齐齐哈尔市富拉尔基区常住居民甲状腺疾病患病现况及碘营养状态调查

目的了解齐齐哈尔市富拉尔基区常住居民甲状腺疾病患病现况及影响因素,并评估碘营养状态与甲状腺疾病之间的关系,为本地区开展甲状腺疾病和碘营养水平监测工作提供科学依据。方法 2017年1月-2018年12月按照整群随机抽样方法,选择在该地居住5年以上、且在3个月内未接受过含碘造影剂检查或者服用乙胺碘呋酮的健康人群为研究对象,依次进行问卷调查、甲状腺彩色多普勒超声检查、甲状腺激素和自身抗体含量及尿碘水平测定。结果本次调查共有2 066名符合条件者被纳入研究,各种甲状腺疾病患病率由高到低依次为:甲状腺结节(20.33%)、亚临床甲减(14.91%)、临床甲减(1.36%)、亚临床甲亢(1.26%)、临床甲亢(0.97%)、甲状腺肿(0.63%)。甲状腺球蛋白抗体(TgAb)阳性率和甲状腺过氧化物酶抗体(TPOAb)阳性率分别为9.73%和8.23%。成人尿碘中位数(MUI)为204.40μg/L,男性和女性MUI分别为210.10μg/L、195.80μg/L,城市及农村人群MUI分别为186.20μg/L、245.70μg/L。单因素分析结果显示,本地区甲状腺疾病的发生与年龄、性别、文化程度、职业、高血糖、高血脂、食用加碘盐、食用富碘水平等有关(P0.05)。Logistic多因素分析结果显示,女性(OR=6.85)、年龄≥60岁(OR=9.66)、初中及以下学历(OR=2.70)、政府部门人员(OR=3.63)、高血糖(OR=9.05)、高血脂(OR=6.44)是甲状腺疾病患病的危险因素(P0.05),而经常食用加碘盐(OR=0.59)、经常食用富碘食品(OR=0.48)是甲状腺疾病发生的保护因素(P0.05)。结论齐齐哈尔市富拉尔基区常住居民甲状腺疾病总体患病率为39.45%,其发病与多因素有关,高龄女性为好发人群。本地区居民碘营养水平处于碘超适宜状态,未发现不同碘水平组人群甲状腺疾病患病率有差别。建议居民定期进行甲状腺疾病筛查、重视加碘盐食用,有利于甲状腺疾病的预防和早期诊治。     

海岛居民甲状腺疾病和碘营养状况的关系

目的 调查舟山海岛地区居民甲状腺疾病和碘营养状况,分析二者的相互关系.方法 通过整群随机抽样的方法选取了3284名舟山成年居民进行了尿碘检测,并进行流行病学问卷调查、甲状腺B超检查、甲状腺功能测定.结果 舟山海岛地区成年居民尿碘中位数为226.0μg/L,其中城镇居民320.7 μg/L、盐民122.2 μg/L、农民188.9 μg/L、渔民193.6 μg/L、僧侣271.7 μg/L.舟山地区3284名居民弥漫性甲状腺肿、结节性甲状腺肿、胶质性甲状腺肿、甲状腺腺瘤、甲状腺癌、甲状腺功能亢进(甲亢)、亚临床甲亢、甲状腺功能减退(甲减)、亚临床甲减的患病率分别为1.7%、25.3%、8.7%、0.2%、0.4%、0.5%、0.8%、0.03%和1.0%,甲状腺过氧化物酶抗体(TPOAb)阳性率为9.5%.甲状腺疾病患病率女性明显高于男性(P＜0.05),且随年龄的增长而增高(P＜0.05).经logistic回归模型分析甲状腺疾病患病率与年收入、食用海产品、吸烟史、饮酒史、饮茶史、尿碘值等均无明显相关性(P＞0.05).结论 舟山地区居民碘摄入充足,是否实施全民食盐加碘值得商榷;舟山海岛地区甲状腺疾病的患病率较高可能与碘过量有关.

