现场干预试验中人群尿碘频数的分析

摘要

Objective Through a two-year follow up program,this study was to analyze the urinary iodine frequency of a cohort in the intervention trial,concerning different doses of salt iodization,so as to explore the selection of appropriate concentration of salt iodization.Methods A multistage cluster sampling method was used to select three townships in two countries for community intervention with different doses [ ( 15 ± 5 ) mg/kg,(25 ± 5 ) mg/kg,( 35 ± 5 ) mg/kg ] of salt iodization.Results After intervention,the median of urinary iodine was reduced among the population.The urinary iodine frequencies of (15 ± 5) mg/kg and (25 ± 5) mg/kg among groups of children were mainly concentrated in 100-200 μg/L and 200-300 μg/L paragraphs in A county.While the 300 μg/Lparagraph had an overall decline in B county,the 100 μtg/L and 200 μg/L paragraph ratio increased but the trend seemed to be slow.The 100-300 μg/L paragraph of the four treatment groups took a larger proportion and kept smooth in a more ideal state.However,the control group still maintained at above 250 μg/L level.Conclusion The iodine supplementation should be gradually implemented in Chongqing.The doses of salt iodization should be reduced from the current (35 ± 15)mg/kg to (25 ± 5) mg/kg in the economically developed areas.At the same time,we need to continuously follow the changes of the condition.%目的 分析不同剂量食盐加碘干预后队列人群的尿碘频数,探索较为适宜且安全的碘盐浓度.方法 2007-2010年采用多级整群随机抽样方法抽取观察对象,以抽样A、B县的各3个乡镇为单位进行不同食盐加碘浓度[(15±5)、(25±5)、(35±5)mg/kg]的社区干预,随访观察分析干预后队列人群的尿碘频数变化.结果 下调浓度后,2县4个试验乡镇人群尿碘中位数随着干预时间逐步降低.A县(15±5)mg/kg和(25±5)mg/kg组儿童尿碘频数主要集中在100～200 μg/L和200～ 300 μg/L.B县儿童尿碘频数＞300 μg/L总体有所下降,100～μg/L和200 ～μg/L比例升高,但趋势较为缓慢.4个试验组尿碘频数100～300μg/L的比例较大且保持平稳,始终处于一个较理想的状态；对照组仍以＞250 μg/L为主.结论 建议在重庆市逐步实施分类补碘,在经济较发达地区可将食盐碘浓度从现行的(35±15)mg/kg下调至(25±5)mg/kg,并继续随访其变化.