Lipid and protein oxidation products,antioxidant status and vascular complications in poorly controlled type 2 diabetes

The inter-relationships between glycaemic control, the progression of diabetes-related vascular complications, oxidative/antioxidative status and inflammation, have not been fully understood. We measured malondialdehyde (MDA) and carbonyl residues, C-reactive protein (CRP) and antioxidant systems by means of ferric reducing ability of plasma (FRAP) and superoxide dismutase (SOD) activity, in well controlled and poorly controlled type 2 diabetic patients without complications (NC) and in poorly controlled patients with microvascular (MicroVC) and with both micro- and macrovascular complications (Micro+Macro VC). All poorly controlled diabetic patients showed higher MDA and carbonyl residues compared to well controlled NC, as did those with Micro+Macro VC compared to poorly controlled NC. The higher CRP and SOD activity levels reached significance in Micro VC and Micro+Macro VC groups. FRAP decreased only in poorly controlled NC compared to well controlled NC (p<0.05). Glycated hamemoglobin (HbA1c) levels were positively correlated with MDA (p<0.05) and CRP (p<0.001) and inversely associated with FRAP (p<0.05) and SOD (p=0.06). An increase in MDA or carbonyl residues could be a marker of high risk for complications in patients with poorly controlled diabetes and they should be considered for monitoring the effectiveness of drug treatment.