Abstract：

Objective To investigate iodine nutrition and thyroid health status among residents in Zhoushan archipelago, and to analyse their relationship.Methods A total of 3 284 residents in Zhoushan archipelago were surveyed by questionnaire and their thyroids were examined by B-mode ultrasound.The levels of urinary iodine and thyroid function were detected.Results The median level of urinary iodine in 3 284 residents was 226.0 μg/L, being 320.7 μg/L in citizens, 188.9 μg/L in farmers, 122.2 μg/L in salt-makers, 193.6 μg/L in fishers, and 271.7 μg/L in buddhist.The prevalence of diffuse goiter, nodular goiter, colloid goiter, thyroid adenoma, thyroid carcinoma, hyperthyroidism, subclinical hyperthyroidism, hypothyroidism, subclinical hypothyroidism, and positve rate of TPOAb were 1.7% ,25.3% ,8.7% ,0.2% ,0.4% ,0.5% ,0.8% ,0.03%,1.0% ,and 9.5% repectively.The prevalence of thyroid diseases was increasing with aging, and higher in women than in men (P＜0.05).There was no significant relationship of the thyroid diseases with seafood, smoking,drinking, and tea (P＞0.05).Conclusions The citizens of Zhoushan archipelago have adequate iodine intake.It is pertinent to discuss Universal Salt Iodization.Excessive iodine intake may contribute to the high prevalence rate of thyroid diseases in Zhoushan.     

哈尔滨地区儿童甲状腺肿发病情况及病因学调查

目的调查哈尔滨市儿童甲状腺肿大的发病情况,分析病因。方法采用PPS抽样法选取3 243名11～13岁的学龄儿童,进行甲状腺触诊检查,对疑诊甲状腺肿大者进行甲状腺超声检查,其中354人进行尿碘测定;对发现的甲状腺肿大者进行甲状腺功能、甲状腺自身抗体和尿碘测定;随机选取30名无甲状腺肿大儿童作为对照。结果哈尔滨市学龄儿童尿碘中位数为241.81μg/L,甲状腺肿大率为2.43%。31名采血化验的甲状腺肿大儿童中,发现临床甲状腺功能减退(甲减)1人,亚临床甲减3人,亚临床甲状腺功能亢进(甲亢)2人,临床甲亢1人,这些儿童甲状腺自身抗体均为阳性。抗甲状腺过氧化物酶抗体(TPOAb)与抗甲状腺球蛋白抗体(TGAb)在甲状腺肿大儿童中阳性率分别为45.2%、38.7%,阳性率与抗体浓度均较对照组明显增高(P< 0.01)。尿碘在甲状腺肿大组与对照组之间以及自身抗体阳性组与阴性组之间差异无统计学意义(P> 0.05)。结论目前哈尔滨市学龄儿童碘营养状况处于超足量水平,儿童中有较高的甲状腺自身抗体表达。     

不同碘摄入量地区居民甲状腺肿和甲状腺结节的流行病学对比研究

目的 研究不同碘摄入量人群甲状腺肿(甲肿)和甲状腺结节的患病率。方法 对盘山县、彰武县和黄骅市的缺碘、碘充足和高碘3个农村地区3386名14岁居民进行甲状腺B超检查、甲状腺功能、甲状腺自身抗体(TAA)和尿碘测定。结果 缺碘、碘充足、高碘地区尿碘中位数(MUI)分别为103、374和615μg/L；弥漫型甲肿患病率分别为19．5％、13．6％和5．1％；结节型甲肿患病率分别为3．7％、3．5％和2．5％。甲状腺单发结节检出率分别为8．8％、8．3％和4．1％；多发结节检出率分别为3．8％、1．9％和6．7％。非毒性甲肿患者血清TSH水平盘山和彰武明显低于同地区无甲肿者(P＜0．01)；TAA阳性率高于正常人群(P＜0．05)，以黄骅为显著。结论 在MUI为100一600μg/L的碘摄入量范围内，随碘摄入量增加弥漫性甲肿患病率逐渐降低，结节性甲肿患病率无明显变化。缺碘地区甲状腺单发结节高发，高碘地区多发结节高发。缺碘和碘充足地区甲肿有自主性功能，高碘地区甲肿无自主功能。非毒性甲状腺肿、特别是高碘甲状腺肿存在自身免疫异常。     

