Zn/Cu Levels in the Field of Autism Disorders: A Systematic Review and Meta-analysis

OBJECTIVE: There is probably a relationship between zinc/cupper concentration in individuals with autism. The present review was written to estimate this probability by using meta-analysis method. MARTIALS & METHODS: In this meta-analysis of Fixed Effect Model, by searching PubMed, Scopus and Google scholar databases, 11 articles were selected and verified published in 1978 to 2012. I² statistics were calculated to examine heterogeneity. The information was analyzed by R and STATA Ver. 11.2. RESULTS: Due to non-uniform measurement methods of Zn/Cu concentrations, the concentration of these elements was measured in various subgroups (plasma, hair and general) in both study cases and controls. There was a significant statistical difference between plasma OR=0.252 (95% CI: -0.001-0.504) and hair OR=0.27(95% CI: 0.059-0.481, P=0.01) concentrations of Zn/Cu statuses between controls and autistic patients. Using a Fixed Effects Model, the overall integration of data from the two groups was significant as risk factor OR=0.31(95% CI:0.16-0.46, P=0.001). CONCLUSION: Significant correlation existed between Zn/Cu levels and the development of autistic disorders in general analysis. Therefore, Zn/Cu levels could be mentioned as a pathogenesis reason of autism spectrum disorders.