Background

Exposure to heavy metals has been considered harmful and can cause cognitive deficits in preschool children.

Objective

To investigate the possible mediation effect of neurotransmitters on the relationship of heavy metal exposure with neurobehaviour.

Methods

The levels of blood heavy metals and neurotransmitters, along with the neurobehavioural scores, were determined in preschool children. Multiple linear regression was used to assess the relationship between heavy metals, neurotransmitters, and neurobehavioural scores. Furthermore, the mediating role of neurotransmitters was investigated.

Results

An interquartile range (IQR) increase in lead (6.10 μg/L) was associated with a decrease of 8.52%, 30.06%, and 20.10% for Glutamic acid (Glu), Glycine (Gly), and gamma-aminobutyric acid (GABA), respectively. An IQR increase in arsenic (19.37 μg/L) was associated with an increase of 6.32% and 2.09% for Gly and GABA, respectively. Further, an IQR increase in zinc (15.58 μg/L) was associated with an increase of 1.44% for Ser, whereas the IQR increase was associated with a decrease of 2.14%, 2.24%, and 1.89% for Glu, Gly, and GABA, respectively. An IQR increase in selenium (38.75 μg/L) was associated with an increase of 1.88% for GABA. Moreover, both Glu and Gly decreased by 2.87% for an IQR increase in manganese (16.92 μg/L). An IQR increase in mercury (15.22 μg/L) was associated with a decrease of 2.43% for Ser, but the IQR increase was associated with an increase of 4.99% and 3.09% for Gly and GABA, respectively. It was found that Glu and Serine (Ser) have a significant linear relationship with conduct score and impulsivity-hyperactivity index, and that there was a significant linear relationship between Ser and the learning disability index. GABA and conduct score and attention-deficit hyperactivity disorder (ADHD) index have a significant linear relationship. There is a significant linear relationship between Gly and conduct, anxiety, ADHD, and impulsivity-hyperactivity index. The results of the mediating effect analysis indicated that Ser, Glu, Gly, and GABA have a specific mediating effect between blood heavy metals and neurobehaviour.

Conclusion

We showed the mediating effect of neurotransmitters. The current study may provide valuable information regarding the prevention and management of metal-related neurological disorders in preschool children.

中文翻译：

---

学龄前儿童横断面调查：探索重金属暴露、神经递质、神经行为关系和中介效应

背景

接触重金属被认为是有害的，会导致学龄前儿童的认知缺陷。

客观的

探讨神经递质对重金属暴露与神经行为关系的可能中介作用。

方法

血液重金属和神经递质的水平以及神经行为评分是在学龄前儿童中测定的。多元线性回归用于评估重金属、神经递质和神经行为评分之间的关​​系。此外，研究了神经递质的中介作用。

结果

铅的四分位间距 (IQR) 增加 (6.10 μg/L) 与谷氨酸 (Glu)、甘氨酸 (Gly) 和 γ-氨基丁酸 (GABA) 分别减少 8.52%、30.06% 和 20.10% 相关， 分别。砷的 IQR 增加（19.37 μg/L）与 Gly 和 GABA 分别增加 6.32% 和 2.09% 相关。此外，锌的 IQR 增加（15.58 μg/L）与 Ser 增加 1.44% 相关，而 IQR 增加与 Glu、Gly 和 GABA 减少 2.14%、2.24% 和 1.89% 相关， 分别。硒的 IQR 增加（38.75 μg/L）与 GABA 增加 1.88% 相关。此外，随着锰的 IQR 增加（16.92 μg/L），Glu 和 Gly 均下降了 2.87%。汞的 IQR 增加（15.22 μg/L）与 Ser 的减少 2.43% 相关，但 IQR 增加与 Gly 和 GABA 分别增加 4.99% 和 3.09% 相关。发现Glu和丝氨酸（Ser）与品行评分和冲动-多动指数呈显着线性关系，Ser与学习障碍指数呈显着线性关系。GABA与品行评分和注意力缺陷多动障碍（ADHD）指数呈显着线性关系。Gly 与行为、焦虑、ADHD 和冲动-多动指数之间存在显着的线性关系。介导效应分析结果表明，Ser、Glu、Gly、GABA在血液重金属与神经行为之间具有特异性介导作用。发现Glu和丝氨酸（Ser）与品行评分和冲动-多动指数呈显着线性关系，Ser与学习障碍指数呈显着线性关系。GABA与品行评分和注意力缺陷多动障碍（ADHD）指数呈显着线性关系。Gly 与行为、焦虑、ADHD 和冲动-多动指数之间存在显着的线性关系。介导效应分析结果表明，Ser、Glu、Gly、GABA在血液重金属与神经行为之间具有特异性介导作用。发现Glu和丝氨酸（Ser）与品行评分和冲动-多动指数呈显着线性关系，Ser与学习障碍指数呈显着线性关系。GABA与品行评分和注意力缺陷多动障碍（ADHD）指数呈显着线性关系。Gly 与行为、焦虑、ADHD 和冲动-多动指数之间存在显着的线性关系。介导效应分析结果表明，Ser、Glu、Gly、GABA在血液重金属与神经行为之间具有特异性介导作用。GABA与品行评分和注意力缺陷多动障碍（ADHD）指数呈显着线性关系。Gly 与行为、焦虑、ADHD 和冲动-多动指数之间存在显着的线性关系。介导效应分析结果表明，Ser、Glu、Gly、GABA在血液重金属与神经行为之间具有特异性介导作用。GABA与品行评分和注意力缺陷多动障碍（ADHD）指数呈显着线性关系。Gly 与行为、焦虑、ADHD 和冲动-多动指数之间存在显着的线性关系。介导效应分析结果表明，Ser、Glu、Gly、GABA在血液重金属与神经行为之间具有特异性介导作用。

结论

我们展示了神经递质的中介作用。目前的研究可能为学龄前儿童金属相关神经障碍的预防和管理提供有价值的信息。