Zelmanovitz T, Gross J L, Oliveira J, de Azevedo M J
Endocrine Unit, Hospital de Clínicas de Porto Alegre, Federal University of Rio Grande do Sul, Brazil.
Diabetes Care. 1998 Jul;21(7):1076-9. doi: 10.2337/diacare.21.7.1076.
To assess the performance of urinary total protein measurements in timed 24-h urine collection (24-h UP) and in a diurnal random urine specimen (RUS) for the screening and diagnosis of overt diabetic nephropathy.
A total of 167 diabetic patients (20 type 1 and 147 type 2 diabetic patients; 78 women and 89 men), aged 20-84 years, collected 217 timed 24-h urine specimens. Albumin was measured by immunoturbidimetry, total protein by sulfosalicylic acid technique, and creatinine by Jaffe's method. According to the timed 24-h urinary albumin excretion rate (UAER), samples were divided into three groups: normoalbuminuric (NORMO) (UAER < 20 micrograms/min; n = 84), microalbuminuric (MICRO) (UAER 20-200 micrograms/min; n = 78), and macroalbuminuric (MACRO) (UAER > or = 200 micrograms/min; n = 55). Eighty-six patients also collected 105 RUSs (NORMO, n = 47; MICRO, n = 37; MACRO, n = 21), and urinary protein concentration (UPC) and urinary protein-to-creatinine ratio (UPCR) were measured. The receiver operating characteristics (ROC) curve approach was used to analyze the performance of the diagnostic tests.
Spearman's coefficient of correlation of 24-h UAER versus 24-h UP was 0.95 (P < 0.001), and of 24-h UAER versus UPC and UPCR were 0.77 and 0.72, respectively (P < 0.001). The calculated areas (+/- SEM) under the ROC curve for the diagnosis of over diabetic nephropathy were 0.9987 +/- 0.001 for 24-h UP, 0.9926 +/- 0.006 for UPC, and 0.9751 +/- 0.014 for UPCR. In the ROC curves, the first points with 100% sensitivity were 541 mg (95.7% specificity) for 24-h UP, 431 mg/l (92.9% specificity) for UPC, and 0.2 (76.2% specificity) for UPCR.
Measurements of proteinuria presented almost perfect accuracy for the screening and diagnosis of overt diabetic nephropathy. Protein measurement in spot urine is a reliable and simple method for the screening and diagnosis of overt diabetic nephropathy.
评估定时24小时尿蛋白定量（24-h UP）及随机尿标本（RUS）中尿总蛋白测定在显性糖尿病肾病筛查及诊断中的性能。
共167例糖尿病患者（1型糖尿病20例，2型糖尿病147例；女性78例，男性89例），年龄20 - 84岁，收集了217份定时24小时尿标本。采用免疫比浊法测定白蛋白，磺基水杨酸法测定总蛋白，Jaffe法测定肌酐。根据定时24小时尿白蛋白排泄率（UAER），样本分为三组：正常白蛋白尿组（NORMO）（UAER < 20微克/分钟；n = 84）、微量白蛋白尿组（MICRO）（UAER 20 - 200微克/分钟；n = 78）和大量白蛋白尿组（MACRO）（UAER≥200微克/分钟；n = 55）。86例患者还收集了105份随机尿标本（NORMO组，n = 47；MICRO组，n = 37；MACRO组，n = 21），并测定尿蛋白浓度（UPC）和尿蛋白/肌酐比值（UPCR）。采用受试者操作特征（ROC）曲线分析法分析诊断试验的性能。
24小时UAER与24小时UP的Spearman相关系数为0.95（P < 0.001），24小时UAER与UPC及UPCR的相关系数分别为0.77和0.72（P < 0.001）。诊断显性糖尿病肾病时，计算得到的ROC曲线下面积（±SEM），24小时UP为0.9987±0.001，UPC为0.9926±0.006，UPCR为0.9751±0.014。在ROC曲线中，灵敏度为100%时的第一个点，24小时UP为541毫克（特异性95.7%），UPC为431毫克/升（特异性92.9%），UPCR为0.2（特异性76.2%）。
蛋白尿测定在显性糖尿病肾病的筛查及诊断中具有几乎完美的准确性。随机尿蛋白测定是显性糖尿病肾病筛查及诊断的一种可靠且简便的方法。
