Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
Ann Nutr Metab. 2010;57(3-4):260-4. doi: 10.1159/000322792. Epub 2010 Dec 16.
To evaluate the variability of 24-hour urinary iodine (UI) excretion intra- and interindividually on three days of a week in healthy subjects, living in southern Brazil, and the correlation among the urinary excretion of iodine and sodium.
Cross-sectional study, including 47 volunteers: 18 individuals with one, 15 individuals with two and 14 individuals with three 24-hour urine samples. Iodine, creatinine and Na(+) excretion in urine during 24-hour were measured.
Mean height, weight, BMI and 24-hour urinary excretion of creatinine were higher in men. UI and urinary sodium were correlated (n = 89, r = 0.524, p = 0.000). UI excretion varied widely, both inter- and intraindividually, on the 3 days of the week, but the mean excretion of UI was similar. In single individuals, the ratio between the maximum and minimum 24-hour UI excretion (m/m) ranged from 1.03 to 2.87, and the median coefficient of variation (CV) was 21% (P₂₅ = 7.0% and P₇₅ = 36.8%), with a range of 1%-51%. 24-hour UI excretion varied greatly among individuals on Sunday (CV = 47.5% and m/m = 7.75), Monday (CV = 38.7% and m/m = 4.60) and Thursday (CV = 40.4% and m/m = 4.50). UI was adequate in the group of 14 people, however, the UI excretion of two women suggested iodine intake persistently below that recommended by WHO.
The variability of 24-hour UI excretion on different days in the same individual is lower than that observed among individuals.
评估生活在巴西南部的健康受试者每周三天内 24 小时尿碘（UI）排泄的个体内和个体间变异性，以及尿碘和钠排泄之间的相关性。
这是一项包括 47 名志愿者的横断面研究：18 名志愿者留取一份 24 小时尿液，15 名志愿者留取两份，14 名志愿者留取三份 24 小时尿液。测量了 24 小时尿液中碘、肌酐和 Na(+)的排泄量。
男性的平均身高、体重、BMI 和 24 小时尿肌酐排泄量较高。UI 和尿钠呈正相关（n = 89，r = 0.524，p = 0.000）。UI 排泄在一周的 3 天内个体内和个体间差异很大，但平均 UI 排泄量相似。在单个个体中，最大和最小 24 小时 UI 排泄比值（m/m）范围为 1.03 至 2.87，中值变异系数（CV）为 21%（P₂₅ = 7.0%，P₇₅ = 36.8%），范围为 1%-51%。周日（CV = 47.5%，m/m = 7.75）、周一（CV = 38.7%，m/m = 4.60）和周四（CV = 40.4%，m/m = 4.50），个体间 24 小时 UI 排泄差异很大。14 名志愿者的 UI 充足，但两名女性的 UI 排泄表明其碘摄入量持续低于世界卫生组织推荐量。
同一个体不同日 24 小时 UI 排泄的变异性低于个体间的变异性。
