The auditory threshold in a school-age population is related to iodine intake and thyroid function

Thyroid. 2000 Nov;10(11):991-9. doi: 10.1089/thy.2000.10.991.


The aim of this study was to determine the relationship between auditory capacity and urinary iodine, taking into account thyroid volume and function, in a population of school-age children. Audiometry was carried out in 150 children (ages 6-14 years), together with measurements of thyroid volume, thyrotropin (TSH), free T3, free T4, thyroglobulin, antiperoxidase and anti-TSH receptor antibodies, as well as iodine in a casual urine sample. Children with a TSH >5 microU/mL were excluded from the study. In the children with palpable goiter, there was an inverse relation between the auditory threshold at all frequencies and ioduria. Children with thyroglobulin values >10 ng/mL had a higher auditory threshold at all frequencies. In the children with palpable goiter and ioduria <100 microg/L, the levels of thyroglobulin and ioduria and the age accounted for 75% of the decibel (dB) variance at 2000 (Hertz), with similar results at other frequencies. The children with a thyroid sized at the >95th percentile had an odds ratio of 3.86 (95% confidence interval: 2.59-5.10) of having a threshold >20 dB. The results warn that iodine prophylaxis is needed to prevent not only goiter but also other iodine-deficiency disorders, such as involvement of the auditory threshold in school-age children.

MeSH terms

  • Adolescent
  • Auditory Threshold / physiology*
  • Bone Conduction / physiology
  • Child
  • Child, Preschool
  • Deafness / etiology
  • Deafness / physiopathology
  • Female
  • Goiter / complications
  • Goiter / drug therapy*
  • Goiter / physiopathology*
  • Hearing Tests
  • Humans
  • Iodine / administration & dosage*
  • Iodine / urine
  • Male
  • Thyroid Gland / physiology*


  • Iodine