A study of urban primary school children has found mild iodine deficiency but no evidence of goitre (an enlarged thyroid most often caused by a lack of dietary iodine).

The results are consistent with a previous study and the researchers are NOW calling for a systematic national survey to determine iodine status in the Australian population using a combination of iodine deficiency indicators.

Dr Kamala Guttikonda and Dr Steven Boyages, from the Department of Diabetes and Endocrinolgy at Westmead Hospital, and Ms Cheryl Travers and Dr Peter Lewis, from the Central Coast Public Health Unit, tested 324 of the 465 children at a Central Coast public primary school in November 2000.

The children's iodine levels and thyroid volumes were compared with World Health Organization reference values.

Endocrine Research Fellow at the Westmead Hospital, Dr Kamala Guttikonda, says that, in the past, iodine deficiency was a recognised health problem in Australia.

"Iodine is an essential element for thyroid function, necessary for the normal growth, development and functioning of the brain and body," Dr Guttikonda says.

"Iodine deficiency can lead to a range of iodine deficiency disorders.

"While goitre is perhaps the best known effect of iodine deficiency, it can also have a deleterious effect on the developing brain of the fetus, ranging from mild brain dysfunction to irreversible intellectual impairment.

"It is the single most common cause of preventable mental retardation and brain damage in the world today."

Australia had remedied its iodine deficiency by the mid 1900s through a range of programs, including supplying iodised salt and iodine-supplemented bread, and public health messages.  With the exception of Tasmania, Australia today is considered iodine sufficient, but there are concerns there may be a re-emergence of iodine deficiency.

The earlier study found evidence of iodine deficiency in patients at a Sydney teaching hospital.  However this study only examined urinary iodine levels. The Central Coast study, using urinary iodine and thyroid size, has found similar deficiencies in school children in the community setting.

Dr Guttikonda says that despite the urinary iodine levels being less than ideal, evidence of goitre was not present.

"Our study highlights the importance of using a combination of iodine deficiency indicators such as urinary iodine, thyroid volume and blood thyroid hormone levels in areas where iodine deficiency is marginal before concluding the need for iodine supplementation based purely on urinary iodine levels

"Overall, our report supports the growing body of evidence for the re-emergence of iodine deficiency in the Australian community".

"Hence, we see the need for a national survey to properly assess how Australia is faring on the iodine deficiency scale to allow us to put in place measures to reverse this trend," Dr Guttikonda said.

The Medical Journal of Australia is a publication of the Australian Medical Association.

CONTACT:     Dr  Kamala Guttikonda, 0412 995 905            

                   Judith Tokley, AMA, 0408 824 306