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The Relationship Between the Level of Copper, Lead, Mercury and Autism Disorders: A Meta-Analysis

Authors Jafari Mohammadabadi H, Rahmatian A, Sayehmiri F, Rafiei M

Received 26 March 2019

Accepted for publication 17 August 2020

Published 21 September 2020 Volume 2020:11 Pages 369—378


Checked for plagiarism Yes

Review by Single anonymous peer review

Peer reviewer comments 4

Editor who approved publication: Professor Roosy Aulakh

Hamed Jafari Mohammadabadi1 *,* Aryoobarzan Rahmatian2 *,* Fatemeh Sayehmiri,3 Mohammad Rafiei4

1School of Medicine, Shiraz University of Medical Sciences, Shiraz, Fars, Iran; 2Faculty of Medicine, Ilam University of Medical Sciences, Ilam, Iran; 3Student Research Committee, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran; 4Department of Biostatistics and Epidemiology, Arak University of Medical Sciences, Arak, Iran

*These authors contributed equally to this work

Correspondence: Mohammad Rafiei
Department of Biostatistics and Epidemiology, Arak University of Medical Sciences, Arak 3819693345, Iran
Tel +98 1988637445

Background and Objectives: There is a likelihood of a possible relationship between the concentrations of copper, lead, and mercury and autism. The present review was carried out to determine the relationship between the concentrations of these elements and autism by meta-analysis.
Methods: In this study, searching Scopus, PubMed, and Science Direct databases, 18 articles conducted in different countries from 1982 to 2019 were collected. Studies’ heterogeneity was investigated using the I2 index. The data were analyzed using R and STATA software.
Results: In these 18 studies, 1797 patients (981 cases and 816 controls) aged 2 to 16 years were examined. Concentration of the samples (blood, hair, and nails) for both case and control groups was evaluated. There was no significant relationship between copper concentration and autism (SMD (95% CI): 0.02 (− 1.16,1.20); I2=97.7%; P=0.972); there was a significant relationship between mercury concentration and autism (SMD (95% CI): 1.96 (0.56,3.35); I2=98.6%; P=0.006); there was also a significant relationship between lead concentration and autism (SMD (95% CI): 2.81 (1.64,3.98); I2=97.8%; P=0.000).
Conclusion: There is, nevertheless, a significant relationship between mercury concentration and autism. Thus, the concentration of mercury can be listed as a pathogenic cause (disease-causing) for autism.

Keywords: autism, copper, lead, mercury, meta-analysis

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