Role of sialic acid in prediction of diabetic nephropathy

Background: Diabetic nephropathy is a major microvascular complication of diabetes mellitus and the most common cause of end stage renal disease worldwide. It has been proposed that inflammatory process seems to play an important role in the development of diabetes and its late complications. Serum sialic acid, an acute phase reactant and acute phase reactants are considered as the indicators of microvascular angiopathy. Microalbuminuria is a predictor of incipient nephropathy in diabetic patients. Aim: The study was undertaken to evaluate serum sialic acid and microalbuminuria levels and to assess the correlation of serum sialic acid and microalbuminuria in diabetic nephropathy patients. Method: The diabetic subjects were divided into two groups. Group I – 120 patients with diabetes mellitus with early stage of nephropathy based on urinary albumin excretion per day and Group II – 120 newly diagnosed or known diabetics on treatment but without any complication. The age and sex matched 120 controls were selected from the healthy persons from same region. Both the cases and controls were selected by a simple random method. Blood samples were analyzed for fasting and post prandial blood sugar, blood urea, serum creatinine, serum sialic acid, glycated hemoglobin (HbA1c) and urine sample for microalbumin levels and systolic, diastolic blood pressure was recorded in both cases and controls. Result: Serum sialic acid levels were found to be significantly increased in diabetes with or without nephropathy compared to controls. Urinary microalbumin in diabetic nephropathy patients was significantly higher compared with diabetics and healthy individuals. In diabetes without any complications, serum sialic acid level had no statistically significant positive correlation with serum urea, creatinine and urinary microalbumin but in diabetes with nephropathy, serum sialic acid level statistically was well correlated with serum urea, creatinine and urinary microalbumin. Conclusion: Elevated serum sialic acid and urinary microalbumin levels are strongly associated with the presence of nephropathy. Serum sialic acid may be a predictor of renal dysfunction in diabetic nephropathy.