Endemic goiter, thiocyanate overload, and selenium status in school-age children

Iodine deficiency (ID) and related disorders are still major, yet unresolve d health concerns. Recently, in a systematic survey of schoolage children ( SAC), we reported severe to moderate ID, in Ankara and three cities from Bl ack Sea region of Turkey. The current study attempted to evaluate selenium (Se) status, thiocyanate (SCN-) overload, and their possible contribution t o the goiter endemics and thyroid hormone profile observed in these cities. Thyroid ultrasonography was performed and serum Se, SCN-, thyroid hormones , sensitive TSH (sTSH) levels, and urinary iodine concentrations (UICs) wer e determined from 251 SAC (9-11 yr old). Thyroid volumes (TVs) exceeding recommended upper normal limits and median UIC indicated goitre endemics and moderate to severe ID in the areas studie d. Mean serum SCN- concentrations were found to be greater than the control s from the literature. The UIC/SCN- ratio was found to be lowest in Bayburt and Trabzon denoting that SCN- overload may contribute to the goiter endem ics. Serum Se concentrations represent a marginal deficiency in the four ar eas studied. No significant correlations between serum Se concentrations an d the other parameters studied (i.e., TV, SCN-, thyroid hormones, sTSH, UIC ) was detected. In conclusion, this study showed that selenium is also marginally deficient in the iodine-deficient endemic areas studied, but this has little or no i mpact on the thyroid hormone profile and the goiter encemics. SCN- overload may contribute to the endemics, especially for the areas where iodine is s everely deficient. An effective iodine supplementation program will not onl y resolve the goiter endemics but also the consequence of SCN- overload as well in the endemic goiter areas studied.