Survey Of Children's Thyroid Diseases In High Iodine Areas After Having Stopped Iodized Salt

ObjectiveTo investigate the level of iodine nutrition as well as the incidence and related factors of thyroid disease in children in the water-sourced high-level iodine(endemic) region, after stopping supplying iodized salt. MethodsThe field epidemiology survey and laboratory tests were used to extract children aged 8-12(n=400) in four primary schools with different water iodine levels to investigate the level of iodine nutrition. Clinical diagnosis and laboratory tests were used to analyze the prevalence of thyroid associated diseases in children(mainly thyroid nodules).Analyze the major risk factors of thyroid related diseases in children by logistic regression analysis. Master the risk factors of thyroid disease in children by studying on thyroid associated diseases in different water iodine regions. Results1. Status of iodine nutritional of children: The total intake of iodine in the water-sourced high-level iodine region, the water-sourced high-level iodine endemic region, the “normal-level iodine” region and the iodine deficiency region were respectively 576.80?g/d,473.87?g/d,369.40?g/d and 441.13?g/d. The intake of iodine of children were all higher than the tolerable upper intake level of iodine. The median urine iodine of children was 229.3?g/L.It was in the normal range,but on the high side. Median of Urine Iodine in the water-sourced high-level iodine region, the water-sourced high-level iodine endemic region, the “normal-level iodine” region and the iodine deficiency region were respectively 476.3?g/d,209.2?g/d,187.7?g/d and 217.2?g/d.2. The prevalence of thyroid dysfunction in children was 4.1%.; the prevalence of thyroid enlargement was 2.5%; the prevalence of thyroid nodules was 10.0%; the prevalence of thyroid disease was 15.8%. In the water-sourced high-level iodine region, the prevalence of thyroid dysfunction was 8.1%; the prevalence of thyroid enlargement was 10.0%, there weren't goiter in children in the other three regions; the prevalence of thyroid nodules was 27.0%, which was significantly higher than the other three regions; the prevalence of thyroid disease was 42.0%, which was significantly higher than the other three regions.3. Family history of cancer and high BMI were risk factors for thyroid dysfunction. High urinary iodine and watching TV and using computer frequently were risk factors for goiter; doing exercise frequently was protective factor for goiter. High urinary iodine and increased age were risk factor for thyroid nodules.4. There was no significant difference between the high-level iodine region and non high-level iodine region in the prevalence of thyroid nodule or thyroid enlargement. ConclusionsThe median urine iodine of children was beyond the suitable range. The prevalence of thyroid disease of children in the water-sourced high-level iodine region was higher than the other regions. High urinary iodine and increased age were risk factor for thyroid disease. We should consider improving water to reduce iodine in the region where the water iodine is above 300?g/L. Scientific iodine supplementation should be implemented according to local conditions. The risk factor of children thyroid disease is not completely in line with that of adults. We need further discussion.