The thyroid is a gland that helps regulate body growth
and metabolism. The gland requires iodine to form thyroid
hormone, a substance that is necessary to keep the body
functioning normally. The condition in which levels of
iodine in the thyroid gland are too low is called hypothyroxinemia.
Based on a study that lasted almost 10 years, the Italian
researchers believe that hypothyroxinemia in mothers during
pregnancy may increase the risk of ADHD in their children.
The researchers followed the children of 16 women in
an area of the Italian island Sicily where iodine deficiency
is common, comparing them to children in a region where
iodine is sufficient.
ADHD was diagnosed in 11 of the 16 children from the
iodine-deficient area, but in none of the children in
the comparison group.
Dr. Francesco Vermiglio, who led the study, stated that
he believes the ADHD and a related reduction in IQ seen
in the study resulted from hypothyroxinemia in the children's
mothers during the first half of pregnancy. Seven of the
11 ADHD children were born to mothers who became hypothyroxinemic
during early pregnancy.
Vermiglio and his colleagues at the University of Messina
in Italy published the findings of their study in the
December issue of the Journal of Clinical Endocrinology
and Metabolism.
They note in their report that hypothyroxinemia in pregnant
women can occur even in places where iodine intake is
adequate, and that they therefore recommend routine thyroid
screening and monitoring for all pregnant women.
SOURCE: Journal of Clinical Endocrinology, December
2004.
