Urinary heparan sulfate excretion depending on microalbuminuria in patients with diabetes

Abstract

The HS is a component of the glomerular filtration barrier, mainly in the form of perlecan and agrin. It has been reported that changes in the amount and concentration of sulfated units of HS are associated with the development of diabetic nephropathy. The lack of or impaired synthesis of HS in GBM leads to the development of microalbuminuria and further excessive urinary protein excretion. To determine the  early stages of diabetic complications we used the quantitative assessment of urinary HS excretion. The aim of the study was searching for differences in urinary HS excretion in patients with diabetes in comparison to the control group, evaluation of the influence of microalbuminuria on urinary HS excretion and evaluation of possible usefulness of urinary HS excretion as a laboratory test for diabetic nephropathy. Results of the conducted research revealed that in patients with diabetes urinary HS excretion in 24-hour urine collection is lower in comparison with the control group. Significant differences were observed in regards to all methods of expression of urinary HS excretion: as a concentration, 24-hour excretion and also as calculation per urine creatinine. Decreased urinary HS excretion in patients with diabetes may result from impaired production or increased degradation of GAG in glomeruli in the course of hyperglycemia. In our research we observed a significant negative correlation between urinary HS excretion and microalbuminuria and positive association with eGFR values. The presented data indicate that determining HS can be a valuable marker in the diagnosis of diabetic nephropathy; however, details of the preanalytic and analytic phase need to be processed. In the clinical aspect further investigations are required on a greater number of cases considering many factors such as the type of diabetes, administered treatment and the duration of the disease.