Evaluation of measures of urinary albumin excretion
Evaluation of measures of urinary albumin excretion
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DOI：
10.1093/aje/kwj271
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发表时间：
2006-10-15
影响因子：
5
通讯作者：
de Zeeuw, Dick
中科院分区：
文献类型：
--
作者：
Gansevoort, Ronald T.;Brinkman, Jacoline;de Zeeuw, Dick
蛋白尿作为心血管和肾脏疾病进展的一个有价值的风险标志物，最近引起了人们的广泛关注。白蛋白尿可以以几种方式测量和表示：1）在晨点尿样中作为尿白蛋白浓度（mg/L）或白蛋白：肌酐比（mg/mmol），和2）在24小时尿液收集中作为尿白蛋白排泄（mg/24小时）。在临床实践中，哪种白蛋白尿测量方法更可取尚未阐明。其中一个选择应该是哪种测量显示最小的人内变异系数。从他们在1997-2001年肾和血管终末期疾病干预试验中的工作角度，作者讨论了在解释关于这一主题的研究时重要的几个方法学问题。有人认为应该使用新鲜尿液，因为在-20 ℃下冷冻会导致白蛋白浓度的相当大的额外变化。此外，重要的是使用专门收集的尿液样本，而不是24小时尿液样本的一部分作为晨尿样本的替代品。蛋白尿遵循昼夜节律。因此，当在24小时尿液采集的一部分中测量时，与晨尿点样相比，人内变异系数的值将因此不同。
Albuminuria has recently drawn much attention as a valuable risk marker for cardiovascular and renal disease progression. Albuminuria can be measured and expressed in several ways: 1) in a spot morning urine sample as urinary albumin concentration (mg/liter) or albumin:creatinine ratio (mg/mmol) and 2) in a 24-hour urine collection as urinary albumin excretion (mg/24 hours). It has not yet been clarified which measure for albuminuria is preferable in clinical practice. One of the points on which a choice should be made is which measure shows the least within-person coefficient of variation. From the perspective of their work in the Prevention of Renal and Vascular Endstage Disease Intervention Trial, 1997-2001, the authors discuss several methodological issues that are important when interpreting studies on this topic. It is argued that fresh urine should be used, since freezing at -20 degrees C results in considerable extra variability in the albumin concentration. Furthermore, it is important to use specifically collected urine samples and not portions of a 24-hour urine sample as a surrogate for a spot morning urine sample. Albuminuria follows a circadian rhythm. Consequently, values for the within-person coefficient of variation will therefore be different when they are measured in a portion of a 24-hour urine collection in comparison with a spot morning urine sample.