PONI and its association with oxidative stress in type I and type II diabetes mellitus

Paraoxonase (PON) is an antioxidant enzyme linked with cardiovascular disease (CVD), diabetes as it prevents LDL oxidation. The relation of PON with the other established risk factor of diabetic complications has not been looked into.

370 subjects were included in the study. Dividing into four group, i.e. group I included type II DM (n=220), group II was age matched control (n=100), group III were type I DM (n=25) and group IV (n=25) were age matched control group. The protocol of the study was approved by the ethical committee of the institute. SOD, GSH, PON (paraoxonase and arylesterase activity), GHb, and MDA were estimated.

A highly significant decrease in paraoxonase and arylesterase activity was seen in the type II DM (p<0.0001) while in type I DM both the activity was not significant (p>0.05). Paraoxonase and arylesterase activity of PONI showed a negative significant correlated with MDA (r=-0.51, p<0.0001 and r=-0.23, p<0.001) in type II DM but was not correlated in type I DM. The GHb and MDA levels were significantly increased (p<0.0001) while the levels of SOD and GSH have been decreased in type I and type II DM.

PONI is definitely associated with development of the complications of diabetes. This may be due to the role of it as an antioxidant. As it also show a negative correlation with MDA like the other antioxidants studied.