Residual goiter in Semirom; iodine status and thiocyanate overload do not play a role.

This study was performed to investigate the role of thiocyanate overload in the etiology of endemic goiter in schoolchildren of Semirom, Iran. A total of 1828 schoolchildren were selected by multi-stage random sampling. Urinary iodine concentration (UIC) and urinary thiocyanate (USCN) were measured in a group of these children. The median UIC was 18.5 microg/dl. The mean +/- SD of USCN in goitrous and nongoitrous subjects did not differ significantly (0.75 +/- 0.78 mg/dl vs. 0.63 +/- 0.40 mg/dl; p = 0.30). Finally, we concluded that neither iodine deficiency nor thiocyanate overload contributed to the high prevalence of goiter in Semirom. The role of other goitrogenic factors should be investigated in this region.