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

Abstract

Introduction. 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. Materials and methods. The case-control study in­volved two groups, T2DM patients (n = 83) and age and sex matched controls (n = 81). 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 = 0.3993, p < 0.0001) whereas TAC showed a negative correlation with glycaemia (r = –0.4796, p < 0.0001). Conclusions. Poor glycaemic control in T2DM causes elevated ROS and NO levels with increased lipid peroxi­dation and lowered antioxidant capacity. MDA and NO being the major risk factors could be used as a param­eter along with antioxidants to assess oxidative stress in T2DM patients.