Use of thyroid hormone in hypothyroid patients and euthyroid subjects in Spain: A THESIS* questionnaire survey.

BACKGROUND: Hypothyroidism is one of the leading conditions in endocrinology. Despite that fact, clinical indications for treatment still vary among Spanish specialists. AIMS: To identify attitudes of Spanish specialists relating to the use of levothyroxine (LT4) and the management of hypothyroidism. METHODS: The members of the Sociedad Española de Endocrinología y Nutrición (Spanish Society of Endocrinology and Nutrition) were invited to participate in a web-based survey. The survey, initially in English, was modified to reflect in accordance with the availability of thyroid hormone formulations in Spain. RESULTS: A total of 505 of 1956 (25.8%) members (66% female) completed the survey; 97.4% declared that LT4 is the first-line therapy for hypothyroidism. The indications for LT4 therapy in euthyroidism were infertility in thyroid antibody-positive women (48.5%) and simple goitre (21.2%). However, 44.2% of specialists reported that there was no indication for LT4 therapy in such patients. Only a minority of respondents (2.6%) considered combining LT4 with liothyronine as the treatment of choice from inception, whereas 49% stated that it should never be used. CONCLUSIONS: The standard of treatment of hypothyroidism in Spain is almost exclusively with LT4 tablets. Availability of other formulations of LT4 or combination therapy for hypothyroidism management remains to be explored, especially in patients with persistent symptoms. Notably, non-evidence-based use of LT4 is widely practiced in Spain for euthyroid women with autoimmune thyroiditis and fertility issues.

Evaluation of thyroid function and metabolic parameters in obese and overweight children: A prospective case-control study / Evaluación de la función tiroidea y los parámetros metabólicos en niños obesos y con sobrepeso: Un estudio prospectivo de casos y controles

Abstract Obesity is considered an important global public health challenge, and its prevalence is rapidly increasing in children. We investigated in this study if the upper-normal TSH level may be associated with metabolic syndrome parameters, including obesity, high blood pressure, and dyslipidemia and changes in insulin sensitivity in overweight and obese children. We also investigated whether there is a relationship between BMI and these parameters. This prospective case-control study comprised 145 participants (74 females, 71 males) aged 5-18 years. Participants were divided into three groups according to their BMI z-score, as overweight, obese and control. The control group included 35 age and sex-matched healthy subjects. Thyroid stimulating hormone levels of control, overweight and obese groups were 2.14 ± 1.27, 2.97 ± 1.26 and 3.13 ± 1.11, respectively (p<0.05). There was a significant positive correlation between TSH and the BMI, BMI z-scores between overweight and obese groups (r=0.302, p=0.000), (r=0.121, p=0.004), respectively. The current study suggests that increased serum TSH levels, even within the normal range, in overweight and obese children is associated with the impairment of metabolic parameters, including dyslipidemia and insulin sensitivity. For that reason, TSH levels in the high-normal range should be considered as a risk factor for metabolic syndrome and its components.

Resumen La obesidad se considera un importante desafío de salud pública mundial y su prevalencia está aumentando rápidamente en los niños. En este estudio, se investigó si el nivel normal superior de TSH puede estar asociado con los parámetros del síndrome metabólico, incluida la obesidad, la presión arterial elevada, cambios en los lípidos y la sensibilidad a la insulina, en niños con sobrepeso y obesidad. También investigamos si existe una relación entre el IMC y estos parámetros. En este estudio prospectivo de casos y controles se incluyeron a 145 participantes (74 hembras, 71 varones) de entre 5 y 18 años. Los participantes se dividieron en 3 grupos según el puntaje z del IMC, como sobrepeso, obesidad y control. El grupo de control incluyó 35 sujetos sanos emparejados por edad y sexo. Los niveles de hormona estimulante de la tiroides de los grupos de control, con sobrepeso y obesos fueron 2,14 ± 1,27, 2,97 ± 1,26 y 3,13 ± 1,11, respectivamente (p <0,05). Hubo una correlación positiva significativa entre la TSH y el BMI, la puntuación z del IMC entre los grupos con sobrepeso y obesidad (r = 0,302, p = 0,000), (r = 0,121, p = 0,004), respectivamente. Por esa razón, el nivel de TSH en el rango normal alto debe considerarse como un factor de riesgo del síndrome metabólico y sus componentes.

