Changed Plasma Levels of Zinc and Copper to Zinc Ratio and Their Possible Associations with Parent- and Teacher-Rated Symptoms in Children with Attention-Deficit Hyperactivity Disorder

Abstract

Attention-deficit hyperactivity disorder (ADHD) is associated with alterations in the metabolism of some trace elements which may participate in the pathogenesis of this disorder. The aims of the present study were to investigate the trace element status (copper (Cu), zinc (Zn), copper to zinc ratio (Cu/Zn ratio), selenium (Se), and lead (Pb)) of ADHD children and compare them with the control group. Associations between examined elements and ratings of ADHD symptoms were also assessed. Fifty-eight ADHD children and 50 healthy children (aged 6-14 years) were included in the study. The concentrations of Cu, Zn, and Se in the plasma and Pb in the whole blood were measured by atomic absorption spectrometry. We found lower Zn level (p = 0.0005) and higher Cu/Zn ratio (p = 0.015) in ADHD children when compared with the control group. Copper levels in ADHD children were higher than those in the control group, but not significantly (p > 0.05). No significant differences in levels of Se and Pb between both groups were found. Zinc levels correlated with parent-rated score for inattention (r = -0.231, p = 0.029) as well as with teacher-rated score for inattention (r = -0.328, p = 0.014). Cu/Zn ratio correlated with teacher-rated score for inattention (r = 0.298, p = 0.015). Significant associations of Se and Pb with parent- and teacher-rated symptoms were not observed. The results of this study indicate that there are alterations in plasma levels of Cu and Zn as well as significant relationships to symptoms of ADHD.

Zinc deficiency and low enterocyte zinc transporter expression in human patients with autism related mutations in SHANK3

“…Participants with low Zn/Cu ratio were frequently found to show symptoms of ADD/ADHD (Supplementary Fig. 1c,d) which is in line with recent findings of an abnormal Zn/Cu ratio in ADHD2839.…”

Maternal copper status and neuropsychological development in infants and preschool children

“…Sensitivity analyses excluding preterm and low birth weight infants from the models provided a 330 similar pattern to that for the whole sample (Supplemental material Cu/Zn ratio in 6-7 year old children with Attention-deficit hyperactivity disorder (ADHD) than 385 in controls (Viktorinova et al, 2016). However, the limited sample size of this study (n=58 386 children with ADHD and n=50 healthy) and the lack of multivariate logistic models warrant the 387 need to confirm these results by further studies.…”

OUP accepted manuscript

“…It was found that silkworm survival rate dramatically decreased when the addition of Cd 2+ reached 10 ppm in silkworm artificial food (Sekimura 2005). Another study found that addition of low concentration nano-TiO 2 to the silkworm feedstuff increased the weight of silkworm (Li et al 2016), while at the transcriptional level, the expression of detoxification genes such as BmCYP6ae22 , BmGSTol , Bmcce were upregulated (Tian et al 2016). Tian et al also observed, at the individual level, growth-inhibiting and toxic effects of Ag nanoparticles (AgNPs) on silkworms.…”