肌酐-胱抑素C公式在糖尿病肾病超滤过检出中的作用

Performance of Creatinine-cystatin C Equation for Detection of Hyperfiltration in Chinese Diabetic Patients

目的比较MDRD公式、胱抑素C公式及肌酐-胱抑素C公式在中国糖尿病患者中的表现,尤其是在高滤过检出中的作用。方法选取笔者医院2155名糖尿病患者,以99mTc-DTPA GFR为金标准,比较MDRD公式、胱抑素C公式及肌酐-胱抑素C公式在估测GFR方面的优劣。观测指标包括偏倚、精确性及准确性,并对各公式检测结果与金标准进行相关性及线性分析。采用ROC曲线评估各公式对肾功能不全及高滤过的诊断效能。结果 MDRD、胱抑素C及肌酐-胱抑素C公式在总体人群中的绝对偏倚分别为18.98、28.74、18.04,肌酐-胱抑素C公式的偏倚显著低于其他公式(P<0.05),精确度最好(P<0.01)。与MDRD及胱抑素C公式相比,肌酐-胱抑素C公式的15%及50%准确性更高(P<0.05),ROC曲线显示,肌酐-胱抑素C公式能够更加准确的筛选超滤过患者(AUC=0.862,P<0.05)。结论肌酐-胱抑素C公式在中国糖尿病人群中的适用性优于MDRD及胱抑素C公式,肌酐-胱抑素C公式可用于筛选超滤过的糖尿病早期肾损伤的患者。

Objective Diabetic nephropathy affects 25%-40% of patients with diabetes,which is the common cause of end-stage renal failure.Early detection can ensure timely intervention and improvement of treatment outcome.Since GFR is known to be affected by hyperglycemia,the aim of this study is to compare the performance of GFR estimations calculated by MDRD,cystatin C,and creatinine-cystatin C equation in Chinese diabetic patients according to glycemic status.Methods The performance of the equations,as compared with measured99mTc-DTPA glomerular filtration rate( m GFR) was analyzed in 2155 diabetic patients.Bias,precision,and accuracy were compared according to Hb A1 c square.Receiver-operating characteristic( ROC) curve method was used to evaluate the diagnostic value of the three equations for detection of moderate renal failure and hyperfiltration.Results The bias of MDRD,cystatin C and creatinine-cystatin C equation was 18.98,28.74 and 18.04,respectively.The bias was the smallest for creatinine-cystatin C equation( P < 0.05) versus both other two equations.The accuracy within ± 15% and 50% of creatinine-cystatin C was significantly higher than that of MDRD and cystatin C equation( P < 0.05).For detection of hyperfiltration,the CDK-EPI equation showed the best performance with the greatest combination of sensitivity and specificity( AUC = 0.862,P < 0.05).Conclusion The creatinine-cystatin C equation appears to be a more generalizable and accurate equation for estimating GFR in comparison with the MDRD and cystatin C equation and could be used as a screening tool for hyperfiltration in diabetes.