Use of thyroid hormone in hypothyroid patients and euthyroid subjects in Spain: A THESIS* questionnaire survey.

BACKGROUND: Hypothyroidism is one of the leading conditions in endocrinology. Despite that fact, clinical indications for treatment still vary among Spanish specialists. AIMS: To identify attitudes of Spanish specialists relating to the use of levothyroxine (LT4) and the management of hypothyroidism. METHODS: The members of the Sociedad Española de Endocrinología y Nutrición (Spanish Society of Endocrinology and Nutrition) were invited to participate in a web-based survey. The survey, initially in English, was modified to reflect in accordance with the availability of thyroid hormone formulations in Spain. RESULTS: A total of 505 of 1956 (25.8%) members (66% female) completed the survey; 97.4% declared that LT4 is the first-line therapy for hypothyroidism. The indications for LT4 therapy in euthyroidism were infertility in thyroid antibody-positive women (48.5%) and simple goitre (21.2%). However, 44.2% of specialists reported that there was no indication for LT4 therapy in such patients. Only a minority of respondents (2.6%) considered combining LT4 with liothyronine as the treatment of choice from inception, whereas 49% stated that it should never be used. CONCLUSIONS: The standard of treatment of hypothyroidism in Spain is almost exclusively with LT4 tablets. Availability of other formulations of LT4 or combination therapy for hypothyroidism management remains to be explored, especially in patients with persistent symptoms. Notably, non-evidence-based use of LT4 is widely practiced in Spain for euthyroid women with autoimmune thyroiditis and fertility issues.

Miocardiopatía dilatada inducida por hipotiroidismo / Thyroid diseases could induce structural and functional changes of the heart

Resumen Las enfermedades tiroideas pueden producir cambios en la estructura y función del corazón. La miocardiopatía dilatada (MCD) con disfunción sistólica inducida por hipotiroidismo, es un fenómeno poco común. El presente artículo describe el caso de un hombre joven que presentó síntomas de insuficiencia cardíaca y se le diagnosticó MCD, con ecocardiografía que revelaba hipoquinesia global y disminución severa de la función sistólica del ventrículo izquierdo. El perfil tiroideo reveló un valor de TSH de 89 UI/dl, con T4 menor a 0.3 ng/ml. Con el tratamiento hormonal se documentó una mejoría progresiva de la función sistólica ventricular izquierda y del cuadro clínico del paciente.

Abstract Dilated cardiomyopathy (DCM) with systolic dysfunction provoked by hypothyroidism is an uncommon phenomenon. In this article we describe a case of young male that presented heart failure symptomatology and was diagnosed with DCM, echocardiography showed global hypokinesia with severe left ventricular systolic dysfunction. Thyroid analysis reveled a TSH of 89 IU/dl with T4 under 0.3 ng/ml. We documented progressive improvement of systolic left ventricular function and symptomatology with thyroid replacement therapy.

Anormalidades tiroideas en recién nacidos con sepsis neonatal temprana y tardia / Thyroid abnormalities in newborns with early and late neonatal sepsis

Purpose: To evaluate thyroid function in newborns with early and late neonatal sepsis by measuring T3, T4, TSH. Methods: The study included 80 newborns with a diagnosis of neonatal sepsis divided into two groups: early neonatal sepsis and late neonatal sepsis, which during the clinical and laboratory manifestations of sepsis showed changes in thyroid hormones, particularly low T3 syndrome and T3-T4 low syndrome. We excluded newborns children of mothers with disease with thyroid disease, those with a history of perinatal asphyxia, congenital malformations and major surgeries. Results: The development of the non-thyroid disease syndrome was confirmed in the two study groups with a prevalence of 54.2% for neonates with early neonatal sepsis and 80.95% for neonates with late neonatal sepsis, the most frequent being the low T3 in neonates with early neonatal sepsis and low T4 syndrome in neonates with late sepsis. These findings are relevant since there is evidence that low levels of thyroid hormones are associated with a worse prognosis and a poor evolution in severely ill neonates Conclusions: The syndrome of non-thyroid disease is frequent in neonates with neonatal sepsis, although it manifests itself with variable patterns according to the type of neonatal sepsis. Larger studies are needed to evaluate in greater depth the prognostic value of the syndrome in critical neonates

