Relationship between different normal serum bilirubin concentrations and diabetic nephropathy in patients with type 2 diabetes mellitus

Background: One of the major complications of type 2 diabetes is diabetic nephropathy (DN). Nephropathy develops in ~20–40% of patients with diabetes and is the single leading cause of end-stage renal disease (ESRD) around the world.(1) Oxidative stress has been considered to be an important pathogenic factor in the development of diabetic vascular complications, including nephropathy. Bilirubin(BIL) has been recognized as an endogenous antioxidant. Objective: The objective of this study is to detect the relationship between serum bilirubin concentrations and diabetic nephropathy in patients with type 2 diabetes mellitus. PATIENTS & METHODS:The study included 92 patient with type 2 diabetes mellitus who visit Sohag University Hospital ,All patients in this study were subjected to full history taking, complete physical examination, and laboratory investigations including urine analysis, albumin creatinine ratio, renal and liver function tests. Patients with T2DM were recruited and bilirubin concentrations were compared between patients with or without diabetic nephropathy. DN was diagnosed according to KDOQI Clinical Practice Guidelines and Clinical Practice Recommendations for Diabetes and Chronic Kidney Disease .(7) Patients were classified according to stage of nephropathy(8): 1-stage 1 ------- albumin creatinine ratio less than 30 mg/g creatinin. 2-stage 2 ------- morphologic lesions without signs of clinical disease. 3-stage 3 ------- albumin creatinine ratio more than 30 , less than 300 mg/g creatinin. 4-stage 4 ------- albumin creatinine ratio more than 300 mg/g creatinin. 5- stage 5 ------- end stage renal disease. Results: Multiple stepwise regression analysis was used to examine the relationship between bilirubin concentrations (within normal range) and albumin creatinin ratio. Conclusions Serum bilirubin concentration correlated negatively with stage of diabetic nephropathy, which suggests that bilirubin has a potential role for protection of diabetic nephropathy.