甲巯咪唑与丙硫氧嘧啶治疗Graves甲状腺机能亢进症疗效比较

目的探讨甲巯咪唑与丙硫氧嘧啶治疗Graves甲状腺机能亢进症（简称甲亢）的临床疗效差异,为Graves甲亢的临床用药提供理论依据。方法选择100例Graves甲亢初诊患者随机分成两组各50例,分别采用剂量相当的甲巯咪唑与丙硫氧嘧啶治疗。于治疗前、治疗第45天、第90天采血检测血清促甲状腺素（TSH）、游离三碘甲状腺原氨酸（FT3）、游离甲状腺素（FT4）、促甲状腺素受体抗体（TRAb）、甲状腺过氧化物酶抗体（TPOAb）,比较两组各时间点TSH、FT3、FT4、TRAb、TPOAb水平的差异。结果治疗前两组TSH、FT3、FT4、TRAb、TPOAb水平无统计学差异（P均〉0.05）。治疗后与治疗前比较,两组TSH、FT3、FT4、TRAb、TPOAb水平均降低（P均〈0.05）。治疗第45天、第90天后丙硫氧嘧啶组FT3、FT4水平均高于甲巯咪唑组（P均〈0.01）。治疗后TRAb、TPOAb水平两组间差异无统计学意义（P均〉0.05）。结论甲巯咪唑治疗Graves甲亢疗效显著性优于丙硫氧嘧啶。     

Graves病甲状腺功能亢进症性肝损害的相关因素分析

目的 探讨影响Graves病甲状腺功能亢进症(甲亢)性肝功能损害的相关因素.方法 回顾性分析天津医科大学总医院2013年1月至2015年12月收治的Graves病住院患者254例,根据肝功能将患者分为Graves病甲亢性肝损害组(A组,n=159)和甲亢肝功能正常组(B组,n=95),比较两组的基础代谢率(BMR)、甲状腺重量、FT3、FT4、促甲状腺激素(TSH)、TSH受体抗体(TRAb)、甲状腺球蛋白抗体(TgAb)、甲状腺过氧化物酶抗体(TPOAb).采用Pearson相关性分析甲状腺重量、BMR、FT3、FT4、TRAb与甲亢性肝损害的相关性,应用Logistic回归分析甲亢性肝损害的独立危险因素.结果 A组的甲状腺重量、BMR、FT3、FT4、TRAb、TPOAb均高于B组,而TSH低于B组(t或z=-4.720～-2.276,P均＜0.05).Pearson相关性分析显示,甲状腺重量、BMR、FT3、FT4、TRAb与甲亢性肝损害的发生呈正相关(r=0.157～ 0.270,P均＜0.05).Logistic回归分析显示,FT3(OR=1.052,95％ CI:1.001～1.105)、BMR(OR=1.019,9.5％ CI:1.006 ～ 1,033)是Graves病甲亢性肝损害发生的独立危险因素(P均＜0.05).结论 Graves病甲亢性肝损害与FT3、FT4、TRAb、BMR、甲状腺重量有关.其中FT3、BMR为甲亢性肝损害发生的独立危险因素.     

女性原发性甲减患者甲状腺功能与肾功能的相关性研究

检测45例女性原发性甲状腺机能减退症（甲减）患者（观察组）与40例健康女性（对照组）的空腹血清游离甲状腺原氨酸（FT3）、游离甲状腺素（FT4）、促甲状腺激素（TSH）、尿素氮（BUN）、肌酐（Cr）、尿酸（UA）、肌酐清除率（CCr）,并进行相关性分析。结果研究组BUN、Cr、UA均明显高于对照组,CCr显著低于对照组（P均〈0.05）;FT3与CCr呈正相关（r=0.665,P〈0.05）。但TSH、FT4与各肾功能指标均无明显相关（P〉0.05）。认为女性原发性甲减患者常伴BUN、Cr、UA升高,CCr下降;其CCr水平下降与FT3关系密切。     

TRAb检测对甲状腺疾病鉴别诊断的意义

促甲状腺激素受体抗体（TRAb）是存在于自身免疫性甲状腺疾病的一种甲状腺自身抗体。目前,此抗体对甲状腺功能亢进症（甲亢）、桥本氏病、自发性甲状腺功能减低症（自发性甲减）、单纯甲状腺肿等患者缺乏大样本研究。本文对1693例甲状腺疾病患者行TRAb测定,探讨其对甲状腺疾病的鉴别诊断价值。     

