Heavy metals and specific porphyrine levels in children with autism

Abstract

Background: The aim of our study was to determine the levels of heavy metals in blood (zinc, copper, aluminium, lead, mercury), as well as the specific porphyrin levels in the urine of patients with ASD compared with patients with other neurological disorders.Methods: The study was performed in a group of children with ASD (N = 52, average age = 6.2y) and control group of children with other neurological disorders (N = 22, average age = 6.6y), matched in terms of intellectual abilities (Mann-Whitney U = 565.0, p = .595). Measurement of heavy metals in blood was performed by atomic absorption spectrometry, while the HPLC method by means of a fluorescence detector was used to test urinary porphyrin levels. Results were compared across groups using a multivariate analysis of covariance (MANCOVA). In addition, a generalized linear model was used to establish the impact of group membership on the blood Cu/Zn ratio.Results: In terms of heavy metal blood levels, no significant difference between the groups was found. However, compared to the control group, ASD group had significantly elevated blood Cu/Zn ratio (Wald χ2 = 6.6, df = 1, p = .010). Additionaly, no significant difference between the groups was found in terms of Uroporphyrin I, Heptacarboxyporphyrin I, Hexacarboxyporphyrin and Pentacarboxyporphyrin I. However, the levels of Coproporphyrin I and Coproporphyrin III were lower in the ASD group compared to the controls.Conclusions: Due to the observed higher Cu/Zn ratio we’d suggest that blood levels of zinc and cupper should be tested in all children with ASD and a Zn supplement should be given as needed.

Keywords

• autism
• children
• heavy metals
• vaccination
• thymerosal