase activity (Aryl) were determined spectrophotometrically using paraoxon and phenylacetate as the substrates.

Results: The QR and RR genotypes were more frequent in stroke population compared to controls, resulting in a higher frequency of the R allele in patients (0.24 vs. 0.18, OR=1.41). Patients had significantly higher Para/Aryl ratio than that of controls (p=0.016). Hypertension significantly increased the risk of stroke by 15-fold among R-containing people, while this was significantly increased 4-fold for QQ homozygotes. In individuals with RR genotype, ratios of Para/Aryl, Para/HDL and Aryl/HDL were found to be higher in strokes compared with controls.

Conclusions: These data highlight the importance of PON1 192 R allele and high Para/Aryl ratio in susceptibility to ischemic stroke in the population. Individuals with RR genotype were associated with an almost doubled susceptibility to stroke. According to 192 Q/R genotypes, among the traditional risk factors, hypertension revealed the greatest interaction with ischemic stroke. The presence of the 192 R allele increases the risk of stoke especially in hypertensive individuals.