Correlation between diabetic nephropathy and the level of urinary mindin in patients with type 2 diabetes mellitus

Abstract

Objective To evaluate the level of urinary mindin in patients with type 2 diabetes mellitus (T2DM), and analyze the association between the renal injury and the lvels of urinary mindin. Methods Type 2 diabetic patients (n=124) with normoalbuminuria(urinary albumin<30 mg/24 h, n=60), microalbuminuria (30≤urinary albumin<300 mg/24 h, n=32), macroalbuminuria (urinary albumin≥300 mg/24 h, n= 32), and normal control group (n=30) were enrolled.The levels of urinary mindin were measured by using ELISA kits, the serum/urine creatinine, serum urea nitrogen, cystatin C, blood glucose, glycated hemoglobin, C-peptide and other clinical indicators were measured by conventional methods.The estimated eGFR level was calculated using the formula proposed by Macisaac, and statistical analysis were made with the SPSS 13.0 software. Results The levels of urinary mindin in the T2DM group were significantly higher than those of the normal control group which were increased gradually with the increases of albuminuric levels.The urinary mindin levels in patients with normoalbuminuria, microalbuminuria, macroalbuminuria and normal controls were 161(119~255), 332(181~445), 426(230~937) and 93(51~121) ng·ml-1·μmol-1·L-1, respectively(F=30.196, P<0.05). Urinary mindin was correlated with urinary albumin( r=0.453, P<0.05); The level of urinary mindin was positively correlated with serum urea nitrogen(r=0.426, P<0.05), creatinine(r=0.236, P<0.05), cystatin C(r=0.383, P<0.05), blood glucose(r=0.344, P<0.05), 24 h-urinary albumin(r=0.453, P<0.05) and the course of diabetic disease(r=0.511, P<0.05), which was negatively correlated with eGFR(r=-0.383, P<0.05); Logistic regression analysis showed that the urinary mindin might be one of the high-risk factors to identify renal injury in patients with T2DM. Conclusion This study indicates that urinary mindin might be closely related to diabetic nephropathy and in participates in the progress of diabetic nephropathy; urinary mindin can reflect the early course of renal injury and be associated with renal function. Urinary mindin needs to be investigated as a potential marker for diabetic nephropathy early diagnosis and indicator of curative effect. Key words: Diabetes mellitus, type 2; Diabetic nephropathy; mindin; Renal injury; Podocyte