轻度碘缺乏城市食盐加碘后甲状腺疾病流行病学调查研究

 目的 评价轻度碘缺乏城市贵阳食盐加碘25年后的碘营养状态及各种甲状腺疾病的患病情况。
方法 采用分层整群抽样方法,抽取贵阳市云岩区宅吉社区20岁及以上居民1509人,测定其血清促甲状腺素（TSH）、游离T₃、游离T₄、甲状腺过氧化物酶抗体（TPOAb）、甲状腺球蛋白抗体（TgAb）水平、尿碘水平及甲状腺B超检查;同时抽取8~10岁学龄儿童80名,测定其尿碘水平。
结果 8~10岁儿童尿碘中位数为228.7 μg/L。成人临床甲状腺功能减退症（甲减）、亚临床甲减、临床甲状腺功能亢进症（甲亢）及亚临床甲亢的患病率分别为1.79%、14.12%、1.52%及1.06%,亚临床甲减的患病率显著高于临床甲减（P < 0.05）;TPOAb及TgAb的阳性率分别为14.38%及 13.59%,自身免疫性甲状腺炎的患病率为4.44%。甲状腺肿大患病率为1.06%,其中,弥漫性甲状腺肿（0.86%）较结节性甲状腺肿（0.20%）多见（P < 0.05）。
结论 食盐加碘25年后,贵阳市处于碘超足量状态,成人临床甲减、亚临床甲减、甲状腺自身抗体阳性及自身免疫性甲状腺炎的患病率均较高。     

水源高碘地方性甲状腺肿并发甲状腺机能亢进的研究

本文报告“水源高碘地方性甲状腺肿并发甲状腺机能亢进”(以下简称水源高碘甲肿甲亢),在高碘地甲肿患者中检出率高达7.76%。临床上有甲状腺Ⅱ°—Ⅲ°弥漫性肿大,有典型甲亢的症状和体征。甲状腺吸~(131)碘率较当地居民明显增高,血清 T_3、T_4偏高,但 TSH 基本正常,有的甚至偏低,T_3抑制试验不抑制,有的 TGAb、TMAb 为阳性,有的 TPO (过氧化物酶活性)增高。病理检查:具有巨滤泡性胶样甲状腺肿和甲状腺机能亢进两组病理学和超微结构特征。     

太原地区健康体检人群甲状腺功能紊乱患病情况调查

目的　调查太原地区人群中甲状腺功能紊乱的患病率。方法　测定太原地区 812 5名体检人群的TSH ,然后再测定FT3、FT4 和甲状腺抗体。结果　在此体检人群中 ,甲状腺功能亢进(甲亢 )患病率为 1.2 0 % ,亚临床甲亢患病率为 0 .87% ,甲状腺功能减退 (甲减 )患病率为 1.0 3 % ,亚临床甲减患病率为 0 .95 %。各种甲状腺功能紊乱的患病率女性均高于男性 (P <0 .0 5～ <0 .0 1)。结论　报道太原地区人群中甲状腺功能紊乱的患病率 ,无论是甲亢和亚临床甲亢或甲减和亚临床甲减 ,女性的患病率均高于男性     

