食盐碘含量调整前后贵阳市成人自身免疫性甲状腺炎患病情况的变化

Study on the change of prevalence of autoimmune thyroiditis in Guiyang city after adjustment of salt iodine content

目的调查分析食盐碘含量调整前后贵阳市城区成人自身免疫性甲状腺炎患病情况的变化，以初步了解碘营养状态对自身免疫性甲状腺炎患病情况的影响。 方法采用分层整群抽样方法，分别于2009年（食盐碘含量调整前，n＝1 509）、2015年（食盐碘含量调整后，n＝1 368）2次对贵阳市云岩区20岁及以上居民进行问卷调查，测定其血清促甲状腺激素（TSH）、甲状腺过氧化物酶抗体（TPOAb）、甲状腺球蛋白抗体（TgAb）水平，TSH异常者测定FT3、FT4；同时于2次调查中分别抽取同城区8～10岁学龄儿童各80、60名，测定其尿碘水平。结果2009年调查中8～10岁学龄儿童尿碘中位数为228.7 μg/L；成人TPOAb、TgAb及甲状腺自身抗体（TAA）的阳性率分别为14.38%、13.59%和18.89%，相应的标准化率为14.35%、13.59%和18.89%；亚临床甲状腺功能减退（亚甲减）、自身免疫性甲状腺炎的患病率分别为14.12%和4.44%，标准化率为14.12%和4.42%。2015年调查中8～10岁学龄儿童尿碘中位数为190.1 μg/L；成人TPOAb、TgAb及TAA的阳性率分别为8.77%、7.82%和11.77%，相应的标准化率为8.98%、7.97%和12.13%；亚甲减、自身免疫性甲状腺炎的患病率分别为22.89%和2.92%，标准化率为23.19%和3.02%。2015年调查的成人TPOAb、TgAb、TAA阳性率及自身免疫性甲状腺炎患病率均较2009年所调查的降低（均P〈0.05）；但亚甲减患病率较2009年所调查的升高（P〈0.05）。结论该市于2013年下调食盐碘含量后，碘营养状态适宜，成人TPOAb、TgAb、TAA的阳性率及自身免疫性甲状腺炎患病率较碘含量调整前均有所下降。

ObjectiveTo investigate the change of prevalence of autoimmune thyroiditis in Guiyang city after adjustment of salt iodine content, and to study the link between the level of iodine intake and the development of autoimmune thyroiditis.MethodsWith cluster sampling method, a cross-sectional study was conducted among adults aged 20 years old or above in Guiyang in 2009 （before adjustment, n=1 509） and 2015 （after adjustment, n=1 368）. After an overnight fasting, thyroid stimulating hormone （TSH）, thyroid peroxidase antibody （TPOAb）, and thyroglobulin antibody （TgAb） were measured. The serum FT4 and FT3 were determined for the subjects with abnormal TSH. Meanwhile, urine iodine levels of children aged 8-10 years old in the same community were measured after an overnight fasting in these two studies.ResultsIn 2009, the median level of 8-10 years old children′s urinary iodine was 228.7 μg/L. The prevalence of positive TPOAb, positive TgAb, and thyroid autoantibodies （TAAs） were 14.38%, 13.59%, 18.89%, the standardized prevalence were 14.35%, 13.59%, 18.89% respectively. The prevalence of subclinical hypothyroidism, autoimmune thyroiditis were 14.12% and 4.44%, with the standardized prevalence were 14.12%, 4.42% respectively. In 2015, the median urinary iodine level of 8-10 years old children was 190.1 μg/L, the prevalence of positive TPOAb, positive TgAb, and TAAs were 8.77%, 7.82%, 11.77%, the standardized prevalence were 8.98%, 7.97%, 12.13% respectively; the prevalence of subclinical hypothyroidism, autoimmune thyroiditis were 22.89%, 2.92%, with the standardized prevalences of 23.19%, 3.02% respectively.ConclusionAfter adjustment of salt iodine content, the iodine nutrition in Guiyang is at the appropriate level, and the values of TPOAb, TgAb, TAA, and autoimmune thyroiditis in adults of Guiyang city were all decreased.