甲亢患者血、尿β2-MG水平及其与甲状腺激素水平的相关性分析

目的探讨甲状腺功能亢进症（下称甲亢）患者血、尿β2-微球蛋白（MG）水平变化及与病情的相关性。方法对40例甲亢患者（观察组）及40例健康查体者（对照组）血清、尿β2-MG及血清游离甲状腺素（FT3）、游离三碘甲状腺原氨酸（FT4）、促甲状腺素（TSH）水平进行检测,并分析其相关性。结果治疗前甲亢患者FT3、FT4水平均高于对照组（P均〈0.01）,TSH水平显著低于对照组（P均〈0.01）,血清和尿β2-MG水平均高于对照组（P〈0.01）;治疗后甲亢患者FT3、FT4水平与治疗前相比明显下降（P〈0.01）,TSH水平有所升高（P〈0.01）,血清和尿β2-MG水平均有明显下降（P〈0.01）。治疗前血清β2-MG水平与FT3、FT4呈正相关,与TSH呈负相关;尿β2-MG水平与FT3、FT4亦呈正相关,与TSH呈负相关。结论甲亢患者血和尿β2-MG水平显著升高,两者均可灵敏反映病情变化,可作为临床疗效评价的重要指标。     

青春期甲状腺肿病人甲状腺功能转归的临床分析

目的观察青春期甲状腺肿病人甲状腺功能的变化,研究其转归情况。方法收集2003~2007年吉林市中心医院内分泌科收治的青春期甲状腺肿病人51例,年龄11~18岁,其中男18例,女33例,根据最终的甲状腺功能分为3个组,A组单纯甲状腺肿组31例,B组甲亢组6例,C组甲减组14例。分别在首诊时,6个月后,及1~2年后测血清FT3、FT4、TSH、TPO-Ab、TG-Ab观察在三个阶段的数值变化,同时设26例健康对照组。结果在开始诊断青春期甲状腺肿的患者血清FT3、FT4、TSH、TPO-Ab均在正常范围。甲亢组6例,1年后,出现FT3、FT4增高,TSH降低,TG-Ab、TPO-Ab在半年后出现阳性。甲低组14例,1年后发展为临床甲减,但其半年时已出现TPO-Ab、TG-Ab阳性。31例单纯性甲状腺肿组,半年及1年后随诊,20例甲状腺肿大消失,11例甲状腺为I°~II°,FT3、FT4、TSH、TPO-Ab均在正常范围。结论甲状腺肿作为甲状腺疾病的首发症状,早期各种检验结果均在正常范围,部分病人可发展为自身免疫病性甲状腺疾病,有时,甲状腺过氧化物酶抗体及球蛋白抗体可在早期存在相应的变化。     

2型糖尿病合并甲状腺功能异常的临床特征研究

目的研究2型糖尿病(T2DM)合并甲状腺功能异常的临床特征。方法选取该院2015年6月—2017年10月收治的T2DM患者共240例,分析临床资料及相关指标,对其中合并甲状腺功能异常患者的临床特征进行研究。结果 240例T2DM患者中,合并甲状腺功能异常患者44例(18.3%)。T2DM合并与未合并甲状腺功能异常患者的病程、CSII时间、UAlb 30～299 mg/24 h、C-P120 min、TSH对比差异有统计学意义(P0.05)。甲亢组较甲减组SBP和FT4升高,IAA降低(P0.05)。低T3组较甲亢组SBP、FT3、FT4降低,TSH升高;较甲减组FT3、TSH降低;较甲亢组和甲亢组年龄增加(P0.05)。结论 T2DM合并甲状腺功能异常的临床表现形式多样,早期监测T2DM患者的甲状腺功能对甲状腺功能异常的筛查具有重要意义。     

