碘摄入量对血清甲状腺球蛋白的影响——5年流行病学随访研究

目的 观察碘摄入量对血清甲状腺球蛋白(Tg)水平的影响.方法 对1999年盘山(轻度碘缺乏地区)、彰武(碘超足量地区)和黄骅(碘过量地区)血清Tg水平正常的3 099人进行随访,将2004年随访到的2 448人作为研究人群.测定Tg、甲状腺球蛋白抗体(TgAb)、甲状腺过氧化物酶抗体(TPOAb)、促甲状腺素(TSH)、甲状腺容积,并询问甲状腺疾病的家族史和个人史.分析Tg的影响因素.结果 1999年初访时,不同碘摄入地区Tg水平差异显著[盘山7.5(4.4～13.1)μg/L、黄骅6.8(3.6～11.2)μg/L彰武5.9(3.2～10.7)μg/L,P<0.01];年龄、性别、TgAb阳性、甲状腺肿大、TSH异< 凹鬃聪偌膊「鋈耸范訲g水平的影响亦显著.为排除混杂因素的影响,对TgAb、甲状腺容积、TSH、甲状腺疾病个人史均无异常的1 856人的随访数据进行分析,其初访及随访的Tg水平均有显著地区差异,轻度碘缺乏以及碘过量地区都显著高于碘超足量地区.三地区随访时Tg水平均显著升高,且增加值(△Tg)存在显著地区差异[盘山3.1(-0.2～8.0)μg/L、黄骅3.5(0.5～9.0)μg/L/35彰武2.5(0.3～6.1)μg/L,P<0.01];碘摄入量、初访时的Tg水平、TSH水平及年龄为ATg的独立影响因素.结论 碘摄入量显著影响血清Tg水平,当用血清Tg水平来估计地区碘摄入水平及其变化时,应该同时考虑年龄及TSH等因素.     

不同碘摄入量地区甲状腺自身抗体的流行病学五年随访研究

目的 利用不同碘摄入量的3个农村社区甲状腺疾病的流行病学随访研究资料，探讨甲状腺功能正常人群甲状腺自身抗体发生和转归的规律和意义，以及环境因素碘对其的影响。方法 1999年本研究组对轻度碘缺乏、超足量碘摄入和过量碘摄人的盘山、彰武和黄骅3个社区进行了甲状腺疾病的流行病学研究，2004年再次对同一人群进行了随访研究，前后采用同样方法采血清测定TSH、甲状腺过氧化物酶抗体（TPPOAb）、甲状腺球蛋白抗体（TgAb）和甲状腺球蛋白（Tg）水平，采尿样测定尿碘浓度及行甲状腺B超检查。结果 （1）初访时TSH正常人群5年后TPOAb的阳性率在彰武社区较前升高，TgAb的阳性率在黄骅社区较前升高（均P〈0．05）。（2）初访时TSH正常但TPOAb或TgAb阳性者多维持抗体阳性，且抗体水平越高随访抗体阳性维持率越高。（3）随访发现1999年TPOAb和（或）TgAb阳性者较抗体阴性者更易发生甲状腺功能异常（P〈0．01），黄骅和彰武社区的抗体阳性者5年随访发生甲状腺功能减低的比率显著高于盘山社区，以黄骅社区最高（P〈0．05）。（4）彰武社区TPOAb阳性的5年累积发生率在3个社区中最高。黄骅社区TgAb阳性的5年累积发生率在3个社区中最高，与盘山相比差异有统计学意义（P〈0．05）。结论 甲状腺自身抗体阳性者发生甲状腺功能异常的比率显著高于抗体阴性者，而碘摄人量增加能增加抗体阳性者发生甲减的危险性。持续处于过量碘摄人状态使甲状腺自身抗体阳性的发生率增加。     

