广东省沿海地区食盐加碘后对甲状腺功能亢进症发病的影响

Effect of universal salt iodization on the incidence of hyperthyroidism in iodine deficiency areas along the coast of Guangdong Province

目的了解广东省实施全民食盐加碘（USI）防治碘缺乏病后甲状腺功能亢进症（甲亢）发病情况，为今后制定消除碘缺乏病的策略提供依据。方法采用整群抽样方法，选择广东省吴川市黄坡镇（补碘区）为调查区和徐闻县迈陈镇（非补碘区）为对照区，采用回顾性调查结合前瞻性调查的方法，对两镇人群的甲亢发病情况进行调查。结果USI前3年，黄坡镇和迈陈镇居民甲亢年平均发病率分别为27．16／10万和18、63／10万，两镇居民甲亢发病率差异无统计学意义（Х^2=2．27，P〉0．05）。USI后的8年中，黄坡镇和迈陈镇居民甲亢年平均发病率分别为48．57／10万和26．79／10万，黄坡镇居民甲亢发病率显著高于迈陈镇（x2：26．2，P〈o．01）。黄坡镇在USI后甲亢发病率开始上升，USI前后甲亢发病率差异有统计学意义（Х^2=19．6，P〈0.01）；USI后第5年，甲亢发病率开始逐年下降，至USI后第8年发病率已经下降至USI前的水平。结论实施USI后，甲亢的发病率呈一过性增加，但随着人群缺碘状况被纠正后．甲亢的发病率下降至USI前的水平。碘缺乏病的防治仍是当前工作的重点，但碘致甲亢的预防和处理也不容忽视。

Objective To explore the effect of universal salt iodization （USI） on the incidence of hyperthyroidism in iodine deficiency areas along the coast of Guangdong Province, and to provide scientific evidence for iodine deficiency disorder （IDD） elimination in the future. Methods A combinion of retrospective and cross- sectional study and cluster sampling was used in Huanpo Town, Wuchuan County with USI and Maichen Town, Xuwen County without USI as investigation spots. The incidence of hyperthyroidism in the two towns was investigated. Results In three years before USI, the yearly averaged incidence of hyperthyroidism was 27.16/100,000 and 18.63/100 000 in Huanpo and Maichen Town respectively, without significant difference （Х^2 = 2.27,P 〉 0.05）. However, a significant difference was observed in the incidence of hyperthyroidism between the two towns after 8 years（Х^2 = 26.2 ,P 〈 0.01 ）. Huanpo Town with USI had an obvious higher incidence of 48.57/100 000 of hyperthyroidism than Maichen did, the latter being 26.79/100 000. There was a significant increase in the yearly averaged incidence of hyperthyroidism in Huanpo after USI （Х^2 = 19.6,P 〈 0.01 ）. In the fifth year after USI, the incidence of hyperthyroidism decreased year by year and to the same level as before USI in the eighth year. Conclusions USI caused a short-time increase in the incidence of hyperthyroidism, which decreased to the same level before USI when iodine deficiency in population was corrected. The prevention and cure of IDD is still the emphasis of present work. However, hyperthyroidism caused by excessive iodine should be not ignored.