title: The Relationship between Zinc Levels and Autism: A Systematic Review and Meta-analysis.
abstract: OBJECTIVE
  Autism is a complex behaviorally defined disorder.There is a relationship between zinc (Zn) levels in autistic patients and development of pathogenesis, but the conclusion is not permanent.
  
  
  METHODS
  The present study conducted to estimate this probability using meta-analysis method. In this study, Fixed Effect Model, twelve articles published from 1978 to 2012 were selected by searching Google scholar, PubMed, ISI Web of Science, and Scopus and information were analyzed. I² statistics were calculated to examine heterogeneity. The information was analyzed using R and STATA Ver. 12.2.
  
  
  RESULTS
  There was no significant statistical difference between hair, nail, and teeth Zn levels between controls and autistic patients: -0.471 [95% confidence interval (95% CI): -1.172 to 0.231]. There was significant statistical difference between plasma Zn concentration and autistic patients besides healthy controls: -0.253 (95% CI: 0.498 to -0.007). Using a Random Effect Model, the overall Integration of data from the two groups was -0.414 (95% CI: -0.878 to -0.051).
  
  
  CONCLUSIONS
  Based on sensitivity analysis, zinc supplements can be used for the nutritional therapy for autistic patients.
authors.affiliation: Research Committee, School of Medicine, Ilam University of Medical Sciences, Ilam, Iran.
authors.forename: Nasim
authors.initials: N
authors.lastname: Babaknejad
authors.affiliation: Research Committee, School of Medicine, Ilam University of Medical Sciences, Ilam, Iran.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Sayehmiri
authors.affiliation: Department of Social Medicine, School of Medicine, Ilam University of Medical Sciences, Ilam, Iran.; Department of Biostatistics, Research Center for Prevention of psychosocial impairment, University of Ilam, Ilam, Iran.
authors.forename: Kourosh
authors.initials: K
authors.lastname: Sayehmiri
authors.affiliation: Liver and Pancreatobiliary Diseases Research Center, Digestive Diseases Research Institute, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Ashraf
authors.initials: A
authors.lastname: Mohamadkhani
authors.affiliation: Research Committee, School of Medicine, Ilam University of Medical Sciences, Ilam, Iran.
authors.forename: Somaye
authors.initials: S
authors.lastname: Bahrami
keywords: Autism Spectrum Disorders; Meta-analysis; Zinc concentration