江苏高碘和适碘地区孕妇甲状腺疾病患病率的调查

目的 通过对江苏省高碘和适碘地区孕早期孕妇甲状腺疾病患病率的调查,初步建立不同水碘含量地区妊娠早期甲状腺疾病的流行病学数据库,为甲状腺疾病的有效防治提供依据.方法 选择徐州丰县和睢宁作为高碘和适碘地区,在两地抽取早孕妇女共439例,均为确认孕3月以内的当地常住妇女.设计并填写调查问卷,记录姓名、年龄、既往史、联系方式等一般资料,留取空腹静脉全血,现场离心血标本,分装血清,冰盒保存运输,实验室-86℃冰箱冷冻待检,以电化学发光法测定游离三碘甲状腺原氨酸(FT3)、游离甲状腺素(FT4)、总甲状腺素(TT4)、促甲状腺激素(TSH)及甲状腺过氧化物酶抗体(TPOAb).调查问卷内容及检验结果全部录入Epidata数据库,筛除既往甲状腺疾病、肾脏疾病、心脏疾病、妊高症等对象后,对符合条件的396例对象之数据进行统计学分析.结果 396例调查孕妇中,有197例(49.7％)患甲状腺疾病,甲状腺功能亢进、亚临床甲亢、甲状腺功能减退、亚临床甲减、低T4血症和甲状腺自身免疫状态的患病率分别为0.5％、6.3％、3.3％、29.3％、9.3％和1.0％.其中,高碘地区孕妇的亚临床甲减患病率明显高于适碘地区,分别为32.4％和19.6％,其余类型甲状腺功能异常如甲减、甲亢、亚临床甲亢、低T4血症及甲状腺自身免疫状态的患病率均无差别.结论 江苏高碘与适碘地区孕妇甲状腺疾病谱以亚临床甲减、亚临床甲亢和低T4血症为主,高碘地区孕妇的亚临床甲减患病率高可能与碘摄入过量有关.     

吉林省不同孕期妇女尿碘水平与甲状腺功能关系的调查

目的为掌握全民食盐加碘后吉林省孕妇在不同孕期碘营养和甲状腺功能状况,为今后实施孕妇甲状腺功能监测的必要性和可能性提供依据。方法以省为单位,按"人口比例概率抽样方法"(PPS)抽取30个抽样单位(县)。用单纯随机抽样法从上述抽到的每个抽样单位中抽取3个乡(镇、街道办事处),每个乡(镇、街道办事处)抽取孕妇8人,每县(市、区、旗)孕妇24人。收集被调查对象尿样、血样及家中的食用盐、饮用水。采用化学发光法检测甲状腺功能(包括甲状腺抗体)指标,砷铈催化分光光度法检测尿、水碘含量,直接滴定法检测食盐碘含量。结果孕早、中、晚期妇女的尿碘中位数分别为188.6μg/L、201.9μg/L、175.7μg/L且不同孕期尿碘中位数及频数分布无显著性差异。孕早、中期妇女甲状腺功能异常主要为低FT4血症和亚临床甲状腺功能减退。孕晚期除低FT4血症和亚临床甲状腺功能减退外还有一定比例4.2%(10/240)甲状腺功能亢进(亚临床甲状腺功能亢进)存在。孕晚期妇女与孕早、中期相比甲状腺功能异常比率明显增加,孕妇抗体阳性率为10.2%(77/755)。抗体阳性者发生亚甲减3例占3.8%(3/77),低FT4血症1例占1.3%(1/77),甲亢(亚甲亢)3例占3.8%(3/77)。结论吉林省孕妇的碘营养处于适宜水平;建议在孕早期开展尿碘监测和甲功筛查。     

舟山市册子岛居民甲状腺功能亢进症多发因素流行病学调查

目的 了解舟山市册子岛近年甲状腺功能亢进症(简称甲亢)发病情况及致病因素。方法 于1999年6月按线索采用入户回顾性调查，设病例组和对照组。结果 核实甲亢病例20例，患病率0．49％，尿碘中位数125．5—130．0μg/L，碘盐合格率平均85％，水质检测锌、铁超标，对照组动物蛋白食用率明显高于病例组(P＜0．01)，加服碘盐后甲亢发病占总数的50％。结论 碘致性甲亢应予重视。动物蛋白有预防甲亢发病作用。     

