血清胱抑素C及β_2-微球蛋白在糖尿病肾损害早期诊断中的临床研究

The application value of serum Cystatinc and Beta2-microglobulin for diagnosing early diabetic nephropathy

目的探讨血清胱抑素C(CysC)及β_2-微球蛋白(β_2-MG)对糖尿病早期肾损害的诊断价值。方法选择106例2型糖尿病患者(实验组)根据尿白蛋白排泄率(UAER)分为A组(UAER<20g/min);B组(UAER 20~200g/min);C组:(UAER>200g/min)。同时选择30例健康查体者设为N组(对照组),检测各组血清CysC和β_2-MG水平,并与血清肌酐(Scr)、内生肌酐清除率(Ccr)等相关指标进行比较。结果 1.CysC:A组与N组比较差异有统计学意义(P<0.05),B组、C组与N组比较差异有统计学意义(P<0.01)。β_2-MG:A组、B组与N组比较差异有统计学意义(P<0.05),C组与N组比较差异有统计学意义(P<0.01)。Scr:A组、B组与N组比较差异无统计学意义(P>0.05),C组与N组比较差异有统计学意义(P<0.05)。Ccr:A组与N组比较差异有统计学意义(P<0.05),B组与N组比较差异无统计学意义(P>0.05),C组与N组比较差异有统计学意义(P<0.01)。2.CysC、β_2-MG和Ccr的诊断敏感性分别为53.77%、41.51%、31.13%;特异性分别为83.33%、66.67%、80.00%;准确性分别为60.29%、47.06%、41.91%。3.CysC、β_2-MG、Ccr均与UAER有良好的相关性,相关系数r分别为0.884、0.756、-0.700,Scr与UAER呈中度相关,r=0.421。CysC、β_2-MG与Scr的相关系数分别为0.470、0.458,与Ccr的相关系数分别为-0.613、-0.559。4.CysC、β_2-MG、Ccr、Scr与糖尿病肾病有良好的相关性,相关系数r分别为0.814、0.785、-0.780、0.520。结论血CysC和β_2-MG是肾脏早期损伤的重要标志,较Scr、Ccr能更敏感、更准确的反映2型糖尿病早期肾损害,其中以血CysC诊断价值更高。

Objective To investigate the diagnostic value of serum cystatinC（CysC） and β2-microglobulin（β2-MG） in early diabetic nephropathy. Methods Serum concentrations of cystatinC and β2-microglo-bulin were measured in 106 diabetes mellitus patients and 30 healthy people（group N）using immune turbidimetry method, which were also compared with serum creatinine （Scr） ,endogenous creatinine clearance （Ccr） and other related indicators. Patients were divided according to the urine albumin excretion rate （UAER） into normal albuminuria （Group A）,microalbuminuria （Group B）, and macroalbuminuria （Group C）. The sensitivity and correlation in diabetic neuropathy （DN） diagnosis between serum CysC,β2-MG.Scr.Ccr concentrations were also respectively compared. Results 1. According to the UAER and compared with group N,CysC and β2-MG in group A have begun to increase while the creatinine started to increase in group C. Ccr increased in group A, while it declined in group C,but no obvious change in group B. All changes were statistically significant. 2. The sensitivity of serum CysC,β2-MG or Ccr were 53.77% ,41.51%,31. 13% ; specificity of these three markers were 83.33%, 66.67%, 80.00% ; and the accuracy were 60. 29 % ,47.06 % 41.91%. The sensitivity, specificity and accuracy of serum CysC are all higher than the other two. 3. Serum CysC,β2-MG or Ccr is well correlated with UAER（r= 0. 884,0. 756,- 0. 700, respectively）. Scr is middle correlated with it（r= 0.421, respectively）. CysC、β2-MG is also correlated with Scr （ r= 0. 470,0. 458, respectively） and Ccr （ r= - 0.613, -- 0. 559, respectively）. CysC correlated more strongly with UAER （P〈0.01）. 4. Serum CysC,β2-MG, Ccr or Scr is well correlated with the diabetic nephropathy （ 〉20 g/min, according to UAER diagnostic criteria） （ r= 0. 814,0. 785, - 0. 780,0. 520, P〈0.01 ）. Among them,cystatinC correlated more strongly with diabetic nephropathy （P〈0.01）. Conclusion The cystatinC and β2-microglobulin are important biochemical markers of early kidney damage of the type 2 diabetes patients. They are more sensitive and accurate than serum creatinine and endogenous creatinine clearance. Of these two markers,cystatinC has better diagnostic value.