血清胱抑素C、^(99m)Tc-DTPA肾小球滤过率和尿微量白蛋白联合诊断2型糖尿病肾病

Combined Measurement of Serum Cystatin C,^(99m)Tc-DTPA and Urine Microalbumin in Early Diagnosis of Type 2 Diabetic Nephropathy

目的以99mTc-DTPA肾动态显像法肾小球滤过率(glomerular filtration rate,GFR)测定为标准,将血清胱抑素C(cystatin C,CysC)检测与其比较,探讨CysC测定在2型糖尿病肾病(type 2diabetic nephropathy,T2DN)诊断中的意义。方法 2010年6月～2011年1月76例2型糖尿病(type 2diabetes mellitus,T2DM)患者按24h尿微量白蛋白(microalbuminuria,m-Alb)分为两组:正常蛋白尿组(31例)和微量蛋白尿组(45例),同时测定GFR、CysC、血清肌酐(serum creatinine,Scr)和糖化血红蛋白(hemoglobin A1c,HbA1c),并设正常自愿者38名作为对照组,进行统计学分析。结果对照组、T2DM正常蛋白尿组及T2DM微量蛋白尿组CysC水平分别为(1.1±0.6)、(1.6±0.7)、(1.0±0.3)mg/L,各组差异均有统计学意义(P<0.05);HbA1c水平分别为(5.4±0.6)%、(7.1±2.7)%、(7.9±3.1)%、两组T2DM患者与对照组比较,差异均有统计学意义(P<0.05);GFR水平分别为(80.9±23.0)、(74.2±26.1)、(79.3±19.7)mL/(min.1.73m2),各组差异无统计学意义(P>0.05);Scr水平分别为(87.7±23.8)、(93.7±38.4)、(81.5±11.4)μmol/L,组间差异无统计学意义(P>0.05)。CysC、Scr和GFR之间呈负相关(r=-0.694,-0.692;P<0.001);CysC和Scr之间呈正相关(r=0.903,P<0.001)。结论 CysC可作为早期T2DN的检测指标,具有较高的敏感性,但对于轻度到中度GFR降低的诊断准确性并不优于Scr。

Objective To demonstrate the clinical value of serum cystatin-C（CysC） in the assessment of renal function in type-2 diabetic nephropathy（T2DN） by comparing it with the glomerular filtration rate（GFR） measured by 99mTc-DTPA method.Methods From June 2010 to January 2011,76 patients with type 2 diabetes mellitus（T2DM） were classified into two groups according to their 24 h microalbuminuria（m-Alb） level： the normal albuminuric group（n=31） and the microalbuminuric group（n=45）.GFR,Serum creatinine（Scr）,CysC,and hemoglobin A1c（HbA1c） were measured.Thirty-eight healthy subjects were recruited as the control group,and statistical analysis was carried out.Results The CysC levels in the control group,the normal albuminuric group and the microalbuminuria group were respectively（1.1±0.6）,（1.6±0.7） and（1.0±0.3） mg/L,with a significant difference among the three groups（P0.05）.HbA1c level in the three groups were respectively（7.1±2.7）%,（7.9±3.1）% and（5.4±0.6）%,with a significant difference between the two diabetic groups and the control group（P0.05）.Scr levels in the three groups were respectively（87.7±23.8）,（93.7±38.4）,（81.5±11.4） μmol/L;GFR levels in the three groups were respectively（80.9±23.0）,（74.2±26.1）,（79.3±19.7） mL/（min·1.73 m2）;among the three groups the differences of both Scr and GFR were not significant.Both CysC and Scr were negatively correlated with GFR（r=-0.694,-0.692;P0.001）,and CysC was positively correlated with Scr（r=0.903,P0.001）.Conclusion Increased CysC may be an early indicator of incipient diabetic nephropathy,but the diagnostic accuracy of CysC is not superior to that of Scr in distinguishing between mildly and moderately reduced GFR.