Teitelbaum S L, Britton J A, Calafat A M, Ye X, Silva M J, Reidy J A, Galvez M P, Brenner B L, Wolff M S
Mount Sinai School of Medicine, Department of Community and Preventive Medicine, 1 Gustave Levy Place, P.O. Box 1043, New York, NY 10029, USA.
Environ Res. 2008 Feb;106(2):257-69. doi: 10.1016/j.envres.2007.09.010. Epub 2007 Oct 31.
Exposure to endocrine disruptors (EDs), including some phthalates, phytoestrogens and phenols can be quantified using biomarkers of exposure. However, reliability in the use of these biomarkers requires an understanding of the timeframe of exposure represented by one measurement. Data on the temporal variability of ED biomarkers are sparse, especially among children.
To evaluate intraindividual temporal variability in 19 individual urinary biomarkers (eight phthalate metabolites from six phthalate diesters, six phytoestrogens (two lignans and four isoflavones) and five phenols) among New York City children.
Healthy Hispanic and Black children (N=35; 6-10 years old) donated several urine samples over 6 months. To assess temporal variability we used three statistical methods: intraclass correlation coefficient (ICC), Spearman correlation coefficients (SCC) between concentrations measured at different timepoints, and surrogate category analysis to determine how well the tertile categories based on a single measurement represented a 6-month average concentration.
Surrogate category analysis indicated that a single sample provides reliable ranking for all analytes; at least three of four surrogate samples predicted the 6-month mean concentration. Of the 19 analytes, the ICC was >0.2 for 18 analytes and >0.3 for 10 analytes. Correlations among sample concentrations throughout the 6-month period were observed for all analytes; 14 analyte concentrations were correlated at 16 weeks.
The reasonable degree of temporal reliability and the wide range of concentrations of phthalate metabolites, phytoestrogens and phenols suggest that these biomarkers are appropriate for use in epidemiologic studies of environmental exposures in relation to health outcomes in children.
接触包括某些邻苯二甲酸盐、植物雌激素和酚类在内的内分泌干扰物（EDs）可通过接触生物标志物进行量化。然而，使用这些生物标志物的可靠性需要了解一次测量所代表的接触时间范围。关于ED生物标志物时间变异性的数据稀少，尤其是在儿童中。
评估纽约市儿童中19种个体尿生物标志物（六种邻苯二甲酸二酯的八种邻苯二甲酸酯代谢物、六种植物雌激素（两种木脂素和四种异黄酮）和五种酚类）的个体内时间变异性。
健康的西班牙裔和黑人儿童（N = 35；6至10岁）在6个月内捐赠了几份尿液样本。为了评估时间变异性，我们使用了三种统计方法：组内相关系数（ICC）、不同时间点测量浓度之间的斯皮尔曼相关系数（SCC），以及替代类别分析，以确定基于单次测量的三分位数类别在多大程度上代表6个月的平均浓度。
替代类别分析表明，单个样本可为所有分析物提供可靠的排名；四个替代样本中至少有三个预测了6个月的平均浓度。在19种分析物中，18种分析物的ICC>0.2，10种分析物的ICC>0.3。在整个6个月期间，观察到所有分析物样本浓度之间的相关性；14种分析物浓度在16周时具有相关性。
邻苯二甲酸酯代谢物、植物雌激素和酚类的时间可靠性程度合理，浓度范围广泛，这表明这些生物标志物适用于儿童环境暴露与健康结果相关的流行病学研究。
