Resumo Objetivo Avaliar associações entre a média da tireotropina (TSH) e tiroxina livre (T4L) mantida durante follow-up, e mortalidade em pacientes idosos eutireoidianos definidos de acordo com a faixa de referência específica para a idade (FR-e) do TSH. Método Coorte retrospectiva tipo análise de sobrevivência incluindo pacientes idosos eutireoidianos acompanhados no ambulatório de hospital universitário entre 2010 e 2013. Todos os participantes haviam sido avaliados quanto ao risco de incapacidade funcional como critério para admissão nesse ambulatório. As médias dos valores de TSH e T4L foram calculadas através das dosagens obtidas no período de acompanhamento. Cada FR-e de TSH foi dividida em quatro partes iguais, considerando níveis mais baixos como variável de exposição (≤1,75 mUI/L para <80 e ≤2,0 mUI/L para ≥80 anos). Os níveis de T4L foram dicotomizados em duas categorias (< e ≥1,37 ng/dL). O desfecho foi o tempo até a morte. A regressão de risco proporcional de Cox foi empregada para estimar a hazard ratio (HR) e o intervalo de confiança (IC) de 95% Resultados 285 participantes (73% mulheres, idade média =80,4 anos) seguidos pela mediana de 5,7 anos (IQR =3,7–6,4; máximo =7), sendo que 114 faleceram. Após o modelo final ajustado, a mortalidade esteve associada ao TSH no limite inferior (HR=1,7; IC=1,1–2,7; p=0,016) e ao T4L mais elevado. (HR=2,0; IC=1,0–3,8; p=0,052). Conclusão Níveis médios de T4L mais altos e de TSH mais baixos foram associados ao risco de morte em coorte de idosos eutireoidianos usando FR-e de TSH. (TSH TL T L (T4L followup, followup follow up, up follow-up FRe FR (FR-e 201 2013 acompanhamento iguais ≤1,75 175 1 75 (≤1,7 mUIL mUI 80 <8 20 2 0 ≤2, ≥8 anos. . < ( 137 37 ≥1,3 ng/dL. ngdL ng/dL ng dL ng/dL) HR (HR IC (IC 95 28 73% 73 (73 mulheres 804 4 =80, 57 5 7 5, IQR =3,7–6,4 3764 3 6 =7, =7 , =7) 11 faleceram ajustado HR=1,7 HR17 (HR=1,7 IC=1,1–2,7 IC1127 p=0,016 p0016 p 016 elevado HR=2,0 HR20 (HR=2,0 IC=1,0–3,8 IC1038 8 p=0,052. p0052 p=0,052 052 p=0,052) ≤1,7 17 (≤1, ≤2 ≥ 13 ≥1, 9 (7 =80 =3,7–6, 376 = HR=1, HR1 (HR=1, IC=1,1–2, IC112 p=0,01 p001 01 HR=2, HR2 (HR=2, IC=1,0–3, IC103 p005 p=0,05 05 ≤1, (≤1 ≤ ≥1 =8 =3,7–6 HR=1 (HR=1 IC=1,1–2 IC11 p=0,0 p00 HR=2 (HR=2 IC=1,0–3 IC10 ≤1 (≤ =3,7– HR= (HR= IC=1,1– IC1 p=0, p0 IC=1,0– =3,7 IC=1,1 p=0 IC=1,0 =3, IC=1, p= =3 IC=1 IC=

