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1.
Theriogenology ; 142: 48-53, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31574400

RESUMO

Hypothyroidism is the most common endocrine disease in dogs and has been shown to have a hereditary nature in many breeds. Previous studies have documented decreased fertility in bitches with experimentally-induced hypothyroidism, decreased viability at birth, increased periparturient mortality, and reduced birth weight in pups born to hypothyroid dogs. Hypothyroid women have an increased demand for exogenous thyroxine throughout gestation in order to maintain normal plasma concentrations of thyroid hormones and produce neuropsychologically normal children. This study was performed to determine if pregnancy causes a similar need for increased levothyroxine dosages in dogs to maintain a euthyroid state. Serum was harvested from blood collected from six bitches with experimentally-induced hypothyroidism that were receiving standard thyroid hormone replacement therapy and from four euthyroid control bitches. Thyroid function tests performed on these samples included total thyroxine (T4), free T4 (fT4), thyroid stimulating hormone (TSH), and 3,5,3'-triiodothyronine (T3). Thyroid function tests were measured from ovulation through the end of pregnancy. All bitches whelped normal litters. Euthyroid bitches had no significant alterations in their hormone concentrations throughout pregnancy. None of the supplemented hypothyroid bitches had clinical signs of hypothyroidism throughout the study. Serum concentrations of T4 and fT4 were elevated compared to ovulation at multiple sample points during gestation in supplemented dogs. The results from this study indicate that standard levothyroxine supplementation is adequate to maintain a euthyroid state during pregnancy in experimentally-induced hypothyroid dogs. In addition, there is no evidence that canine thyroid profiles in euthyroid dogs are altered during gestation.


Assuntos
Doenças do Cão/tratamento farmacológico , Hipotireoidismo/veterinária , Prenhez , Tiroxina/uso terapêutico , Animais , Cães , Feminino , Hipotireoidismo/tratamento farmacológico , Gravidez , Tireotropina/sangue , Tiroxina/administração & dosagem , Tiroxina/sangue , Tri-Iodotironina/sangue
2.
Bol. pediatr ; 59(249): 181-187, 2020. graf
Artigo em Espanhol | IBECS | ID: ibc-190960

RESUMO

El hipotiroidismo subclínico es uno de los motivos de consulta más frecuentes en la consulta de Endocrinología Pediátrica y su manejo continúa siendo objeto de controversia. Ante un niño que presente una elevación aislada de TSH debemos tener presente que no siempre implica que presente una disfunción tiroidea y que se debe confirmar con una segunda determinación, ya que en más del 70% de los casos no se confirmará. Asimismo, deben descartarse interferencias analíticas, así como otras situaciones que pueden elevar la TSH de forma transitoria. En los casos persistentes está indicado el estudio etiológico, principalmente la determinación de anticuerpos antitiroideos y la realización de una ecografía. La mayoría de los casos el origen será idiopático o autoinmune. En general, el hipotiroidismo subclínico es una condición benigna, con bajo riesgo de evolución de hipotiroidismo franco, algo más elevado en los casos de origen autoinmune. El seguimiento de esos pacientes vendrá condicionado por la etiología y el riesgo de progresión a hipotiroidismo. Dado que no se ha demostrado que el hipotiroidismo subclínico afecte negativamente al crecimiento y tampoco al desarrollo cognitivo en mayores de 3 años, el tratamiento con levotiroxina no está justificado de forma rutinaria. En los últimos años algunos estudios han demostrado la relación entre el hipotiroidismo subclínico en niños y alteraciones proaterogénicas sutiles, pero existe controversia sobre si realmente se asocia a un riesgo aumentado de enfermedad cardiovascular en la edad adulta. Por otro lado, aunque el tratamiento con levotiroxina puede tener algún efecto beneficioso sobre dichas alteraciones, no está claro el impacto que puede tener a largo plazo


Subclinical hypothyroidism is one of the most frequent reasons in the medical visit in the Pediatric Endocrinology office and its management continues to be an object of controversy. When a child has a single isolated elevation of TSH it should be kept in mind that this does not always imply that there is a thyroid disorder and it should be verified with a second measurement, since it will not be confirmed in over 70% of the cases. Furthermore, analytic interferences should be ruled out as well as other situations that may cause a transitory increase in the TSH. The etiological study is indicated in persistent cases, mainly the measurement of antithyroid antibodies and an ultrasound. In most of the cases, the origin will be idiopathic or autoimmune. In general, subclinical hypothyroidism is a benign condition, with low risk of evolution to frank hypothyroidism, which is somewhat higher in the cases having an autoimmune origin. Follow-up of these patients will be conditioned by the etiology and risk of progression to hypothyroidism. Since it has not been demonstrated that subclinical hypothyroidism negatively affects growth or cognitive development in children over 3 years of age, treatment with levothyroxine is not routinely justified. In recent years, some studies have demonstrated the relationship between sub-clinical hypothyroidism in children and subtle peroatherogenic alterations, however there is existing controversy on whether it is associated to an increased risk of cardiovascular disease in the adult age. On the other hand, although treatment with levothyroxine may have a beneficial effect on said alterations, the impact it may have in the long term is not clear