Actualización hipotiroidismo equino / Equine hypohyroiidism: an update

Objetivo: Realizar una actualización en hipotirodismo en equinos. Materiales y Métodos: Se analizó la literatura disponible de los últimos 50 años en las bases de datos BBCS-LILACS, Fuente Académica, IB-PsycINFO, IB-SSCI, IB-SciELO, Scopus y Scirus, al igual que artículos históricos, textos y referencias citadas en trabajos públicos. Resultados: Se obtuvo información pertinente relacionada con los objetivos propuestos en la presente revisión, por lo cual puede clasificarse en 7 secciones a saber: etiología, signos clínicos, diagnóstico, factores que alteran las pruebas diagnósticas, síndrome de enfermedad no tiroidea, prevención y tratamiento. Conclusión: El hipotiroidismo una de las alteraciones endocrinas más comunes en los equinos, los signos clínicos son muy característicos incluyendo letargia, retraso en el crecimiento, debilidad e incoordinación. El método diagnóstico más exacto es la medición de las concentraciones de T4L en suero por diálisis. La levotiroxina sódica continúa siendo el tratamiento de elección para el hipotiroidismo en equinos.

Objective: To carry out an update on equines hypothyroidism. Material and Methods: Available literature from the last 50 years included in the BBCS-LILACS, Fuente Académica, IB-PsycINFO, IB-SSCI, IB-SciELO, Scopus and Scirus, data base as well as historical articles, texts and references cited in work published to date were analyzed. Results: Important information related to the objectives proposed in the present review were found and analyzed. It was then divided in seven sections as follows: etiology, clinical signs, diagnosis, factors which alter the diagnostic tests, no thyroid disease syndrome, prevention and treatment. Conclusion: Hypothyroidism is one of the most common alterations in equines; clinical signs are very characteristic including lethargy, failure to thrive, debility and lack of coordination problems. The most exact diagnostic method is serum measurement of T4L concentration per dialysis. Levothyroxine sodium continues to be the ideal treatment for equine hypothyroidism.

Síndrome de resistencia a las hormonas tiroideas: reporte de un caso / Syndrome of resistance to thyroid hormone: a case report

El síndrome de resistencia a las hormonas tiroideas es una entidad poco frecuente que se caracteriza por concentraciones elevadas de tiroxina libre y triyodotironina libre, tirotropina normal o ligeramente elevada, en ausencia de cualquier otra enfermedad, medicación o antagonista que causen alteraciones sobre la función tiroidea. Se reporta un caso de una mujer a quien se le realizó diagnóstico de resistencia a las hormonas tiroideas con base en los antecedentes personales, las manifestaciones clínicas y los hallazgos de laboratorio; además, se realiza una revisión de la literatura, con énfasis en el diagnóstico y el tratamiento de la enfermedad.

The syndrome of resistance to thyroid hormones is a rare disease characterized by high levels of both free thyroxin and free triiodothyronine, as well as normal or slightly elevated levels of thyrotropin in absence of any disease, medication or antagonist that cause alterations on thyroid function. It is reported a case of a woman who was diagnosed with syndrome of resistance to thyroid hormones based on personal history, signs and symptoms, and laboratory findings. In addition, a literature review is presented, with emphasis in diagnosis and treatment of the disease.

Funcionamiento normal y aumentado de la glándula tiroides en equinos / Normal and ncreaased functioning of thyroid gland in equines

Objetivo: Describir y analizar el funcionamiento normal de la glándula tiroides en equinos y los factores que aumentan en ellos los niveles de hormonas tiroideas. Materiales y métodos: Mediante la revisión de la literatura disponible de los últimos 50 años en las bases de datos BBCS-LILACS, fuente académica, IB-PsycINFO, IB-SSCI, IB-SciELO, Scopus y Scirus, al igual que artículos históricos, textos y referencias citadas en trabajos publicados. Resultados: la información obtenida relacionada con los objetivos propuestos en la presente revisión, permite clasificar en 4 secciones a saber: síntesis y secreción de hormonas tiroideas; transporte y metabolismo; funciones; hipertiroidismo en los equinos. Conclusión: La glándula tiroides juega un papel importante, como productora de hormonas tiroideas, las cuales son necesarias para la diferenciación celular y crecimiento del organismo. El buen funcionamiento de las vías metabólicas depende de estas hormonas, las que tienen efectos específicos sobre diferentes órganos, manteniendo la homeostasis en todos los tejidos.