Abstract Objective To assess the associations between the mean thyrotropin (TSH) and mean free thyroxine (FT4), detected during follow-up, and mortality in a group of older euthyroid patients according to age-specific reference range (as-RR) for TSH. Method Retrospective survival analysis cohort including euthyroid elderly patients who were being monitored at the outpatient clinic of a university hospital from 2010 to 2013. All participants had been assessed for the risk of functional disability as a criterion for admission to this outpatient clinic. Mean TSH and FT4 values were calculated using hormone dosages obtained during the follow-up period. Each as-RR for TSH was divided into four equal parts, considering the lower levels as the main exposure variable (≤1.75 mlU/L for <80, and ≤2.0 mlU/L for ≥80 years). FT4 levels were explored according to two categories (< e ≥1.37 ng/dL). The outcome was time to death. We used Cox proportional hazard regression to estimate the hazard ratio (HR) and 95% confidence interval (CI). Results 285 participants (73% females, mean age =80.4 years) followed by a median of 5.7 years (IQR =3.7–6.4; maximum =7), of which 114 died. After the adjusted final model, mortality was associated with the lowest mean TSH (HR=1.7; CI=1.1–2.7; p=0.016) and with the upper mean of FT4 (HR=2.0; CI=1.0–3.8; p=0.052). Conclusions Higher FT4 and lower TSH mean levels were associated with risk of death in a cohort of euthyroid older adults using an as-RR of TSH. (TSH FT4, FT , (FT4) followup, followup follow up, up agespecific specific asRR RR (as-RR 201 2013 period parts ≤1.75 175 1 75 (≤1.7 mlUL mlU L 80 <80 20 2 0 ≤2. ≥8 years. . < ( 137 37 ≥1.3 ng/dL. ngdL ng/dL ng dL ng/dL) HR (HR 95 CI. CI (CI) 28 73% 73 (73 females 804 4 =80. 57 5 7 5. IQR =3.7–6.4 3764 3 6 =7, =7 =7) 11 died model HR=1.7 HR17 (HR=1.7 CI=1.1–2.7 CI1127 p=0.016 p0016 p 016 HR=2.0 HR20 (HR=2.0 CI=1.0–3.8 CI1038 8 p=0.052. p0052 p=0.052 052 p=0.052) (FT4 ≤1.7 17 (≤1. <8 ≤2 ≥ 13 ≥1. 9 (CI (7 =80 =3.7–6. 376 = HR=1. HR1 (HR=1. CI=1.1–2. CI112 p=0.01 p001 01 HR=2. HR2 (HR=2. CI=1.0–3. CI103 p005 p=0.05 05 (FT ≤1. (≤1 ≤ ≥1 =8 =3.7–6 HR=1 (HR=1 CI=1.1–2 CI11 p=0.0 p00 HR=2 (HR=2 CI=1.0–3 CI10 ≤1 (≤ =3.7– HR= (HR= CI=1.1– CI1 p=0. p0 CI=1.0– =3.7 CI=1.1 p=0 CI=1.0 =3. CI=1. p= =3 CI=1 CI=

ABSTRACT Primary hypothyroidism is a common disorder in clinical practice. The management of most cases of hypothyroidism is usually straightforward, but the best approach in some special situations may raise questions among physicians. This position statement was prepared by experts from the Brazilian Society of Endocrinology and Metabolism to guide the management of three special situations, namely, hypothyroidism in the elderly, subclinical hypothyroidism in patients with heart disease, and difficult-to-control hypothyroidism. The authors prepared the present statement after conducting a search on the databases MEDLINE/PubMed, LILACS, and SciELO and selecting articles with the best evidence quality addressing the selected situations. The statement presents information about the current approach to patients in these special situations.

ABSTRACT The fundamental objective of military field training exercises (FTX) is to prepare military personnel for real-life operations through simulated scenarios. These training sessions often require extreme physical efforts with prolonged, high-intensity exercises that can be combined with food restrictions and partial, or total, sleep deprivation. Such conditions can compromise an individual’s physical performance and cause tissue damage, thus affecting their health. This study aimed to perform a systematic review of the literature to identify studies that measured the changes in hormone levels and biomarkers of cellular injury and oxidative stress resulting from FTX with high levels of energy expenditure combined with food and sleep restrictions. PubMed and the Scopus database were searched for articles that combined physical effort/food restriction/sleep deprivation with military training. The initial database search identified 158 articles that were reduced to 18 after confirmation. Significant reductions were reported in thyroid hormones, T3, T4, and anabolic hormones such as testosterone, insulin and androstenedione. An exception for GH was found, which increased throughout FTX. Less distinct responses to FTX were observed with cortisol, TSH and LH. The presence of biomarkers for cellular damage (myoglobin, TNF, and CRP) and increased immune response activities were also described. The scarcity of information on oxidative stress, analyses of cellular injury and biomarkers of inflammatory responses warrants the future study of these topics, which could be helpful in facilitating the safe and effective physical preparations of the members of the armed forces. (FTX reallife real life scenarios prolonged highintensity intensity partial total individuals individual s health effortfood effort restrictionsleep restriction 15 1 confirmation T3 T T4 testosterone androstenedione found cortisol LH myoglobin, myoglobin (myoglobin TNF CRP described topics forces

