EFFECT OF THYROID HORMONE DOSAGE ON THYROID FUNCTION TESTS IN T4-REPLACED HYPOTHYROID PATIENTS

To examine the relative importance of serum thyroxine (T4), free thyroxine (fT4) and triiodo thyronine (T3) in monitoring adequate T4 dose in patients on T4-replacement therapy, the effect of T4 dose on total T4, fT4 and T3, basal thyroid stimulat- ing hormone (TSH) and TSH-response to thyrotropin releasing hormone (TRI'I) were investigated in 33 patients taking T4 doses of 50-200\µg/day. The T4- treated patients had highly elevated mean T4 (total and free) and lower basal TSH levels compared to the mean values in normal subjects. But serum T3 was not significantly different. The patients on T4 doses greater than 150Ug/day frequently had more suppressed TSH response tol TRH than those on T4 doses less than 150µg/day. Total T4 and T4, but not serum T3 levels, cerrelated significantly with T4 dosage. Changes in T4 dosage led to concomi tant changes in total T4 and fT4 and inverse changes in TSH-response to TRH. The study also revealed a high incidence (33%) of elevated serum fT4 (hyperthyroxinemia) dLtring therapy. The hyperthyroxinemic group was characterised by clevated serum T4 (total ancl free), T3 and T4 dose, and suppressed TSH-response to TRH compared to the T4-treated group with normal serum T4 Ievels. These findings may be indicative of excessive T4 treatment iri these patients and suggest serum T4 may be more useful than T3 in monitoring T4 dosage in T4-replacement therapy. The discrepancy between normal serum T4 levels and TSH-response to TRH may reflect hetero- geneity in returning normal function of the pituitary- thyroid axis. Clearly, measurement of TSH or TRH test can ~ot be used alone in assessing thyroid status iki these patients, particularly when serum T4 is in normal'range.     

5: Diagnosis and management of hyperthyroidism and hypothyroidism

The most common cause of hyperthyroidism in Australia is Graves disease, caused by a defect in immunoregulation in genetically predisposed individuals, leading to production of thyroid-stimulating antibodies. Each of the three modalities of therapy for Graves disease--thionamide drugs, subtotal or total thyroidectomy, and radioactive iodine ablation--can render the patient euthyroid, but all have potential adverse effects and may not eliminate recurrences. Hypothyroidism occurs in about 5% of the adult population; most present with "subclinical" hypothyroidism (mild thyroid failure), characterised by raised levels of serum thyroid stimulating hormone (TSH) but normal free thyroxine (T(4)). The most common cause of hypothyroidism in Australia is autoimmune chronic lymphocytic thyroiditis, characterised by raised circulating levels of thyroid peroxidase antibody. Symptoms and signs of hypothyroidism are often mild or subtle and, when there is clinical suspicion, thyroid function tests are needed; if serum TSH level is raised, free T(4) and thyroid peroxidase antibody should be measured. Replacement therapy with thyroxine is the cornerstone of therapy (1.6 microg/kg lean body weight daily, taken on an empty stomach); combination therapy with thyroxine and liothyronine (T(3)) is promoted, but there is little evidence of its clinical benefit. Despite the development of highly sensitive laboratory tests, clinical assessment and judgement remain paramount     

不同孕期孕妇甲状腺激素水平变化及与抗甲状腺过氧化物酶抗体的关系

目的测定不同孕期孕妇甲状腺激素以及抗甲状腺过氧化物酶抗体（TPOAb）的水平,并探讨两者的关系。方法常规检查的孕妇400例,用全自动生化仪对其促甲状腺激素（TSH）、游离甲状腺激素（FT4）、总甲状腺素（TT4）以及TPOAb的水平进行检测。结果甲状腺功能正常的孕妇及TPOAb阴性的孕妇中,妊娠早期、中期、晚期TSH水平不同（P〈0.05）;TPOAb阴性的孕妇组早期、中期、晚期的TSH的中位数显著低于TPOAb阳性组（P〈0.05）;与采用血清FT4为诊断标准比较,采用TT4水平进行诊断,临床甲状腺功能减退症的检出率较低（P〈0.05）,而亚临床甲状腺功能减退症的检出率则无明显差异（P〉0.05）。结论在筛查时,应重视TPOAb阳性的孕妇,并且注意FT4与TT4在诊断上的差异。     

