Association Between Plasma Selenium and Glutathione Peroxidase Levels And Severity of Diabetic Nephropathy in Patients With Type Two Diabetes Mellitus

BACKGROUND Oxidative stress is thought to be involved in the pathogenesis of diabetic nephropathy. Selenium (Se), and antioxidant enzymes such as glutathione peroxidase (GPx) play an important protective role in diabetes complications. OBJECTIVES This study aimed to evaluate the association between plasma Se and GPx levels with severity of diabetic nephropathy. PATIENTS AND METHODS In a case-control study, we measured plasma Se and GPx concentrations in patients with type two diabetes without microalbuminuria (group 1), with microalbuminuria (group 2), with macroalbuminuria (group 3), and healthy control subjects (group 4). We also assessed plasma glucose, urea, creatinine, and glycated hemoglobin levels in all study patients. RESULTS Plasma Se and GPx concentrations were significantly lower in diabetic patients with macroalbuminuria than other study groups (P < 0.001). Albuminuria (Alb/Cr in random urine sample) had a negative correlation with plasma Se (r = -0.40, P = 0.01), and GPx (r = -0.23, P = 0.03) concentrations. CONCLUSIONS Plasma Se and GPx levels were lower in type two diabetic patients with macroalbuminuria and related to the stage of diabetic nephropathy.