Sun Qi, Bertrand Kimberly A, Franke Adrian A, Rosner Bernard, Curhan Gary C, Willett Walter C
Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA;
Departments of Nutrition.
Am J Clin Nutr. 2017 Jan;105(1):159-168. doi: 10.3945/ajcn.116.139758. Epub 2016 Nov 9.
Limited knowledge regarding the reproducibility of biomarkers in 24-h urine samples has hindered the collection and use of the samples in epidemiologic studies.
We aimed to evaluate the reproducibility of various markers in repeat 24-h urine samples.
We calculated intraclass correlation coefficients (ICCs) of biomarkers measured in 24-h urine samples that were collected in 3168 participants in the NHS (Nurses' Health Study), NHSII (Nurses' Health Study II), and Health Professionals Follow-Up Study.
In 742 women with 4 samples each collected over the course of 1 y, ICCs for sodium were 0.32 in the NHS and 0.34 in the NHSII. In 2439 men and women with 2 samples each collected over 1 wk to ≥1 mo, the ICCs ranged from 0.33 to 0.68 for sodium at various intervals between collections. The urinary excretion of potassium, calcium, magnesium, phosphate, sulfate, and other urinary markers showed generally higher reproducibility (ICCs >0.4). In 47 women with two 24-h urine samples, ICCs ranged from 0.15 (catechin) to 0.75 (enterolactone) for polyphenol metabolites. For phthalates, ICCs were generally ≤0.26 except for monobenzyl phthalate (ICC: 0.55), whereas the ICC was 0.39 for bisphenol A (BPA). We further estimated that, for the large majority of the biomarkers, the mean of three 24-h urine samples could provide a correlation of ≥0.8 with true long-term urinary excretion.
These data suggest that the urinary excretion of various biomarkers, such as minerals, electrolytes, most polyphenols, and BPA, is reasonably reproducible in 24-h urine samples that are collected within a few days or ≤1 y. Our findings show that three 24-h samples are sufficient for the measurement of long-term exposure status in epidemiologic studies.
关于24小时尿液样本中生物标志物可重复性的知识有限，这阻碍了这些样本在流行病学研究中的收集和使用。
我们旨在评估重复的24小时尿液样本中各种标志物的可重复性。
我们计算了在NHS（护士健康研究）、NHSII（护士健康研究II）和卫生专业人员随访研究中3168名参与者收集的24小时尿液样本中测量的生物标志物的组内相关系数（ICC）。
在742名女性中，每人在1年的时间里收集了4份样本，NHS中钠的ICC为0.32，NHSII中为0.34。在2439名男性和女性中，每人在1周至≥1个月的时间里收集了2份样本，不同收集间隔下钠的ICC在0.33至0.68之间。钾、钙、镁、磷酸盐、硫酸盐和其他尿液标志物的尿排泄量通常显示出更高的可重复性（ICC>0.4）。在47名有两份24小时尿液样本的女性中，多酚代谢物的ICC在0.15（儿茶素）至0.75（肠内酯）之间。对于邻苯二甲酸盐，除单苄基邻苯二甲酸盐（ICC：0.55）外，ICC通常≤0.26，而双酚A（BPA）的ICC为0.39。我们进一步估计，对于绝大多数生物标志物，三份24小时尿液样本的平均值与真实的长期尿排泄量的相关性≥0.8。
这些数据表明，在几天内或≤1年内收集的24小时尿液样本中，各种生物标志物（如矿物质、电解质、大多数多酚和BPA）的尿排泄量具有合理的可重复性。我们的研究结果表明，三份24小时样本足以在流行病学研究中测量长期暴露状况。
