Background

Biomarker selenium concentrations vary greatly between studies. Concentrations in erythrocytes, urine, and hair vary even at similar plasma concentrations, suggesting that unknown factors influence the distribution of selenium between body compartments.

Objective

To assess predictors of the different selenium biomarkers in children.

Design

We used a mother-child cohort, nested in a population-based supplementation trial in rural Bangladesh (MINIMat), established for evaluation of arsenic toxicity. Selenium was measured in plasma (n = 223), erythrocytes, urine, and hair at 9 years (n = 395) and in erythrocytes and urine at 4.5 years (n = 259) using inductively coupled plasma mass spectrometry. We also measured concentrations of arsenic (all biospecimen) and cadmium (erythrocytes and urine). Genotyping for INMT, a methyltransferase involved in selenium metabolism, was performed using TaqMan probes.

Results

At 9 years, the selenium concentrations ranged 51–139 μg/L in plasma, 128–281 μg/L in erythrocytes, 2.2–55 μg/L in urine, and 258–723 μg/kg in hair. Correlations (r_S) between biomarkers ranged 0.12–0.37, and were strongest between blood compartments and between erythrocytes and hair (long-term markers). In multivariable-adjusted linear regression analyses, plasma selenium differed by sampling season (highest in food-secure pre-monsoon season) and was inversely associated with plasma arsenic (range < 0.0080–20 μg/L; B = −1.1, 95% CI: -1.8, −0.41). In contrast, erythrocyte selenium was positively associated with erythrocyte arsenic (range 0.95–50 μg/L; B = 0.58, 95% CI: 0.26, 0.91) and inversely associated with erythrocyte cadmium (range 0.27–3.1 μg/L; B = −12, 95% CI: −17, −6.9). These associations were similar at 4.5 years. Only selenium in hair and urine were influenced by INMT polymorphisms. Finally, chronic malnutrition seemed to increase selenium retention, measured as the ratio plasma/urinary selenium.

Conclusions

Selenium biomarkers seem to be influenced by malnutrition, genetics, and exposure to metal pro-oxidants. This might affect the evaluation of deficiency/sufficiency, normally assessed by selenium in plasma/serum.

中文翻译：

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孟加拉4-9岁儿童中硒生物标志物动力学的预测因子

背景

研究之间的生物标志物硒浓度差异很大。即使在相似的血浆浓度下，红细胞，尿液和头发中的浓度也会发生变化，这表明未知因素会影响硒在车厢之间的分布。

客观的

评估儿童中不同硒生物标志物的预测因子。

设计

我们使用了一个母婴队列，该队列嵌套在孟加拉国农村地区（MINIMat）的一项基于人群的补充试验中，该试验旨在评估砷的毒性。使用电感耦合等离子体质谱法测定血浆中硒（n = 223），红细胞，尿液和头发中的硒含量为9年（n = 395），以及血浆中红细胞和尿液的硒浓度为4.5年（n = 259）。我们还测量了砷（所有生物样本）和镉（红细胞和尿液）的浓度。使用TaqMan探针对INMT（涉及硒代谢的甲基转移酶）进行基因分型。

结果

在9年时，血浆中硒的浓度范围为51–139μg/ L，红细胞中的硒浓度范围为128–281μg/ L，尿液中的硒浓度范围为2.2–55μg/ L，头发中的浓度为258–723μg/ kg。相关性（r _S）之间的生物标志物范围在0.12-0.37之间，并且在血室之间以及红细胞和头发之间（长期标志物）最强。在多变量调整的线性回归分析中，血浆硒随采样季节不同（在粮食安全的季风前季节最高），并且与血浆砷呈负相关（范围<0.0080–20μg/ L； B = −1.1，95％CI ：-1.8，-0.41）。相反，红细胞硒与红细胞砷呈正相关（范围0.95–50μg/ L； B = 0.58，95％CI：0.26，0.91），与红细胞镉呈负相关（范围0.27–3.1μg/ L； B =- 12，95％CI：-17，-6.9）。这些关联在4.5年时相似。INMT仅影响头发和尿液中的硒多态性。最后，以血浆/尿中硒的比例来衡量，慢性营养不良似乎会增加硒的保留。

结论

硒生物标志物似乎受到营养不良，遗传和金属促氧化剂暴露的影响。这可能会影响缺乏/充足性的评估，通常通过血浆/血清中的硒来评估。