Assuntos
Humanos , Lactente , Pré-Escolar , Criança , Adolescente , Tireotropina/análise , Hipotireoidismo/diagnóstico , Hipotireoidismo/tratamento farmacológico , Obesidade/complicações , Tiroxina/administração & dosagem , Antitireóideos/administração & dosagem , Doenças da Glândula Tireoide/etiologia , Prognóstico
3.
Trials ; 20(1): 742, 2019 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-31847914

RESUMO

BACKGROUND: The aging population is associated with increased multimorbidity and polypharmacy. Older adults are at a higher risk of adverse events and reduced therapeutic response. This phenomenon is partially explained by drug interactions and treatment adherence. Most randomized clinical trials have found no significant differences between morning and evening levothyroxine (LT4) administration in young adults, but there is little evidence regarding alternative LT4 regimens in older populations. Thus, the MONIALE trial aims to test an alternative schedule for LT4 administration in older adults. METHODS/DESIGN: This randomized crossover clinical trial will include participants aged 60 years or older with primary hypothyroidism. The trial groups will consist of morning LT4 intake (60 min before breakfast) or evening LT4 intake (60 min after supper). The primary outcome will be variation in serum thyrotropin (TSH) levels after 24 weeks of the LT4 protocol. The secondary outcomes will be the prevalence of drugs that potentially interact with LT4 and hypothyroidism control according to interaction status. The sample size was calculated to detect a minimum mean difference of 1 mUI/L in serum TSH level between the groups with 80% power and a 5% probability of type I error, resulting in 91 patients per group. The project was approved by the Hospital de Clínicas de Porto Alegre Ethics Committee. DISCUSSION: Considering the aging population, the increased prevalence of multimorbidity and polypharmacy, as well as potential drug interactions and treatment adherence difficulties, an alternative LT4 protocol could be useful for hypothyroidism treatment in the elderly. Prior studies comparing alternative LT4 administration protocols have mainly included young adult populations and have not addressed potential drug interactions. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03614988. Registered 30 July 2018.


Assuntos
Hipotireoidismo/tratamento farmacológico , Tiroxina/administração & dosagem , Idoso , Idoso de 80 Anos ou mais , Desjejum , Estudos Cross-Over , Esquema de Medicação , Interações Medicamentosas , Feminino , Humanos , Hipotireoidismo/sangue , Masculino , Refeições , Pessoa de Meia-Idade , Ensaios Clínicos Controlados Aleatórios como Assunto , Tireotropina/sangue
4.
Rev. Hosp. Ital. B. Aires (2004) ; 39(4): 149-152, dic. 2019. ilus
Artigo em Espanhol | LILACS | ID: biblio-1099849

RESUMO

La presencia de tejido tiroideo ectópico en la base de la lengua es muy infrecuente, y la mayoría de los pacientes tienen hipotiroidismo. La indicación de tratamiento depende de la presencia o no de síntomas; la cirugía es la primera elección. Diversas técnicas quirúrgicas han sido descriptas, pero para nosotros el abordaje transoral con endoscopios constituye la mejor opción, por la buena exposición y la mínima morbilidad que produce. Se describe el caso clínico de una mujer que consultó por odinofagia, con diagnóstico de tiroides lingual y que fue tratada con éxito mediante un abordaje transoral con asistencia de endoscopios. (AU)


The presence of ectopic thyroid tissue at the base of the tongue is very rare, and most patients have hypothyroidism. The indication of treatment depends on the presence or not of symptoms, surgery being the first choice. Various surgical techniques have been described, being for us the transoral approach with endoscopes the best option, due to the good exposure, and minimum morbidity that it produces. The clinical case of a woman who consulted for odynophagia, with a diagnosis of lingual thyroid and who was successfully treated by a transoral approach with endoscopic assistance is described. (AU)


Assuntos
Humanos , Feminino , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Operatórios/métodos , Neoplasias da Língua/cirurgia , Tireoide Lingual/cirurgia , Sinais e Sintomas , Procedimentos Cirúrgicos Operatórios/classificação , Tiroxina/administração & dosagem , Neoplasias da Língua/patologia , Neoplasias da Língua/diagnóstico por imagem , Enalapril/uso terapêutico , Faringite , Tireoide Lingual/fisiopatologia , Tireoide Lingual/terapia , Tireoide Lingual/epidemiologia , Tireoide Lingual/diagnóstico por imagem , Dispneia , Endoscopia/métodos , Hemorragia , Hipertensão/tratamento farmacológico , Hipotireoidismo/complicações
5.
Endocrine ; 66(1): 35-42, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31617164

RESUMO

Hypothyroidism is the most frequent pregnancy-related thyroid dysfunction, including overt and subclinical hypothyroidism. Studies show that even mild hypothyroidism may eventuate in adverse gestational outcomes and intellectual impairment of offspring. Women with overt hypothyroidism (OH) must be treated by levothyroxine (LT4) pre- and during pregnancy, however, it is controversial that when and how to initiate LT4 therapy and further optimize dosing so that pregnant women and their offspring may truly benefit. In the review we will analyze the changes in thyroid hormone requirements in pregnant women, the timing of LT4 treatment and adjustment of LT4 dose according to etiology in patients with hypothyroidism during pregnancy, and adjustment of LT4 after delivery.


