Significant association of urinary toxic metals and autism-related symptoms - A nonlinear statistical analysis with cross validation

James Adams, Daniel P. Howsmon, Uwe Kruger, Elizabeth Geis, Eva Gehn, Valeria Fimbres, Elena Pollard, Jessica Mitchell, Julie Ingram, Robert Hellmers, David Quig, Juergen Hahn

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

Introduction: A number of previous studies examined a possible association of toxic metals and autism, and over half of those studies suggest that toxic metal levels are different in individuals with Autism Spectrum Disorders (ASD). Additionally, several studies found that those levels correlate with the severity of ASD. Methods: In order to further investigate these points, this paper performs the most detailed statistical analysis to date of a data set in this field. First morning urine samples were collected from 67 children and adults with ASD and 50 neurotypical controls of similar age and gender. The samples were analyzed to determine the levels of 10 urinary toxic metals (UTM). Autismrelated symptoms were assessed with eleven behavioral measures. Statistical analysis was used to distinguish participants on the ASD spectrum and neurotypical participants based upon the UTM data alone. The analysis also included examining the association of autism severity with toxic metal excretion data using linear and nonlinear analysis. "Leave-one-out" cross-validation was used to ensure statistical independence of results. Results and Discussion: Average excretion levels of several toxic metals (lead, tin, thallium, antimony) were significantly higher in the ASD group. However, ASD classification using univariate statistics proved difficult due to large variability, but nonlinear multivariate statistical analysis significantly improved ASD classification with Type I/II errors of 15% and 18%, respectively. These results clearly indicate that the urinary toxic metal excretion profiles of participants in the ASD group were significantly different from those of the neurotypical participants. Similarly, nonlinear methods determined a significantly stronger association between the behavioral measures and toxic metal excretion. The association was strongest for the Aberrant Behavior Checklist (including subscales on Irritability, Stereotypy, Hyperactivity, and Inappropriate Speech), but significant associations were found for UTM with all eleven autism-related assessments with cross-validation R2 values ranging from 0.12-0.48.

Original languageEnglish (US)
Article numbere0169526
JournalPLoS One
Volume12
Issue number1
DOIs
StatePublished - Jan 1 2017

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Poisons
Autistic Disorder
Statistical methods
statistical analysis
Metals
metals
excretion
autism
Antimony
Tin
Autism Spectrum Disorder
thallium
Thallium
antimony
Nonlinear analysis
Checklist
tin
Multivariate Analysis
multivariate analysis
signs and symptoms (animals and humans)

ASJC Scopus subject areas

  • Medicine(all)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Agricultural and Biological Sciences(all)

Cite this

Significant association of urinary toxic metals and autism-related symptoms - A nonlinear statistical analysis with cross validation. / Adams, James; Howsmon, Daniel P.; Kruger, Uwe; Geis, Elizabeth; Gehn, Eva; Fimbres, Valeria; Pollard, Elena; Mitchell, Jessica; Ingram, Julie; Hellmers, Robert; Quig, David; Hahn, Juergen.

In: PLoS One, Vol. 12, No. 1, e0169526, 01.01.2017.

Research output: Contribution to journalArticle

Adams, J, Howsmon, DP, Kruger, U, Geis, E, Gehn, E, Fimbres, V, Pollard, E, Mitchell, J, Ingram, J, Hellmers, R, Quig, D & Hahn, J 2017, 'Significant association of urinary toxic metals and autism-related symptoms - A nonlinear statistical analysis with cross validation', PLoS One, vol. 12, no. 1, e0169526. https://doi.org/10.1371/journal.pone.0169526
Adams, James ; Howsmon, Daniel P. ; Kruger, Uwe ; Geis, Elizabeth ; Gehn, Eva ; Fimbres, Valeria ; Pollard, Elena ; Mitchell, Jessica ; Ingram, Julie ; Hellmers, Robert ; Quig, David ; Hahn, Juergen. / Significant association of urinary toxic metals and autism-related symptoms - A nonlinear statistical analysis with cross validation. In: PLoS One. 2017 ; Vol. 12, No. 1.
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