AECOPD血清甲状腺激素变化规律探讨

目的探讨慢性阻塞性肺疾病急性加重期（AECOPD）血清甲状腺激素水平变化规律。方法 AECOPD 150例作为观察组,同期健康体检者150例作为对照组,统计观察组正常甲状腺病态综合征（ESS）发生率及与预后的关系;比较观察组与对照组、观察组中存活组与病死组、观察组中ESS者治疗前后甲状腺激素检查差异。结果观察组ESS 46.67%,死亡率28.57%高于未发生甲状腺激素变化的8.75%（P〈0.05）。观察组T3、FT3低于对照组（P〈0.05）,T4、FT4、TSH无显著性差异（P〉0.05）。观察组患者中病死组T3、FT3、T4、FT4均低于存活组（P〈0.05）,TSH无显著性差异（P〉0.05）。ESS患者治疗后T3、FT3、T4、FT4均高于治疗前（P〈0.05）。结论血清甲状腺激素水平的变化反映了AECOPD患者严重程度,检测血清中甲状腺激素水平有助于判断病情发展和转归。     

018 甲状腺功能亢进和减退患者的血清脱氢表雄酮等的含量

[英]/Noriko T…//Clin Chem.-2000，46.-523-528 　　脱氢表雄酮(DHEA)和脱氢表雄酮硫酸盐(DHEA-S)对心血管病、肿瘤等疾病具有保护作用。目前，已将DHEA和DHEA-S用于多种病征的治疗。因此，血清DHEA和DHEA-S的浓度对多种疾病的病理生理具有重要的作用。但对甲状腺功能紊乱患者血清DHEA和DHEA-S的含量研究较少，故本研究测定了甲状腺功能亢进(甲亢)和甲状腺功能减退(甲减)患者血清DHEA、DHEA-S及孕烯醇酮硫酸盐(PREG-S)含量，并探讨了在甲状腺功能紊乱患者中，这些类固醇激素含量变化的机制。 　　材料和方法　血清样品取自22例未经治疗的甲亢患者，24例未经治疗的甲减患者和43例健康对照者。3组间年龄和性别均无差别。甲亢的诊断依据是游离T4(FT4)、游离T3(FT3)升高、促甲状腺激素(TSH)下降、TSH受体抗体阳性和(或)放射性碘吸收率升高；甲减的诊断依据是FT4、FT3降低、TSH升高和抗甲状腺微粒体和(或)甲状腺球蛋白抗体阳性。 　　用HPLC分离DHEA、DHEA-S和PREG-S，DHEA浓度测定应用酶免疫分析法，DHEA-S、PREG-S测定应用气相色谱质谱分析法。性激素结合球蛋白(SHBG)应用ELISA法，血清白蛋白测定应用干化学法，FT4、FT3、TSH浓度应用商品试剂盒测定，TSH受体抗体应用放射受体分析法，抗甲状腺微粒体抗体和甲状腺球蛋白抗体应用被动颗粒凝集法测定。 　　结果　甲亢患者中，血清DHEA-S浓度较对照组显著升高(P<0.001)，但DHEA正常；甲减患者中，血清DHEA和DHEA-S浓度均较对照组显著下降(P<0.001)。甲亢患者中，与DHEA和DHEA-S结合的白蛋白下降(P<0.001)，SHBG升高(P<0.001)。DHEA和DHEA-S浓度无性别差异。 　　相关性研究显示，DHEA、DHEA-S、PREG-S的对数与FT4的对数有良好的相关性(相关性分别为r=0.465，P<0.001；r=0.640，P<0.001；r=0.795，P<0.001)，与FT3对数也有一定的相关性。DHEA、DHEA-S、PREG-S与抗甲状腺微粒体抗体、甲状腺球蛋白抗体滴度、TSH受体抗体间无相关性。 　　DHEA、DHEA-S的浓度在3组中均呈对数正态分布。在甲减和对照组中，DHEA和DHEA-S之间呈良好的相关性(其相关性分别为r=0.701，P<0.001；r=0.546，P<0.05)。在甲亢组中，两者无相关性(r=-0.073)。DHEA-S与DHEA的比例，对照组为181，而甲亢组为480，提示在甲亢患者中DHEA-S起更重要的作用。 (陈松劲摘　董来荣校)     

