Abstract
Background: Diabetic nephropathy (DN) is currently the leading cause of end-stage renal disease globally. Oxidative stress which is classically defined as an event resulting from the magnitude of imbalance between oxidant and antioxidant substances, generated in a setting of oxidation-reduction reactions, and is hypothesized to play a role in the development of diabetic nephropathy.

Aim and Objectives: The aim of the study was to assess lipid peroxidation by estimating serum malondialdehyde (MDA) and antioxidant status by assaying paraoxonase-1 (PON-1) in diabetes patients with nephropathy and healthy controls. Furthermore, the study aimed the correlation between MDA and PON-1 levels in patients with diabetic nephropathy.

Materials and Methods: A cross-sectional comparative study was conducted in 152 participants, which were divided into two groups as control (n = 76) non-diabetic, healthy, age-, and sex-matched individuals and diabetic patients with nephropathy(n = 76). The study was conducted in Government Medical College, Kozhikode. All the subjects who satisfied the inclusion and exclusion criteria and who gave informed consent were included in a consecutive manner till sample size is achieved. Serum MDA and PON-1 were estimated using spectrophotometry. The data were analyzed using statistical package for the social sciences (SPSS) version 18.

Results: Oxidative stress was increased in diabetic nephropathy patients as evidenced by significantly elevated MDA and reduced PON-1 than the normal controls. There was a significant negative correlation of serum MDA with serum PON-1 in patients with diabetic nephropathy.

Conclusion: Oxidative stress is an important pathophysiological process for the development of diabetic nephropathy. This study reveals the importance of screening all diabetes patients for oxidative stress. Dietary management and antioxidant supplementation would help them to prevent development of diabetic nephropathy and related complications, which, in turn, improve their quality of life.

Key words: Oxidative Stress; Malondialdehyde; Paraoxonase 1; Diabetic Nephropathy