Background and objective: In 1983 goitre prevalence in Catalonia (Spain) was 21% and average urinary iodine (UI) 88.5 microg/l (SD 47.5). Surveys carried out in the nineties, after a campaign promoting the use of iodized salt, showed a significant improvement in UI. In the framework of Catalan Health Examination (2002), the assessment of iodine deficiency was included. The aim of this study was to determine UI and its distribution among a representative sample of population aged 18-74 in Catalonia.
Subjects and method: A sample of 2,100 people were stratified in accordance with the eight Catalan health areas (CHA). A questionnaire was prepared and urinary samples were collected for iodine testing.
Results: 1,115 urinary samples were collected (in 7 of the 8 CHA). Median UI was 147 microg/l and average UI 182.8 (SD 140). UI < 50 microg/l was found in 5% (95% CI, 3.8-6.5) of the sample. No difference in average UI was found between sexes. In fertile women (< 45 years) the 25th percentile of UI was 98 microg/l. Among CHA, average UI ranges from 141 to 159 microg/l. No difference in social class, education or employment was found in average UI.
Conclusions: Our results show a significant improvement in iodine level of the Catalan population. Average UI is within the levels recommended by the WHO. However, it must be taken into account that 25% of fertile women have UI < 98 microg/l. This implies a risk in the event of pregnancy.