Hisada Aya, Suzuki Yayoi, Yoshinaga Jun
Department of Environmental Studies, University of Tokyo, Tokyo, Japan.
Nihon Eiseigaku Zasshi. 2011 Sep;66(4):711-6. doi: 10.1265/jjh.66.711.
To quantitatively assess the intra- and inter-individual variation of urinary iodine concentration in Japanese to determine whether urinary analysis is applicable to assessing habitual iodine intake in subjects on an individual basis.
Five urine samples (first void) were taken from each of the 14 healthy female subjects at 2-3 week intervals over 4-5 months. Information on diet and medication use on the previous day of urine sampling was obtained by a questionnaire during each urine sampling. The concentration of iodine in urine samples was measured by inductively coupled plasma mass spectrometry (ICP-MS). Intra- and inter-individual variation was assessed by intra class correlation coefficient (ICC).
The median concentration of iodine in 70 urine samples was 91 µg/g-cre (range: 15-4400 µg/g-cre). The mean iodine concentration in urine samples from subjects who took iodine-rich foods/medications on the day before sampling was statistically significantly higher than that from subjects who did not take such foods/medications (p < 0.01, t-test). The ICC of urinary iodine concentration of the 14 subjects was 0.55, indicating good reproducibility; however, this was 0.28 when one subject who routinely used an iodine-containing gargle was excluded from analysis.
Urine sampled on a single occasion is not a suitable medium for the assessment of long-term intake levels of iodine in subjects on an individual basis.
定量评估日本人尿碘浓度的个体内和个体间差异，以确定尿液分析是否适用于个体层面评估受试者的习惯性碘摄入量。
在4至5个月的时间里，每隔2至3周从14名健康女性受试者中每人采集5份晨尿样本。每次尿液采样时，通过问卷调查获取尿液采样前一天的饮食和用药信息。采用电感耦合等离子体质谱法（ICP-MS）测定尿液样本中的碘浓度。个体内和个体间差异通过组内相关系数（ICC）进行评估。
70份尿液样本中碘的中位数浓度为91µg/g肌酐（范围：15至4400µg/g肌酐）。采样前一天食用富碘食物/药物的受试者尿液样本中的平均碘浓度显著高于未食用此类食物/药物的受试者（p<0.01，t检验）。14名受试者尿碘浓度的ICC为0.55，表明重复性良好；然而，当排除一名常规使用含碘漱口水的受试者后，ICC为0.28。
单次采集的尿液并非个体层面评估受试者碘长期摄入量的合适介质。
