Función tiroidea en una población con aporte extra de yodo / Thyroid function in a population with an extra iodine intake

ABSTRACT

Background: After 20 years of iodine salt fortification, the prevalence of goiter has decreased significantly in the rural area of Pirque, central Chile. In this location, equipment has been installed that efficiently and economically adds 0.5 mg of elemental iodine per liter of water to render it potable. Aim: To study thyroid function and urinary iodine excretion in scbool age cbildren of this zone, after two years of extra iodine intake. Material and methods: One hundred thirty four children aged 6 to 12 years old were examined. In 56 randomly chosen children a morning urine sample was obtained to measure iodine excretion. In 45 children without goiter, a blood sample was obtained to measure TSH and thyroxin. Results: In nine cbildren (7 percent) a diffuse goiter was found. Median urinary iodine excretion was 158 ug/dl. Thyroxin and TSH levels were within normal limits (8.4Ý1.1 ug/dl and 2.2Ý1.5 uU/ml respectively). During the period of iodine water supplementation there were 47 births in the zone. All newborns had normal TSH values and none had goiter. Conclusions: When present results are compared with the period before water iodination (when the prevalence of goiter was 9.6 percent and mean urinary iodine excretion was 57.6 ug/dl), it can be concluded that extra iodine intake in this rural population has not caused additional thyroid problems