249名老年人中甲状腺疾病的发生及转归临床分析

目的研究老年人甲状腺疾病的患病率和发生发展特点。方法249例来自我国辽宁省、河北省的老年人(男102名,女147名;年龄60~88岁)参加了1999年的横断面调查,5年后进行了随访。初访和随访时均测定血清促甲状腺激素(TSH)、甲状腺过氧化物酶抗体(TPOAb)和甲状腺球蛋白抗体(TgAb),TSH异常者加测游离甲状腺激素(FT3、FT4)。结果该研究人群TSH正常范围为0.28~4.75mU/L。甲状腺功能异常(含临床和亚临床型)的总患病率10.84%,TPOAb和TgAb的阳性率分别为12.85%和11.65%。初访时确定为正常甲状腺功能的老年人(n=222,随访率79.7%),5年后新发临床甲状腺功能亢进(甲亢)1例、亚临床甲亢2例(均为男性),亚临床甲减3例(均为女性)。初访时甲状腺自身抗体阴性者,随访时有6例出现抗体的阳转,但未伴有甲状腺功能的异常。结论老年人甲状腺疾病患病率较高,应当开展甲状腺疾病筛查;老年人的亚临床甲状腺疾病多数可自行缓解,可采取以观察为主的处理方式。     

不同碘摄入量社区甲状腺功能亢进症的五年流行病学随访研究

目的 在3个不同碘摄入量农村社区进行的甲状腺疾病流行病学随访调查，分析和探讨不同碘摄入量对甲状腺功能亢进症（甲亢）发病率的影响及其意义，同时研究与甲亢发病相关的危险因素。方法 在轻度碘缺乏的盘山社区、超足量碘摄入（既往轻度缺碘补碘后3年）的彰武社区和过量碘摄入的黄骅社区对3761人进行了甲状腺疾病的流行病学的横断面研究，5年后以相同的检查指标对此人群进行了随访研究。结果（1）盘山、彰武和黄骅社区的学龄儿童尿碘中位数分别为87．6、213．9和633．5μg／L（P〈0．05），随访人群的碘营养状态与原始调查相比无明显变化；3个社区的随访人群总数为3018人，随访率为80．2％。（2）3个社区的临床甲亢累积发病率分别为13．6／1000、9．4／1000和8．1／1000（P〉0．05），女性的累积发病率分别为16．4／1000、11．2／1000和9．1／1000（P〉0．05）。（3）初访时任一甲状腺自身抗体阳性[甲状腺过氧化物酶抗体（TPOAb）〉50IU／ml或甲状腺球蛋白抗体（TgAb）〉40IU／ml]但无甲状腺病史及甲状腺功能改变者，5年后临床甲亢的发生率3个社区之间差异无统计学意义。（4）初访时TSH〈0．3mIU／L、TPOAb阳性和甲状腺肿与临床甲亢的发生相关，其OR值分别为5．7（95％CI，2．1-15．0）、3．8（95％CI，1．7-8．7）和3．1（95％CI，1．4-6．8）。结论 在轻度缺碘地区补碘后最终不会使甲亢的发病率增加。慢性碘过量不会对临床甲亢的发病率和病因组成产生明显影响。TSH〈0．3mIU／L、TPOAb阳性和甲状腺肿是临床甲亢发病的危险因素。     

血清TSH、TPOAb、TgAb水平与冠心病PCI术预后的关系分析

目的:探讨血清促甲状腺激素(TSH)、抗甲状腺过氧化物酶抗体(TPOAb)、抗甲状腺球蛋白抗体(TgAb)水平与冠心病经皮冠状动脉介入术(PCI)预后的关系。方法:选择在我院住院接受PCI治疗的冠心病患者310例，根据预后情况分为预后良好组(258例)和预后不良组(52例)。比较两组患者的临床资料及TSH、TPOAb、TgAb水平，分析冠心病PCI术预后不良的影响因素。结果:与预后良好组比较，预后不良组冠脉C型病变(17.83%比30.77%)、植入支架数≥3枚(13.57%比26.92%)比例及TSH[(2.63±0.16)mU/L比(2.81±0.15)mU/L]、TPOAb[(24.51±3.49)IU/ml比(41.89±7.24)IU/ml]、TgAb[(113.30±10.60)IU/ml比(147.60±13.22) IU/ml]水平均显著升高(P<0.05或<0.01);二元Logistic回归分析显示冠脉C型病变、植入支架数≥3枚、TSH、TPOAb、TgAb是冠心病患者PCI手术预后不良的独立危险因素(OR=1.384～3.002,P<0.05或&...     

