尿碘浓度(UIC),碘摄入量的生物标志物,用于通过得出UIC中位数来评估人群碘状况,但这并不能量化习惯性缺乏或过量碘摄入量的个体的百分比。UIC<100μg/L或≥300μg/L的个体通常被错误地归类为摄入不足或过量。但这可能高估了真正的患病率。
我们的目的是通过碘调查的点UIC分布来估计儿童(4-14岁)碘摄入不足和过量的患病率。
利用国家碘研究的数据(科威特,阿曼,泰国,和卡塔尔)和儿童的区域研究(中国)(n=6117),其中在子样本(n=1060)中获得了重复的UIC,我们使用重复UIC,根据体重与24小时尿量之间的关系以及人内变化,从斑点UIC计算出每日碘摄入量。我们还估计了按地区划分的外部人员内部占总方差的比例。我们使用人内差异比例,通过使用估计平均需求(EAR)/可耐受的上摄入量(UL)截止方法来获得通常碘摄入量不足或过量的患病率。
科威特的UIC中位数,阿曼,中国,泰国,卡塔尔分别为132、192、199、262和333μg/L,分别。内部人内差异比例从25.0%到80.0%,汇总区域外部估计范围为40.4%至77.5%。调整后的EAR/UL截止方法定义的摄入不足和过量的患病率比斑点UIC<100μg/L或≥300μg/L定义的低45-99%(P<0.01)。
将EAR/UL截止方法应用于调整后的UIC分布的碘摄入量是一种有前途的方法,可以估计碘摄入量不足或过量的个体数量。
The urinary iodine concentration (UIC), a biomarker of iodine intake, is used to assess population iodine status by deriving the median UIC, but this does not quantify the percentage of individuals with habitually deficient or excess iodine intakes. Individuals with a UIC <100 μg/L or ≥300 μg/L are often incorrectly classified as having deficient or excess intakes, but this likely overestimates the true prevalence.
Our aim was to estimate the prevalence of inadequate and excess iodine intake in children (aged 4-14 y) with the distribution of spot UIC from iodine surveys.
With the use of data from national iodine studies (Kuwait, Oman, Thailand, and
Qatar) and a regional study (
China) in children (n = 6117) in which a repeat UIC was obtained in a subsample (n = 1060), we calculated daily iodine intake from spot UICs from the relation between body weight and 24-h urine volume and within-person variation by using the repeat UIC. We also estimated pooled external within-person proportion of total variances by region. We used within-person variance proportions to obtain the prevalence of inadequate or excess usual iodine intake by using the Estimated Average Requirement (EAR)/Tolerable Upper Intake Level (UL) cutoff method.
Median UICs in Kuwait, Oman,
China, Thailand, and
Qatar were 132, 192, 199, 262, and 333 μg/L, respectively. Internal within-person variance proportions ranged from 25.0% to 80.0%, and pooled regional external estimates ranged from 40.4% to 77.5%. The prevalence of inadequate and excess intakes as defined by the adjusted EAR/UL cutoff method was ∼45-99% lower than those defined by a spot UIC <100 μg/L or ≥300 μg/L (P < 0.01).
Applying the EAR/UL cutoff method to iodine intakes from adjusted UIC distributions is a promising approach to estimate the number of individuals with deficient or excess iodine intakes.