Objective: to describe and analyze the normal functioning of the thyroid gland in equines and the factors which increase the thyroid hormone levels. Materials and methods: information from the last 50 years included in the BBCS-LILACS, Fuente Académica, IB-PsycINFO, IB-SSCI, IB-SciELO, Scopus and Scirus, data bases as well as historical articles, texts and references cited in work published to date were analyzed. Results: important information related to the objectives proposed in the present review was found and analyzed. It was then divided into two sections as follow: synthesis, liberation and metabolism of thyroid hormones; factors that modify the thyroid hormone levels. Conclusion: the thyroid gland plays an important role producing thyroid hormones which are necessary for cellular differentiation and organic growth. The adequate functioning of metabolic ways depends on these hormones, which have specific effects on different organs maintaining homeostasis between all the tissues.

Factores que modifican los niveles de hormonas tiroideas en aves domesticas / Factrs which moddify thyroid hormones levels in domestic birds

Objetivo: analizar los factores que modifican los niveles de hormonas tiroideas en aves domésticas. Materiales y métodos: se analizó la literatura disponible de los últimos 50 años en las bases de datos BBCS-LILACS, Fuente Académica, IB-PsycINFO, IB-SSCI, IB-SciELO, Scopus y Scirus, al igual que artículos históricos, textos y referencias citadas en trabajos públicos. Resultados: se obtuvo información pertinente relacionada con los objetivos propuestos en la presente revisión, por lo cual puede clasificarse en 2 secciones a saber: síntesis, liberación y metabolismo de hormonas tiroideas; factores que modifican los niveles de hormonas tiroideas. Conclusión: la liberación de hormonas tiroideas puede ser afectada por factores tales como temperatura, incubación, dieta, ayuno, producción, fotoperiodos y estrés.

Objective: to analyze the factors which modify the thyroid hormone levels in domestic birds. Materials and methods: information from the last 50 years included in the BBCS-LILACS, Fuente Académica, IB-PsycINFO, IB-SSCI, IB-SciELO, Scopus and Scirus, data bases as well as historical articles, texts and references cited in work published to date were analyzed. Results: important information related to the objectives proposed in the present review was found and analyzed. The information was later divided into two sections as follows: synthesis, liberation and metabolism of thyroid hormones and factors which modify the thyroid hormones levels. Conclusion: thyroid hormones production can be influenced by factors such as temperature, incubation, diet, fasting, photoperiods and stress.

Hipertiroidismo y sistema cardiovascular: A propósito de un caso / Cardiovascular system and hyperthyroidism: Study of a case / Hipertireoidismo e sistema cardiovascular: A propósito de um caso

La glándula tiroidea y el corazón están estrechamente relacionadas fisiológicamente, concepto reforzado por los predecibles cambios de la función cardiovascular en los distintos trastornos tiroideos. Para entender, diagnosticar y tratar las cardiopatías que acompañan al hipertiroidismo, es importante conocer bien los mecanismos celulares de la acción de las hormonas tiroideas sobre el corazón y sobre las células del músculo liso. Se presenta el caso de una mujer de 40 años que ingresa con signos y síntomas de insuficiencia cardíaca descompensada a predominio de cavidades derechas. Se constató su grado de hipertiroidismo que producía la descompensación cardiovascular, fibrilación auricular de alta respuesta ventricular e hipertensión pulmonar. En su evolución eutiroidea, la paciente normaliza los parámetros cardiovasculares.

The thyroid gland and heart are closely related physiologically, a concept reinforced by the predictable changes of cardiovascular function in various thyroid disorders. To understand, diagnose and treatment of heart disease associated with hyperthyroidism is important to know the cellular mechanisms of action of thyroid hormones on the heart and smooth muscle cells. A case of a 40 year old woman was admitted with signs and symptoms of decompensated heart failure prevalence of right cavities. It was found that the degree of hyperthyroidism produced cardiovascular decompensation, atrial fibrillation, rapid ventricular response and pulmonary hypertension. In its evolution the patient euthyroid normalized cardiovascular parameters.

