肌酐校正尿碘指标的准确性研究

EFFECT OF URINE IODINE/CREATININE RATIO IN EVALUATING URINARY IODINE EXCRETION FROM SPOT URINES

目的探索肌酐校正的尿碘指标估计尿碘排出量的准确性。方法在山东省德州市宁津县和陵县选取6所小学,间隔3w两次收集3~6年级全部儿童的一次性随机尿和24h尿。量取24h尿液体积,检测尿碘和肌酐浓度。计算得到实际24h尿碘排出量,而估计24h尿碘排出量则通过一次性随机尿尿碘肌酐的浓度比值乘以24h肌酐排出量得到。结果比较两次重复采样,随机尿的尿碘肌酐比值、24h尿碘浓度和24h尿碘排出量未见统计学差异（P〉0.05）。但是在每次采样中,估计24h尿碘排出量显著低于实际24h尿碘排出量（P〈0.001）。此外,在两次重复采样中,随机尿碘浓度（rs=0.585,P〈0.001;rs=0.570,P〈0.001）,随机尿尿碘肌酐比值（rs=0.620,P〈0.001;rs=0.612,P〈0.001）,估计24h尿碘排出量（rs=0.843,P〈0.001;rs=0.845,P〈0.001）分别与实际24h尿碘排出量呈良好线性关系。结论在学龄儿童中,由肌酐校正的一次性随机尿估计出的24h尿碘排出量,可以作为评价个体碘摄入量的有效指标。今后的研究有必要建立学龄儿童尿肌酐日排出量的标准。

Objective To study the effectiveness effectiveness of urinary iodine/creatinine ratio from spot urines in estimating 24 h urinary iodine excretion（24h UIE）. Methods 24 h urine and spot urine samples were collected from students in 6 primary schools in Ningjin and Lingxian, Dezhou city of Shandong province. 24 h urinary iodine concentration（UIC）, 24 h urinary creatinine concentration（24h UCr）, 24 h urinary volume（24h U-vol）, spot UIC and spot UCr were measured for all samples. Measured 24 h UIE was calculated by 24 h UIC multiplying 24 h U-vol, while estimated 24 h UIE was calculated by spot urinary iodine/creatinine ratio（spot UI/Cr） multiplying 24 h urinary creatinine excretion（24h UCr E）. Results No significant differences were observed in spot UI/Cr, 24 h UIC and measured 24 h UIE between twice sampled urines（P0.05）. The estimated 24 h UIE was lower than measured 24 h UIE in both collections（P0.01）. In addition, spot UIC（r_s=0.585, P0.001;r_s=0.570, P0.001）, spot UI/Cr（r_s=0.620, P0.001;r_s=0.612, P0.001）and estimated 24 h UIE（r_s=0.843, P0.001;r_s=0.845, P0.001） were strongly correlated with measured 24-h UIE. Conclusion Estimated 24 h UIE from spot urine could be a reliable alternative for the measured 24-h UIE in evaluating individual iodine intake in school-age children, and it is necessary to establish national school-age children standards of 24 h UCr E.