Treatment of iodine deficiency in children increases IGF‐1 and IGFBP‐3 concentrations and improves somatic growth

• Published in: The FASEB journal Vol. 21; no. 5; p. A724
• Main Authors: Zimmermann, Michael, Jooste, Pieter, Mabapa, Ngoako, Mbhenyane, Xikombiso, Grimci, Lindita
• Format: Journal Article
• Language: English
• Published: Federation of American Societies for Experimental Biology 01-04-2007
• ISSN: 0892-6638; 1530-6860
• DOI: 10.1096/fasebj.21.5.A724

Background Iodine deficiency in utero impairs fetal growth, but its affect on postnatal growth is less clear.
Aim To determine if iodine repletion improves somatic growth in iodine‐deficient (ID) children and to investigate the role of insulin‐like growth factor (IGF)‐1 and insulin‐like growth factor binding protein (IGFBP)‐3 in this effect.
Methods Three prospective, double blind 10 month intervention studies were done in school‐age children:
severely ID Moroccan children (n=71) used iodized salt or control;
moderately ID Albanian children (n=310) and
mildly ID South African children (n=188) were given 400 mg oral iodine or placebo.
At baseline and follow‐up, height, weight, urinary iodine (UI), total thyroxine (TT4), thyroid‐stimulating hormone (TSH) and IGF‐1 and IGFBP‐3were measured.
Results In South Africa, iodine repletion modestly increased IGF‐1, but did not have a significant effect on IGFBP‐3, TT4 or growth. In Albania and Morocco, iodine repletion significantly increased TT4, IGF‐1, IGFBP‐3, weight‐for‐age z scores and height‐for‐age z scores.
Conclusion This is the first controlled study to demonstrate iodine repletion in children increases IGF‐1 and IGFBP‐3 concentrations and improves somatic growth.