ABSTRACT Objective Maternal hypothyroidism during pregnancy may lead to adverse outcomes. Recently published guidelines by the American Thyroid Association (ATA) do not advocate for universal screening but recommend a case-finding approach in high-risk pregnant women. The present study aims to evaluate the accuracy of this approach in identifying women with thyroid dysfunction during early pregnancy. Subjects and methods This is a multiple-center, cross-sectional study. Three hundred and one pregnant women were enrolled. Anamnesis and a physical examination were performed to detect which women fulfilled the criteria to undergo laboratory screening of thyroid dysfunction, according to the ATA’s 2017 guidelines. The Zulewski’s validated clinical score was applied to assess signs and symptoms of hypothyroidism. Serum levels of thyrotropin (TSH), free thyroxine (FT4), anti-thyroperoxidase (TPO-Ab), and anti-thyroglobulin (Tg-Ab) antibodies were determined. Results Two hundred and thirty one women (78%) were classified as high risk, and 65 (22%) were classified as low risk for thyroid dysfunction. Regarding the clinical score, 75 patients (31.2%) presented mild symptoms that were compatible with SCH, of which 22 (7.4%) had symptoms as the only risk factor for thyroid disease. 17 patients (5.7%) had SCH, of which 10 (58.8%) belonged to the high-risk group, and 7 (41.2%) belonged to the low-risk group. OH was found in 4 patients (1.4%): 3 (75%) in the high-risk group and 1 (25%) in the low-risk group. Conclusions The ATA’s proposed screening criteria were not accurate in the diagnosis of thyroid dysfunction in pregnancy. Testing only the high-risk pregnant women would miss approximately 40% of all hypothyroid patients.

ABSTRACT The indolent evolution of low-risk papillary thyroid microcarcinoma (mPTC) in adult patients and the consequences of thyroidectomy require a revision of the management traditionally recommended. Aiming to spare patients unnecessary procedures and therapies and to optimize the health system in Brazil, we suggest some measures. Fine-needle aspiration of nodules ≤ 1 cm without extrathyroidal extension on ultrasonography should be performed only in nodules classified as “very suspicious” (i.e., high suspicion according to ATA, high risk according to AACE, TI-RADS 5) and in selected cases [age < 40 years, nodule adjacent to the trachea or recurrent laryngeal nerve (RLN), multiple suspicious nodules, presence of hypercalcitoninemia or suspicious lymph nodes]. Active surveillance (AS) rather than immediate surgery should be considered in adult patients with low-risk mPTC. Lobectomy is the best option in patients with unifocal low-risk mPTC who are not candidates for AS because of age, proximity of the tumor to the trachea or RLN, or because they opted for surgery. The same applies to patients who started AS but had a subsequent surgical indication not due to a suspicion of tumor extension beyond the gland or multicentricity. Molecular tests are not necessary to choose between AS and surgery or, in the latter case, between lobectomy and total thyroidectomy. The presence of RAS or other RAS-like mutations or BRAFV600E or other BRAF V600E-like mutations should not modify the management cited above; however, the rare cases of mPTC exhibiting high-risk mutations, like in the TERT promoter or p53, are not candidates for AS.