A glândula tireóide e coração estão intimamente relacionados fisiologicamente, um conceito reforçado pelas mudanças previsíveis da função cardiovascular em vários distúrbios da tireóide. Para entender, diagnosticar e tratar doenças cardíacas associadas com hipertireoidismo é importante conhecer os mecanismos celulares de ação dos hormônios tireoidianos sobre o coração e células musculares lisas. Informa-se o caso de uma mulher de 40 anos de idade foi internada com sinais e sintomas de insuficiência cardíaca descompensada predominância das cavidades direitas. Verificou-se que o grau de hipertireoidismo provocou descompensação cardiovascular, fibrilação atrial, a resposta ventricular rápida e hipertensão pulmonar. Na sua eutireóidea evolução, a paciente normalize os parâmetros cardiovasculares.

Hipertiroidismo y sistema cardiovascular: Bases fisiopatológicas y su manifestación clínica / Cardiovascular system and hyperthyroidism: Pathophysiological bases and its clinical manifestation / Hipertireoidismo e sistema cardiovascular: Bases fisiopatológicas e sua manifestação clínica

La glándula tiroides y el corazón están estrechamente relacionados fisiológicamente, concepto reforzado por los predecibles cambios de la función cardiovascular en los distintos trastornos tiroideos. Para entender, diagnosticar y tratar las cardiopatías que acompañan al hipertiroidismo, es importante conocer bien los mecanismos celulares de la acción de las hormonas tiroideas (HT) sobre el corazón y sobre las células del músculo liso. El objetivo de esta revisión es profundizar en los mecanismos de acción de la HT sobre el corazón y sistema vascular periférico, los cambios anátomo-estructurales que se producen a nivel miocárdico, la interacción con el sistema nervioso simpático, los trastornos en la actividad eléctrica, las alteraciones hemodinámicas sobre la contractilidad miocárdica y la relajación ventricular. Las manifestaciones clínicas del hipertiroidismo pueden presentar síntomas iniciales como palpitaciones hasta avanzar a un estado de mayor complejidad como es la insuficiencia cardíaca (IC), entidad de alta morbimortalidad. Esta última puede manifestarse con alteraciones del ritmo, deterioro en la función ventricular y afectación valvular, que dejadas a su evolución natural pueden llevar a la muerte del paciente, dando relevancia al reconocimiento temprano por parte del profesional de la probable etiología hormonal de la IC y/o como causa de su descompensación. Este diagnóstico permite realizar un tratamiento precoz y eficaz, ya que estados de eutiroidismo llevan a la normalización de los trastornos cardiovasculares en la mayoría de los pacientes.

The thyroid gland and the heart are closely related physiologically, this concept is reinforced by the predictable change in cardiovascular function in various thyroid disorders. To understand, diagnose and treat heart diseases that accompany hyperthyroidism is important to understand the cellular mechanisms of action of thyroid hormones (TH) on the heart and smooth muscle cells. The aim of this review is to reinforce the mechanisms of action of TH on the heart and peripheral vascular system, anatomic and structural changes that occur at myocardial level, interaction with the sympathetic nervous system, impaired electrical activity, hemodynamic changes on myocardial contractility and ventricular relaxation. The clinical manifestations of hyperthyroidism can lead to symptoms such as palpitations initial advance to a state of greater complexity such as heart failure (HF), an entity of high morbidity and mortality, could be expressed with rhythm disturbances, damage and impaired ventricular function valve, which left to their natural evolution may lead to death of the patient, giving relevance to the early recognition by professionals of the hormonal etiology of HF and/or the cause of his decompensation. This diagnosis allows early treatment and effective as euthyroid states lead to the normalization of cardiovascular disease in most patients.

