糖尿病患者微量白蛋白尿筛查试验的评估

Evaluation of tests for microalbuminuria screening in patients with diabetes.

作者信息

Incerti Juliane, Zelmanovitz Themis, Camargo Joiza Lins, Gross Jorge Luiz, de Azevedo Mirela Jobim

机构信息

Endocrine Division, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.

出版信息

Nephrol Dial Transplant. 2005 Nov;20(11):2402-7. doi: 10.1093/ndt/gfi074. Epub 2005 Aug 16.

DOI:10.1093/ndt/gfi074

PMID:16105865

Abstract

BACKGROUND

The first step in the diagnosis of diabetic nephropathy is to measure albumin in a spot urine sample. The aim of this study was to assess the accuracy of urinary albumin concentration (UAC), urinary albumin-to-creatinine ratio (UACR), and the Micral-Test II in a random urine specimen (RUS) for microalbuminuria screening in diabetes mellitus.

METHODS

Two hundred and seventy-eight patients collected 24 h timed urine specimens followed by RUS. Albumin (immunoturbidimetry) and creatinine were measured in protein-negative (Combur-Test) urine samples. Samples were classified as normoalbuminuric [24 h urinary albumin excretion rate (UAER) <20 microg/min; n = 189] and microalbuminuric (UAER =20-199 microg/min; n = 89). Micral-Test II readings were performed in 130 RUS. Receiver operating characteristics (ROC) curves were constructed using UAER as the reference standard.

RESULTS

The areas under the ROC curves were similar for UAC (0.934+/-0.032) and UACR (0.920+/-0.035; P = 0.626), but the Micral-Test II had lower accuracy to diagnose microalbuminuria (area = 0.846+/-0.047) than UAC (P = 0.014). The first cutoff point with 100% sensitivity for UAC was 14.4 mg/l (specificity =77.2%), and 15.7 mg/g for UACR (specificity =73.0%). Concerning the Micral-Test II, sensitivity and specificity for the 20 mg/l cutoff point were 90.0 and 46.0%, respectively. The agreement between UAER and the Micral-Test II for microalbuminuria diagnosis was 55.8% (kappa = 0.22; P < 0.001). The cost of diagnosing microalbuminuria was 1.74 dollars(UAC), 2.00 dollars (UACR) and 4.09 dollars (Micral-Test II) per patient.

CONCLUSIONS

Measurement of UAC in a RUS was the best choice for the diagnosis screening of microalbuminuria in diabetic patients, considering cost and accuracy.

摘要

背景

糖尿病肾病诊断的第一步是检测随机尿样中的白蛋白。本研究旨在评估随机尿标本（RUS）中尿白蛋白浓度（UAC）、尿白蛋白与肌酐比值（UACR）及Micral-Test II检测微量白蛋白尿的准确性。

方法

278例患者先收集24小时定时尿标本，随后留取RUS。采用免疫比浊法检测蛋白阴性（尿蛋白定性试纸）尿样中的白蛋白和肌酐。样本分为正常白蛋白尿组[24小时尿白蛋白排泄率（UAER）<20μg/min；n = 189]和微量白蛋白尿组（UAER = 20 - 199μg/min；n = 89）。对130份RUS进行Micral-Test II检测。以UAER作为参考标准绘制受试者工作特征（ROC）曲线。

结果

UAC（0.934±0.032）和UACR（0.920±0.035；P = 0.626）的ROC曲线下面积相似，但Micral-Test II诊断微量白蛋白尿的准确性（面积 = 0.846±0.047）低于UAC（P = 0.014）。UAC灵敏度为100%时的第一个截断点为14.4mg/l（特异性 = 77.2%），UACR为15.7mg/g（特异性 = 73.0%）。对于Micral-Test II，20mg/l截断点的灵敏度和特异性分别为90.0%和46.0%。UAER与Micral-Test II诊断微量白蛋白尿的一致性为55.8%（kappa = 0.22；P < 0.001）。每位患者诊断微量白蛋白尿的成本分别为：UAC 1.74美元、UACR 2.00美元和Micral-Test II 4.09美元。