Evaluation of the relationship between serum uric acid level and proteinuria in patients with type 2 diabetes

Abstract

Introduction: Diabetes mellitus and diabetic nephropathy are the most common causes of end-stage renal disease (ESRD) in developed countries, accounting for about 30% of these cases. Up to 40% of patients with type 2 diabetes with micro albumin uria progress to overt nephropathy and develop ESRD after one to two decades. Albumin uria is the most important indicator of diabetic nephropathy and its progression. Also, hyperuricemia has been suggested as a risk factor for kidney damage, this study was designed to determine the relationship between serum uric acid level and proteinuria in patients with type 2 diabetes. Materials and methods: In this descriptive-analytical and cross-sectional study, data collection was performed among patients with type 2 diabetes referred to the diabetic Center in Gorgan from the years 2015 to 2018. The data collection tool was a two-part questionnaire including demographic and anthropometric characteristics and information about the disease. Serum levels of Uric Acid, Blood Urea Nitrogen (BUN), Creatinine (Cr), Fasting Blood Sugar (FBS) and Hemoglobin A1C (HbA1C) were measured in all patients. 24-hour urine collection was performed for proteinuria, albuminuria, urinary volume, and Cr volume. Patients’ GFR was also calculated using the CKD-EPI formula. Patients were re-evaluated 1 year after the initial evaluation in terms of measured factors and the relationship between serum uric acid and albuminuria, proteinuria, kidney function, and other serum factors were evaluated. Results: Among 823 diabetic patients that were referred to the nephrology center in this study, 90 patients were included. 34 (37.8%) of these patients were men. The age range of patients was between 32 years to 70 years with a mean of 56.31 and a standard deviation of 7.84 years. According to the Pearson correlation coefficient, a direct correlation was observed between uric acid with proteinuria and creatinine levels, and an inverse correlation was observed between uric acid and GFR. But we didn’t find any correlation between uric acid and microalbuminuria. Conclusion: According to the results of this study, the relationship between uric acid level and the severity of nephropathy (based on proteinuria) is proven. It seems that maintaining serum uric acid levels in patients with type 2 diabetes within the normal range and treatment with serum uric acid-lowering drugs may be possible to reduce the progression of diabetic nephropathy and proteinuria.