Hypothyroidism

Hypothyroidism, due to deficiency of circulating thyroid hormones, is a disease with wide ranging symptoms and signs affecting many systems and presenting to various specialists. Once suspected it can be easily diagnosed by a simple blood test measuring serum thyroxine (T4) and thyroid stimulating hormone (TSH) levels. Treatment of hypothyroidism is by giving levothyroxine orally, and the dose is to be titrated to keep the serum TSH within the normal range. The clinical entity of subclinical hypothyroidism, characterised by normal T4 and elevated TSH is being diagnosed more frequently, and is emerging as a new indication for thyroxine therapy.     

Screening for congenital hypothyroidism. Results in the newborn population of New England

During the first year of operation, the New England Regional Hypothyroidism Screening Program determined the concentration of thyroxine (T4) levels in dried blood on filter paper from 129,028 infants born in Connecticut, Maine, Massachusetts, New Hampshire, and Rhode Island. Specimens from approximately 3,800 neonates were found to have levels of T4 below the lower limit of normal (less than 6.0 microgram/dl) and were assayed for thyroid-stimulating hormone (TSH) content. Levels of TSH were elevated (greater than 20 muU/ml) in 31 infants, 23 of whom eventually proved to have unequivocal hypothyroidism. Based on these figures and including two hypothyroid infants who were not tested, the incidence of congenital hypothyroidism in the New England region is approximately 1:5,200 births. The estimation of T4 values supplemented by measurement of TSH values on specimens with low T4 values has proved to be a satisfactory approach to large-scale screening for congenital hypothyroidism.     

甲减中甲状腺激素水平与心脏电生理活动的相关性研究

目的探讨甲状腺功能减退症甲状腺激素水平与心脏电生理活动的相关性。方法对100例原发性甲减患者（甲减组）和100例正常人（正常对照组）进行常规十二导联ECG检查,分别检测心率（HR）、PR间期（PR）、QRS波时限（QRS）、QT间期（QT）、ST段压低幅度、T波等,同时用化学发光法测定血清总三碘甲状腺原氨酸（TT3）、总甲状腺素（TT4）和促甲状腺激素（TSH）水平,对心电图指标和血清TH水平行相关性分析。结果甲减组心电图异常率高于正常对照组（x2=34.557,P=0.000）。TSH、T3及病程判断心电图异常的能力较好,差异有统计学意义（P〈0.05）。甲减组心率显著低于正常对照组,PR间期、QRS时间、QT间期较正常对照组显著延长（P〈0.01）,心率与TSH、T3、T4呈显著正相关。PR间期、QRS时间、QT间期与T3、T4呈显著负相关,与TSH呈显著正相关。ST段压低、T波异常（倒置、低平或双向）与TSH呈显著负相关,与T3、T4呈显著正相关,差异有统计学意义（P〈0.05）。结论原发性甲状腺功能减退症可对患者窦房结起搏产生显著影响,引起心脏自律性改变,并造成明显的心肌缺血损伤。     

初始小剂量L-甲状腺素治疗先天性甲状腺功能低下症疗效研究

目的:探讨左旋甲状腺素替代治疗先天性甲状腺功能低下症(CH)的最适剂量.方法:138例CH患儿按总T3(TT3)、总T4(TT4)和TSH的水平分为亚临床型、轻型和重型三组,各组分别给予(3.5±1.0)μg/(kg.d)、(4.3±0.7)μg/(kg.d)、(4.7±0.6)μg/(kg.d)剂量的左旋甲状腺素片,并于1、2、3个月复测血清TT3、TT4和TSH浓度,结合临床表现及时调整剂量;治疗至2岁左右测试发育商.结果:138例患儿左旋甲状腺素起始平均剂量为(4.3±0.9)μg/(kg.d).治疗1个月后各组患儿的平均TT3和TT4水平达正常范围;2个月后TT3和TT4水平达正常范围的上 1/2,临床无甲状腺功能低下的表现,但此时仍有32.6%的患儿TSH水平高于正常范围.治疗后各组临床和生化指标达正常的时间无差异(P＝0.925),三组间的起始剂量有显著性差异(P<0.01);各组间3个月内的平均用药剂量亦有显著性差异(P<0.01).18例患儿治疗至2岁,智力测试平均发育商为116.7±17.0.结论:治疗CH的起始用药剂量以(4.3±0.9)μg/(kg.d)为宜;CH的治疗最好根据临床症状和生化指标及时调整药量,做到剂量个体化.     