A glândula tireóide e coração estão intimamente relacionados fisiologicamente, um conceito reforçado pela previsíveis alterações da função cardiovascular em várias doenças da tireóide. Para entender, diagnosticar e tratar das doenças do coração, que acompanham o hipertireoidismo, é importante compreender os mecanismos celulares de ação dos hormônios tireóideos (HT) no coração e células musculares lisas. O objetivo desta revisão é o de reforçar os mecanismos de ação dos HT sobre o coração e sistema vascular periférica, anatômico e variações estruturais que ocorrem a nível do miocárdio, a interação com o sistema nervoso simpático, alteração da atividade elétrica alterações hemodinâmicas na contratilidade miocárdica e relaxamento do miocárdio ventricular. As manifestações clínicas do hipertireoidismo podem levar a sintomas como palpitações adiantamento inicial para um estado de maior complexidade, tais como insuficiência cardíaca (IC), uma entidade de alta morbidade e mortalidade, pode ser expressa com distúrbios do ritmo, disfunção ventricular e envolvimento valvular, que deixou a sua evolução natural pode levar à morte do paciente, dando relevância para o reconhecimento precoce pelos pro-fissionais da etiologia hormonal de IC e/ou a causa de sua descompensação. Este diagnóstico permite o tratamento precoce e eficaz como os estados de eutireoidismo conduzir à normalização da doença cardiovascular na maioria dos pacientes.

Resistencia a Hormonas Tiroideas (RHT): Descripción de una nueva mutación / Resistance to Thyroid Hormones (RTH): Description of a new mutation

Introducción: La resistencia a hormonas tiroideas (RHT) es un desorden genético de transmisión dominante poco frecuente, caracterizado por una respuesta reducida de los tejidos blanco a las hormonas tiroideas. RHT está ligada al gen del receptor beta de hormona tiroidea (TRβ). El síndrome se identifica por niveles persistentemente elevados de T4 y T3 totales y libres en presencia de TSH no suprimida. Materiales y Métodos: Paciente femenina de 62 años de edad con antecedente de hemitiroidectomía a los 22 años por bocio. Clínicamente, la mujer se encontraba eutiroidea y hemodinámicamente estable. En los exámenes complementarios se constató la presencia de nódulo tiroideo, con estudio citológico benigno y en el laboratorio hormonas tiroideas totales y libres elevadas con TSH no suprimida. La impresión diagnóstica fue RHT, siendo el principal diagnóstico diferencial el tirotropinoma. Se realizó perfil tiroideo completo en el caso índice y en dos familiares de primer grado. Se dosaron gonadotropinas y prolactina, y se realizó RMN de hipófisis en el caso índice. Se estudiaron mutaciones del gen TRβ en ADN genómico en la paciente y en uno de sus familiares. Resultados: Avalando la impresión diagnóstica, tanto el caso índice como los dos familiares mostraron un perfil tiroideo compatible con RHT. El estudio genético identificó una nueva mutación en el exón 10: c.1339C>A que resulta en una sustitución p.P447T. La misma fue observada tanto en el caso índice como en el familiar estudiado. Conclusión: La historia de esta paciente con RHT, al igual que otros casos descriptos en la bibliografía, remarcan la importancia de un diagnóstico adecuado y temprano de esta patología poco frecuente para evitar conductas terapéuticas iatrogénicas y con consecuencias relevantes en la vida de estos pacientes. Paralelamente, se describe una nueva mutación genética en esta familia.

Introduction: Resistance to thyroid hormones (RTH) is an unusual autosomal dominant inherited disorder characterized by a reduced target organ responsiveness to thyroid hormones. RTH is linked to the gene encoding the thyroid receptor β (TR β). This syndrome is characterized by persistent high levels of total and free T4 and T3 while TSH is not inhibited. Materials and Methods: 62 years old female who underwent a partial thyroidectomy because of goiter forty years ago. Clinically, she seemed to be an euthyroid patient and her hemodynamic status was normal. The exams revealed the existence of a benign thyroid nodule, high levels of total and free thyroid hormones and normal values of TSH. Our diagnostic impression was RTH, though differential diagnosis with thyrotropin secreting pituitary adenoma was mandatory. Complete assays of thyroid hormones were performed in the patient and in two first degree relatives. Basal LH, FSH and prolactin were assayed in the patient; and a magnetic resonance imaging of her pituitary gland was obtained. Finally we performed genetic testing in patient's DNA and a relative's DNA to demonstrate gene defect. Results: According to our diagnostic impression, not only the patient's laboratory was compatible with RTH, but so was the laboratory of the two relatives. DNA mutation analisys demonstrated a new mutation in exon 10: c.1339C>A responsible for the substitution p.P447T. This mutation was found in DNA of the patient and DNA of her relative. Conclusion: This patient with RTH, as well as other reported cases, reminds us about the importance of a certain and early diagnosis of this rare disorder in order to avoid iatrogenic treatments. A new mutation is described in this family.