Assuntos
Hipotireoidismo/tratamento farmacológico , Complicações na Gravidez/tratamento farmacológico , Tiroxina/administração & dosagem , Animais , Feminino , Humanos , Hipotireoidismo/diagnóstico , Hipotireoidismo/epidemiologia , Gravidez , Complicações na Gravidez/diagnóstico , Complicações na Gravidez/epidemiologia
6.
Endocrine ; 66(1): 70-78, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31617166

RESUMO

Guidelines on T4 + T3 combination therapy were published in 2012. This review investigates whether the issue is better understood 7 years later. Dissatisfaction with the outcome of T4 monotherapy remains high. Persistent symptoms consist mostly of fatigue, weight gain, problems with memory and thinking and mood disturbances. T4 monotherapy is associated with low serum T3 levels, which often require TSH-suppressive doses of L-T4 for normalization. Peripheral tissue thyroid function tests during T4 treatment indicate mild hyperthyroidism at TSH < 0.03 mU/L and mild hypothyroidism at TSH 0.3-5.0 mU/L; tissues are closest to euthyroidism at TSH 0.03-0.3 mU/L. This is explained by the finding that whereas T4 is usually ubiquinated and targeted for proteasomal degradation, hypothalamic T4 is rather stable and less sensitive to ubiquination. A normal serum TSH consequently does not necessarily indicate a euthyroid state. Persistent symptoms in L-T4 treated patients despite a normal serum TSH remain incompletely understood. One hypothesis is that a SNP (Thr92Ala) in DIO2 (required for local production of T3 out of T4) interferes with its kinetics and/or action, resulting in a local hypothyroid state in the brain. Effective treatment of persistent symptoms has not yet realized. One may try T4 + T3 combination treatment in selected patients as an experimental n = 1 study. The 2012 ETA guidelines are still valid for this purpose. More well-designed randomized clinical trials in selected patients are key in order to make progress. In the meantime the whole issue has become rather complicated by commercial and political overtones, as evident from skyrocketing prices of T3 tablets, aggressive pressure groups and motions in the House of Lords.


Assuntos
Hipotireoidismo/tratamento farmacológico , Tiroxina/administração & dosagem , Tri-Iodotironina/administração & dosagem , Quimioterapia Combinada , Terapia de Reposição Hormonal , Humanos
7.
Endocrine ; 66(1): 87-94, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31617168

RESUMO

Levothyroxine (T4) is a critical-dose drug, because little variations in the blood concentration may cause treatment failure as well as iatrogenic thyrotoxicosis. Despite the dose response of this drug being more carefully titrated nowadays, several papers still report that a significant fraction of patients treated with levothyroxine demonstrate a TSH which is not on target. Moreover, some widespread gastrointestinal disorders as well as interfering drugs and foods may cause the "refractoriness" of a significant number of patients to an expected dose of thyroxine. The increasing awareness of the mechanisms interfering with the oral thyroid hormone bioavailability and the body of evidence regarding the complexity of treatment in certain classes of patients prompted pharmaceutical research to identify new hormonal formulations to optimize the performance of this drug. In this brief review, the progression of the scientific knowledge of novel T4 formulations use has been analyzed.


Assuntos
Tiroxina/administração & dosagem , Formas de Dosagem , Humanos , Medicina de Precisão
8.
BMJ Case Rep ; 12(10)2019 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-31586959

RESUMO

Neuropsychiatric and muscular symptoms can develop as part of hypothyroidism. However, frank psychosis or rhabdomyolysis due to hypothyroidism are uncommon and have been reported rarely as the first presenting features of hypothyroidism. We report a case of a 44-year-old man who presented with a 2-week history of delusions, hallucinations and mild bilateral leg pain, without apparent signs of myxedema. Investigations revealed raised thyroid stimulation hormone >100 mIU/L and high creatine kinase >21 000 U/L. Diagnosis of hypothyroidism-induced psychosis and rhabdomyolysis was made. He received thyroxine, olanzapine and a short course of steroids. His symptoms improved after 2 weeks of treatment and he remained free of symptoms at 6 months of follow-up. To the best of our knowledge, this is the first case of concomitant psychosis and rhabdomyolysis leading to hypothyroidism diagnosis. This case highlights the importance of hypothyroidism screening when faced with unexplained psychosis or rhabdomyolysis, especially if combined.