冠状动脉搭桥围手术期甲状腺激素代谢变化的研究

目的 研究冠状动脉搭桥患者术前、术中、术后甲状腺激素的动态变化.方法 对30名健康志愿者于空腹时、62例冠心病患者于术前、术中及术后定时采血,用化学发光法及放射免疫法测定TT3,TT4、FT3、FT4、TSH、rT3水平,并以SPSS 10.0进行统计分析.结果 术前患者的甲状腺激素水平与正常对照组之间差异无统计学意义;术中肝素化后10 min及60 min时,TT4、FT4水平显著高于术前(P<.01),而术后2 h TT3、,TT4、FT3、FT4、rT3、TSH水平无显著变化;术后24 h和72 h TT3、TT4、FT3、FT4、TSH水平显著低于术前(P<0.01),24 hTT3,FT3,较术前分别下降了52.7%和46.6%,而rT3水平显著高于术前(P<0.01);术后7 dTT3、rT3水平显著低于术前(P<0.01),TT4、FT3、FT4、TSH浓度仍未恢复到术前正常浓度水平.结论 冠状动脉搭桥术中患者的血清TT4、FT4水平升高,术后血清TT3,FT3,水平降低可能提示预后不良.     

甲状腺素片联合左甲状腺素钠片治疗甲减的疗效观察

目的探究甲减患者采用甲状腺素片联合左甲状腺素钠片治疗的疗效。方法选取2017年5月至2019年5月于本院诊治的100例甲减患者,按随机数字表法分为两组,各50例。对照组采用左甲状腺素钠片治疗,观察组在对照组基础上联合甲状腺素片治疗,比较两组疗效及甲状腺功能。结果治疗后,观察组总有效率(86.00%)高于对照组(64.00%),差异有统计学意义(P<0.05);两组治疗后总甲状腺素(TT4)、游离三碘甲状腺原氨酸(FT3)、游离甲状腺素(FT4)水平均高于治疗前,而促甲状腺激素(TSH)水平低于治疗前,且观察组TT4、FT3、FT4水平高于对照组,TSH水平低于对照组,差异有统计学意义(P<0.05)。结论甲减患者采用甲状腺素片联合左甲状腺素钠片治疗的效果较好,有利于改善患者的甲状腺功能。     

甲状腺素联合多奈哌齐对成年期甲状腺功能减退症大鼠海马syntaxin-1的影响

目的 观察甲状腺素( T4 )联合多奈哌齐对成年期甲状腺功能减退症(甲减)大鼠的海马内突触前膜相关蛋白1 (syntaxin-1)表达的影响,探讨甲减脑损伤及可能的恢复机制. 方法 44只SD大鼠随机分为4组:对照组、甲减组、T4替代治疗组及T4和多奈哌齐联合治疗组. 通过饮水给予丙基硫氧嘧啶0. 05%建立成年期大鼠甲减模型共6 周. 第5周开始,对照组腹腔注射等量生理盐水, T4替代治疗组每日给予左旋甲状腺素(L-T4) 6 μg/100 g 体重(BW)腹腔注射,联合治疗组每日给予6 μg/100g BW L-T4腹腔注射及饮用水中加入0. 005%多奈哌齐. 采用免疫组织化学法和West-ern blot法分析4 组大鼠海马syntaxin-1 的表达情况. 结果与对照组比较,甲减组大鼠血清三碘甲状腺原氨酸( T3 )、T4水平减低,促甲状腺激素(TSH)水平升高(P<0. 01),海马内syntaxin-1在CA1、CA3 各层及齿状区多形层( DG-PL)表达显著增加( P <0. 01 );T4 替代治疗后,血清 T3、T4 和TSH水平恢复至正常水平, syntaxin-1 蛋白的表达未完全恢复到对照组水平(P<0. 05);T4联合多奈哌齐治疗后syntax-in-1蛋白表达与对照组比较差异无统计学意义. 结论 T4联合多奈哌齐治疗可以修复成年期甲减导致的脑损伤.     