不同碘营养地区甲状腺球蛋白抗体亚类分布及其意义研究

目的研究不同碘营养地区甲状腺球蛋白抗体(TgAb)IgG亚类的分布,为疾病的早期预防和治疗提供线索。方法选择本研究组2004年对辽宁省盘锦、彰武社区以及河北省黄桦社区共3018名居民的流行病学调查资料。分别从轻度碘缺乏、超足量碘摄入和过量碘摄入地区选取TgAb>40 kU/L,甲状腺过氧化物酶抗体(TPOAb)<50kU/L,促甲状腺激素(TSH)为0.3～4.8 mU/L(即甲状腺功能正常)的研究对象共102例,另选取阴性对照83名。采用抗原特异性酶联免疫吸附法(ELISE)测定IgG亚类。结果超足量碘摄入组和过量碘摄入组的IgG4亚类浓度明显高于轻度碘缺乏组(P均<0.05)。超足量碘摄入组IgG4亚类阳性率明显高于轻度碘缺乏组(P<0.05)。其余各亚类浓度及阳性率组间比较差异无统计学意义。结论超足量及过量碘营养地区TgAb的IgG4亚类浓度明显升高,可能与长期暴露于碘所致的Tg抗原决定簇改变相关。该亚类的升高,可能提示疾病的前期或慢性状态。     

不同碘摄入量社区甲状腺过氧化物酶抗体和甲状腺球蛋白抗体五年随访研究

甲状腺过氧化物酶抗体(TPOAb)和甲状腺球蛋白抗体(TgAb)是自身免疫性甲状腺病(AITD)患者体内常见的甲状腺自身抗体.我们进行了一项5年的流行病学随访研究,探讨了普通人群中TPOAb和TgAb阳性率及其阳性的发生率和抗体的自然转门,并探讨了环境因素碘对其的影响.     

妊娠早期碘营养状况与甲状腺功能关系的流行病学调查

目的 探讨妊娠早期碘营养状况与甲状腺功能的关系.方法 随机选取2005-2007年碘充足的沈阳地区10所医院妇产门诊妊娠8周以内孕妇1154例,测定空腹尿碘、空腹血清促甲状腺素(TSH)、甲状腺过氧化物酶抗体(TPOAb)、游离甲状腺素(FT4).结果 在碘充足地区仍有42.63%的孕妇存在碘缺乏.妊娠早期碘缺乏、碘适量、碘超足量、碘过量孕妇的亚临床甲减患病率分别为11.79%、8.60%、11.24%、18.75%,碘营养状况与患病率呈"U"字形关系曲线.碘超足量和碘过量的孕妇血清FT4水平均显著高于碘适量组.碘营养状况对TPOAb无影响.结论 孕早期碘缺乏可以导致母体亚临床甲减患病率增加,碘超足量和碘过量可以导致母体亚临床甲减患病率和低L血症的增加.     

妊娠糖尿病与甲状腺自身免疫的相关性研究

目的 研究妊娠糖尿病与甲状腺功能异常及甲状腺自身抗体阳性的相关性.方法 选取妊娠糖尿病患者共80例作为妊娠糖尿病组,另外选择糖耐量正常孕妇36名作为正常对照组.同时选择产后18 ～ 120个月曾诊断为妊娠糖尿病者作为曾患妊娠糖尿病组(36例),并以产后18～96个月的正常妊娠者28名作为随访对照组.检测4组受试者空腹血糖、餐后2h血糖、游离T4、促甲状腺激素(TSH)、血脂水平,以及谷氨酸脱羧酶65(GAD65)抗体、甲状腺过氧化物酶抗体(TPOAb)、甲状腺球蛋白抗体(TgAb).曾患妊娠糖尿病组根据甲状腺自身抗体情况分为甲状腺自身抗体阳性组与阴性组,统计两个亚组糖代谢异常的发生情况.结果 妊娠糖尿病组空腹血糖、餐后2h血糖高于其他组(P均’＜0.05),4组间血脂水平差异没有统计学意义(P均＞0.05).与正常对照组相比,妊娠糖尿病组游离T4、TSH水平差异均没有统计学意义(P均＞0.05).妊娠糖尿病组GAD65抗体阳性者有4例,曾患妊娠糖尿病组有3例.分别与正常对照组及随访对照组相比,妊娠糖尿病组及曾患妊娠糖尿病组TPOAb、TgAb阳性发生率均增加(x2=7.459,P＜0.05).曾患妊娠糖尿病组总体TSH水平异常的发生率、同时存在TSH水平异常及甲状腺自身抗体阳性的发生率显著高于其他3组(x2=5.925,8.766,P均＜0.05).曾患妊娠糖尿病组47.2％(17/36)在随访时发生高血糖,甲状腺抗体阳性组60.0％(6/10)出现糖代谢异常,而甲状腺抗体阴性组42.3％(11/26)有糖代谢异常,但两组间差异没有统计学意义(P＞0.05).结论 产后甲状腺自身免疫与糖代谢受损无关.妊娠糖尿病可能是发生甲状腺自身免疫异常的危险因素.     

