Evaluation of Iodine Deficiency in Children with Attention Deficit/Hyperactivity Disorder

J Clin Res Pediatr Endocrinol. 2016 Mar 5;8(1):61-6. doi: 10.4274/jcrpe.2406. Epub 2015 Dec 18.

Abstract

Objective: To investigate the incidence of iodine deficiency (ID) and its effects on mental function in children referred to the Dr. Sami Ulus Maternity and Children's Training and Research Hospital with a prospective diagnosis of attention deficit/hyperactivity disorder (ADHD).

Methods: The study was conducted on 89 children referred in the period from September 2009 to June 2010 with a diagnosis of ADHD. A questionnaire was given to all parents. Conners' rating scales were applied to the parents (CPRS) and teachers (CTRS), and revised Wechsler intelligence scale for children (WISC-R) to the children. Serum thyroid-stimulating hormone, free triiodothyronine and free thyroxine, thyroglobulin, anti-thyroid peroxidase, anti-thyroglobulin, and urinary iodine levels were measured in all children.

Results: Median age was 9.41±1.95 years, and 83.1% of subjects were male. The mean urinary iodine level of the children was 92.56±22.25 μg/L. ID was detected in 71.9% of subjects and all were mild ID. There was no significant relationship between urinary iodine levels with WISC-R subtest scores and CPRS. However, a significant association was found between urinary iodine levels and hyperactivity section of CTRS (p<0.05). Likewise, a significant relationship was found between learning disorder/mental retardation diagnosis and freedom subtest of WISC-R (p<0.05).

Conclusion: This study highlights the effects of ID on comprehension, perception, attention, and learning. However, the results need to be supported by new randomized controlled trials.

MeSH terms

  • Adolescent
  • Attention Deficit Disorder with Hyperactivity / complications*
  • Attention Deficit Disorder with Hyperactivity / psychology*
  • Biomarkers / analysis
  • Child
  • Child, Preschool
  • Female
  • Follow-Up Studies
  • Humans
  • Incidence
  • Intellectual Disability / diagnosis*
  • Intellectual Disability / epidemiology
  • Intellectual Disability / etiology*
  • Iodine / adverse effects
  • Iodine / deficiency*
  • Male
  • Prognosis
  • Prospective Studies
  • Psychometrics
  • Severity of Illness Index*
  • Surveys and Questionnaires
  • Turkey / epidemiology

Substances

  • Biomarkers
  • Iodine