ABSTRACT Objective: Life expectancy is increasing worldwide and studies have been demonstrating that elevated serum thyroid stimulating hormone (TSH) concentration in elderly is associated with some better health outcomes. This elevation is somewhat physiological as aging. The aim of this study was to investigate the heart rate (HR) response during a graded exercise test and its recovery in healthy elderly, comparing subjects within serum TSH in the lower limit of reference range to those within the TSH in the upper limit. Subjects and methods: A cross-sectional study was conducted with 86 healthy elderly aged 71.5 ± 5.1 years, with serum TSH between 0.4 – 4.0 mUl/mL. The participants were divided into two groups according to TSH level: < 1.0 mUl/mL (n = 13) and ≥ 1.0 µUI/mL (n = 73). All participants performed an ergometric test on a treadmill. The HR was recorded and analyzed at rest, during exercise and during the three minutes immediately after exercise. Results: No differences were observed in relation to HR at peak of exercise (TSH < 1.0 µUI/mL: 133.9 ± 22.5 bpm vs. TSH ≥ 1.0 µUI/mL: 132.4 ± 21.3 bpm; p = 0.70) and during the first minute of recovery phase (TSH < 1.0 µUI/mL: 122.3 ± 23.1 bpm vs. TSH ≥ 1.0 µUI/mL: 115.7 ± 18.4 bpm p = 0.33). The groups also presented similar chronotropic index (TSH < 1.0 µUI/mL: 78.1 ± 30.6 vs. TSH ≥ 1.0 µUI/mL: 79.5 ± 26.4; p = 0.74). Conclusion: In this sample studied, there were no difference between lower and upper TSH level concerning HR response during rest, peak of exercise and exercise recovery.

ABSTRACT Objectives: American Thyroid Association (ATA)'s new guidelines recommend use of population-based trimester-specific reference range (RR) for thyrotropin (TSH) in pregnancy. The aim of this study was to determine first trimester TSH RR for a population of pregnant women in Rio de Janeiro State. Subjects and methods: Two hundred and seventy pregnant women without thyroid illness, defined by National Academy of Clinical Biochemistry, and normal iodine status were included in this sectional study. This reference group (RG) had normal median urinary iodine concentration (UIC = 219 μg/L) and negative anti-thyroperoxidase antibodies (TPOAb). Twin pregnancy, trophoblastic disease and use of drugs or supplements that influence thyroid function were excluded. In a second step, we defined a more selective reference group (SRG, n = 170) by excluding patients with thyroiditis pattern on thyroid ultrasound and positive anti-thyroglobulin antibodies. This group also had normal median UIC. At a final step, a more selective reference group (MSRG, n = 130) was defined by excluding any pregnant women with UIC < 150 μg/L. Results: In the RG, median, 2.5th and 97.5th percentiles of TSH were 1.3, 0.1, and 4.4 mIU/L, respectively. The mean age was 270 ± 5.0 and the mean body mass index was 25.6 ± 5.2 kg/m2. In the SRG and MSRG, 2.5th and 975th percentiles were 0.06 and 4.0 (SRG) and 0.1 and 3.6 mIU/L (MSRG), respectively. Conclusions: In the population studied,TSH upper limit in the first trimester of pregnancy was above 2.5 mIU/L. The value of 3.6 mIU/L, found when iodine deficiency and thyroiditis (defined by antibodies and ultrasound characteristics) were excluded, matches recent ATA guidelines.

ABSTRACT Objective: The aim of this study was to evaluate the association between this characteristic and outcomes in patients with lymph node metastasis in a Brazilian cohort. Subjects and methods: This study examined a retrospective cohort of adult patients diagnosed with differentiated thyroid cancer and lymph node metastases from 1998 to 2015 in two referral centers. Number, location, size and extranodal extension (ENE) of metastatic lymph nodes were assessed and correlated with response to initial therapy. Results: A greater number of metastatic nodes, larger size, presence of lateral neck disease and ENE were all associated with a lower probability of achieving an excellent response to initial therapy (p ≤ 0.05 for all these parameters). Local recurrent disease had a significant association with lymph node number (6 in the recurrence/persistence group versus 4 in the non-recurrent group; p = 0.02) and ENE (19.2 versus 75%, p = 0.03). Lateral neck disease was the only characteristic associated with distant metastasis and was present in 52.1% of the group without metastasis and 70.4% of the group with metastasis (p = 0.001). Conclusion: The lymph node characteristics were associated with response to initial therapy and neck recurrence/persistence, confirming the importance of the analysis of these factors in risk stratification in a Brazilian population and its possible use to tailor initial staging and long term follow-up.