不同碘摄入量社区甲状腺功能减退症的五年随访研究

目的 研究不同碘营养状态社区甲状腺功能减退症（甲减）的流行病学特点，探讨影响其发生及转归的因素。方法 1999年对盘山（轻度碘缺乏）、彰武（轻度碘缺乏基础上补碘至超足量）和黄骅（长期碘过量）社区的3761人开展了甲减的横断面调查，5年后其中3018人接受了随访研究（随访率80．2％）。结果 盘山、彰武和黄骅3个社区临床甲减的5年累积发病率分别为0．23％，0．47％和0．35％。自身免疫性甲状腺炎所致临床甲减的自然转归：55％恢复正常，20％转归为亚临床甲减，25％维持临床甲减；其转归在3个社区间差异无统计学意义。亚临床甲减5年累积发病率分别为0．23％、2．60％和2．89％，彰武和黄骅显著高于盘山（均P〈0．01）。随访亚临床甲减100例，其中5％进展为临床甲减，66％恢复正常。初访时TSH〉6mU／L（OR=3．4）、随访时甲状腺自身抗体阳性（OR=5．3）及对轻度碘缺乏人口过量补碘至超足量（OR=8．0）可能是影响亚临床甲减恢复的不利因素。结论 对轻度碘缺乏社区过量补碘可能导致l临床和亚临床甲减的发生，并影响亚临床甲减的转归，但对临床甲减的转归无显著影响。     

Antithyroperoxidase and antithyroglobulin antibodies in a five-year follow-up survey of populations with different iodine intakes

OBJECTIVE: In a follow-up study, we determined the prevalence, incidence, and natural course of positive antithyroperoxidase antibodies (TPOAbs) and antithyroglobulin antibodies (TgAbs) in the general population and examined the influences of iodine intake. DESIGN: The study was conducted in Panshan, Zhangwu, and Huanghua, regions with mildly deficient, more than adequate, and excessive iodine intake, respectively. Of the 3761 unselected subjects who were enrolled at baseline, 3018 participated in the 5-yr follow-up study. Serum TSH, TPOAb, and TgAb levels were measured. RESULTS: Among subjects in Panshan, Zhangwu, and Huanghua, the prevalence of positive TPOAbs was 11.23, 11.83 and 12.02%, respectively, whereas 11.23, 11.17, and 11.26% of subjects were TgAb positive, respectively. In the older population (> or =45 yr), TgAb-positive individuals were more frequent in Huanghua than Panshan and Zhangwu (P < 0.05). The 5-yr cumulative incidence of positive TPOAb was 2.08, 3.84, and 2.84% in Panshan, Zhangwu, and Huanghua, respectively, whereas 2.91, 3.64, and 5.07% of subjects were TgAb positive, respectively (P < 0.05), corresponding to the increase in iodine intake. Subjects who were TPOAb and/or TgAb positive at baseline developed thyroid dysfunctions more frequently than those without antibodies (14.44 vs. 3.31%, P < 0.01); their incidence of elevated TSH levels was 1.32, 8.46, and 15.38% in Panshan, Zhangwu, and Huanghua, respectively (P < 0.05). CONCLUSIONS: Subjects who were TPOAb and TgAb positive at baseline developed thyroid dysfunctions more frequently than seronegative subjects. High iodine intake was a risk factor for developing hypothyroidism in antibody-positive subjects. A constant exposure to excessive iodine intake increased the incidence of positive TgAb.     

