Paraoxonasel activity and paraoxonase 192 gene polymorphism in non insulin dependent diabetes mellitus patients among Egyptian population

Abstract EN

Background / Aim : Paraoxonasel (PON1) is an esterase enzyme that has antioxidant activity and is tightly associated with high density lipoprotein (HDL) in blood.

Decreased activity of PONl was reported in many diseases and could be partially attributed to PON1 glutamine 192 arginine polymorphism.

In the present work we studied the effect of PON1192 polymorphism on serum PON1 activity and lipid profiles in 30 non-insulin dependent diabetes mellitus (NIDDM) subjects and 30 healthy controls among the Egyptian population.

Subjects & ethos : polymerase chain reaction-based restriction fragment was used to determine PON1 192 gene polymorphism.

Fasting blood glucose, serum lipids, lipid peroxidation (malondialdehyde - MDA) and PON1 activity were measured by spectrophotometric method.

Insulin serum levels were measured by ELISA technique and (HOMA) index was calculated as an index for presence insulin resistance.

Results : No significant difference was found in the distribution of PON1 192 genotypes (QQ, RR and QR) between patient and control groups.

Also, the R allele was insignificantly predominant among diabetic patients.

PON1 enzyme activity was significantly lower in diabetics than in control subjects.

PON1 192 RR homozygote had significantly lower PON1 activity and HDL-C level than QQ and QR genotypes among the NIDDM populations (p < 0.001).

Total cholesterol, triglycerides, LDL-C serum level were significantly higher in patients than controls.

Fasting serum insulin level and HOMA index were significantly increased in those patients compared to controls.

This indicated the development of insulin resistance which could be attributed to the decrease of peroxidase antioxidant activity.

Conclusion : the present results suggest that the paraoxonasel activities are affected by PON1 genetic variability in NIDDM patients and may precipitate to insulin resistance among those patients.