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 Ul (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 Ul was 267.6 mu g/L, but the median UI of the younger group (191.8 mu g/L) was significantly decreased compared to that of the older group (383.9 mu g/L). Conclusions: This study showed that the median of Ul in Korean urban population was in a more than adequate iodine nutritional state, but Ul was significantly different between the younger age group and the older age group. (C) 2012 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.