165例甲状腺硬度不同的Graves病患者^131I治疗效果观察

目的观察^131I治疗Graves病的效果及甲状腺硬度对其的影响。方法对165例甲状腺硬度不同的Graves病患者[质地为软65例（质软组）、韧70例（质韧组）、硬30例（质硬组）]行^131I治疗,^131I治疗剂量按个体计算法确定;治疗后6个月根据游离三碘甲腺原氨酸（FT3）、游离甲状腺素（FT4）、促甲状腺激素（TSH）水平判定甲状腺功能减退症（甲减）发生率及疗效,并采用Spearman相关分析法对甲状腺硬度与治愈率、甲减率行相关分析。结果治愈率及甲减发生率在质软组、质韧组、质硬组均逐渐降低（P〈0.01、0.05）,甲状腺硬度与治愈率、甲减率均呈高度负相关（r均=-1,P=0.000）。结论 131I治疗Graves病效果确切,随甲状腺硬度增加治愈率和甲减发生率均下降;临床可根据甲状腺硬度调节^131I治疗剂量。     

EVALUATION OF TSH RECEPTOR ANTIBODY BY ''NATURAL IN VIVO HUMAN ASSAY'' IN NEONATES BORN TO MOTHERS WITH GRAVES'' DISEASE

Neonatal thyrotoxicosis induced by transferred TSH receptor antibody (TRAb) is the ideal human in-vivo experimental system for the evaluation of TRAb. The clinical significance of circulating TRAb in Graves' disease was evaluated by this 'natural in-vivo human assay'. TRAb activity in vitro was measured by radioreceptor assay (thyrotrophin-binding inhibitor immunoglobulin, TBII) and sensitive cAMP accumulation assay using FRTL-5 cells (thyroid-stimulating antibody, TSAb). Further, the binding-stimulation index (B-S index) was newly introduced, which was the most useful indicator for prediction of neonatal thyrotoxicosis, calculated as the product of TBII and TSAb (Tamaki et al., 1988a). Maternal serum TRAb indices showed highly significant correlations with the serum free T4 index (FT4I) and free T3 index (FT3I) in neonates (5-10 days after birth) born to 20 mothers with Graves' disease who had positive TBII and/or TSAb (FT4I: r = 0.825 for TBII, r = 0.908 for TSAb, r = 0.944 for the B-S index, P less than 0.001; FT3I: r = 0.622 for TBII, P less than 0.01, r = 0.812 for TSAb, r = 0.791 for the B-S index, P less than 0.001; n = 20). In contrast, in 57 untreated adult patients with hyperthyroid Graves' disease, the FT4I and FT3I levels were not correlated with any of the TRAb indices. The linear regression relationship between the B-S index and FT4I found in neonates was applied to values in adult patients with Graves' disease, and the patients were divided into three groups on the basis of the 95% confidence limit: high, normal, and low responders of thyroid hormone (FT4I) secretion to the B-S index. FT4I and the ratio of FT4I to the B-S index were highest and the TRAb indices were lowest in the high responders, while FT4I and the FT4I/B-S index ratio were lowest and the TRAb indices were highest in the low responders. The FT4I/B-S index ratio was inversely correlated with the titres of antithyroid microsomal antibody in all the adult patients with untreated Graves' disease (r = -0.288, P less than 0.05). The results suggest that in-vitro assays using animal thyroid cells and cAMP as an index of response are suitable for detecting circulating thyroid stimulating activity in vivo. Secretion of thyroid hormones in Graves' disease may be regulated not only by circulating thyroid-stimulating antibodies but also by intrathyroidal stimulatory factors or by inhibitory or destructive factors.     

不同碘摄入水平对大鼠甲状腺功能影响的实验研究

目的研究不同碘摄入水平对大鼠甲状腺功能的影响。方法将Wistar大鼠分为低碘(LI)组、正常碘(NI)组、5倍、10倍、50倍、100倍高碘(5HI、10HI、50HI、100HI)组,在喂养3、6、12个月后处死,分别检测血清总T4(TT4)、总T3(TT3)、游离T3(FT3)、游离T4(FT4)、反T3(rT3)水平,以及甲状腺组织中T4、T3、rT3水平。结果3个月时血清TT4、FT4、TT3、FT3、rT3以及甲状腺组织中T4、T3、rT3水平,组间比较差异均有统计学意义(F值分别为54．07、67．80、15．51、27．71、19．73、61．51、40．67、53．86,P<0．01);6个月时上述指标组间比较差异均有统计学意义(F值分别为58．80、58．75、19．64、17．22、47．21、46．01、47．22、126．87,P<0．01);12个月时甲状腺组织中T4、T3、rT3水平组间比较差异均有统计学意义(F值分别为20．44、17．69、29．23,P<0．01)。与NI组相比较,LI组血清和甲状腺组织内各激素水平明显降低,而高碘组随着时间的延长和摄入碘量的增加,血清各激素和甲状腺组织内T3水平出现逐渐降低趋势。结论碘缺乏和碘过量均可导致大鼠甲状腺功能低下,而碘缺乏的作用更明显;大鼠对长期高碘摄入比碘缺乏具有更强的耐受性,只有在长期补充过量碘(>50倍正常需要量)才发生甲状腺功能低下。     