rT3、TSH对肾脏病患者甲状腺功能的评价

目的：了解肾脏病患者血清甲状腺激素（ＴＨ）水平的变化及反三碘甲状腺素氨酸（ｒＴ３）、血清促甲状腺激素（ＴＳＨ）对其甲状腺功能的评估作用。方法：实验分为３组,采用放射免疫分析法测定其ＴＨ及ｒＴ３、ＴＳＨ水平。结果：肾病组血清总Ｔ３（（ＴＴ３）、总Ｔ４（ＴＴ４）、游离Ｔ３（ＦＴ３）、游离Ｔ４（ＦＴ４）水平均显著低于对照组（Ｐ＜０．０１）,ＴＳＨ水平无明显变化,ｒＴ３水平无显著改变;甲减组血清ＴＳＨ水平显著升高,ｒＴ３水平降低（Ｐ＜０．０１）。结论：ｒＴ３、ＴＳＨ对于甲状腺功能的评价具有重要意义。     

200例血清TT_3、TT_4、FT_3、FT_4和TSH测定的临床价值

本文测定３５例正常人、１００例甲状腺疾病患者及６５例非甲状腺疾病患者血清ＴＴ３、ＴＴ４、ＦＴ３、ＦＴ４和ＴＳＨ－ＩＲＭＡ水平。结果表明，甲状腺机能亢进组ＦＴ３、ＦＴ３、ＴＴ３和ＴＴ４明显增高；甲状腺机能减退组ＦＴ３、ＦＴ４、ＴＴ３和ＴＴ４明显减低；ＴＳＨ－ＩＲＭＡ变化与此相反，均与正常人有显著差异（Ｐ＜０．０５）。各项指标中，ＴＳＨ－ＩＲＭＡ最为灵敏，ＦＴ３、ＦＴ４远较ＴＴ３、ＴＴ４准确。非甲状腺疾病组主要表现为ＦＴ３、ＴＴ３降低，呈低Ｔ３综合征。因此，甲状腺激素水平尤其是游离激素的测定．其作用和意义不仅仅限于观察甲状腺本身的功能，对判断其它系统疾病病情和机体功能状态，估计发展趋势及判定预后均有一定的临床意义。     

儿童亚临床甲状腺功能减退症15例临床分析

目的 通过15例亚临床甲状腺功能减退症临床分析,提高对此病的认识.方法 对江西省儿童医院2006年1月至今到内分泌门诊就诊的15例亚临床甲状腺功能减退症临床资料进行分析,15例均行甲状腺功能(FT3、T3、FT4、T4、TSH)测定、甲状腺彩超检查及甲状腺微粒体抗体(TMAb)、甲状腺球蛋白抗体(TGAb)测定.结果 15例亚临床甲状腺功能减退症均无明显甲状腺功能低下临床特征性表现,仅表现为轻微、非特异的症状,实验室检查示15例患儿FT3、T3、FT4、T4均正常,TSH升高,11例行TMAb、TGAb测定均正常,2例TMAb、TGAb均阳性,2例中TMAb阳性和TGAb阳性各一例,其中2例甲状腺彩超示轻度血流增加,3例甲状腺彩超示示甲状腺回声弥漫性降低,内部回声不均匀.结论 儿童亚临床甲状腺功能减退症无明显甲状腺功能低下临床特征性表现,FT3、T3、FT4、T4均正常,仅TSH升高.亚临床甲状腺功能减退症患儿临床表现很不典型,容易被患儿家长及临床医师忽视,在临床诊治过程中应提高对此病的认识,特别是对矮小、性早熟患儿常规行甲状腺功能测定.     

