A Study on the Urinary Iodine Excretion in Normal subjects and Patients with Thyroid disease / 대한내분비학회지

ABSTRACT

An adequate supply of dietary iodine is essential for the synthesis of the thyroid hormons. The measurement of dietary iodine intake is important for the clinical assessment of thyroid disease, especially in areas where iodine intake is excessive or deficient.To evaluate dietary iodine intake in Korean and its effects on thyroid function, we measured urinary iodine excretion with morning urine by electrode method in 184 normal subjects, 96 postpartum women and 181 patients with thyroid disease from October 1994 to February 1995. The results were as follows;1) In normal control, the mean value of urinary iodine excretion was 3.8+-2.7mg/L (range 0.1-15.0mg/L). However, there was no sex and age differences in the urinary iodine excretion.2) In postpartum women, the urinary iodine excretion was 9.0+-10.8mg/L who were not taken high iodine diet(Miyok-Guk), the mean value was statistically higher than normal control(p<0.01) and significant increased the urinary iodine excretion after eating of high iodine diet(p<0.01).3) In volunteer, there were increase of urinary iodine excretion more than 10 folds after high iodine diet and medication.4) The urinary iodine excretion in patients with thyroid diseases was not different from normal control, and there were no significant differences of urinary iodine excretion among the patient groups. The urinary iodine excretion in the acute stage of patients with subactue thyroiditis or painless thyroiditis was significantly increased compared to the recovery stage. However, it was not significantly different from that of normal control.In conclusion, urinary iodine excretion in Korean population is very high comparing to the reported data in Western population but similar with Japanese. The urinary iodine excretion is significant increase( more than 10-folds of basal level) after high iodine diet or high iodine containing medication in postpartum women or healthy persons. As a clue of destruction induced thyrotoxicosis, the urinary iodine excretion measurement is not valid in area where iodine intake is excessive like Korea.