Evaluating of significance of thyroglobulin (Tg) level in blood as a biomarker of iodine deficiency disorders severity in Uzbekistan

Iodine deficiency has serious adverse effects on growth and development of humans, such as mental impairment. It is known, that thyroglobulin level in blood is promising biomarker that can determine iodine deficiency disorders severity in a given region. The Aim of study: Evaluating of significance of thyroglobulin level in blood as a biomarker of iodine deficiency disorders severity in Uzbekistan.. Materials and Methods: We evaluated thyroglobulin level in blood in schoolchildren of Uzbekistan. In this purpose we studied 366 schoolchildren in 8-12 age group, of that 163 boys and 203 girls living in Tashkent city, Fergana, Samarkand, Bukhara, Kashkadarya, Khoresm and Republic of Karakalpakistan. Such parameters as urinary iodine concentration, diffuse goiter plasma TSH, fT4 were analyzed too. Results: Diffuse goiter prevalence was 27 % among children, the overall mean thyroglobulin concentration was 12,8 ± 10.4 ng/ml, the overall median urinary iodine concentration (UIC) was 120.27 μg/L indicating iodine sufficiency. Plasma TSH was 2.75 ± 1.69 mIU/l and plasma fТ4 14.48 ± 3,96 pmol/l.  Thyroglobulin level depended on goiter size, so that in children without goiter (grade 0) mean thyroglobulin concentration was 11,9 ± 7.9 ng/ml, in children with goiter grade 1 mean thyroglobulin concentration was 14,24 ± 13.5 ng/ml and in children with goiter grade 2 mean thyroglobulin concentration was 18,82±18,3 ng/ml. Overall mean thyroglobulin concentration of goitrous children (grade 1 and 2) was 16,4±10,5 ng/ml. Conclusions: Though international studies in school-aged children showed that iodine-sufficient children typically had a median Tg u003c13 ng/ml, our investigation showed that while study group’s  UIC was 120.27 μg/L and overall mean thyroglobulin concentration was 12,8 ± 10.4 ng/ml, that is equal to median thyroglobulin concentration – 11,73 ng/ml, 39% of children in this group still have UIC below 100 μg/L.