天津市食盐加碘后甲状腺肿大率与碘营养状况的调查

目的：调查和研究食盐加碘后天津市居民的甲状腺肿大率和碘营养状况,方法：在6个区共调查居民31530人,7－14岁在校儿童4415人,对调查对象进行甲状腺肿大率,尿碘浓度,食盐碘含量等项目的调查。结果：（1）食盐加碘后天津市居民的平均甲状腺肿大率为5．5％,8－10岁儿童平均甲状腺肿大率为19．7％,甲状腺肿大率较食盐加碘以前有了明显下降,但下降的速度较缓慢,（2）天津市食盐加碘以后各区居民的平均尿碘中位数为287．2ug/L,各区儿童尿碘中位数平均为271．6u/L,证明总体人群碘营养充足,（3）天津市居民总体盐碘含量超过20mg/kg水平,各区居民户盐含碘量有9．9％－41．1％超过60mg/kg,说明碘盐的含碘是偏高是一个新的现象。结论：经过3年左右的食盐加碘防治工作,天津市碘缺乏情况已得到控制。     

舟山海岛居民碘营养状况调查与分析

目的了解舟山市人群碘营养状况,为制定和完善科学补碘策略提供依据。方法随机抽取舟山市2县区中2个居委会（村）419名当地常住居民,共采集60份碘盐、7份水样、412份尿样分别进行盐碘、水碘、尿碘浓度检测,并对调查对象开展甲状腺超声检查,采集血样进行甲状腺功能检测。结果盐碘浓度的中位数为1．72mg／kg,仅有21份为合格碘盐,合格碘盐食用率为35％;水碘浓度均数为12．00μg/L;尿碘中位数为126．76μg/L;甲状腺异常73人,总异常率20．28％;甲状腺功能异常人数132人,总异常率为31．50％。结论舟山市居民的尿碘水平处于较适宜的水平,孕妇的尿碘水平明显低于WHO／UNICEF／ICCIDD推荐的标准。人群甲状腺异常率略高于省内平均水平,甲状腺功能异常率与全省水平无明显差异。     

Reappraisal of the risk of iodine-induced hyperthyroidism: an epidemiological population survey

The occurrence of iodine-induced hyperthyroidism (IIH) has been reported after iodine supplementation from clinics and hospitals, but not following an epidemiologic survey. We studied the prevalence of thyroid derangement in a population following iodine supplementation. One yr after more than 75% of the population had been consuming 40 ppm iodized salt; information regarding history of endemic goiter and iodized salt production, distribution, consumption and monitoring were collected in four cities of the Islamic Republic of Iran. A total of 6048 subjects were randomly selected. All subjects were assessed for size of goiter, and urinary iodine and serum T4, T3, TSH, anti-thyroglobulin and anti-thyroperoxide were measured. Before iodine supplementation, all four cities were areas of endemic goiter. The rate of household consumption of iodized salt was 50, 75 and 90% in 1994, 1995 and 1996, respectively. Ninety-one percent of the salt samples contained 15-55 ppm iodide. Total goiter rate was 57, 62 and 68%; median urinary iodine was 188, 197 and 190 microg/l in the age groups of 6-18, 19-40 and >40 yr, respectively. Prevalence of clinical and subclinical hyperthyroidism was 0.34 and 0.41 and those of clinical and subclinical hypothyroidism were 0.51 and 1.07%, respectively. Nine point eight and 18% in the 19-40 yr age group and 17.6 and 25.6% in >40 yr old subjects had positive anti-thyroperoxidase and anti-thyroglobulin, respectively. This systemic epidemiologic study in an iodine deficient population showed that, following a well-executed iodine supplementation program, the occurrence of IIH is rare.     

舟山海岛成人碘营养状况调查与分析

目的了解舟山海岛成人碘营养状况,为制定和完善科学补碘策略提供依据。方法抽取舟山市2个县、区中6个居委会(村)3 098名当地18岁以上的常住居民,共采集1 683份碘盐、20份水样、2 872份尿样分别进行盐碘、水碘、尿碘浓度检测,并对调查对象开展甲状腺超声检查,采集血样进行甲状腺功能检测。结果盐碘浓度的中位数为0 mg/kg、均数5.63 mg/kg;有283份为合格碘盐,合格碘盐食用率为16.82%;水碘浓度均数为11.40μg/L;尿碘中位数为112.50μg/L;甲状腺超声检查总异常率30.63%;甲状腺功能总异常率为21.98%。结论舟山市成人居民的尿碘水平处于较适宜的水平;成人整体甲状腺超声检查异常率高于全省水平,18～65岁成人甲状腺超声检查异常率明显低于全省水平,成人女性甲状腺超声检查异常率明显高于男性,65岁以上老年人甲状腺结节发生率为38.49%,明显高于全省水平;甲状腺功能激素异常率低于全省水平。     