孕周与母儿血甲状腺激素含量的关系

目的：观察不同孕周与母儿血甲状腺激素的关系。方法：应用放射免疫分析法对67例中、晚期妊娠要求引产患者，10例早产及78例孕足月自然分娩患者进行了母血及胎儿脐静脉、脐动脉血中TSH、T3、T4的测定。结果：TSH值在母血及胎儿血中随着孕周的增加而增加．T3值在胎儿血中与母血中比较，显示低T3血症，T4值接近正常母体水平。结论：测定母血中的甲状腺激素，可动态观察不同孕周甲状腺激素变化，可及时发现胎儿低甲血症。     

先天性甲状腺功能减退症对儿童肝功能的影响

目的观察先天性甲状腺功能减退症（CH,甲低）儿童的肝功能改变,及与血清甲状腺激素（TH）水平的相关性,探讨TH对儿童肝功能的影响。方法对40例CH儿童和35例健康儿童进行肝脏彩超及肝功能检查,同时用化学发光法测定血清游离三碘甲状腺原氨酸（FT3）、游离甲状腺素（TT4）、总三碘甲状腺原氨酸（TT3）、总甲状腺素（讯）和促甲状腺素（TSH）水平,对肝功能指标和血清TH水平进行相关性分析。结果与健康儿童组相比,CH组血清FT3、TT3、FT4、TT4水平显著下降,TSH水平显著升高（P〈0．001）;CH组肝功能异常明湿高于健康组（P〈0．001）,且肝功能异常与FT3、FT4、TT3、TT4呈显著负相关,与TSH呈显著正相关（P〈0．05）,两组肝脏彩超检查无显著差异（P〉0．05）,表明先天性甲状腺功能减退症会对患儿的肝功能造成一定的损伤。结论CH对儿童肝功能产生显著影响,临床医师应加强对此类疾病的重视。     

银屑病分型与甲状腺功能障碍的关系

 目的 探讨银屑病分型与甲状腺功能障碍的关系。方法 收集复旦大学附属华山医院皮肤科2013年月至2018年10月临床确诊为银屑病并做过甲状腺功能检查的住院患者,共计468例。检测血清游离三碘甲状腺原氨酸（free triiodothyronine,FT3）、游离甲状腺素（free thyroxine,FT4）、总三碘甲状腺原氨酸（total triiodothyronine,TT3）、总甲状腺激素（total thyroxine,TT4）、促甲状腺激素（thyroid-stimulating hormone,TSH）、甲状腺球蛋白抗体（anti-thyrogloblin antibody,TGAb）和甲状腺过氧化物酶抗体（anti-thyroperoxidase antibody,TPOAb）;分析寻常型、脓疱型、红皮病型和关节病型银屑病患者的甲状腺功能,比较各型银屑病中垂体-甲状腺轴各项激素和抗体水平的差异。结果 寻常型银屑病患者血清垂体-甲状腺轴各项激素水平正常的比例更高（P<0.001）,而在红皮病型银屑病患者中更易发生FT3或FT4下降但TSH正常（P<0.001）。脓疱型银屑病患者中FT3水平更低（P<0.05）,红皮病型银屑病患者中FT4水平更低（P<0.05）,关节病型银屑病患者中TSH水平更高（P<0.05）。各组银屑病患者TPOAb平均水平均高于正常值,但在4组银屑病患者中TPOAb和TGAb水平差异无统计学意义。结论 银屑病与桥本氏甲状腺炎相关的甲状腺功能障碍存在一定的关联,尤其在非寻常型银屑病中,但在红皮病型银屑病中需注意合并正常甲状腺病态综合征的可能。     

