Trace Elements in Medicine (Moscow)
2019, 20(4): 24-30
ORIGINAL PAPERS

ZINC AND COPPER IMBALANCE IN CHILDREN WITH ATTENTION DEFICIT/HYPERACTIVITY

A.A. Tinkov^1,2,3, A.A. Skalny³, A.L. Mazaletskaya¹, L.N. Chernova³, Yu.E. Uvarova¹, K.A. Aleksandrova¹

¹ Yaroslavl State University named after P.G. Demidov, Sovetskaya St., 14, Yaroslavl, 150000, Russia
² First Sechenov Moscow State Medical University, 19c1, Bolshaya Pirogovskaya Street, Moscow, 119146, Russia
³ Peoples' Friendship University of Russia, Miklukho-Maklai Street, 6, Moscow, 117198, Russia

DOI: 10.19112/2413-6174-2019-20-4-24-30 

ABSTRACT. The objective of the study was investigation of serum zinc (Zn) and copper (Cu) levels in blood serum, urine, and hair of preschool and primary school aged children with attention deficit/hyperactivity (ADHD) syndrome. A total of 50 children aged 4-9 y.o. with ADHD as well as 50 neurotypical controls were involved in the study. Assessment of serum Zn and Cu levels was performed using ICP-MS. It is demonstrated that children with ADHD are characterized by a significant 8% (p = 0.001) decrease in serum Zn levels. In the case of hair, copper levels were 16% (p = 0.039) lower than the control values. Urinary metal concentrations were relatively stable. Serum Cu/Zn ratio in ADHD exceeded the control values by 12% (p = 0.003). The observed 15% decrease in urinary Cu/Zn ratio was nearly significant (p = 0.080), being indicative of predominant increase in zinc excretion in comparison to copper. In regression models adjusted for age, gender, body weight and height, hair Zn (β = -0.277; p = 0.027) and Cu/Zn ratio (β = -0.536; p = 0.008), as well as urinary Zn levels (β = 0.418; p = 0.049) were significantly associated with ADHD. Therefore, the obtained data indicate the potential role of zinc deficiency in ADHD, with increased zinc loss being considered as the potential factor leading to reduced Zn status.

KEYWORDS: zinc, copper, neurodevelopmental disorders, hyperactivity, inductively-coupled plasma mass spectrometry.