The Relationship Between Ankle Brachial Index And Cystatin C In Patients With Type 2 Diabetes And Diabetic Kidney Disease

Background:Diabetic kidney disease(DKD)is one of the most common chronic microvascular complications of diabetes and has become a major cause of end-stage renal disease(ESRD),and these patients are also a high-risk population with cardiovascular and cerebrovascular diseases.With the increasing number of diabetes,especially type 2 diabetes mellitus(T2DM)in China,the incidence of DKD is also increasing annually.There is still a lack of effective treatments to prevent the development and progression of DKD,and thus identification of early predictive biomarkers for DKD is essential to prevent renal damage and improve clinical outcomes in patients with T2 DM.Although microalbuminuria is considered to be an early biomarker of DKD,it is not an ideal marker for screening DKD due to its variability.Additionally,when microalbuminuria occurs in T2 DM patients,these patients usually already have renal damage.Therefore,there is an urgent need to develop reliable and versatile biomarkers for risk assessment of DKD.Methods:We performed a retrospective analysis of 265 patients with type 2 diabetes who were hospitalized in the Department of Endocrinology and Nephrology of Jingdezhen First People’s Hospital from Sep 2017 to Dec 2019.According to urinary albumin excretion rate(UAER),T2 DM patients with were divided into three groups: normal albuminuria group(n=107),microalbuminuria group(n=111)and macroalbuminuria group(n=47).Fasting venous blood was extracted from all subjects,and serum total cholesterol(TC),triglyceride(TG),low-density lipoprotein(LDL-c),high-density lipoprotein(HDL-c),cystatin C(Cys C),urea nitrogen(BUN),creatinine(Cr),uric acid(UA)and blood glucose(FBG)were detected by automatic biochemical analyzer.HbA1 c was determined by HPLC and ABI was measured by doppler flow detector(ES 1000 SPM).Finally,SPSS18.0 software was applied for data analysis,and P<0.05 was considered to be statistically significant.Result:1.Analysis of clinical parameters of T2 DM patients in each group: Compared to normal albuminuria group,there were significant differences in age,diabetic duration,SBP,UAER,HDL-c,LDL-c,BUN,Cr,eGFR,ABI,and Cys C in microalbuminuria group,and significant differences in age,sex,BMI,diabetic duration,DBP,SBP,UAER,TG,HDL-c,LDL-c,BUN,Cr,eGFR,ABI,and Cys C in macroalbuminuria group.In contrast to microalbuminuria group,macroalbuminuria group has significant differences in sex,DBP,SBP,FPG,UAER,TG,BUN,Cr,eGFR,ABI,and Cys C.No significant differences were observed in HbA1 c and TC between three groups.2.Pearson correlation analysis between ABI and clinical data showed that ABI was negatively correlated with BUN(r=-0.47,P<0.001),Cr(r=-0.54,P<0.001),SBP(r=-0.0.25,P<0.001),and UAER(r=-0.3616,P<0.001),while positively correlated with eGFR(r=0.33,P<0.001)and HDL-c(r=0.15,P=0.0138).No correlation was found with disease course,BMI,DBP,HbA1 c,FPG,TC,TG,LDL-c and Cys C.3.Pearson correlation analysis of Cys C and clinical data showed that Cys C positively correlated with Cr(r=0.6661,P<0.001),BUN(r=0.438,P<0.001),UAER(r=0.484,P<0.001),SBP(r=0.1947,P=0.001),DBP(r=0.1653,P=0.007),and TG(r=0.15,P=0.04),while negatively correlation with eGFR(r=-0.7129,P<0.001).No correlation was found with disease course,BMI,HbA1 c,FPG,TC,LDL-c,HDL-c and ABI.4.Multivariate logistic regression analysis showed that disease course,increased BMI,SBP,HbA1 c,TC,Cr,BUN,Cys C levels and decreased DBP,HDL and ABI levels may be independent risk factors for DKD.5.The ROC curve results of ABI and Cys C in the abnormal albuminuria group showed that areas under curve(AUC)of ABI was 0.776(P<0.001,95%CI:0.721-0.832)with sensitivity of 75.6% and specificity of 67.4%.AUC of Cys C was0.808(P<0.001,95% CI: 0.756-0.859)with sensitivity of 86.8% and specificity of81.6%.AUC of combined test was 0.824(P<0.001,95% CI: 0.775-0.872)with sensitivity of 88.4% and specificity of 80.4%.Conclusions:Decreased ABI level and increased Cys C level may be independent risk factors for T2 DM patients with renal damage.Moreover,the sensitivity and specificity of screening DKD can be improved through combined ABI and Cys C tests.