Correlation of Glycemic Status with Oxidative/ Antioxidant Status in Diabetic Retinopathy

Context: Diabetes is a chronic disease and sustained hyperglycemia attacks both micro vessels and macro vessels throughout the body. It is the leading cause of retinopathy, nephropathy, end stage renal disease and cardiovascular diseases. In Diabetes and its complication, oxidative stress is caused by both increased production of reactive oxygen species, sharp reduction in antioxidant defenses and altered cellular redox status.

Aims: The aim of the present study was to assess the correlation of glycemic status with lipid peroxidation and antioxidant vitamin levels in patient with diabetic retinopathy. Setting and design: 50 patients with diabetic retinopathy and 50 age and sex matched healthy controls were included in the study. Fasting blood glucose levels, post prandial blood glucose levels were estimated to assess the severity of Diabetes. Glycated haemoglobin was estimated to assess glycemic control. The degree of lipid peroxidation in terms of serum malondialdehyde (MDA) by Thiobarbituric acid method along with antioxidant defenses, vitamin A, vitamin C and vitamin E were estimated in 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 HbA1c and other parameters was performed to assess the relationship in each group.

Results: The serum FBS, PPBS, HbA1c and MDA were found to be increased significantly (p<0.001) in diabetic retinopathy patients while plasma Vitamin A, C and E levels were significantly reduced (p<0.001) as compared to controls. Correlation study conducted between HbA1c and other parameters revealed that there was statistically significant negative correlation between HbA1c and vitamin A and vitamin C.

Conclusions: The present study concludes that sustained hyperglycemia leads to excessive peroxidation and antioxidant deficiency in diabetic retinopathy. Therapeutic measures to increase the antioxidant levels and to control lipid peroxidation are warranted for effective control of diabetic complications.