Urinary iodine and sodium status of urban Korean subjects: a pilot study

Abstract

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.