Low serum PON1 activity: An independent risk factor for coronary artery disease in North–West Indian type 2 diabetics

The paraoxonase (PON1) gene polymorphisms are known to affect the PON1 activity and coronary artery disease (CAD) risk. Studies done so far have given conflicting results. In the present study, we determined the role of PON1 genetic variants and PON1 activity in the development of CAD in North–West Indian Punjabis, a distinct ethnic group, having high incidence of both CAD and type 2 diabetes. 300 angiographically proven CAD with type 2 diabetics and 250 type 2 diabetics with no clinically evident CAD were enrolled. Serum PON1 activity and genotyping of coding (Q192R, L55M) and promoter (−909G/C, −162A/G, −108C/T) region polymorphisms were carried out and haplotypes were determined using PHASE software. The serum PON1 activity was significantly lower in CAD with type 2 diabetics as compared to diabetics alone (51.0 vs. 114.2nmol/min/ml). In logistic regression model after adjusting for confounding variables, lower PON1 activity was found to be significantly associated with CAD risk in type 2 diabetics with OR being 16.8 (95% CI: 10.2–27.7). The lower serum PON1 activity, irrespective of genotypes and haplotypes is a risk factor for development of CAD in North–West Indian Punjabis with type 2 diabetics. ► PON1 activity significantly lowers in CADT2DM patients as compared to T2DM. ► Lower PON1 activity significantly associated with CAD risk in T2DM with high OR. ► Irrespective of PON1 polymorphisms lower activity is a risk factor for CAD in T2DM.