Levels of Metals in the Blood and Specific Porphyrins in the Urine in Children with Autism Spectrum Disorders

Abstract

The aim of the present study was to determine the levels of metals in blood (zinc (Zn), copper (Cu), aluminium (Al), lead (Pb) and mercury (Hg)), as well as the specific porphyrin levels in the urine of patients with autism spectrum disorder (ASD) compared with patients with other neurological disorders. The study was performed in a group of children with ASD (N = 52, average age = 6.2 years) and a control group of children with other neurological disorders (N = 22, average age = 6.6 years), matched in terms of intellectual abilities (Mann-Whitney U = 565.0, p = 0.595). Measurement of metals in blood was performed by atomic absorption spectrometry, while the HPLC method via 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. In terms of blood levels of metals, no significant difference between the groups was found. However, compared to the control group, ASD group had significantly elevated blood Cu/Zn ratio (Wald χ (2) = 6.6, df = 1, p = 0.010). Additionally, 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. Due to observed higher Cu/Zn ratio, it is suggested to test blood levels of Zn and Cu in all autistic children and give them a Zn supplement if needed.

Immune dysfunction and neuroinflammation in autism spectrum disorder

“…A recent study suggests that increased levels of BPb in some children with ASD may trigger the production of serum anti-ribosomal P antibodies (Mostafa et al 2016b). It has been reported that ASD children often have a lower zinc (Zn)-to-copper (Cu) ratio in blood compared to healthy controls (Faber et al 2009, Li et al 2014, Crăciun et al 2016) and children with other neurological disorders (Macedoni-Lukšič et al 2015). It has been suggested that metallothionein (MT) dysfunction may occur as a cause of Hg accumulation in children with ASD, and the same dysfunction may also lead to Zn deficiency (Bjørklund 2013).…”

Can zinc supplementation ameliorate cadmium-induced alterations in the bioelement content in rabbits?

“…It should be emphasised that literature data underscore the Cu/Zn ratio as a potential blood biomarker of different health disorders. Thus, increased values of the Cu/Zn ratio were determined in developmental and behavioural disorders in children (52) and in some cases of cancer (53).…”

Background lead and mercury exposures: Psychological and behavioral problems in children

“…Most studies have considered metal levels in blood, hair, and urine for those with diagnosed ASD compared to controls. This research has yielded inconsistent results with respect to Pb and Hg, with most studies finding non-significant differences (10, 11) or even a reduced level of some non-essential metals (Pb) in those with ASD (12). …”