Kemperman F A, Silberbusch J, Slaats E H, Prins A M, Krediet R T, Arisz L
Department of Internal Medicine, Internal Medicine of the Academic Medical Centre, University of Amsterdam, The Netherlands.
Clin Nephrol. 2000 Oct;54(4):255-60.
The glomerular filtration rate (GFR) can be estimated from plasma creatinine according to the formula of Cockcroft and Gault (CG). When tubular secretion of creatinine is inhibited by cimetidine the mean difference between the Cockcroft-Gault clearance (CG(Cim) and GFR approximates zero, but there is still some interindividual difference, especially in type-2-diabetic patients. We studied during longitudinal follow-up, whether the discrepancies between CG(Cim) and GFR per patient are consistent in time in type-2-diabetic patients.
In 1996 and 1998 (interval 20-26 months) GFR was measured in 21 patients as the urinary clearance of continuously infused 125I-iothalamate. Plasma creatinine was analyzed with an enzymatic assay before and after oral cimetidine 800 mg t.i.d. during 24 hours. GFR estimations were calculated with the Cockcroft-Gault formula before (CG) and after cimetidine (CG(Cim)) and expressed as means +/- SEM.
GFR deteriorated from 89.7 +/- 5.7 to 81.3 + 5.8 ml/min/1.73 m2 and CG(Cim) from 85.3 +/- 5.7 to 81.1 +/- 6.6 ml/min/1.73 m2, whereas CG decreased from 102.4 +/- 6.8 to 98.4 +/- 7.0 ml/min/1.73 m2. Changes in GFR and changes in CG(Cim) were correlated (r = 0.72, p < 0.001) and were not significantly different from each other. The discrepancy between CG(Cim) and GFR per patient in 1996 also correlated with the discrepancy between CG(Cim) and GFR in 1998 (r = 0.85, p < 0.001 ).
In individual patients the discrepancies between the CG(Cim) and GFR are consistent in time and the change in GFR is reflected by the change in CG(Cim). This small variability means that CG(Cim), based on an enzymatic plasma creatinine assay, would be suitable for follow-up of GFR in type-2-diabetic patients, independent of albuminuria.
肾小球滤过率（GFR）可根据Cockcroft和Gault（CG）公式由血浆肌酐估算得出。当西咪替丁抑制肌酐的肾小管分泌时，Cockcroft - Gault清除率（CG(Cim)）与GFR之间的平均差异接近零，但个体间仍存在一些差异，尤其是在2型糖尿病患者中。我们在纵向随访期间研究了2型糖尿病患者中每位患者的CG(Cim)与GFR之间的差异在时间上是否一致。
1996年和1998年（间隔20 - 26个月），对21例患者进行了GFR测量，采用持续输注125I - 碘肽酸盐的尿清除率方法。在口服西咪替丁800 mg每日3次共24小时前后，用酶法分析血浆肌酐。在服用西咪替丁之前（CG）和之后（CG(Cim)）用Cockcroft - Gault公式计算GFR估计值，并表示为平均值±标准误。
GFR从89.7±5.7降至81.3 + 5.8 ml/min/1.73 m2，CG(Cim)从85.3±5.7降至81.1±6.6 ml/min/1.73 m2，而CG从102.4±6.8降至98.4±7.0 ml/min/1.73 m2。GFR的变化与CG(Cim)的变化相关（r = 0.72，p < 0.001），且两者之间无显著差异。1996年每位患者的CG(Cim)与GFR之间的差异也与1998年CG(Cim)与GFR之间的差异相关（r = 0.85，p < 0.001）。
在个体患者中，CG(Cim)与GFR之间的差异在时间上是一致的，GFR的变化由CG(Cim)的变化反映出来。这种小的变异性意味着基于酶法血浆肌酐分析的CG(Cim)适用于2型糖尿病患者GFR的随访，与蛋白尿无关。
