三种补碘方式对缺碘地区儿童甲状腺肿消长速度的影响

Effects of three different iodine interventions on the speed of normalization of enlarged thyroid gland due to iodine deficiency

目的 比较三种不同补碘方式对甲状腺肿消长速度的影响。方法 将 2 0 5名 8～ 10岁学生随机分成三组 :每 2个月由研究人员将加碘量为 2 5mg kg的碘盐送到A组学生家庭 ;B组学生及其家庭食用市场供应的加碘盐 ,该次研究与市场碘盐供应同时启动 ;C组学生及其家庭也食用市场供应的碘盐 ,同时在研究开始时服用 4 0 0mg碘油丸。每 2个月检测学生家中正在食用碘盐的碘含量 ;研究开始前及开始后 6、9、12和 18个月时对甲状腺大小、尿碘水平、身高、体重进行测量。结果 实验前三组学生B超法甲状腺肿大率均为 18% ,12个月后A组和C组学生降至 5 %以下 ,18个月时C组学生降至 9%。触诊法甲状腺肿大率与B超法相近。实验前三组学生尿碘中位数为 94μg L ,6个月时尿碘中位数均保持在 2 0 0 μg L以上。 结论 在一个实验前为轻度至中度缺碘的人群中 ,稳定供应碘含量为 2 5mg kg的碘盐 ,18个月后所有指标均表明碘营养状况为正常 ,如果盐碘含量波动较大 ,如B组学生 ,肿大的甲状腺至

Objective To compare the effects of three different iodine interventions on the speed of normalization of enlarged thyroid gland. Methods Schoolchildren aged 8 10 years were randomized divided into one of three groups: group A was given iodized salt by researchers with an iodine concentration of 25 mg/kg; group B used iodized salt purchased from the market; and group C was similar to group B with additional intake of iodized oil capsules containing 400 mg iodine at the beginning of the study. Salt iodine content was measured bimonthly for 18 months and indicators of iodine deficiency were measured at baseline and 6, 9, 12 and 18 months thereafter. Results The prevalence of goiter measured by ultrasound, based on the World Health Organization (WHO) body surface area reference >97 th percentile, was 18% at baseline and declined to less than 5% by 12 month in groups A and C respectively, and to 9% after 18 months in group B. Rates of goiter were similar by palpation or by ultrasound. The median urinary iodine was 94 μg/L at baseline and increased in all groups to >200 μg/L at the 6 month follow up. Conclusions In this sample of schoolchildren with initially low or moderate level of iodine deficiency, the group receiving salt with 25 mg/kg (group A) recovered from iodine deficient on all indicators after 18 months of study. However when the iodine content of salt was floating, as seen in group B, the sizes of thyroid did not yet achieve normal status by 18 months.