Evaluation of Oxidative Stress and Antioxidant Status in Diabetic Retinopathy Cases

Abstract

CONTEXT: Diabetes is the most rapidly growing chronic metabolic disorder in the world. In diabetes mellitus, the oxidative stress resulting from enhanced free radical formation and a defect in antioxidant defenses has been implicated in the pathogenesis of diabetes and its complications like neuropathy, retinopathy, nephropathy, etc. AIMS: The objective of the study is to know the oxidative stress by estimating serum malondialdehyde (MDA) levels and antioxidant status by measuring serum vitamin levels, and to know the correlation between MDA and other parameters in cases of diabetic retinopathy. SETTINGS AND DESIGN: Present study involved 100 participants of which 50 were diagnosed as having diabetic retinopathy and 50 were age and sex matched healthy controls. The degree of lipid peroxidation in terms of serum malondialdehyde (MDA) along with antioxidant defenses, vitamin A, vitamin C and vitamin E levels were estimated in cases and controls. Fasting blood sugar (FBS), post prandial blood sugar (PPBS) and HbA1c were also estimated in both cases and controls. STATISTICAL ANALYSIS USED: Student t test (two tailed, independent) has been used to find the significance of study parameters on continuous scale between two groups (Inter group analysis) on metric parameters. Pearson correlation between MDA and other parameters was performed to assess the relationship in each group. RESULTS: In diabetic retinopathy patients statistically highly significant increase in levels of FBS, PPBS and HbA1c (P<0.001) was observed when compared to controls. The levels of serum MDA (P<0.001) was increased significantly in diabetic retinopathy cases as compared to controls. The levels of serum vitamin A, vitamin C and vitamin E were significantly (P<0.001) reduced in all diabetic retinopathy patients. A positive correlation was observed between MDA and FBS, PPBS, HbA1c. A negative correlation was found between MDA and vitamin A and vitamin C. CONCLUSIONS: The present study concludes that excessive peroxidation damage and antioxidant deficiency occurs in diabetic retinopathy. Further trials regarding the therapeutic measures to control lipid peroxidation and to increase the antioxidant levels are warranted for effective control of diabetic complications.