舟山海岛孕妇碘营养状况调查与分析

目的了解舟山海岛孕妇碘营养状况,为制定和完善科学补碘提供依据。方法抽取舟山市2个县、区中2个居委会（村）的105名当地不同孕期的常住居民,共采集碘盐、水样、尿样分别进行盐碘、水碘、尿碘浓度检测,并对调查对象开展甲状腺超声检查,采集血样进行甲状腺功能检测。结果盐碘浓度的中位数为0mg/kg、均数10．21m∥kg,合格碘盐食用率为17．47％;水碘浓度均数为11．55μg∥L;尿碘中位数为98．72μg∥L;甲状腺超声检查总异常率35．53％;甲状腺功能总异常率为58．10％。结论舟山海岛孕妇的尿碘水平明显低于wH0／uNIcEF／IccIDD推荐的标准,甲状腺超声检查异常率、甲状腺功能异常率明显高于全省水平。     

Iodine supplementation in Austria: methods and results.

Until 1963 Austria was an extremely iodine-deficient area with low iodine intake and high goiter prevalence. Therefore, for the first time in 1963, salt iodination with 10 mg of potassium iodide per kilogram of salt was introduced by federal law. Twenty years after this salt iodination, however, investigations in schoolchildren demonstrated iodine deficiency grade I to II according to the World Health Organization (WHO) (urinary iodine excretion, 42-75 microg/g Crea) and goiter prevalence of far more than 10%. In 1990, salt iodination was increased to 20 mg of potassium iodide per kilogram of salt. In 1994, further investigations in schoolchildren demonstrated an increase of urinary iodine excretion (121 microg/g Crea) and a reduction of goiter prevalence below 5%, with the exception of pupils ages 14-19 (12%). In the year 2000, 10 years after the increase of salt iodination in Austria, 430 nonselected adult inhabitants of three communities in Carinthia (a county of Austria) were investigated for iodine excretion, goiter prevalence, and prevalence of thyroid autoantibodies. This study demonstrated that although iodine supply is sufficient now in Austria (males, 163.7 microg of Crea; females, 183.3 microg of iodine per gram of Crea), goiter prevalence is still high in the elderly, who lived for a longer period of iodine deficiency (34.3% in women and 21.3% in men), whereas goiter prevalence in younger people up to age 40 years is below 5%. It could also be shown that the percentage of thyroid autoantibodies is now as high as in other countries with sufficient iodine supply (3.19% in males, 5.17% in females). In addition to the changes of urinary iodine excretion and goiter prevalence because of salt iodination, changes of incidence in hyperthyroidism and histologic types of thyroid cancer are discussed in this paper. In conclusion, the introduction of salt iodination led to an improvement in iodine supply with a marked reduction of goiter prevalence in people who were born after 1963, but also to an increase in hyperthyroidism and autoimmune thyroid diseases as well as changes in histologic types of thyroid cancer.     

Thyroid autoimmunity is associated with higher urinary iodine concentrations in an iodine-deficient area of Northwestern Greece.

Northwestern Greece was identified in the 1960s for its high prevalence of endemic goiter and iodine deficiency. Although iodized salt has been commercially available since then, a recent epidemiological survey of 3916 schoolchildren found that low-grade goiter is still prevalent in endemic proportions (21%). The aim of this study was to further assess the cause of goiter and the severity of iodine deficiency in children from this endemic area of Greece. Of the 800 children with clinically detectable goiter, 97 children (60 girls and 37 boys, 8-15 years) were recruited for determination of urinary iodine excretion, as well as assessment of thyroid volume and function and detection of antithyroid antibodies. The median urinary iodine concentration was 8.4 microg/dL, indicative of a mild iodine deficiency. Thyroid function was normal in all but 11 children who had subclinical hypothyroidism. Sixteen children (16.5%), including all those with subclinical hypothyroidism, were positive for antithyroid antibodies. Their median urinary iodine concentration (20.6 microg/dL) was higher compared to children who were negative for antibodies (7.4 microg/dL; p<0.001). The mean thyroid volume by ultrasonography (12.2+/-4.1 mL) was above the upper limit of normal for this age group. Thyroid volume was inversely related to the urinary iodine content in the children with negative antithyroid antibodies. Iodine deficiency is still prevalent in northwestern Greece although of mild severity and constitutes the primary cause of goiter among schoolchildren. However, it appears that autoimmune thyroiditis is emerging as a frequent cause of goiter in those children with sufficient iodine intake.     