Assuntos
Hipotireoidismo/diagnóstico , Transtornos Psicóticos/etiologia , Rabdomiólise/diagnóstico , Adulto , Diagnóstico Diferencial , Humanos , Hipotireoidismo/sangue , Hipotireoidismo/complicações , Hipotireoidismo/tratamento farmacológico , Masculino , Rabdomiólise/sangue , Rabdomiólise/complicações , Rabdomiólise/tratamento farmacológico , Tiroxina/administração & dosagem , Tiroxina/uso terapêutico
9.
BMJ ; 366: l4892, 2019 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-31481394

RESUMO

OBJECTIVE: To explore whether thyroid stimulating hormone (TSH) concentration in patients with a diagnosis of hypothyroidism is associated with increased all cause mortality and a higher risk of cardiovascular disease and fractures. DESIGN: Retrospective cohort study. SETTING: The Health Improvement Network (THIN), a database of electronic patient records from UK primary care. PARTICIPANTS: Adult patients with incident hypothyroidism from 1 January 1995 to 31 December 2017. EXPOSURE: TSH concentration in patients with hypothyroidism. MAIN OUTCOME MEASURES: Ischaemic heart disease, heart failure, stroke/transient ischaemic attack, atrial fibrillation, any fractures, fragility fractures, and mortality. Longitudinal TSH measurements from diagnosis to outcomes, study end, or loss to follow-up were collected. An extended Cox proportional hazards model with TSH considered as a time varying covariate was fitted for each outcome. RESULTS: 162 369 patients with hypothyroidism and 863 072 TSH measurements were included in the analysis. Compared with the reference TSH category (2-2.5 mIU/L), risk of ischaemic heart disease and heart failure increased at high TSH concentrations (>10 mIU/L) (hazard ratio 1.18 (95% confidence interval 1.02 to 1.38; P=0.03) and 1.42 (1.21 to 1.67; P<0.001), respectively). A protective effect for heart failure was seen at low TSH concentrations (hazard ratio 0.79 (0.64 to 0.99; P=0.04) for TSH <0.1 mIU/L and 0.76 (0.62 to 0.92; P=0.006) for 0.1-0.4 mIU/L). Increased mortality was observed in both the lowest and highest TSH categories (hazard ratio 1.18 (1.08 to 1.28; P<0.001), 1.29 (1.22 to 1.36; P<0.001), and 2.21 (2.07 to 2.36; P<0.001) for TSH <0.1 mIU/L, 4-10 mIU/L, and >10 mIU/L. An increase in the risk of fragility fractures was observed in patients in the highest TSH category (>10 mIU/L) (hazard ratio 1.15 (1.01 to 1.31; P=0.03)). CONCLUSIONS: In patients with a diagnosis of hypothyroidism, no evidence was found to suggest a clinically meaningful difference in the pattern of long term health outcomes (all cause mortality, atrial fibrillation, ischaemic heart disease, heart failure, stroke/transient ischaemic attack, fractures) when TSH concentrations were within recommended normal limits. Evidence was found for adverse health outcomes when TSH concentration is outside this range, particularly above the upper reference value.


Assuntos
Doenças Cardiovasculares/epidemiologia , Fraturas Ósseas/epidemiologia , Hipotireoidismo/tratamento farmacológico , Tireotropina/sangue , Tiroxina/administração & dosagem , Adulto , Idoso , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/prevenção & controle , Feminino , Fraturas Ósseas/etiologia , Fraturas Ósseas/prevenção & controle , Humanos , Hipotireoidismo/sangue , Hipotireoidismo/complicações , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Valores de Referência , Estudos Retrospectivos , Fatores de Risco , Glândula Tireoide/metabolismo , Tireotropina/metabolismo , Tireotropina/normas
10.
Horm Res Paediatr ; 92(1): 45-51, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31553976

RESUMO

BACKGROUND: Congenital hypothyroidism (CH) can be divided into 2 types, transient CH (T-CH) and permanent CH (P-CH), depending on the requirement of levothyroxine (LT4) for life-long treatment. Several studies have recently reported that the LT4 dosage is useful for predicting the LT4 requirement, but none of the studies followed their patients to puberty. OBJECTIVE: To determine the cutoff value for the LT4 dosage as a predictor of the LT4 requirement after puberty in patients with CH. METHODS: The LT4 dosage and clinical data on 99 patients with CH who were followed at the participating hospitals from the neonatal period to 15 years of age or older were retrospectively analyzed. Based on their LT4 requirement at their last hospital visit, the participants were divided into the P-CH group (n = 75), who were treated with LT4, and the T-CH group (n = 24), who were not. RESULTS: At age 1 year, a higher LT4 dosage was required for the P-CH group (median 3.75 vs. 2.88 µg/kg/day; p < 0.001). When the LT4 dosage cutoff value at age 1 year was set at 4.79 and 1.74 µg/kg/day, the specificity of P-CH and T-CH (for denying T-CH and P-CH, respectively) was 100 and 97%, respectively. CONCLUSIONS: An LT4 dosage above 4.7 µg/kg/day and below 1.8 µg/kg/day at age 1 year may help predict P-CH and T-CH, respectively.


