Correlation Between Tumor Necrosis Factor Alpha and Proteinuria in Type-2 Diabetic Patients

Introduction: Diabetic Nephropathy (DN) is the single most common cause of end stage renal disease (ESRD) in many countries. Inflammation is a potential factor in the development and progression of DN and recent data indicate that diabetes includes an inflammatory component which may contribute to diabetic complications. Methods: This study was conducted at Ain Shams University Hospital on 95 patients with type-2 diabetes mellitus complicated with retinopathy and fifteen age- and sex-matched healthy volunteers. Diabetic patients were divided into 4 groups according to the degree of proteinuria. Serum tumor necrosis factor-α (TNF-α), urine TNF-α and C-reactive protein (CRP) levels were measured in all subjects. Correlations between these inflammatory parameters and degree of proteinuria, duration of diabetes and degree of glycemic control were examined. Results: Levels of the three inflammatory parameters were significantly higher in diabetic patients when compared to control subjects, and they were positively correlated to urinary protein excretion. There was significant positive correlation between serum and urine TNF-α and duration of diabetes, as well as between serum TNF-α and glycemic control. Serum and urine TNF-α remained as independent predictors of urine protein excretion in diabetic patients with overt proteinuria after forward stepwise multiple regression analysis. Conclusion: Serum and urine TNF-α and CRP levels are significantly elevated in this group of diabetic patients, and correlate positively with severity of proteinuria. This suggests a significant role for TNF-α in the pathogenesis and progression of renal injury in diabetes mellitus. Keywards: Diabetic nephropathy; Proteinuria; Tumor necrosis factor-