Identification Of Diabetic Nephropathy And Idiopathic Membranous Nephropathy By Detection Of Urine Smad1 Protein

ObjectiveThe expanion of mesangial matrix is a pathologic feature of diabetic kidney disease(DKD).Recent studies indicated that the levels of urine smad1 protein positively corelated to the deposit of mesangial matrix.This study try to examine the serum and urine smad1 protein in patients with DKD and idiopathic membranous nephropathy(IMN);access its efficacy in distinguish these two types of frequently handled adult glomerular disease;and evaluate the possibility of using this marker to identify DN from IMN,especially those IMN with diabetes mellitus.MethodsForty cases of type 2 diabetic kidney disease patients from department of endocrinology and 15 cases of idiopathic membranous nephropathy patients from department of nephropathy were recruit from the hospitalized patients from June 2018 to September 2019.The basic entry criteria is the baseline 24 hours of urinary protein≥ 500 mg.20 health persons for check-up in this hospital were enrolled as control group.The general data,such as age,sex,weight,height,course of disease,common complications,body mass index,systolic blood pressure,diastolic blood pressure,total cholesterol,triglycerides,low-density lipoproteins,high-density lipoproteins,fasting blood sugar,glycated hemoglobin,creatinine,uric acid,aspertate aminotransferase,alanine aminotransferase,glomerular filtration rates,C-Peptide were measured by automatic biochemical analyzer.24-hour proteinuria were measured for all patients.The concentrations of smad1 in serum and morning urine were examined by enzyme-lnked immunosorbent assay(ELISA).In addition to the data that need special introduced,the other data are represented by mean ± standard deviation.All statistical analyses were performed on computer using SPSS 23.0 for windows.SPSS 23.0 was used to analyze the differences among the groups,and the correlation between the serum and urineSmad1 with 24-hour urinary protein levels.At the same time,the logistic regression was used to analyze various influencing factors in type 2 diabetic kidney disease.P < 0.05 indicate the difference is statistically significant.Results1.There were no significant differences in gender,age,height,body weight,body mass index,fasting blood glucose,uric acid,blood pressure,creatinine,glomerular filtration rate,glutamic oxaloacetylase,glutamic pyruvic transaminase,total cholesterol,triglyceride,fasting C-peptide and glycosylated hemoglobin among the three groups(P>0.05);there were no significant differences in course of disease between the IMN group and DKD group(P>0.05).2.There was a significant difference between the IMN group and DKD group with control group for 24 hour urinary protein level(2596.25±825.02 vs 77.75±27.94,P<0.05;2228.32±920.95 vs 77.75±27.94;P<0.05).But there is no difference for this parameter between IMN with DKD group(2596.25±825.02 vs 2228.32±920.95,P>0.05).3.Smad1 levels in urine of DKD group were significantly higher than that of IMN group and normal control group(100.88±37.59 vs 1.91±0.78,P <0.05;100.88±37.59 vs 2.22±0.87,P<0.05).Smad1 levels in serum were no significant difference between that of three groups(1.09±0.36 VS 1.12±0.41,P>0.05;1.09±0.36 VS 1.04±0.38;P>0.05).4.In DKD group,urine smad1 were positively correlated with 24 h urinary protein levels(r=0.84,P<0.05),while,in IMN group,urine smad1 levels were not correlated to 24 h urinary protein levels(r=-0.49,P>0.05).5.The logistic regression indicated that urine smad1 and 24 h urinary protein levels were a dependent risk factor of DKD(OR>1,P<0.05).6.The sensitivity and specificity of urine smad1 to identify DKD was significant higher(Sensitivity 97%,specificity 86.70%).ConclusionLevels of urinary smad1 protein increased in DKD but not in IMN patients.The degree of this increases was positively corelated to the levels of glomerular injury.Examination of urine smad1 may be a useful and easily performed tool to identify DKD from IMN.