Evaluation of Oxidative Stress and Antioxidant Enzyme Activity in Patients with Type 2 Diabetes Mellitus: A Cross-Sectional Study

Abstract

Background: Oxidative stress plays a pivotal role in the pathogenesis and complications of type 2 diabetes mellitus (T2DM). Imbalances between reactive oxygen species (ROS) and antioxidant defense mechanisms such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) contribute to ?-cell dysfunction and insulin resistance.

Objective: To assess oxidative stress markers and the activity of key antioxidant enzymes in T2DM patients compared to healthy controls.

Methods: A cross-sectional study was conducted on 100 subjects (60 T2DM patients and 40 healthy controls). Serum malondialdehyde (MDA) levels were used as a marker of lipid peroxidation, and activities of SOD, CAT, and GPx were measured spectrophotometrically. Group comparisons were done using independent t-test; correlations between glycemic parameters and oxidative stress markers were evaluated using Pearson’s correlation.

Results: MDA levels were significantly elevated in T2DM patients (5.6 ± 1.1 µmol/L) compared to controls (2.9 ± 0.6 µmol/L; p < 0.001). Antioxidant enzymes SOD, CAT, and GPx were significantly reduced in T2DM group (p < 0.001). HbA1c showed a strong positive correlation with MDA (r = 0.52, p < 0.01) and negative correlations with SOD (r = –0.44), CAT (r = –0.41), and GPx (r = –0.38).

Conclusion: Increased oxidative stress and reduced antioxidant defense were observed in T2DM patients. These findings support the role of oxidative stress in diabetic pathophysiology and highlight the importance of antioxidant therapy in diabetes management.

Keywords: Oxidative stress, Antioxidant enzymes, Diabetes mellitus, SOD, GPx, Catalase, MDA