Zelmanovitz T, Gross J L, Oliveira J R, Paggi A, Tatsch M, Azevedo M J
Endocrine Unit, Hospital de Clinicas de Porto Alegre, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
Diabetes Care. 1997 Apr;20(4):516-9. doi: 10.2337/diacare.20.4.516.
To assess the performance of measurements of urinary albumin concentration (UAC) and urinary albumin:creatinine ratio (UACR) in a diurnal random urine specimen (RUS) for the screening of diabetic nephropathy.
A total of 95 ambulatory NIDDM patients (49 women, ages 40-75 years) collected 123 RUSs during the morning after completing a timed 24-h urine collection. Albumin was measured by immunoturbidimetry. According to timed urinary albumin excretion rate (UAER) measured in the 24-h collection (criterion standard), samples were classified as normoalbuminuric (UAER < 20 micrograms/min; n = 54), microalbuminuric (UAER 20-200 micrograms/min; n = 44), and macroalbuminuric (UAER > 200 micrograms/min; n = 25). The receiver operating characteristics (ROC) curve approach was used. The ROC curves of UAC and UACR in RUS for screening of microalbuminuria (normo- and microalbuminuric samples; n = 98) and macroalbuminuria (micro- and macroalbuminuric samples; n = 69) were plotted.
Spearman's coefficients of correlation of 24-h UAER vs. UAC and UACR were 0.91 and 0.92, respectively (P < 0.001). The calculated areas (+/- SE) under the ROC curves to screen microalbuminuria for UAC (0.9766 +/- 0.015) and UACR (0.9689 +/- 0.014) were similar (P > 0.05) as were the corresponding areas for macroalbuminuria (0.9868 +/- 0.0094 and 0.9614 +/- 0.0241, respectively; P > 0.05). The first point with 100% sensitivity and the point of intersection with a 100%-to-100% diagonal for microalbuminuria were as follows: 16.9 and 33.6 mg/l for UAC and 15.0 and 26.8 mg/g for UACR; for macroalbuminuria 174.0 and 296.2 mg/l for UAC and 116.0 and 334.3 mg/g for UACR, respectively.
Albumin measurements (UAC and UACR) in an RUS presented almost perfect accuracy for the screening of micro- and macroalbuminuria and UAC measured in an RUS is simpler and less expensive than UACR and UAER. It is suggested as a valid test for use in screening for diabetic nephropathy.
评估在日间随机尿标本（RUS）中测量尿白蛋白浓度（UAC）和尿白蛋白：肌酐比值（UACR）用于筛查糖尿病肾病的性能。
总共95例非卧床NIDDM患者（49名女性，年龄40 - 75岁）在完成定时24小时尿液收集后的早晨收集了123份RUS。白蛋白通过免疫比浊法测量。根据在24小时收集（标准对照）中测量的定时尿白蛋白排泄率（UAER），样本被分类为正常白蛋白尿（UAER < 20微克/分钟；n = 54）、微量白蛋白尿（UAER 20 - 200微克/分钟；n = 44）和大量白蛋白尿（UAER > 200微克/分钟；n = 25）。采用受试者工作特征（ROC）曲线方法。绘制了RUS中UAC和UACR用于筛查微量白蛋白尿（正常和微量白蛋白尿样本；n = 98）和大量白蛋白尿（微量和大量白蛋白尿样本；n = 69）的ROC曲线。
24小时UAER与UAC和UACR的Spearman相关系数分别为0.91和0.92（P < 0.001）。用于筛查微量白蛋白尿时，UAC（0.9766 +/- 0.015）和UACR（0.9689 +/- 0.014）的ROC曲线下计算面积（+/- SE）相似（P > 0.05）；用于筛查大量白蛋白尿时，相应面积分别为0.9868 +/- 0.0094和0.9614 +/- 0.0241（P > 0.05）。微量白蛋白尿的100%灵敏度的第一个点以及与100%至100%对角线的交点如下：UAC为16.9和33.6毫克/升，UACR为15.0和26.8毫克/克；大量白蛋白尿的UAC为174.0和296.2毫克/升，UACR为116.0和334.3毫克/克。
RUS中的白蛋白测量（UAC和UACR）在筛查微量和大量白蛋白尿方面具有几乎完美的准确性，并且RUS中测量的UAC比UACR和UAER更简单、成本更低。建议将其作为筛查糖尿病肾病的有效检测方法。
