Endocrine Abstracts

Iodine deficiency is the most common cause of preventable mental impairment worldwide. Recent evidence suggests the re-emergence of mild iodine deficiency in the UK. A recent multicentre survey in the UK reported that 68% of school girls were iodine deficient with the lowest levels seen in Northern Ireland (NI). Unlike many countries, the UK does not have a salt or food iodination program. World Health Organisation defines deficiency as follows: mild 50–99 μg/l; moderate 20–49 μg/l; severe <20 μg/l. A cross-sectional survey of 264 schoolgirls, aged 14–15 years of age, was carried out in Belfast and Derry/Londonderry as the initial part of an Island of Ireland wide survey (seven centres). These are the two largest cities in NI and both located on the coast. Participants were surveyed in spring and winter months to look for seasonal differences. Urinary iodine levels were measured from morning spot urine samples using a standardised Sandell-Kolthoff colorimetry method. Median urinary iodine level was 119.1 μg/l (IQR 78.3–166.3). Ninety participants had mild deficiency (34%) while 14 had moderate deficiency (5.3%) and none surveyed had severe deficiency. There was no significant difference in urinary iodine level between spring and winter seasons and no difference between the two cities. In this survey 39% of schoolgirls were iodine deficient. These results are in keeping with the previous UK data and completion of the study in the other five geographical areas will enable a clearer understanding of the extent of this public health issue. Changing farming techniques and dietary habits may account for this re-emergence.