Improvement of infiltrative ophthalmopathy in parallel with decrease of thyroid-stimulating antibody (TSAb) activity in two patients with hypothyroid Graves' disease

Two patients with primary hypothyroidism associated with infiltrative ophthalmopathy without previous history of hyperthyroidism are presented. Anti-TSH receptor antibodies (TRAb) were detected by radioreceptor assay (TBII), and unexpectedly their biological activity was not of a blocking (TSBAb), but of a thyroid-stimulating type (TSAb). After the initiation of levothyroxine therapy, the TBII and TSAb activities both decreased gradually with normalization of the elevated TSH level. The inflammatory eye signs improved strikingly in parallel with decrease of these antibody activities. These data indicate that (1) TRAb in primary hypothyroidism do not always show TSAb activity, (2) the decrease in TRAb following levothyroxine therapy in these patients appeared to correlate with suppression of TSH, (3) changes in infiltrative ophthalmopathy were associated with that of TSAb even in primary hypothyroidism, and (4) the hypothyroidism in these patients is justifiably diagnosed as "hypothyroid Graves' disease". TSAb might be somewhat related to the pathogenesis of ophthalmopathy in autoimmune thyroid diseases.     

甲状腺激素对仔鼠大脑皮质中NO/cGMP信号转导通路的作用

目的研究甲状腺激素对大鼠仔鼠大脑皮质中一氧化氮(NO)水平、一氧化氮合酶(NOS)活性和环鸟苷酸(cGMP)水平的影响,为探讨甲状腺激素对神经系统发育的作用机制提供实验资料。方法取怀孕3d的SD大鼠10只,随机分为实验组与对照组。实验组饮含1%高氯酸钠的自来水,对照组饮自来水,直至仔鼠产下15d(其产下的仔鼠分别为甲状腺功能低下仔鼠及正常仔鼠)。采用放射免疫法测定仔鼠血清中游离三碘甲状腺原氨酸(FT3)、游离四碘甲状腺原氨酸(FT4)和仔鼠大脑皮质cGMP水平,采用硝酸还原酶法测仔鼠大脑皮质中NO水平,采用分光光度计法测NOS活性。结果实验组仔鼠血清FT3、FT4明显低于对照组(P<0.01)。实验组仔鼠大脑皮质中NO水平、NOS活性及cGMP水平也较对照组显著降低(P<0.01)。相关分析表明:血清FT3与大脑皮质中NO、cGMP水平呈显著正相关,r值分别为0.91、0.97,P<0.01;血清FT4与大脑皮质中NO、cGMP水平也呈显著正相关,r值分别为0.90、0.96,P<0.01;大脑皮质中NO与cGMP水平呈显著正相关,r值为0.90,P<0.01。结论甲状腺激素的缺乏可降低仔鼠大脑皮质中NO、cGMP水平,NO/cGMP信号转导系统在甲状腺功能低下导致脑发育障碍中发挥重要作用。     

Circulating free T3 in pregnancy, liver diseases, diabetes mellitus and thyroid diseases

Measurement of serum concentrations of free triiodothyronine (FT3) is considered to be an accurate index of thyroid function in the patient. In this study, we measured serum concentrations of FT3, free thyroxine (FT4) and reverse triiodothyronine (rT3) by radioimmunoassay in blood samples taken from the navel cord of 20 newborns as well as 20 nonpregnant women, 20 pregnant women, 10 patients with liver diseases, 25 patients with diabetes mellitus, 65 patients with hyperthyroidism, 30 patients with primary hypothyroidism and 29 normal subjects. In pregnant women, serum FT3 and FT4 levels gradually decreased as the pregnancy progressed. In cord blood, FT3 levels were less than a quarter of the values found during the first trimester of pregnancy or that of non-pregnant women, whereas serum rT3 levels were drastically increased. In chronic hepatitis, liver cirrhosis and diabetes mellitus, serum FT3 and FT4 levels were significantly lower than that in the controls. In thyroid diseases, serum FT3 levels varied parallel to other thyroid hormone levels. In primary hypothyroidism, however, serum FT3 levels were still lower than these in the controls after treatment with 1-thyroxine, whereas other thyroid hormone levels and TSH levels returned to control levels.(ABSTRACT TRUNCATED AT 250 WORDS)     