甲状腺自身抗体阳性妇女孕期干预对婴儿甲状腺功能的影响

目的 探讨甲状腺自身抗体阳性妇女孕期甲状腺功能干预对婴儿甲状腺功能的影响.方法选择产前检查发现的甲状腺过氧化物酶抗体(TPOAb)和(或)甲状腺球蛋白抗体(TgAb)阳性妊娠妇女55例.随机分为干预组(子代为A)36例和非干预组(子代为B)19例,设同期自身抗体阴性对照组(子代为N)30例.选择左旋甲状腺素片作为干预制剂.采用化学发光酶免疫分析法测定3组入选后和分娩前空腹血清TPOAb、TgAb、TSH、TT3、TT4、FT3、FT4水平,同时测定母体尿碘含量.新生儿出生后测定脐血、出生后3～4周及8～10周静脉血TSH、TT3、TT4、FT3、FT4水平.结果干预组、非干预组母体基线血清TSH水平显著高于对照组(P＜0.05).分娩前非干预组与另两组比较,血清TSH增高和TT3、TT4、FT4降低具有统计学差异(P＜0.05或P＜0.01).胎儿出生后脐血TSH水平在B组(7.06±1.31)mIU/L和A组(6.23±1.26)mIU/L均显著高于N组(5.48±1.17)mIU/L(P＜0.01或P＜0.05).出生3～4周新生儿B组血清TSH(3.21±0.70)mIU/L高于N组[(2.72±0.51)mIU/L]和A组[(2.78±0.42)mIU/L,均P＜0.05].出生8～10周婴儿B组血清TSH[(2.99±0.57)mIU/L]高于N组[(2.48±0.68)mIU/L,P＜0.05].多元逐步回归分析,母体TSH、TPOAb及尿碘含量与婴儿TSH独立相关.结论不同甲状腺功能状态的妊娠妇女,其子代出生后的甲状腺功能存在差异.胎儿出生后甲状腺功能与母亲甲状腺自身抗体及孕期甲状腺功能状态有关.     

原发性胆汁性胆管炎患者血清甲状腺激素水平和抗甲状腺抗体阳性率变化*

目的 探讨原发性胆汁性胆管炎(PBC)患者血清甲状腺激素水平和抗甲状腺抗体阳性率变化。方法 2018年1月～2020年1月我院收治的PBC患者94例,其中肝硬化50例(Child-Pugh A级29例,B级15例,C级6例)和胆管炎44例,另选择同期于我院健康体检者60名,采用化学发光免疫法测定血清游离三碘甲状腺原氨酸(FT3)、游离甲状腺素(FT4)和促甲状腺激素(TSH)水平及血清甲状腺过氧化物酶抗体(TPOAb)和甲状腺球蛋白抗体(TGAb)。结果 胆管炎患者血清FT3、FT4和TSH水平分别为(2.4±0.5)ng/L、(1.4±0.2)ng/L和(8.9±2.3)ng/L,血清TPOAb和TGAb阳性率分别为77.3%和81.8%,肝硬化患者血清FT3、FT4和TSH水平分别为(1.9±0.3)ng/L、(1.0±0.1)ng/L和(19.7±4.9)ng/L,血清和TPOAb和TGAb阳性率分别为70.0%和64.0%,而健康人血清FT3、FT4和TSH水平分别为(2.8±0.8)ng/L、(1.8±0.3)ng/L和(3.4±1.2)ng/L,血清TPOAb和TGAb阳性率均为0.0%,肝硬化和胆管炎患者血清FT3和FT4水平显著低于,血清TSH水平显著高于健康人(P＜0.05),而肝硬化患者血清FT3和FT4水平显著低于,血清TSH水平显著高于胆管炎患者(P＜0.05),肝硬化和胆管炎患者血清TPOAb和TGAb阳性率比较,无统计学差异(P＞0.05);在肝硬化患者中,Child-Pugh A级患者血清FT3和FT4水平显著高于,血清TSH水平显著低于Child-Pugh B级或C级患者(P＜0.05),而Child-Pugh B级患者血清FT3和FT4水平显著高于,血清TSH水平显著低于Child-Pugh C级患者(P＜0.05),不同肝功能分级的肝硬化患者血清TPOAb和TGAb阳性率比较,无统计学差异(P＞0.05)。结论 原发性胆汁性肝硬化和胆管炎患者血清FT3、FT4和TSH水平显著不同于健康人,血清TPOAb和TGAb阳性率较高,其临床意义值得进一步观察和研究。     

Goiter rate, serum thyrotropin, thyroid autoantibodies and urinary iodine concentration in Tehranian adults before and after national salt iodization

