肾小球滤过率和肾有效血浆流量“分离现象”对诊断早期糖尿病肾病的意义

Significance of the separation between glomerular filtration rate and effective renal plasma flow in evaluation of early diabetic nephropathy

目的探讨肾小球滤过率(GFR)和肾有效血浆流量(ERPF)的变化对诊断早期糖尿病肾病(DN)的意义。方法根据尿白蛋白排泄率(UAER)将105例2型糖尿病(T2DM)患者分为3组:无DN(NDN)组,早期DN(EDN)组,临床DN(CDN)组。用SPECT测定GFR、ERPF值,并测定尿白蛋白(UAlb)、尿免疫球蛋白G(UIgG)、α1微球蛋白(Uα1-MG)、β2微球蛋白(Uβ2-MG)、血清肌酐(SCr)和尿素氮(BUN)。结果NDN组GFR和ERPF值增高,与UAlb负相关;EDN组GFR增高与UAlb正相关,ERPF低于正常对照组,与UAlb负相关,出现GFR和ERPF"分离现象";CDN组GFR和ERPF明显降低,与UAlb负相关。UAlb、UIgG、Uα1-MG、Uβ2-MG与SCr、BUN正相关。结论核素显像测定GFR、ERPF"分离现象"能够及时反映糖尿病的早期肾脏损害,与UAlb联合检测有助于了解DN的病变程度。

Objective To observe the role of changes of GFR and ERPF in the different stages of diabetic nephropathy. Methods 105 patients with T2DM were divided into three groups according to urinary albumin excretion rate （UAER）： group without diabetic nephropathy（NDN） （UAER〈20 μg/min, n=35）; early DN （EDN, UAER 20-200 μg/min, n=35）; clinical DN （CDN, UAER〉 200 μg/min, n= 35）. GFR and ERPF determination were performed by nuclide renal dynamic imaging, together with the assays of albuminuria （Alb）, IgG, α1-MG, β2-MG, SCr and BUN. Results Compared with control group, the NDN group showed that GFR and ERPF were increased and negatively correlated with amount of albuminuria （r=-0. 488, P〈0. 01 for GFR; r=-0. 453, P〈0. 01 for ERPF）, while EDN group showed that GFR was increased and positively correlated with amount of albuminuria, ERPF was slightly decreased and negatively correlated with amount of albuminuria（r =0. 312, P〈0. 05 for GFR; r=-0. 331, P〈0. 05 for ERPF）, which were called ＂GFR and ERPF separation＂. GFR and ERPF were decreased, and negatively correlated with amount of albuminuria in CND group （r= -0. 485, P〈0.01 for GFR; r= -0. 467, P〈0. 01 for ERPF）. Alb, IgG, α1-MG and β2-MG were positively correlated with Scr and BUN（all P〈0.01）. Conclusions GFR and ERPF separation can reflect the degree of renal damage of diabetic patients,and may be helpful to evaluate progression of DN when combined with assay of albuminuria.