Heavy Metal and Thiol/Disulfide in Children with Attention-Deficit and Hyperactivity Disorder

Abstract

Background: In the etiology of attention-deficit and hyperactivity disorder (ADHD), oxidative stress and heavy metal exposure are still controversial topics. In this study, our goal was to examine heavy metal levels and oxidative balance in newly diagnosed patients with ADHD and reveal whether heavy metal levels have an effect on the oxidation balance. Methods: The study included 35 patients with newly diagnosed ADHD and 31 healthy control groups of similar age and gender. Participants’ parents or caregivers completed a semi-structured questionnaire regarding their children’s breastfeeding and prenatal and postnatal smoking exposures. The levels of heavy metals lead (Pb), mercury (Hg), and cadmium were measured with inductively coupled plasma optical emission spectroscopy, and a unique automated spectrophotometric approach was used to quantify serum total thiol, native thiol, and disulfide quantities and ratios. Results: The rate of smoking during pregnancy was significantly higher in the ADHD group than in the control group (P =.030). Compared to the control group, the native and total thiol levels of children with ADHD were significantly higher (P