Goiter rate, serum TSH, antithyroperoxidase (TPOAb), antithyroglobulin (TgAb) antibodies, and urinary iodine concentration (UIC) were evaluated 10-11 yr prior (1983-1984) and 5-6 yr after (1999-2000) national salt iodization in Iran. Pre- and post-iodization groups consisted of 465 and 1426 adults aged > or =20 yr, respectively, selected by random cluster sampling in Tehran province. Total, grade 1 and grade 2 goiter rates were 65.2, 53.1, and 12.1% in 1983-1984 vs 25.2, 15.5, and 9.7% in 1999-2000 (p<0.0001). Median serum TSH was 1.5 mIU/l in 1983-1984 vs 0.8 mIU/l in 1999-2000 (p<0.0001). Median TSH also decreased in 20-29, 30-39, 40-49, 50-59, and > or =60- yr-adults in 1983-1984 vs 1999-2000 (p<0.0001). In 1983-1984, positive TPOAb and positive TgAb were detected in 3.2 and 4%, respectively, using agglutination test. Corresponding values were 12.5 and 16.8% using immunoenzymometric assay in 1999-2000. Overt and subclinical hypothyroidism was present in 0 and 32.8/1000 in 1983-1984 vs 3.5 and 21.7/1000 in 1999-2000, respectively. Overt and subclinical hyperthyroidism was detected in 4.4 and 4.4/1000 in 1983-1984 vs 0.7 and 5.6/1000 in 1999-2000, respectively. Subclinical hypothyroidism in males was significantly more frequent in 1983-1984 vs 1999-2000 (odds ratio 5.02, 95% confidence interval 1.72-14.68; p=0.004). Salt iodization resulted in adequate UIC, decrease in serum TSH and subclinical hypothyroidism in males, and an increase in thyroid autoantibodies without significant change in thyroid abnormalities. Benefits of iodine supplementation far outweigh its hazards in Tehranian adults.     

Effect of iodine restriction on thyroid function in patients with primary hypothyroidism.

Dietary iodine intake in Japan varies from as little as 0.1 mg/day to as much as 20 mg/day. The present study was undertaken to assess the frequency of iodine-induced reversible hypothyroidism in patients diagnosed as having primary hypothyroidism, and to clarify the clinical backgrounds responsible for the spontaneous recovery of thyroid functions. Thirty-three consecutive hypothyroid patients (25 women and eight men) with a median age of 52 years (range, 21-77 years) without a history of destructive thyroiditis within 1 year were asked to refrain from taking any iodine-containing drugs and foods such as seaweed products for 1-2 months. The median serum thyrotropin (TSH) level, which was initially 21.9 mU/L (range, 5.4-285 mU/L), was reduced to 5.3 mU/L (range, 0.9-52.3 mU/L) after iodine restriction. Twenty-one patients (63.6%) showed a decrease in serum TSH by >50% and to <10 mU/L. Eleven patients (33.3%) became euthyroid with TSH levels within the normal range (0.3-3.9 mU/L). The ratios of TSH after iodine restriction to TSH before iodine restriction (aTSH/bTSH) did not correlate significantly with titers of anti-thyroid peroxidase antibody and anti-thyroglobulin antibody or echogenicity on ultrasonography, but correlated inversely with (99m)Tc uptake (r = 0.600, p < 0.001). Serum non-hormonal iodine levels, although not correlated significantly with aTSH/bTSH values, were significantly higher in the 21 patients with reversible hypothyroidism than in the remaining 12 patients. TSH binding inhibitor immunoglobulin was negative in all except one weakly positive case. In conclusion, (1) primary hypothyroidism was recovered following iodine restriction in more than half of the patients, and (2) the reversibility of hypothyroidism was not significantly associated with Hashimoto's thyroiditis but with increased (99m)Tc uptake and elevated non-hormonal iodine levels.     

Trimester- and method-specific reference intervals for thyroid tests in pregnant Chinese women: methodology, euthyroid definition and iodine status can influence the setting of reference intervals