Assuntos
Hipotireoidismo Congênito/tratamento farmacológico , Tiroxina/administração & dosagem , Adolescente , Criança , Pré-Escolar , Hipotireoidismo Congênito/sangue , Hipotireoidismo Congênito/diagnóstico , Hipotireoidismo Congênito/epidemiologia , Feminino , Seguimentos , Humanos , Lactente , Recém-Nascido , Japão/epidemiologia , Masculino , Estudos Retrospectivos
11.
BMJ Case Rep ; 12(8)2019 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-31413055

RESUMO

A 79-year-old man, who had significant cardiovascular morbidities, presented with out-of-hospital respiratory arrest. He regained breathing after brief cardiopulmonary resuscitation by his paramedic son. After meticulous investigations, acute cardiovascular events and metabolic causes were ruled out while features of obstructive sleep apnoea were elicited. The findings on in-laboratory polysomnography were compatible with severe obstructive sleep apnoea, with unusually prolonged apnoea duration of up to 2.7 min which most likely accounts for the presentation as 'respiratory arrest'. Thyroid function test for investigation of his weight gain confirmed hypothyroidism. His symptoms improved gradually after positive airway pressure therapy with bi-level support and thyroxine replacement. On further evaluation, his hypothyroidism is believed to be a complication of long-term amiodarone exposure. The case highlights that the combination of obstructive sleep apnoea and hypothyroidism can lead to catastrophic manifestation and the unusually long apnoea could be a feature prompting further workup for possible hypothyroidism.


Assuntos
Hipotireoidismo/diagnóstico , Insuficiência Respiratória/diagnóstico , Apneia Obstrutiva do Sono/diagnóstico , Idoso , Reanimação Cardiopulmonar , Pressão Positiva Contínua nas Vias Aéreas , Diagnóstico Diferencial , Humanos , Hipotireoidismo/complicações , Hipotireoidismo/tratamento farmacológico , Masculino , Polissonografia , Insuficiência Respiratória/complicações , Insuficiência Respiratória/terapia , Apneia Obstrutiva do Sono/complicações , Apneia Obstrutiva do Sono/terapia , Tiroxina/administração & dosagem , Tiroxina/uso terapêutico
12.
BMJ Case Rep ; 12(8)2019 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-31434663

RESUMO

A 53-year-old woman was admitted with thyroid storm and severe behavioural problems. She had longstanding bipolar affective disorder. She was psychotic and obstructed in-patient medical management for thyroid storm. She required one-to-one psychiatric nursing and was placed under section 3 of the Mental Health Act meaning she could be detained in hospital for psychiatric treatment for up to 6 months. She underwent a total thyroidectomy. Due to her paranoid mental state, she refused treatment and the administration of thyroid hormone replacement was difficult. Postoperatively, intramuscular levothyroxine was used effectively to stabilise her thyroid function. There are no consensus guidelines on the use of parenteral levothyroxine and intramuscular levothyroxine is rarely used. This case uniquely illustrates its utility with bi-weekly blood tests showing a fast and stable response to intramuscular hormone replacement.


Assuntos
Transtorno Bipolar/fisiopatologia , Transtornos Mentais/fisiopatologia , Crise Tireóidea/cirurgia , Tireoidectomia , Tiroxina/administração & dosagem , Feminino , Terapia de Reposição Hormonal , Humanos , Injeções Intramusculares , Serviços de Saúde Mental , Pessoa de Meia-Idade , Guias de Prática Clínica como Assunto , Crise Tireóidea/fisiopatologia , Resultado do Tratamento
13.
BMJ Case Rep ; 12(8)2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31420436

RESUMO

Fetal goitrous hypothyroidism is a rare entity and is caused mainly by maternal treatment of Graves' disease (GD). We report a case of a 22-year-old woman referred at 12 weeks of gestation due to hyperthyroidism subsequent to recently diagnosed GD. She started treatment with propylthiouracil and, at 21 weeks of gestation, fetal goitre was detected. A cordocentesis confirmed the diagnosis of fetal goitrous hypothyroidism, and intra-amniotic administration of levothyroxine (LT4) was performed and repeated through the pregnancy due to maintenance of fetal goitre. The pregnancy proceeded without further complications and a healthy female infant was born at 37 weeks of gestation, with visible goitre and thyroid function within the normal range at birth. Although there is no consensus on the optimal dose, the number of injections and the interval between them, intra-amniotic LT4 administration is recommended once fetal goitrous hypothyroidism is suspected, in order to prevent long-term complications of fetal hypothyroidism.