Effect of iodine supplementation on a pediatric population with mild iodine deficiency.

A cross-sectional study in two stages consisted of healthy children to assess the effect of iodine supplementation on a pediatric population with mild iodine deficiency in an ongoing program in the Province of Pontevedra, northwestern Spain. In the first survey (1984), 1565 schoolchildren and in the second survey (1995) 907 schoolchildren were randomly selected from the population. In January 1985, a mandatory consumption of iodized salt in our region was begun. In both surveys we studied prevalence of goiter, urinary iodine excretion, and prevalence of thyroid dysfunction. Similar prevalences of goiter were observed in both surveys, 3.7% versus 3.9%; however, significantly lower prevalence of Ib and II degree goiters were observed in the second survey. The mean iodine excretion was 88.6 +/- 73 microg/L (median 66.3) and 146.4 +/- 99 microg/L (median 115.7), p < 0.01 for the first and second surveys, respectively. Finally, the overall prevalence of thyroid dysfunction was similar in both surveys, 9.2% versus 7.0%; however, significantly lower prevalence of suppressed serum thyrotropin (TSH), considered as a marker of subclinical hyperthyroidism, was observed in the second survey when compared to the first, 0.1% versus 2%, p < 0.01. Our results are in agreement with the recent data from Denmark, where the prevention of subclinical hyperthyroidism occurring in the elderly as a consequence of longstanding mild iodine deficiency is the reason that the Danish finally started iodine supplementation on a national basis. In conclusion, long-term correction of mild iodine deficiency in a pediatric population has beneficial effects on the prevalence of high-degree goiters, and this correction reduces significantly the prevalence of subclinical hyperthyroidism. The present observation constitutes a strong argument for correcting even mild iodine deficiency.     

Introduction of iodized salt to severely iodine-deficient children does not provoke thyroid autoimmunity: a one-year prospective trial in northern Morocco.

To determine if introduction of iodized salt induces thyroid autoimmunity in goitrous children, we conducted a prospective trial in iodine-deficient Moroccan schoolchildren (n = 323). Local salt was iodized at 25 microg iodine per gram of salt and distributed to households. Before introduction of iodized salt and at 10, 20, 40, and 52 weeks, we measured antithyroid peroxidase antibodies (TPO-Ab), antithyroglobulin antibodies (Tg-Ab), urinary iodine (UI), and thyroid hormones, and examined the thyroid using ultrasound. At baseline, median UI was 17 microg/L and the prevalence of goiter and hypothyroidism was 72% and 18%, respectively. Provision of iodized salt maintained median UI at 150-200 microg/L for the year (p < 0.0001). There was a significant increase in mean total thyroxine (T(4)) and a significant reduction in the prevalence of hypothyroidism (p < 0.001). There was a transient increase in the prevalence of detectable antibodies after introduction of iodized salt (p < 0.0001) with levels returning to baseline at 1 year. Only congruent with 1% of children had elevated TPO-Ab and none had elevated Tg-Ab over the course of the study, and no child with elevated TPO-Ab had abnormal thyrotropin (TSH) or T(4) concentrations. None developed clinical or ultrasonographic evidence of thyroid autoimmune disease and/or iodine-induced hypothyroidism or hyperthyroidism. Rapid introduction of iodized salt does not provoke significant thyroid autoimmunity in severely iodine-deficient children followed for 1 year.