Urinary Iodine and Sodium Status of Urban Korean Subjects: a Pilot Study

Objectives: We estimated iodine status of Korean population by determining the concentration of spot urinary iodine (UI) with a reliable method based on the Sandell-Kolthoff reaction.

Materials And Methods: A total of 540 urine samples from apparently healthy subjects were collected, and UI, urinary sodium (UNa), and urinary creatinine (UCr) were determined from those samples and analyzed with age.

Results: There were significant decreases in either UI (P<0.0001), UI/UCr ratio (P=0.0001), UNa (P<0.0001), or UNa/Cr ratio (P=0.0001) in younger subjects than older ones. The median value of UI was 267.6 μg/L, but the median UI of the younger group (191.8 μg/L) was significantly decreased compared to that of the older group (383.9 μg/L).

Conclusions: This study showed that the median of UI in Korean urban population was in a more than adequate iodine nutritional state, but UI was significantly different between the younger age group and the older age group.