Abstract:

Objective To investigate the roles of serum afamin（AFM） and adropin（AD） in patients with diabetic nephropathy（DN）. Methods According to the urinary albumin to creatinine ratio（UACR）,180 patients with type 2 diabetes mellitus（T2DM） were classified into 3 groups,normal UACR group（UACR<30 mg/g）,low UACR group（UACR 30-<300 mg/g） and high UACR group（UACR≥300 mg/g）. Totally,52 healthy subjects were enrolled as healthy control group. General information was collected. The levels of AFM,AD,fasting blood glucose（FBG）,triglyceride（TG）,total cholesterol（TC）,serum creatinine（SCr）,aspartate aminotransferase（AST）,blood urea nitrogen（BUN）,total protein（TP）,albumin（Alb）,glycated hemoglobin A_1c（HbA_1c）,fasting insulin（FINS）and urinary microalbumin（mAlb）,24 h urine protein were determined. The homeostasis model assessment for insulin resistance（HOMA-IR）,estimated glomerular filtration rate（eGFR）,urinary albumin excretion（UAE） and UACR were calculated. Spearman correlation analysis and multiple linear regression analysis were used to assess the correlation between AFM and AD levels with various influencing factors. Receiver operating characteristic（ROC） curve was used to evaluate the diagnostic roles of AFM and AD for the diagnosis of DN. Results The AFM levels increased and the AD levels decreased in healthy control group,normal UACR group,low UACR group and high UACR group（P<0.05）. Spearman correlation analysis showed that AFM levels were positively correlated with systolic blood pressure,BUN,SCr,FBG,HbA_1c,FINS,HOMA-IR,mAlb,UAE,UACR and 24 h urine protein（P<0.05）,and were negatively correlated with TP,Alb and AD（P<0.05）. The AD levels were positively correlated with TP and Alb（P<0.05）,and were negatively correlated with systolic blood pressure,BUN,SCr,FBG,HbA_1c,FINS,HOMA-IR,mAlb,UAE,UACR,24 h urine protein and AFM（P<0.05）. Multiple linear regression analysis showed that the influencing factors of serum AFM levels were AD,HbA_1c,UACR and 24 h urine protein（β =-0.90,0.11,0.16 and 0.11,P<0.05）. The AFM,UACR and HbA_1c were influencing factors of serum AD levels（β =-0.53,-0.45 and -0.11,P<0.05）. ROC curve analysis showed that the area under curve（AUC） of AFM and AD for the diagnosis of DN were 0.80 and 0.96,and the optimal cut-off values were 87.57 mg/L and 171.86 pg/mL,with the sensitivities of 78.30% and 97.50% and the specificities of 71.50% and 92.00%,respectively. Conclusions Serum AFM and AD have certain clinical values for DN,which can be used for the auxiliary diagnosis of DN.

Key words: Afamin, Adropin, Diabetic nephropathy