MON-680 Might Podocyturia Be an Early Marker for Diabetic Nephropathy in Males

Renal involvement can develop before detection of microalbuminuria in type 2 diabetes. There is an interest in finding biomarkers to detect diabetic nephropathy (DN) earlier and identify progression risk. Podocyturia emerge as a marker for early kidney damage however standardization problems hamper its widespread use. We aimed to investigate the value of podocyturia for the detection of early DN. Herein we report our preliminary results. Our study population was composed of three type 2 diabetic patient groups and a healthy control group. Diabetic groups were defined as follows; group 1: patients without microalbuminuria who had HbA1c <7%; group 2: patients without microalbuminuria who had HbA1c> 8.5%; group 3: patients with diabetic retinopathy who had proteinuria >1g/day and/or microalbuminuria >300 mg/day and group 4: healthy volunteers without any known disease. Patients with glomerular filtration rate (GFR) below 30 ml/min were excluded. GFR was calculated using the abbreviated MDRD formula. Microalbuminuria was measured in 24 hour urine. Number of podocytes in the urine was determined by immunocytochemical staining of podocalyxin. Due to the known expression of podocalyxin in the female genital tract, only males were included. Statistical analyses were carried out using Statistical Package for the Social Sciences version (SPSS) 24.0 and statistical significance was set as p<0.05. We examined a total of 119 patients (mean age 57.35 ± 12.75 yrs.). Patient distribution in each group was as follows; group 1: 24(20%); group 2: 26(22%); group 3: 24(20%) and group 4: 45(38%) patients. There was no significant difference in mean age (p=0.582) and duration of diabetes (p=0.517) between the diabetic groups. The mean GFR was significantly lower in group 3 than in group 1 and 2 (p<0.001, p:0.007; respectively). The median podocyte measurement in urine was 0,25 (IQR: 0- 2.68) podx/ml in group 1; 0,37 (IQR: 0-2.12) podx/ml in group 2; 1,37 (IQR: 0.56-5.18) podx/ml in group 3; 0.0 (IQR: 0-0.75) podx/ml in group 4. The mean number of podocytes in urine was significantly different between the 4 groups (p=0.001). In posthoc analysis with Bonferoni correction, the mean podocytes measurement was significantly higher in group 3 than in group 1 and 4 (p=0.033, p=0.001; respectively). According to our preliminary results; podocyturia assessed by podocalyxin immunostaining does not seem to be increased in male diabetic patients without proteinuria. Further studies on larger patient groups and using different podocyte markers might clarify the value of podocyturia as an early marker of DN.