Resumo Objetivo Investigar a relação entre tireotrofina sérica (TSH), resistência à insulina (RI) e fatores de risco cardiovascular (FRC) em uma amostra de adolescentes brasileiros acima do peso e obesos. Métodos Foi realizada uma análise longitudinal retrospectiva de 190 adolescentes púberes acima do peso e obesos. Foram analisados os níveis de TSH e T4 livre (T4l), as medidas antropométricas e os resultados de exames laboratoriais desses pacientes. Resultados 27 indivíduos (13,56%) apresentaram níveis de TSH acima do normal (hipotireoidismo subclínico (HSC)). Eles apresentaram circunferência da cintura (CC) significativamente maior que os indivíduos eutireoideos. A TSH sérica foi positivamente correlacionada ao índice do modelo de avaliação da homeostase de resistência à insulina (HOMA-IR), triglicerídeos (TG) e lipoproteína de alta densidade-colesterol (HDL-C). Usando TSH e IMC como variáveis independentes, os níveis de TSH estavam relacionados ao HOMA-IR (p = 0.001) e a TG (p = 0.007) de forma independente. Entre os pacientes eutireoideos, indivíduos com valores de TSH < 2.5 mIU/mL apresentaram reduções estatisticamente significativas na razão cintura/quadril, nos níveis de HDL-C e nos escores de HOMA-IR e tendência a menores valores de CC. Conclusão O HSC em adolescentes acima do peso e obesos parece estar associado ao excesso de peso, principalmente de peso visceral. Em adolescentes eutireoideos, parece haver uma relação direta entre TSH e alguns FRC. Concluindo, em nossa amostra de adolescentes acima do peso e obesos, os níveis de TSH parecem estar associados a RI e FRC.

Abstract Objective: To investigate the relationship between serum thyrotropin (TSH), insulin resistance (IR), and cardiovascular risk factors (CRF) in a sample of overweight and obese Brazilian adolescents. Methods: A retrospective, longitudinal analysis of 199 overweight and obese pubescent adolescents was performed. The TSH and free T4 (fT4) levels, anthropometric measurements, and laboratory test results of these patients were analyzed. Results: 27 individuals (13.56%) presented with TSH levels above the normal level (subclinical hypothyroidism [SCH]). Their waist circumference (WC) was significantly higher than those of euthyroid individuals. Serum TSH was positively correlated with the homeostasis model assessment of insulin resistance (HOMA-IR) index, triglycerides (TG) and high-density lipoprotein cholesterol (HDL-C). Using TSH and BMI as independent variables, TSH levels were shown to be independently related to HOMA-IR (p = 0.001) and TG (p = 0.007). Among euthyroid subjects, individuals with TSH values <2.5 mIU/mL exhibited statistically significant decreases in waist-to-hip ratio, HDL-C levels, and HOMA-IR scores and a tendency toward lower WC values. Conclusion: SCH in overweight and obese adolescents appears to be associated with excess weight, especially visceral weight. In euthyroid adolescents, there appears to be a direct relationship between TSH and some CRF. In conclusion, in the present sample of overweight and obese adolescents, TSH levels appear to be associated with IR and CRF.

Objective Much controversy relates to the risk of non-synchronous second primary malignancies (NSSPM) after radioactive iodine treatment (RAI-131) in differentiated thyroid cancer (DTC) patients. This study evaluated the relationship between RAI-131 and NSSPM in DTC survivors with long-term follow-up. Materials and methods Retrospective analysis of 413 DTC cases was performed; 252 received RAI-131 and 161 were treated with thyroidectomy alone. Exclusion criteria were: prior or synchronous non-thyroidal malignancies (within the first year), familial syndromes associated to multiple neoplasms, ionizing radiation exposure or second tumors with unknown histopathology. Results During a mean follow-up of 11.0 ± 7.5 years, 17 (4.1%) patients developed solid NSSPM. Patients with NSSPM were older than those without (p = 0.02). RAI-131 and I-131 cumulative activity were similar in patients with and without NSSPM (p = 0.18 and p = 0.78, respectively). Incidence of NSSPM was 5.2% in patients with RAI-131 treatment and 2.5% in those without RAI-131 (p = 0.18). Using multivariate analysis, RAI-131 was not significantly associated with NSSPM occurrence (p = 0.35); age was the only independent predictor (p = 0.04). Under log rank statistical analysis, after 10 years of follow-up, it was observed a tendency of lower NSSPM-free survival among patients that received RAI-131 treatment (0.96 vs . 0.87; p = 0.06), what was not affected by age at DTC diagnosis. Conclusion In our cohort of DTC survivors, with a long-term follow-up period, RAI-131 treatment and I-131 cumulative dose were not significantly associated with NSSPM occurrence. A tendency of premature NSSPM occurrence among patients treated with RAI-131 was observed, suggesting an anticipating oncogenic effect by interaction with other risk factors.