Assuntos
Doenças Fetais/tratamento farmacológico , Bócio/tratamento farmacológico , Doença de Graves/tratamento farmacológico , Hipotireoidismo/tratamento farmacológico , Tiroxina/administração & dosagem , Vias de Administração de Medicamentos , Feminino , Bócio/embriologia , Bócio/etiologia , Doença de Graves/complicações , Doença de Graves/embriologia , Humanos , Hipotireoidismo/embriologia , Hipotireoidismo/etiologia
14.
BMJ Case Rep ; 12(8)2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31439564

RESUMO

A 56-year-old woman with a history of hypothyroidism and chronic constipation presented with an acute abdomen due to colonic pseudo-obstruction. Thyroid function tests were consistent with central hypothyroidism prompting intravenous administration of stress-dose glucocorticoids and levothyroxine. The patient then underwent emergency exploratory laparotomy with sigmoid resection and end-colostomy. The postoperative endocrine evaluation revealed that the patient had panhypopituitarism due to Sheehan's syndrome (SS). The diagnosis had been missed by physicians who had been treating her for several years for presumed primary hypothyroidism with a low dose of levothyroxine, aimed at normalising a minimally elevated thyroid-stimulating hormone (TSH) level. This is the second reported case of SS presenting with colonic pseudo-obstruction and it illustrates the potential danger of relying on measurement of TSH alone in the evaluation and treatment of thyroid dysfunction.


Assuntos
Pseudo-Obstrução do Colo/diagnóstico , Hipopituitarismo/diagnóstico , Pseudo-Obstrução do Colo/complicações , Pseudo-Obstrução do Colo/diagnóstico por imagem , Pseudo-Obstrução do Colo/cirurgia , Diagnóstico Diferencial , Feminino , Humanos , Hipopituitarismo/sangue , Hipopituitarismo/complicações , Hipopituitarismo/tratamento farmacológico , Pessoa de Meia-Idade , Tiroxina/administração & dosagem , Tiroxina/uso terapêutico , Tomografia Computadorizada por Raios X
15.
BMJ Case Rep ; 12(8)2019 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-31401581

RESUMO

In patients with substituted hypothyroidism, laparoscopic sleeve gastrectomy may interfere with thyroid balance by varying body weight or by altering the absorption of hormone therapy. A 58-year-old female patient presented with a major thyroid imbalance after sleeve gastrectomy, manifesting itself in large-scale changes in thyroid stimulating hormone (TSH) levels. The transition from a tablet treatment to a liquid form alleviated burden of treatment, unfortunately without normalising TSH. Our case emphasises the importance of the understanding of hypothalamic-pituitary-thyroid feedback control mechanisms together with good galenic choice, management of associated conditions and the elimination of other causes of variations of TSH levels during the management of hypothyroid patients after sleeve gastrectomy.


Assuntos
Gastrectomia/efeitos adversos , Derivação Gástrica/efeitos adversos , Hipotireoidismo/tratamento farmacológico , Tiroxina/administração & dosagem , Relação Dose-Resposta a Droga , Feminino , Terapia de Reposição Hormonal/métodos , Humanos , Hipotireoidismo/sangue , Pessoa de Meia-Idade , Obesidade Mórbida/cirurgia , Tireotropina/sangue , Tiroxina/sangue
16.
Poult Sci ; 98(12): 7003-7008, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31287884

RESUMO

Published data on the beneficial effect of short-term administration of thyroxine (T4) in broiler breeder hens to reduce the ascites incidence in their progeny chicks raises the question as to what extent might the long-term maternal administration of T4 affect the blood hematological and biochemical attributes in breeder hens. A total of 70 broiler breeder hens (47-wk-old) were randomly allotted to control or thyroxine treated (T4) groups. Pure T4 (0.3 mg/bird per day) was orally administered to T4 birds for 14 successive weeks, whereas the control group received the drinking water only. Blood samples were obtained from the brachial vein prior to the initiation of the trial as well as weeks 50, 53, 55, 57, 59, and 61 of age. Body weight was decreased but egg production was not affected by T4 treatment. Plasma concentration of T4, but not triiodothyronine (T3), was increased in T4-treated hens (P < 0.05). The total number of leukocytes and erythrocytes were also higher in T4 birds. A significant effect of time was observed for erythrocyte number and plasma cholesterol concentration (P < 0.05). The long-term administration of T4 did not affect the concentrations of serum calcium and plasma total protein, albumin, globulin, cholesterol, triglyceride, high density lipoprotein, low density lipoprotein, very low density lipoprotein, alanine amino transferase, and aspartate amino transferase (P > 0.05). However, serum concentrations of phosphorus, glucose, and alkaline phosphatase were higher in T4 hens as compared to their control counterparts. In spite of differences in circulatory concentrations of a number of traits between the experimental groups, the recorded values were within their reference ranges. Therefore, the administration of T4 for an extended period of time had no apparent adverse effect on the clinical profile in subjected hens, which may practically support the implementation of this preventative treatment as an approach to decrease the ascites incidence; however, a lower incidence rate in the progeny chicks produced from hens receiving T4 for long-term periods of time remains to be elucidated.


