Department of Experimental Pharmacology & Toxicology, Faculty of Pharmacy, University of Port Harcourt, PMB, 5323 Port Harcourt, Choba, Nigeria.
Department of Anatomy, Faculty of Basic Medical Sciences, College of Health Sciences, University of Port Harcourt, PMB, 5323 Port Harcourt, Choba, Nigeria.
Pharmacol Biochem Behav. 2022 Jan;212:173313. doi: 10.1016/j.pbb.2021.173313. Epub 2021 Dec 9.
Environmental factors have been associated with the etiology of autism spectrum disorder ASD in recent times. The involvement of toxic metals in the generation of reactive oxygen species and their epigenetics effects have been implicated in ASD. This systemic review examines the association of toxic metals with autism in children. A systematic literature search was performed in scientific databases such as PubMed, Google scholar, and Scopus. Case-control studies evaluating toxic metal levels in different tissues of ASD children and comparing them to healthy children (control group) were identified. The Newcastle-Ottawa Scale was used to evaluate the risk of bias of the included studies. Six case-control studies with 425 study subjects met our inclusion criteria. A total of four studies indicated higher levels of As, Pb, Hg, Cd, Al, Sn, Sb, Ba, TI, W, and Zr in whole blood, RBC, in whole blood, RBC, and hair samples of children with autism compared with control suggestive of a greater toxic metal exposure (immediate and long-term). Three studies identified significantly higher concentrations of Cd, Pb and Hg in urine and hair samples of autistic children compared to control suggesting decreased excretion and possible high body burden of these metals. The findings from this review demonstrate that high levels of toxic metals are associated with ASD, therefore, critical care is necessary to reduce body burden of these metals in children with ASD as a major therapeutic strategy.
近年来，环境因素与自闭症谱系障碍（ASD）的病因有关。有毒金属参与活性氧的产生及其表观遗传效应，与 ASD 有关。本系统评价研究了有毒金属与儿童自闭症之间的关系。在 PubMed、Google Scholar 和 Scopus 等科学数据库中进行了系统的文献检索，以确定评估 ASD 儿童不同组织中毒金属水平并将其与健康儿童（对照组）进行比较的病例对照研究。使用纽卡斯尔-渥太华量表评估纳入研究的偏倚风险。符合纳入标准的病例对照研究共有 6 项，涉及 425 名研究对象。共有 4 项研究表明，自闭症儿童的全血、RBC、全血、RBC 和头发样本中的 As、Pb、Hg、Cd、Al、Sn、Sb、Ba、TI、W 和 Zr 水平较高，提示其有毒金属暴露量更大（即刻和长期）。三项研究发现，自闭症儿童的尿液和头发样本中 Cd、Pb 和 Hg 的浓度明显较高，表明这些金属的排泄减少，可能体内负荷较高。本综述的研究结果表明，有毒金属水平较高与 ASD 有关，因此，对于 ASD 儿童，需要严格控制这些金属的体内负荷，作为一种主要的治疗策略。