Objective Thyroid diseases are common in individuals with type 1 diabetes mellitus (T1DM) and should be investigated annually in these individuals. The aim of this study was to evaluate the frequency of thyroid diseases in first degree relatives (FDR) of patients with T1DM. Subjects and methods Eighty individuals (40 patients with T1DM and 40 FDR) were interviewed and blood was sampled for thyroid-stimulating hormone (TSH), free thyroxine (FT4) and thyroid peroxidase (TPO) antibodies measurement. Autoantibodies against glutamic acid decarboxylase 65 (GAD65), islet antigen-2 (IA2) and autoantibodies against insulin (AAI) were measured in FDR. Results We found a similar prevalence of thyroid dysfunction in patients with T1DM and their FDR (22.5% vs. 27.5%; p = 0,79). There were no differences in serum TSH levels (p = 0.29), FT4 (p = 0,45), frequency of abnormal TSH (p = 0.28), positive TPO antibodies (p = 0.13), titers of TPO antibodies (in positive cases) between patients with T1DM and their FDR (p = 0.94). Conclusions Thyroid abnormalities seem to be common not only in patients with T1DM but also in their FDR, which suggests that screening strategies for thyroid diseases might also be useful to these individuals.

INTRODUÇÃO: O hipotiroidismo é amplamente reconhecido por seus efeitos sobre os diferentes sistemas orgânicos, levando ao hipometabolismo. No entanto, o hipotiroidismo subclínico, sua apresentação mais prevalente, tem sido recentemente relacionado ao risco cardiovascular e também com complicações materno-fetais em gestantes. OBJETIVOS: Nestas diretrizes clínicas, vários aspectos do hipotiroidismo foram discutidos com objetivos claros de ajudar os médicos a tratar pacientes com hipotiroidismo e de compartilhar algumas das nossas experiências clínicas na América Latina. MATERIAIS E MÉTODOS: A Sociedade Latino-Americana de Tireoide formou uma Força-Tarefa para desenvolver diretrizes baseadas em evidências clínicas sobre o hipotiroidismo. Foi realizada uma revisão sistemática da literatura existente, com foco em bancos de dados primários do MedLine/PubMed e Lilacs/SciELO. Foram feitas análises para avaliar a qualidade metodológica no sentido de selecionar os melhores estudos. A força de recomendação em uma escala de A-D foi baseada no Centro de Oxford para a Medicina Baseada em Evidência - Níveis de Evidência 2009 - , permitindo uma opinião imparcial, desprovida de pontos de vista subjetivos. As áreas de interesse compreenderam estudos de diagnóstico, triagem, tratamento e uma seção especial de hipotiroidismo na gravidez. RESULTADOS: Foram feitos vários questionamentos relacionados ao diagnóstico, triagem e tratamento do hipotiroidismo na população adulta e, especificamente, em mulheres grávidas. Foram elaboradas vinte e seis recomendações baseadas nas respostas a essas perguntas. Apesar da falta de evidências em algumas áreas como o tratamento do hipotiroidismo, de 279 referências, 73% eram de Grau A e B, 8% de Grau C e 19% de Grau D. CONCLUSÕES: Essas diretrizes baseadas em evidências clínicas sobre o hipotiroidismo poderão fornecer um critério consensual de como tratar o hipotiroidismo na América Latina. Apesar de a maior parte dos estudos referidos ser da experiência internacional em hipotiroidismo, o ponto de vista dos tiroidologistas da América Latina foi contemplado.