开展亚临床甲状腺功能减退症的临床研究

亚临床甲状腺功能减退症 (甲减 )是一种常见的内分泌专业亚临床疾病 ,主要诊断依据是血清TSH水平增高 ,而血清FT4正常。亚临床甲减的主要不良后果是发展为临床甲减和促进缺血性心脏病的发生。影响亚临床甲减发展为临床甲减的主要因素有两个 :血清TSH水平和甲状腺自身抗体 ,两个因素有叠加作用。甲状腺激素替代治疗对于阻止亚临床甲减发展为临床甲减的效果尚不确切 ;亚临床甲减与高胆固醇血症、高血压、吸烟和糖尿病一样 ,构成动脉粥样硬化和心肌梗塞的独立危险因素 ,其对此两病的危险度分别为 1.9和 3 .1。甲状腺素纠正亚临床甲减对降低血清胆固醇有一定效果 ;妊娠妇女的亚临床甲减对后代的智力影响已经引起高度关注。我国一组根据对流行病学调查的结果 ,提出了血清TSH、甲状腺自身抗体 (TPOAb、TgAb)的正常值范围 ,以及与疾病相关的甲状腺自身抗体的切割点值 ,可供参考。     

A case of rheumatoid arthritis associated with silent thyroiditis.

A 41-year-old female with rheumatoid arthritis had nontender enlarged thyroid gland. Thyroid function tests revealed increased concentrations of serum free T3 (FT3, 10.8 pmol/L) and free T4 (FT4, 31.1 pmol/L) with suppressed concentration of thyrotropin (TSH, lower than 0.1 mU/L) and low 24-hour thyroidal radioactive iodine uptake (1.6%). Serum thyrotropin receptor antibody (TRAb) was negative (0%) and she had positive anti-thyroglobulin and anti-microsomal antibodies. A diagnosis of silent thyroiditis was made based on laboratory findings. Serum concentrations of FT3 and FT4 normalized one month later without treatment. The causal relationship between the two diseases is discussed.     

Are thyroid function tests too frequently and inappropriately requested?

In spite of data supporting the use of the serum thyrotropin (TSH) concentration as the best test to detect abnormal thyroid function, measurement of circulating thyroid hormones with or without a serum TSH continues to be frequently requested to evaluate thyroid function. We have analyzed how combinations of thyroid function tests were ordered by referring physicians and the results of the tests in order to offer some suggestions as to how to use thyroid function tests in a cost effective manner. During 1995, 19,181 inpatient and outpatient requests (45,865 different tests) for thyroid function tests were received by the laboratory of a 1600 bed University Hospital in Parma, Italy. The following tests were carried out: T4, free T4, T3, free T3 and TSH. Serum TSH values below and above the normal range were considered to reflect abnormal thyroid function i.e. hyperthyroidism, or hypothyroidism including subclinical disease independent of the results of the other tests. Combinations of ordered tests and the percent of the total for each combination were: TSH+T4+T3 (56%), TSH+FT4+FT3 (14%), TSH (12%), TSH+FT4 (9%), TSH+T4 (1%), TSH+T4+T3+FT4+FT3 (5%), others (3%). The T4+T3+TSH panel (10,780 requests) had normal serum TSH values in 80.6% and the FT4+ FT3+TSH panel (2,590 requests) had normal TSH values in 73.2%. Elevated serum TSH concentrations were observed more frequently in hospitalized than in ambulatory patients (9.7% vs 7.4% p<0.001). T3 (elevated serum T3, normal T4 and low TSH concentrations) and T4 (elevated serum T4, normal T3 and low TSH concentrations) toxicosis were observed in 8.1% and 9.4%, respectively, of the requested test (NS). FT3 and FT4 toxicosis, defined as for T3 and T4 toxicosis, were observed in 7.5% and 4.9%, respectively (NS). The low T3 and low FT3 syndrome in hospitalized patients was present in 1.6% and 2.3% of the requests, respectively (NS). The low T4+low T3 and low FT4+low FT3 syndrome was present in only 0.3% and 0.2%, respectively, of the requests. Our study shows that a) in hospitalized patients thyroid function tests were requested in 20% of the patients and only one in 14 of these patients at the highest could have abnormal thyroid function, as indicated by abnormal TSH value b) FT4 (or T4) is as useful as FT3 (or T3) in the diagnosis of hyperthyroidism, c) in hospitalized patients the low T3 syndrome was far less common than that reported in the literature, probably due to the lower severity of illness, d) panels which include T3 and FT3 are not justified, and e) serum TSH alone is the most appropriate initial thyroid function test.     

