高碘地区儿童碘营养影响因素和甲状腺肿大及结节的流行特征

目的了解高碘地区停供碘盐前儿童碘营养的影响因素和甲状腺肿大和结节的状况。方法采用单纯随机法在河北省衡水市水碘中位数在200～300μg/L高碘乡(镇)中随机抽取3个进行调查。结果在3个乡(镇)共采集测定8～10岁儿童1次即时尿样326份,尿碘中位数在478.4～571.3μg/L之间,尿碘含量>300μg/L尿样所占比例在77.9%～86.6%之间。12个村儿童的尿碘中位数与其所在村的水碘中位数成正相关(Spearsman,R=0.79,P=0.002),而与盐碘中位数不相关(Spearsman,R=-0.17,P=0.6)。儿童尿碘中位数与水碘中位数成直线相关(R=0.83,F=22.0,P=0.001),直线回归方程为:尿碘=318.1+0.829*水碘。在3个乡(镇)共用B超检测8～10岁儿童452名,甲状腺肿大37例,肿大率为8.2%;不同性别和年龄组甲状腺肿大率无显著差异。在其中2个乡共发现甲状腺结节15例,平均检出率为5.6%,不同性别和年龄组甲状腺结节检出率无显著差异。结论高碘地区儿童碘营养过剩主要由高水碘造成,碘盐加重了这种状况;存在甲状腺肿大流行,甲状腺结节的检出率也较高。甲状腺结节的成因和发生强度有待于进一步研究。

Determinants of children’s iodine nutrition and epidemiological features of goiter and nodule in iodine-excessive areas

Objective To identify the determinants of children’s iodine nutrition and their goitrous and nodular prevalence in iodine excessive areas before withdrawing iodized salt.Methods Three townships were selected by simple random sampling among the townships with median water iodine being 200~300 μg/L in Hengshui prefecture of Hebei Province.Results A total of 326 spot urinary samples of children aged 8~10 years were collected and measured.The median iodine of these samples ranged from 478.4~571.3 μg/L,and the proportions of urinary samples with iodine content over 300 μg/L varied from 77.9% to 86.6%.Children’s urinary median iodine in each of 12 villages showed correlated positively with the median water iodine of the corresponding village(Spearsman,R=0.79,P=0.002),but not with median salt iodine(Spearsman,R=-0.17,P=0.6).Children’s urinary median iodine had a linear correlation with median water iodine(R=0.83,F=22.0,P=0.001),and the linear regression equation was as follows:urinary iodine=318.1+0.829*water iodine.A total of 452 children aged 8~10 years were measured by ultrasound in these 3 townships,identifying 37 cases of goiter with goiter rate being 8.2%.There was no significant difference in goiter rates across gender and age groups.In 2 out of the 3 townships,15 cases of nodules were detected with average detection rate being 5.6%.The detection rates across gender and age groups were not significantly different.Conclusions Children’s iodine over-nutrition could be mainly attributed to excessive water iodine,while being aggravated by iodized salt.Goiter was prevailing in these areas,and a high detection rate of thyroid nodules was also identified.The cause and prevalence of thyroid nodule need to be further studied.