The paraoxonase-2-310 polymorphism is associated with the presence of microvascular complications in diabetes mellitus.

OBJECTIVE

To investigate the paraoxonase-2 (PON 2)-C/S 310 polymorphism and its relationship to the presence of diabetic complications and glycaemic control.

DESIGN

Case-control study.

SETTING

One study centre at University hospital.

MATERIALS AND METHODS

The subjects were people with type 2 diabetes (n=252), type 1 diabetes (n=152) and healthy controls (n=282). The PON 2-C/S 310 polymorphism was measured by restriction fragment length polymorphism analysis. Lipids and lipoproteins were measured by standard clinical chemistry methods. Diabetes and diabetic complications were defined by World Health Organization criteria.

RESULTS

There was an over-representation of the C/C 310 genotype in those with diabetes and microvascular complications (type 2 diabetes P=0.043, type 1 diabetes P=0.052, both populations combined P=0.014). The PON 2-C/S 310 polymorphism was also associated with glycaemic control. C 310/C 310 homozygotes had the highest HbA(1c) concentration (P=0.020 type 2 diabetes, P=0.065 type 1 diabetes, P=0.035 both populations combined). There was no association between the PON 2-310 polymorphism and lipid and lipoprotein concentrations.

CONCLUSIONS

PON 2 could be directly involved in protecting critical enzymes or organelles against oxidative damage; PON2 may thus predispose to the development of microvascular complications.