INTRODUCTION: Hypothyroidism has long been known for its effects on different organ systems, leading to hypometabolism. However, subclinical hypothyroidism, its most prevalent form, has been recently related to cardiovascular risk and also to maternal-fetal complications in pregnant women. OBJECTIVES: In these clinical practice guidelines, several aspects of this field have been discussed with the clear objectives of helping physicians treat patients with hypothyroidism, and of sharing some of our Latin American-based clinical experience. MATERIALS AND METHODS: The Latin American Thyroid Society commissioned a Task Force on Hypothyroidism to develop evidence-based clinical guidelines on hypothyroidism. A systematic review of the available literature, focused on the primary databases of MedLine/PubMed and Lilacs/SciELO was performed. Filters to assess methodological quality were applied to select the best quality studies. The strength of recommendation on a scale from A-D was based on the Oxford Centre for Evidence--based Medicine, Levels of Evidence 2009, allowing an unbiased opinion devoid of subjective viewpoints. The areas of interest for the studies comprised diagnosis, screening, treatment and a special section for hypothyroidism in pregnancy. RESULTS: Several questions based on diagnosis, screening, treatment of hypothyroidism in adult population and specifically in pregnant women were posed. Twenty six recommendations were created based on the answers to these questions. Despite the fact that evidence in some areas of hypothyroidism, such as therapy, is lacking, out of 279 references, 73% were Grade A and B, 8% Grade C and 19% Grade D. CONCLUSIONS: These evidence-based clinical guidelines on hypothyroidism will provide unified criteria for management of hypothyroidism throughout Latin America. Although most of the studies referred to are from all over the world, the point of view of thyroidologists from Latin America is also given.

INTRODUÇÃO: O hipotireoidismo subclínico (HSC), definido por concentrações elevadas do TSH em face de níveis normais dos hormônios tireoidianos, tem elevada prevalência no Brasil, particularmente entre mulheres e idosos. Embora um número crescente de estudos venha associando o HSC com maior risco de doença arterial coronariana e de mortalidade, não há ensaio clínico randomizado sobre o benefício do tratamento com levotiroxina na redução dos riscos e o tratamento permanece controverso. OBJETIVO: Este consenso, patrocinado pelo Departamento de Tireoide da Sociedade Brasileira de Endocrinologia e Metabologia e desenvolvido por especialistas brasileiros com vasta experiência clínica em tireoide, apresenta recomendações baseadas em evidências para uma abordagem clínica do paciente com HSC no Brasil. MATERIAIS E MÉTODOS: Após estruturação das questões clínicas, a busca das evidências disponíveis na literatura foi realizada inicialmente na base de dados do MedLine-PubMed e posteriormente nas bases Embase e SciELO - Lilacs. A força da evidência, avaliada pelo sistema de classificação de Oxford, foi estabelecida a partir do desenho de estudo utilizado, considerando-se a melhor evidência disponível para cada questão e a experiência brasileira. RESULTADOS: Os temas abordados foram definição e diagnóstico, história natural, significado clínico, tratamento e gestação, que resultaram em 29 recomendações para a abordagem clínica do paciente adulto com HSC. CONCLUSÃO: O tratamento com levotiroxina foi recomendado para todos os pacientes com HSC persistente com níveis séricos do TSH > 10 mU/L e para alguns subgrupos especiais de pacientes.

INTRODUCTION: Subclinical hypothyroidism (SCH), defined as elevated concentrations of thyroid stimulating hormone (TSH) despite normal levels of thyroid hormones, is highly prevalent in Brazil, especially among women and the elderly. Although an increasing number of studies have related SCH to an increased risk of coronary artery disease and mortality, there have been no randomized clinical trials verifying the benefit of levothyroxine treatment in reducing these risks, and the treatment remains controversial. OBJECTIVE: This consensus, sponsored by the Thyroid Department of the Brazilian Society of Endocrinology and Metabolism and developed by Brazilian experts with extensive clinical experience with thyroid diseases, presents these recommendations based on evidence for the clinical management of SCH patients in Brazil. MATERIALS AND METHODS: After structuring the clinical questions, the search for evidence in the literature was initially performed in the MedLine-PubMed database and later in the Embase and SciELO - Lilacs databases. The strength of evidence was evaluated according to the Oxford classification system and established based on the experimental design used, considering the best available evidence for each question and the Brazilian experience. RESULTS: The topics covered included SCH definition and diagnosis, natural history, clinical significance, treatment and pregnancy, and the consensus issued 29 recommendations for the clinical management of adult patients with SCH. CONCLUSION: Treatment with levothyroxine was recommended for all patients with persistent SCH with serum TSH values > 10 mU/L and for certain patient subgroups.

