Background: Previous nation-wide survey on iodine deficiency disorders (IDD) in Latvia showed a mild iodine deficiency in 587 schoolchildren (median UI 59 μg/l). At the time less than 1% of all edible salt was iodized. Despite of the results of National IDD Elimination Committee study, all preventive measures were limited to production of leaflets promoting voluntary iodine salt consumption and convincing industry to use iodized salt. In order to perform a 10-year follow-up study we performed a survey with similar design in the same regions of Latvia.
Study design and methods: We conducted a cross-sectional school-based 20-cluster survey of children aged 912 in randomly selected 24 schools in all regions of Latvia. In total 508 samples of urine and questionnaires on diet, consumption of iodized salt were collected. UIE was measured by ammonium persulphate method.
Results: Self-reported prevalence of regular iodized salt consumption was 52.5%. The median creatinine-standardized UI concentration in Latvian schoolchildren was 129.7 (IQR 90.76) μg/g Cr. Frequency distribution of UI values showed that 68.5% (95% CI: 64.372.4) of samples had normal levels (≥100 μg/g) of iodine in urine, while 27.8% (95% CI: 24.031.8) of schoolchildren had mild (5099 μg/g), 3.3% (95% CI: 2.15.3) moderate (2049 μg/g) and 0.4% severe (<20 μg/g) decrease in urinary iodine concentrations. Socioeconomic status of parents or self-reported iodized salt consumption was not associated with iodine status.
Conclusion: Ten-year follow-up indicated an impressive increase in self-reported prevalence of regular iodized salt consumption and urinary iodine excretion among schoolchildren. It shows that iodine deficiency could be effectively eliminated even without Universal Salt Iodization programme by gradual changes in population eating habits, spreading of supermarket chains or increased iodized salt usage.
30 Apr - 04 May 2011
European Society of Endocrinology