抑郁症患者甲状腺激素水平变化的临床探讨

目的探讨血清甲状腺激素水平与抑郁症的关系。方法采用放射免疫法(RIA)分别测定32例正常对照组、56例精神抑郁症患者(其中单相抑郁症25例,双相抑郁症31例)治疗前后TT3、TT4、FT3、FT4、TSH浓度。结果患者治疗前TT3水平明显高于对照组(P<0.01),FT3明显低于对照组(P<0.01);经过治疗,TT4低于治疗前(P<0.05),且恢复到正常范围;双相抑郁症患者血清FT3明显低于单相抑郁症患者(P<0.05)。结论提示抑郁症患者甲状腺激素水平变化与症状的消失有关,甲状腺激素水平异常是继发于情绪障碍;FT3水平降低可能是双相抑郁症的一个生物学指标。     

甲状腺激素对糖化白蛋白作用的研究

目的 评价甲状腺激素对糖化白蛋白（GA）的影响.方法 选择32例甲状腺功能亢进初发病患者作为甲亢组,7例甲状腺功能减退初发病患者作为甲减组,17例健康体检者作为对照组,采用酶法检测GA、餐后2h血糖（2hBG）,采用化学发光酶免疫分析法检测促甲状腺激素（TSH）、游离甲状腺素（FT4）、游离三碘甲状腺原氨酸（FT3）,统计分析TSH、FT4、FT3与GA的相互关系.结果 甲亢组GA水平[（10.4±1.82）%]较对照组[（12.0±1.13）%]低,甲减组GA水平[（14.6±3.01）%]较对照组[（12.0±1.13）%]高,差异均有统计学意义（均P＜0.01）.血清GA水平与TSH水平正相关（r=0.39,P＜0.01）;与FT3、FT4水平负相关（r =-0.512,P＜0.01;r =-0.619,P＜0.01）.结论 甲状腺激素负调节GA水平;GA检测应考虑甲状腺激素的影响.     

原发性甲状腺功能减退症与心外膜脂肪组织厚度的关系

目的：探讨原发性甲状腺功能减退症与心外膜脂肪组织厚度的关系。方法选取2014年6月至2015年6月在我院就诊的原发性甲状腺功能减退症患者46例,并选取同期在我院体检中心体检的健康者32名作为对照组。用 Vivid7心脏彩超仪超声测量受试者的心外膜脂肪组织厚度。同时收集受试者的一般资料和实验室资料。结果原发性甲减组患者的心外膜脂肪组织厚度、TG、TC、LDL-C、Lp(a)、CRP、CK、TPOAb 显著高于正常对照组;心外膜脂肪组织厚度与病程、TSH、BMI、TC、TG、LDL-C、Lp-(a)、CRP、CK、TPOAb 呈正相关(r =0.905,0.989,0.970,0.933,0.817,0.830,0.933,0.991,0.919,0.945,P <0.01),与 FT4、FT3呈负相关(r=-0.993,0.969,P <0.01),与 HDL-C 无相关性(P >0.05);心外膜脂肪组织厚度随着 TSH、TPOAb 水平的增加而增加,随着 FT3、FT4水平的升高而减少。结论甲状腺功能减退症患者的心外膜脂肪组织厚度较健康者显著增加;心外膜脂肪组织厚度随甲状腺功能减退症程度的增加而增加。     

Thyroid failure in the elderly. Microsomal antibodies as discriminant for therapy

Thyrotropin (thyroid-stimulating hormone [TSH]) levels were elevated above 4.0 mU/L (microU/mL) in serum samples from 13.2% of 258 healthy elderly subjects. To investigate the natural history of progressive thyroid failure, serial thyroid functions were measured for four years in 26 of these subjects with elevated TSH levels. In one third of these subjects, biochemical thyroid failure developed (thyroxine level less than 58 nmol/L [4.5 micrograms/dL]) within the course of the study. All subjects with initial TSH levels above 20 mU/L (microU/mL), and 80% of those with high-titer thyroid antimicrosomal antibodies (regardless of initial TSH level), became overtly hypothyroid. Compared with subjects with high-titer antibody, those with antibody titer less than 1:1600 had lower TSH and higher thyroxine levels, and thyroid failure developed in none during the study. These results suggest that among older patients with isolated elevations of the TSH level, only those with markedly elevated TSH levels or high-titer antimicrosomal antibodies should be prophylactically treated with levothyroxine sodium replacement.