Variance components of short-term biomarkers of manganese exposure in an inception cohort of welding trainees.
Variance components of short-term biomarkers of manganese exposure in an inception cohort of welding trainees.
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DOI：
10.1016/j.jtemb.2014.05.004
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发表时间：
2015-01
期刊：
影响因子：
--
通讯作者：
Seixas N
中科院分区：
文献类型：
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作者：
Baker MG;Simpson CD;Sheppard L;Stover B;Morton J;Cocker J;Seixas N
已经探索了暴露的各种生物标志物作为定量估计锰（Mn）暴露的内部剂量的方式，但是考虑到Mn在体内的严格调节、基线Mn水平的个体间变异性以及暴露与吸收到各种生物组织中之间的时间的变异性，识别Mn暴露的有价值且有用的生物标志物一直是难以捉摸的。因此，使用限制最大似然法估计方差分量的混合模型用于评估一组9名新暴露的学徒焊工的全血、血浆和尿液（分别为MnB、MnP和MnU）中受试者内和受试者间方差分量，在三个月的时间内采集基线和随后的纵向样本。在MnB中，发现大部分方差在受试者之间（94%），而在MNP和MnU中，发现大部分方差在受试者内（分别为79%和99%），即使在控制采样时间时也是如此。虽然血液似乎表现出锰的稳态控制，但血浆和尿液（受试者内的大部分变异）却没有。本文提供的结果表明，在评估锰的生物标志物时，重复测量或纵向研究设计的重要性，以及可能由横断面分析产生的虚假关联。
Various biomarkers of exposure have been explored as a way to quantitatively estimate an internal dose of manganese (Mn) exposure, but given the tight regulation of Mn in the body, inter-individual variability in baseline Mn levels, and variability in timing between exposure and uptake into various biological tissues, identification of a valuable and useful biomarker for Mn exposure has been elusive. Thus, a mixed model estimating variance components using restricted maximum likelihood was used to assess the within- and between-subject variance components in whole blood, plasma, and urine (MnB, MnP, and MnU, respectively) in a group of nine newly-exposed apprentice welders, on whom baseline and subsequent longitudinal samples were taken over a three month period. In MnB, the majority of variance was found to be between subjects (94%), while in MnP and MnU the majority of variance was found to be within subjects (79% and 99%, respectively), even when controlling for timing of sample. While blood seemed to exhibit a homeostatic control of Mn, plasma and urine, with the majority of the variance within subjects, did not. Results presented here demonstrate the importance of repeat measure or longitudinal study designs when assessing biomarkers of Mn, and the spurious associations that could result from cross-sectional analyses.