Assuntos
Galinhas/sangue , Tiroxina/farmacologia , Animais , Galinhas/fisiologia , Esquema de Medicação , Feminino , Hipertireoidismo/induzido quimicamente , Hipertireoidismo/veterinária , Oviposição/efeitos dos fármacos , Oviposição/fisiologia , Tiroxina/administração & dosagem
17.
J Surg Res ; 244: 102-106, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31279993

RESUMO

BACKGROUND: After thyroidectomy, patients require Levothyroxine (LT4). It may take years of dose adjustments to achieve euthyroidism. During this time, patients encounter undesirable symptoms associated with hypo- or hyper-thyroidism. Currently, providers adjust LT4 dose by clinical estimation, and no algorithm exists. The objective of this study was to build a decision tree that could estimate LT4 dose adjustments and reduce the time to euthyroidism. METHODS: We performed a retrospective cohort analysis on 320 patients who underwent total or completion thyroidectomy at our institution. All patients required one or more LT4 dose adjustments from their initial postoperative dose before attaining euthyroidism. Using the Classification and Regression Tree algorithm, we built various decision trees from patient characteristics, estimating the dose adjustment to reach euthyroidism. RESULTS: The most accurate decision tree used thyroid-stimulating hormone values at first dose adjustment (mean absolute error = 13.0 µg). In comparison, the expert provider and naïve system had a mean absolute error of 11.7 µg and 17.2 µg, respectively. In the evaluation dataset, the decision tree correctly predicted the dose adjustment within the smallest LT4 dose increment (12.5 µg) 79 of 106 times (75%, confidence interval = 65%-82%). In comparison, expert provider estimation correctly predicted the dose adjustment 76 of 106 times (72%, confidence interval = 62%-80%). CONCLUSIONS: A decision tree predicts the correct LT4 dose adjustment with an accuracy exceeding that of a completely naïve system and comparable to that of an expert provider. It can assist providers inexperienced with LT4 dose adjustment.


Assuntos
Árvores de Decisões , Cálculos da Dosagem de Medicamento , Terapia de Reposição Hormonal/métodos , Tireoidectomia/efeitos adversos , Tiroxina/administração & dosagem , Adulto , Idoso , Feminino , Humanos , Hipertireoxinemia/sangue , Hipertireoxinemia/etiologia , Hipertireoxinemia/prevenção & controle , Hipotireoidismo/sangue , Hipotireoidismo/tratamento farmacológico , Hipotireoidismo/etiologia , Aprendizado de Máquina , Masculino , Pessoa de Meia-Idade , Cuidados Pós-Operatórios/métodos , Estudos Retrospectivos , Tireotropina/sangue , Tiroxina/efeitos adversos
18.
Oxid Med Cell Longev ; 2019: 7471890, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31281590

RESUMO

Hyperthyroidism is an endocrine disorder characterized by excessive secretion of thyroid hormones T3 and T4. Thyroid hormones exert pleiotropic actions on numerous tissues and induce an overall increase in metabolism, with an increase in energy demand and oxygen consumption. Therefore, the purpose of this study was to investigate the effects of hyperthyroidism on the production of reactive oxygen species (ROS) in lymph node and spleen cells of euthyroid and hyperthyroid mice, analyzing antioxidant mechanisms involved in the restitution of the cellular redox state. For this, thirty female Balb/c (H-2d) mice were randomly divided into two groups: euthyroid (by treatment with placebo) and hyperthyroid (by treatment with 12 mg/l of T4 in drinking water for 30 days). We found a significant increase in ROS and an increase in the genomic and protein expression of the antioxidant enzymes catalase (CAT) and glutathione peroxidase-1 (GPx-1) in lymph node and spleen cells of hyperthyroid mice. In vitro treatment with H2O2 (250 µM) of the lymphoid cells of euthyroid mice increased the expression levels of CAT and GPx-1. The hyperthyroidism increased the phosphorylation levels of Nrf2 (nuclear factor erythroid 2-related factor) and the kinase activity of protein kinase C (PKC) and extracellular signal-regulated kinase (ERK). Additionally, we found an increase in the expression of the classic isoenzymes of PKCα, ß and γ. In conclusion, these results indicated that the increase in ROS found in the hyperthyroid state induces the antioxidant enzyme transcription through the activation of the Nrf-2 factor in lymphoid tissues. This shows the influence of hyperthyroidism on the regulation of the cellular antioxidant system.


Assuntos
Catalase/genética , Glutationa Peroxidase/genética , Hipertireoidismo/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo/fisiologia , Superóxido Dismutase-1/genética , Animais , Catalase/biossíntese , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Feminino , Glutationa Peroxidase/biossíntese , Hipertireoidismo/sangue , Hipertireoidismo/enzimologia , Hipertireoidismo/genética , Tecido Linfoide/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Fator 2 Relacionado a NF-E2/genética , Proteína Quinase C/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase-1/biossíntese , Tireotropina/sangue , Tiroxina/administração & dosagem , Tiroxina/sangue , Ativação Transcricional , Tri-Iodotironina/sangue
19.
Endocrine ; 66(1): 10-17, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31321670