INTRODUÇÃO: O hipertireoidismo é caracterizado pelo aumento da síntese e liberação dos hormônios tireoidianos pela glândula tireoide. A tireotoxicose refere-se à síndrome clínica decorrente do excesso de hormônios tireoidianos circulantes, secundário ao hipertireoidismo ou não. Este artigo descreve diretrizes baseadas em evidências clínicas para o manejo da tireotoxicose. OBJETIVO: O presente consenso, elaborado por especialistas brasileiros e patrocinado pelo Departamento de Tireoide da Sociedade Brasileira de Endocrinologia e Metabologia, visa abordar o manejo, diagnóstico e tratamento dos pacientes com tireotoxicose, de acordo com as evidências mais recentes da literatura e adequadas para a realidade clínica do país. MATERIAIS E MÉTODOS: Após estruturação das questões clínicas, foi realizada busca das evidências disponíveis na literatura, inicialmente na base de dados do MedLine-PubMed e posteriormente nas bases Embase e SciELO - Lilacs. A força das evidências, avaliada pelo sistema de classificação de Oxford, foi estabelecida a partir do desenho de estudo utilizado, considerando-se a melhor evidência disponível para cada questão. RESULTADOS: Foram definidas 13 questões sobre a abordagem clínica inicial visando ao diagnóstico e ao tratamento que resultaram em 53 recomendações, incluindo investigação etiológica, tratamento com drogas antitireoidianas, iodo radioativo e cirurgia. Foram abordados ainda o hipertireoidismo em crianças, adolescentes ou pacientes grávidas e o manejo do hipertireoidismo em pacientes com oftalmopatia de Graves e com outras causas diversas de tireotoxicose. CONCLUSÕES: O diagnóstico clínico do hipertireoidismo, geralmente, não oferece dificuldade e a confirmação diagnóstica deverá ser feita com as dosagens das concentrações séricas de TSH e hormônios tireoidianos. O tratamento pode ser realizado com drogas antitireoidianas, administração de radioiodoterapia ou cirurgia de acordo com a etiologia da tireotoxicose, as características clínicas, disponibilidade local de métodos e preferências do médico-assistente e paciente.

INTRODUCTION: Hyperthyroidism is characterized by increased synthesis and release of thyroid hormones by the thyroid gland. Thyrotoxicosis refers to the clinical syndrome resulting from excessive circulating thyroid hormones, secondary to hyperthyroidism or due to other causes. This article describes evidence-based guidelines for the clinical management of thyrotoxicosis. OBJECTIVE: This consensus, developed by Brazilian experts and sponsored by the Department of Thyroid Brazilian Society of Endocrinology and Metabolism, aims to address the management, diagnosis and treatment of patients with thyrotoxicosis, according to the most recent evidence from the literature and appropriate for the clinical reality of Brazil. MATERIALS AND METHODS: After structuring clinical questions, search for evidence was made available in the literature, initially in the database MedLine, PubMed and Embase databases and subsequently in SciELO - Lilacs. The strength of evidence was evaluated by Oxford classification system was established from the study design used, considering the best available evidence for each question. RESULTS: We have defined 13 questions about the initial clinical approach for the diagnosis and treatment that resulted in 53 recommendations, including the etiology, treatment with antithyroid drugs, radioactive iodine and surgery. We also addressed hyperthyroidism in children, teenagers or pregnant patients, and management of hyperthyroidism in patients with Graves' ophthalmopathy and various other causes of thyrotoxicosis. CONCLUSIONS: The clinical diagnosis of hyperthyroidism usually offers no difficulty and should be made with measurements of serum TSH and thyroid hormones. The treatment can be performed with antithyroid drugs, surgery or administration of radioactive iodine according to the etiology of thyrotoxicosis, local availability of methods and preferences of the attending physician and patient.