Iodine deficiency in a megalopolis bordering the gulf of Finland: myth or reality?

Abstract

The purpose of this research was to assess iodine levels in the population of St. Petersburg, and to study ultrasound goiter criteria in children taking into account controversial data at our disposal. Iodine concentration was measured in samples of morning urine by cerium arsenite method in 883 children aged 610 in 30 clusters. The total of 138 children of the same age underwent ultrasound examination of the thyroid; all the children are residents of Krasnoselsky District of the city, which is free from goitrogenous substances. A retrospective analysis of screening results for innate hypothyroidism was performed on 106 066 blood samples collected in 2004 and 2012. The medi an ioduria was 67.8 mkg/l; the proportion of urine samples with iodine concentrations below 50 mcg/l was 31%. The frequency of TSH > 5mE/l in newborn babies was 11% and 3.8% (in 2004 and 2012, respectively). The occur rence of goiter, as defined in 1997 WHO regulations, was 4.4%; however, according to the 2001 and 2003 criteria, it exceeded 30% in (34% and 63% respectively). The research results show that St.Petersburg, despite its favourable geographical location and economical status, is a region with mild iodine insufficiency; when 2001 and 2003 goiter criteria are employed, the degree of iodine insufficiency becomes severe.