Impact of hyperglycaemia on molecular markers of oxidative stress and antioxidants in type 2 diabetes mellitus

Background and Objectives: The pathogenesis of type 2 diabetes mellitus (T2DM) is strongly linked to oxidative stress mainly caused by chronic hyperglycaemia. The present study investigates the association between hyperglycaemia with oxidative stress markers, antioxidants and lipid profile. Subjects and Methods: The case-control study involved two groups, T2DM patients (n=83) and age-sex matched controls (n=129). Serum levels of various molecular markers malondialdehyde (MDA), reactive oxygen species (ROS) and nitric oxide (NO), superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), vitamin C, total antioxidant capacity (TAC) and lipid parameters total cholesterol, triglycerides, low density lipoprotein (LDL) and high density lipoprotein (HDL) were measured using spectrophotometric assays. Results were analysed to compare and correlate glycaemic levels with these molecular markers. Results: T2DM patients had a higher body mass index (BMI) and body fat percentage. 2 hour blood glucose, glycated haemoglobin A1c % (HbA1c), total cholesterol, triglycerides and LDL were higher in diabetics, HDL was found to be lower in diabetics than in controls. Mean levels of enzymatic and non-enzymatic antioxidants SOD, CAT, GSH, vitamin C and TAC were significantly lower while oxidative stress markers NO, ROS and MDA were higher in T2DM patients. NO showed a positive correlation (r= 0.3841, P < 0.0001) whereas TAC showed a negative correlation with glycaemic levels (r= -0.4834, P < 0.0001). Conclusion: Poor glycaemic control in T2DM causes elevated ROS and NO levels with increased lipid peroxidation and lowered antioxidant capacity. MDA and NO being a major risk factor for diabetic pathogenesis and vascular complications could be used as a parameter along with antioxidants to assess oxidative stress in T2DM patients.