Evaluation of the adequacy of levothyroxine replacement therapy in patients with central hypothyroidism

As there are few data on the evaluation of the adequacy of levothyroxine (L-T4) therapy in patients with central hypothyroidism (CH), a prospective study was performed to assess the accuracy of various parameters in the follow-up of 37 CH patients. Total and free thyroid hormones, TSH, and a series of clinical and biochemical indexes of peripheral thyroid hormone action have been evaluated off and on L-T4 therapy. Samples were taken before the daily administration of L-T4. In all patients off therapy, clinical hypothyroidism and low levels of free T4 (FT4) were observed, whereas values of FT3, total T4, and total T3 were below the normal range in 73%, 57%, and 19% of cases, respectively. Most of the indexes of thyroid hormone action were significantly modified after L-T4 withdrawal and exhibited significant correlation with free thyroid hormone levels. During L-T4 replacement therapy, 32 patients had circulating levels of FT4 and FT3 and indexes within the normal range with a mean L-T4 daily dose of 1.5 +/- 0.3 microg/kg BW. Despite normal serum FT4, 3 patients had borderline high values of FT3 and a clear elevation of serum-soluble interleukin-2 receptor concentrations, suggesting overtreatment. Low or borderline low FT4/FT3 levels indicated undertreatment in 2 patients. The clinical parameters lack the required specificity for the diagnosis or follow-up of CH patients. The L-T4 daily dose should be established, taking into account the weight, the age, and the presence of other hormone deficiencies or pharmacological treatment of CH patients. In conclusion, our results indicate that the diagnosis of CH is reached at best by measuring TSH and FT4 concentrations. In the evaluation of the adequacy of L-T4 replacement therapy, both FT4 and FT3 serum levels together with some biochemical indexes of thyroid hormone action are all necessary to a more accurate disclosure of over- or undertreated patients.     

Serum free thyroid hormones in different degrees of hypothyroidism and in euthyroid autoimmune thyroiditis

Serum total and free T4 and T3, thyroxine-binding globulin (TBG) and TSH, basal and 20, 30 and 60 min after TRH (200 micrograms, iv), were evaluated in 125 hypothyroid patients (38 with severe, 23 with mild, and 64 with subclinical hypothyroidism), in 35 euthyroid subjects with autoimmune thyroiditis, and in 51 healthy controls. T4/TBG and T3/TBG ratios were also calculated. A significant decrease in all indices of thyroid function except for T3 occurred simultaneously with a significant increase in basal and TRH-stimulated TSH levels from healthy subjects to subclinical hypothyroids, from subclinical to mild and from mild to severe hypothyroids; euthyroid patients with autoimmune thyroiditis did not differ from healthy subjects. All severe hypothyroid patients had low T4 as well as free T4 (FT4), free T3 (FT3), T4/TBG and T3/TBG ratios, but among mild and subclinical hypothyroids direct determination of FT4 and FT3 proved to be a better index of thyroid function than determination of T4 and T3 even after correction for TBG levels. FT4 was the most commonly abnormal index (19 of 23 subjects with mild and 14 of 64 with subclinical disease). Regression analysis showed that FT4, T4/TBG ratio, T4, and FT3 had a significant inverse correlation with TSH in hypothyroid patients. Discriminant analysis showed that among the thyroid parameters, FT4 is the variable which discriminates best between control subjects and the 3 groups of hypothyroid patients. These data extend previous reports and in a large series of patients confirm the biological meaning and the clinical value of direct measurement of serum free thyroid hormones in hypothyroidism.(ABSTRACT TRUNCATED AT 250 WORDS)