The Evaluation of Serum Paraoxanase Activity and Malondialdehyde Levels in Type 2 Diabetic Patients with Retinopathy

Purpose: In the present study, we aimed to evaluate paraoxonasel (PON1) activities and malondialdehyde (MDA) levels, one of the end products of lipid peroxidation induced by reactive oxygen species in diabetic patients with retinopathy. Material and Methods: Serum MDA levels and PON1 levels were measured spectrophotometrically in 57 diabetic patients with retinopathy and in 24 healthy subjects which constituted the control group. Results: In the DM group, mean serum basal PON1, stimulated PON 1 and MDA levels are detected as 151.72 +/- 76.26 U/L, 329.86 +/- 234.05 U/L and 3.79 +/- 2.11 nmol/mL, respectively. In the control group, mean serum basal PON1, stimulated PON 1 and MDA levels are detected as 272.69 +/- 104.44 U/L, 554.29 +/- 214.58 U/L and 1.12 +/- 0.29 nmol/mL, respectively. When compared to healthy controls, there was a statistically significant decrease in serum basal PON1, stimulated PON 1 levels (p <0.001) and a significant increase in serum MDA levels (p <0.001) in diabetic patients. Conclusion: Increased oxidative stress caused by hyperglycemia results in a decrease in PON activities, therefore, PON might be used as a marker in the management of glycemic control and the development of complications.