Yamaguchi T, Kadono K
First Department of Internal Medicine, Kansai Medical University, Osaka.
Nihon Jinzo Gakkai Shi. 1991 Mar;33(3):283-93.
For the early diagnosis of diabetic nephropathy, it is best to use the albumin excretion rate (AER). However, it is a complicated test to perform in the outpatient setting, and it is sometimes affected by inaccurate urine collection. Therefore, we have used the albumin/creatinine ratio, which is measured simply with randomly collected urine, for evaluation of microalbuminuria and found it to be of equal diagnostic value to the AER. The AER, albumin/creatinine ratio, and creatinine excretion rate were measured in 86 patients with NIDDN who were negative for proteinuria. Urine was obtained after bed rest and in the outpatients department (without rest). 1) The reproducibility of time-restricted urine sampling was investigated using the rate of creatinine excretion. The mean coefficient of variation was found to be 42%, and inaccurate urine sampling appeared to cause variation in the AER. 2) The AER and albumin/creatinine ratio obtained in the outpatient setting were higher than those after bed rest, and urine collection at the time of outpatient examination was considered to be more useful than that after bed rest. To check variations in urine collection at the time of outpatient examination, the albumin/creatinine ratio in random urine samples was superior on the basis of the correlation coefficients to urine obtained after bed rest. 3) The urinary creatinine excretion rate showed a significant sex difference (males: 0.823 +/- 0.152 mg/g. creat., females: 0.577 +/- 0.194 mg/g. creat) (p less than 0.001), but there was no significant difference for BMI and age. The relationship between each level of microalbuminuria and the creatinine excretion rate did not change significantly. 4) The following formula was used to calculate the albumin/creatinine ratio corresponding to the AER. Albumin/creatinine ratio formula; (see text) An AER of 30 micrograms/min thus corresponds to an albumin/creatinine ratio of 36 mg/g. creat. for males and 51 mg/g. creat. for females. 5) The percentage of positive results for microalbuminuria in patients with NIDDM showed that the albumin/creatinine ratio and the AER were equal as diagnostic criteria, when the sex difference was taken into consideration. Thus, the albumin/creatinine ratio is equal to the AER for evaluation of microalbuminuria, and it is a simple and convenient test to use in daily clinical practice.
对于糖尿病肾病的早期诊断，最好使用白蛋白排泄率（AER）。然而，在门诊环境中进行该项检测较为复杂，且有时会受到尿液收集不准确的影响。因此，我们采用了白蛋白/肌酐比值，该比值通过随机收集的尿液简单测量，用于评估微量白蛋白尿，并发现其与AER具有同等的诊断价值。对86例非胰岛素依赖型糖尿病（NIDDN）且蛋白尿阴性的患者测量了AER、白蛋白/肌酐比值和肌酐排泄率。尿液分别在卧床休息后及门诊（未休息）时采集。1）利用肌酐排泄率研究了限时尿液采样的可重复性。发现平均变异系数为42%，尿液采样不准确似乎会导致AER出现变化。2）门诊环境下获得的AER和白蛋白/肌酐比值高于卧床休息后的值，门诊检查时的尿液收集被认为比卧床休息后更有用。为检查门诊检查时尿液收集的差异，基于相关系数，随机尿液样本中的白蛋白/肌酐比值优于卧床休息后采集的尿液。3）尿肌酐排泄率存在显著的性别差异（男性：0.823±0.152mg/g肌酐，女性：0.577±0.194mg/g肌酐）（p＜0.001），但体重指数（BMI）和年龄无显著差异。各水平微量白蛋白尿与肌酐排泄率之间的关系无明显变化。4）使用以下公式计算与AER对应的白蛋白/肌酐比值。白蛋白/肌酐比值公式；（见原文）因此，AER为30微克/分钟时，男性对应的白蛋白/肌酐比值为36mg/g肌酐，女性为51mg/g肌酐。5）非胰岛素依赖型糖尿病（NIDDM）患者微量白蛋白尿阳性结果的百分比表明，考虑性别差异时，白蛋白/肌酐比值和AER作为诊断标准是等效的。因此，白蛋白/肌酐比值在评估微量白蛋白尿方面与AER等效，且在日常临床实践中是一种简单方便的检测方法。
