Background

Telomere length has been associated with the occurrence and progression of common chronic and age-related diseases, and in younger populations, may represent a biomarker of disease susceptibility. Early childhood is a critical period for telomere biology as this period is characterized by a rapid decline in telomere length due to a large turnover of highly proliferative cells and may represent a period of unique sensitivity to environmental insults. Arsenic (As) exposure has been associated with both telomere lengthening and shortening in adults and children and some evidence suggests the effects may differ by level and timing of exposure.

Objectives

Given the lack of clarity across studies, we investigated the association between urinary As and leukocyte telomere length among 476 five- to seven-year-old children enrolled in the Bangladesh Environmental Research in Children's Health (BiRCH) cohort.

Methods

In a series of multivariable models, adjusted for key covariates, we examined associations between urinary As and relative telomere length (RTL) of whole blood DNA.

Results

We observed small but consistent, negative associations between urinary As and RTL, such that a doubling of urinary As was associated with a −0.017 (95% CI: −0.030, −0.005; p = 0.0056) decrease in RTL, in fully adjusted models. We also observed a somewhat stronger inverse relationship between urinary As concentration and RTL among children born to fathers ≥ 30 years of age at the time of birth, than those < 30 years; however, we did not observe a statistically significant interaction.

Discussion

Our study suggests that As influences RTL, with detectable associations in early to mid-childhood. Further studies are needed to confirm our findings and investigate the potential long-term impacts of telomere shortening in childhood on later life health outcomes. Additional studies exploring how dose and timing of exposure may relate to RTL are critical to understanding As’s relationship to telomere length.

中文翻译：

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孟加拉国 5-7 岁儿童的尿砷和相对端粒长度

背景

端粒长度与常见慢性和年龄相关疾病的发生和进展有关，在年轻人群中，端粒长度可能代表疾病易感性的生物标志物。儿童早期是端粒生物学的关键时期，因为这一时期的特点是由于高度增殖细胞的大量更新，端粒长度迅速下降，并且可能代表对环境损伤的独特敏感性时期。砷 (As) 暴露与成人和儿童的端粒延长和缩短有关，一些证据表明影响可能因暴露水平和时间而异。

目标

鉴于各项研究缺乏明确性，我们调查了参加孟加拉国儿童健康环境研究 (BiRCH) 队列的 476 名 5 至 7 岁儿童的尿砷与白细胞端粒长度之间的关联。

方法

在针对关键协变量进行调整的一系列多变量模型中，我们检查了尿 As 与全血 DNA 的相对端粒长度 (RTL) 之间的关联。

结果

我们观察到尿 As 和 RTL 之间存在小但一致的负相关性，因此在完全调整的模型中，尿 As 增加一倍与 RTL 降低 -0.017 (95% CI: -0.030, -0.005; p = 0.0056) 相关. 我们还观察到，在父亲 ≥ 30 岁的父亲所生的孩子中，尿砷浓度与 RTL 之间的负相关关系要强于小于 30 岁的孩子；然而，我们没有观察到统计学上显着的相互作用。

讨论

我们的研究表明，As 影响 RTL，在儿童早期至中期具有可检测的关联。需要进一步的研究来证实我们的研究结果，并调查儿童期端粒缩短对以后生活健康结果的潜在长期影响。探索暴露剂量和时间如何与 RTL 相关的其他研究对于理解 As 与端粒长度的关系至关重要。