Objective The importance of diagnosis and treatment of thyroid dysfunction during pregnancy has been widely recognized. We therefore established trimester‐ and method‐specific reference intervals for thyroid testing in pregnant women according to the NACB recommended criteria. Several factors can affect the setting of reference intervals, in particular manufacturer’s methodology, euthyroid definition and iodine status. Design Cross‐sectional dataset analysis. Subjects Five hundred and five normal pregnant women at different stages of gestation were rigorously selected for setting reference intervals. All were healthy, iodine sufficient, euthyroid and negative for both serum thyroid peroxidase antibody (TPOAb) and thyroglobulin antibody (TgAb). Measurements Thyrotrophin (TSH), total and free thyroxine (TT4 and FT4), total and free triiodothyronine (TT3 and FT3) and anti‐TPOAb and anti‐TgAb were measured using the Bayer ADVIA Centaur system. Iodine content in drinking water, salt and urine was determined by national standard methods. The 2·5th and 97·5th percentiles were calculated as the reference intervals for thyroid hormone levels during each trimester. Results All participants had long‐term consumption of iodized salt and median urinary iodine of 150–200 μg/l during each three trimester. The reference intervals for the first, second and third trimesters were, respectively, TSH 0·03–4·51, 0·05–4·50 and 0·47–4·54 mIU/l and FT4 11·8–21·0, 10·6–17·6 and 9·2–16·7 pmol/l. The manufacturer’s method, euthyroid definition and iodine status may influence TSH and FT4 reference intervals. Alterations in thyroid hormone concentrations during pregnancy differed at different stage of gestation and to those of a nonpregnant state. Conclusions The trimester‐ and method‐based reference intervals for thyroid tests during pregnancy are clinically appropriate. Some variables should be controlled when establishing reference intervals.     

Prevalence of thyroid disease, thyroid dysfunction and thyroid peroxidase antibodies in a large, unselected population. The Health Study of Nord-Trondelag (HUNT)

OBJECTIVE: To examine the prevalence of thyroid disease and dysfunction including thyroid autoimmunity in Norway. MATERIALS AND METHODS: All inhabitants 20 years and older (94009) in Nord-Trondelag were invited to participate in a health survey with a questionnaire and blood samples. RESULTS: The prevalence of former diagnosed hyperthyroidism was 2.5% in females and 0.6% in males, hypothyroidism 4.8% and 0.9%, and goitre 2.9% and 0.4% respectively. In both sexes the prevalence increased with age. In individuals without a history of thyroid disease the median, 2.5 and 97.5 percentiles for TSH (mU/l) were 1.80 and 0.49-5.70 for females and 1. 50 and 0.56-4.60 for males. The TSH values increased with age. When excluding individuals with positive thyroid peroxidase antibodies (TPOAb) (>200U/ml), the 97.5 percentiles dropped to 3.60 mU/l and 3. 40 mU/l respectively. The prevalence of pathological TSH values in females and males were TSH >/=10mU/l 0.90% and 0.37%; TSH 4.1-9. 9mU/l 5.1% and 3.7%; and TSH200U/ml) was 13.9% in females and 2.8% in males. In females the lowest percentage (7.9%) of positive TPOAb was seen with TSH 0.2-1.9mU/l and increased both with lower and higher levels of TSH. The percentage of males with positive TPOAb was lower than in females in all TSH groups except for those with TSH>10mU/l (85% TPOAb positive). CONCLUSIONS: In spite of a high prevalence of recognised thyroid disease in the population a considerable number of inhabitants have undiagnosed thyroid dysfunction and also positive TPOAb.     

Increased prevalence of thyroglobulin antibodies in Sri Lankan schoolgirls--is iodine the cause?

OBJECTIVE: Iodine deficiency was the likely cause of a high prevalence of goitre previously in Sri Lankan schoolchildren. Salt iodination was made compulsory in 1993 but there has been no recent study, using modern techniques, of its benefits or harmful effects. METHODS: Three hundred and sixty-seven schoolgirls between the ages of 11 and 16 years had ultrasound thyroid volume, free thyroxine (T4), free tri-iodothyronine (T3), thyrotrophin (TSH), anti-thyroglobulin (TgAb) and thyroid peroxidase (TPOAb) antibodies, and urine iodine concentrations measured. RESULTS: Median ultrasound thyroid volume ranged from 4.8 ml (11-year-old girls) to 8.6 ml (16-year-old girls) with an age-related increase. Median urine iodine concentrations ranged from 105 to 152 microg/l. Free T4 and free T3 were normal in all, but TSH was elevated in four subjects (5. 53-41.29 mU/l). However, the prevalence of TgAb was markedly raised, ranging between 14.3% (11-year-old girls) and 69.7% (16-year-old girls) (P<0.03). In contrast, the prevalence of TPOAb was 10% or less in all age groups. CONCLUSIONS: Normal median thyroid volumes, iodine concentrations and thyroid function would indicate that iodine deficiency is not a major problem in this group. The high prevalence of TgAb, hitherto unreported, most likely reflects excessive iodination of Tg resulting in increased immunogenicity. There is an urgent need to continuously monitor the adequacy and risks of iodination in this population.