RESUMO

Hypothyroidism is one of the most common endocrine disorders, affecting as much as 10% of the global population. There is a rich cultural milieu of treatment history and interventions dating as far back as 2 millennia. Chinese cretins were treated with sheep thyroid in the 6th century. In 1890, transplanted animal thyroid tissue resulted in a prompt clinical response in a myxedematous patient, and in 1891 injections of sheep thyroid were reported. One year later, the oral administration of fresh sheep thyroid glands was noted to be effective. Within a few years, the danger of over-dosage with extracts was recognized and dosing guidance indicated a low dose start and gradual increase as required based on symptoms. Orally ingested extracts became widespread and by 1914 thyroxine had been crystallized. In 1927, thyroxine, was synthesized as an acid, limiting oral absorption. Finally a sodium salt of thyroxine was introduced in 1949. These synthetic preparations were then made available for clinical use. Prior to 1970, extracts and combination therapy with synthetic LT4 and LT3 were standard replacement until the peripheral deiodinase-mediated T4 to T3 conversion documented the endogenous generation of T3 from LT4 in athyreotic subjects. This resulted in advocacy for patients previously treated with combinations and desiccated thyroid be transitioned to L-thyroxine monotherapy. The determination of the optimal dose has evolved such that now a general recommendation for replacement dosage of LT4 is 1.6-1.7 mcg/kg/day. Thyroid hormone extracts were established prior to the FDA's establishment in 1906, and when the Food, Drug, and Cosmetic act of 1938 enhanced the FDA's regulatory authority. In 1997, FDA declared LT4 products to be new drugs subject to regulation and quickly a pharmacokinetic process to determine interchangeability among approved LT4 products ensued. Differences in bioavailability of 12.5% or more may be considered therapeutically equivalent and therefore such products interchangeable. To assure refill to refill consistency, all levothyroxine sodium products now meet a 95-105% potency specification throughout their labeled shelf-lives. Seventy years after Kendall's great achievement in isolating thyroxine, we have thyroxine products with precise amounts of synthetic hormone that meet demanding regulations to assure high product quality, predictable bioavailability given its narrow therapeutic range, and now are left with potential variance in the therapeutic efficacy among different preparations.


Assuntos
Endocrinologia/história , Hipotireoidismo/tratamento farmacológico , Tiroxina/administração & dosagem , História do Século XIX , História do Século XX , História do Século XXI , Humanos , Testes de Função Tireóidea , Estados Unidos , United States Food and Drug Administration
20.
BMC Pregnancy Childbirth ; 19(1): 232, 2019 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-31277608

RESUMO

BACKGROUND: We examined whether inferior thyroid artery peak systolic velocity (ITA-PSV) predicts an increase in levothyroxine (LT4) dosage in pregnant women with Hashimoto's thyroiditis. METHODS: Twenty-two women with Hashimoto's thyroiditis who were planning and later achieved pregnancy or confirmed as pregnant were enrolled in this retrospective longitudinal observational study. ITA-PSV and thyroid volume were measured using ultrasonography. Serum concentrations of free thyroxine (F-T4), free triiodothyronine (F-T3), and thyroid stimulating hormone (TSH) were simultaneously determined. We adjusted LT4 dosage to maintain serum TSH at < 2.5 µIU/mL (1st trimester) and later at < 3 µIU/mL (2nd, 3rd trimester). RESULTS: Eighteen patients (81.8%) required an increase in LT4 dosage during pregnancy, of whom 7 (31.8%) required an increase ≥50 µg. Multivariable regression analysis showed that TSH (ß = 0.507, p = 0.008) and ITA-PSV (ß = - 0.362, p = 0.047), but not thyroid volume, F-T4, or F-T3, were independently associated with increased LT4 dosage. Receiver-operating characteristic analysis for predicting an increase in LT4 ≥ 50 µg/day showed that the area under the curve (0.905) for ITA-PSV with TSH was not significantly increased (p = 0.123) as compared to that (0.743) for TSH alone, whereas integrated discrimination improvement was significantly increased (27.9%, p = 0.009). CONCLUSIONS: In pregnant patients with Hashimoto's thyroiditis, ITA-PSV was a significant predictor of increase in LT4 dosage independent of TSH level, while ITA-PSV plus TSH showed significantly improved predictability as compared to TSH alone. These results suggest that ITA-PSV reflects residual thyroid function and is useful for evaluating the need for increased thyroid hormone production in pregnant patients with Hashimoto's thyroiditis.


Assuntos
Monitoramento de Medicamentos/métodos , Doença de Hashimoto/tratamento farmacológico , Complicações na Gravidez/tratamento farmacológico , Cuidado Pré-Natal/métodos , Glândula Tireoide/fisiopatologia , Tiroxina/administração & dosagem , Adulto , Biomarcadores/sangue , Velocidade do Fluxo Sanguíneo , Relação Dose-Resposta a Droga , Esquema de Medicação , Feminino , Doença de Hashimoto/sangue , Doença de Hashimoto/fisiopatologia , Humanos , Estudos Longitudinais , Gravidez , Complicações na Gravidez/sangue , Complicações na Gravidez/fisiopatologia , Curva ROC , Estudos Retrospectivos , Glândula Tireoide/irrigação sanguínea , Glândula Tireoide/diagnóstico por imagem , Tiroxina/uso terapêutico , Ultrassonografia
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