Disfunción tiroidea y corazón / Thyroid dysfunction and heart

Los trastornos de la función tiroidea afectan profundamente al sistema cardiovascular. En esta revisión se presentan algunos aspectos fisiológicos de la interrelación entre tiroides y corazón, como también las consecuencias de la tirotoxicosis e hipotiroidismo sobre el aparato cardiovascular. Se analiza la influencia del hipertiroidismo en la gèc)nesis de la fibrilación auricular y del hipotiroidismo en el metabolismo de las lipoproteínas. Adicionalmente, el artículo se referirá a los potenciales efectos adversos del antiarrítmico amiodarona sobre la función tiroidea y cómo se investigan y tratan. Finalmente, se expone un caso clínico real para ilustrar con mayor claridad la enorme importancia que pueden alcanzar las relaciones fisiopatológicas entre el corazón y las afecciones de esta glándula endocrina.

Disorders of thyroid function profoundly affect the cardiovascular system. Inthisreviewsomephysiologicalaspectsoftherelationship between thyroid and the heart as well as the consequences of thyrotoxicosis and hypothyroidism on the cardiovascular system are presented. The influence of hyperthyroidism is analyzed in the genesis of atrial fibrillation and of hypothyroidism on lipoprotein metabolism. Furthermore, we refer to the potential adverse effects of the antiarrhythmic amiodarone on thyroid function and how they are investigated and treated. Finally, a real clinical case is exposed to more clearly illustrate the enormous importance that can reach the pathophysiological relationships between the heart and the diseases of the thyroid gland.

The multiple effects of thyroid disorders on bone and mineral metabolism / Os múltiplos efeitos das disfunções tireoidianas sobre o metabolismo osteomineral

Differently from most hormones, which commonly are specialized molecules able to influence other cells, tissues and systems, thyroid hormones (TH) are pleiotropic peptides, whose primordial function is difficult to identify. The complex action of TH on human economy can be easily witnessed by examining the diverse consequences of TH excess and deficiency during development and after maturity. In particular, different manifestations in bone modeling and remodeling reflect the circumstantial consequences of thyroid disturbances, which are age dependent. While hyperthyroidism during childhood enhances bone mineralization and accelerates epiphyseal maturation, in adults it induces bone loss by predominant activation of osteoclast activity. Furthermore, the syndrome of TH resistance is a multifaceted condition in which different sites exhibit signs of hormone excess or deficiency depending on the configuration of the TH receptor isoform. The investigation of the impact of TH resistance on the skeleton still remains to be elucidated. We present here a thorough review of the action of TH on bone and of the impact of thyroid disorders, including hyper- and hypothyroidism and the syndrome of TH resistance, on the skeleton.

Diferentemente da maioria dos hormônios, que usualmente são moléculas especializadas capazes de influenciar outras células, tecidos e sistemas, os hormônios da tireoide (HT) são peptídeos pleiotrópicos, cuja função primordial é difícil de identificar. A ação complexa dos HT na fisiologia humana pode ser facilmente reconhecida ao observar as diversas consequências do excesso e da deficiência de HT durante e após o pleno desenvolvimento. Em particular as diferentes manifestações na modelação e remodelação óssea refletem que as consequências esqueléticas das disfunções tireoidianas dependem das circunstâncias e variam com a idade. Enquanto o hipertireoidismo durante a infância aumenta a mineralização óssea e acelera a maturação epifisária, em adultos induz a perda óssea pela ativação predominante da ação osteoclástica. Além disso, a síndrome de resistência ao HT é uma condição multifacetada na qual diferentes tecidos apresentam sinais de excesso ou deficiência hormonal, dependendo da predominância da expressão das diversas isoformas do receptor de HT. O impacto da resistência ao HT sobre o esqueleto ainda é motivo de investigação. Apresentamos aqui uma revisão abrangente sobre as ações ósseas dos HT e o impacto no esqueleto dos distúrbios da tireoide, incluindo hipo e hipertireoidismo e síndrome de resistência ao HT.

Thyroid malignancy association with cortical & subcortical brain SPECT changes in patients presenting with a myalgic encephalomyelitis/chronic fatigue syndrome

Thyroid malignancy in ME/CFS patients greatly exceeds the normal incidence of thyroid malignancy in any known subgroup. The thyroid malignancy incidence in the ME/CFS group may exceed 6,000 / 100,000. As part of their investigation, Myalgic Encephalomyelitis / Chronic Fatigue Syndrome (ME/CFS) patients should be examined by thyroid ultrasound for evidence of thyroid pathology and malignancy. Thyroid pathology may be missed in this group of patients if investigation relies only upon serum testing for TSH, FT3, FT4, microsomal and thyroglobulin antibodies, which are usually normal. Thyroid uptake scans tend also to be normal and may also miss malignant lesions. A newly recognized syndrome may exist in ME/CFS patients characterized by: (a) thyroid malignancy, (b) persistent abnormal cortical and subcortical SPECT brain scans (NeuroSPECT), (c) failure of thyroidectomy surgery and hormone replacement to correct the fatigue syndrome, and (d) an unusual high incidence of cervical vertebrae osteoarthritic changes. ME/CFS patients with treated non-malignant thyroid disease and abnormal NeuroSPECT scans may also fail to improve despite adequate thyroid hormone replacement. A brief summary of the differences between ME and CFS is discussed. Lee, Hur and Ahn [1] stated that thyroid malignancy is said to be an infrequent occurrence found in 0.5 to 3 patients per 100,000 in the general population. They noted that in a subgroup of patients booked for mammography, a thyroid ultrasound was also performed. In this group, they found thyroid malignancy frequency was as high as 3 per 100,000. It is not known if their subgroup was at a higher risk for malignancy. Mittelstaedt [2] in the Globe and Mail states that thyroid malignancy was 15 per 100,000. In the past 100 patients whom I have investigated for (ME/CFS)[3], with or without associated Fibromyalgia Syndrome (FS)...

A relação entre a função tireoidiana e a depressão: uma revisão / The relation between thyroid function and depression: a review

OBJETIVO: O papel da função tireoidiana nas doenças depressivas é pouco claro. Embora existam algumas evidências de que discretas alterações tireoidianas predisponham a casos de depressão, as anormalidades específicas envolvendo a tireóide e os quadros depressivos permanecem pouco conhecidas. Serão destacados nesta revisão os principais achados envolvendo os quadros depressivos e a função tireoidiana, com especial atenção na participação das monoaminas cerebrais nesta relação. MÉTODO: Foram realizados levantamento no sistema Medline e na literatura. RESULTADOS: Existem evidências de atividade alterada do eixo hipotálamo-hipófise-tireóide (HHT) em alguns casos de depressão, que incluem: aumento dos níveis de T4, resposta alterada do TSH pós-estímulo com TRH, presença de anticorpos antitireoidianos e concentração elevada de TRH no LCR. A relação entre estas anormalidades, as principais monoaminas cerebrais e os subtipos de quadros depressivos é complexa e ainda não permite o estabelecimento de hipóteses diretas de compreensão. CONCLUSÕES: Após anos de pesquisas, permanece pouco esclarecida a importância da relação entre o eixo HHT e as depressões, assim como os mecanismos subjacentes às alterações tireoidianas encontradas nos pacientes deprimidos. Portanto, mais pesquisas serão necessárias para uma melhor compreensão do papel do eixo HHT na patogênese e no tratamento dos quadros depressivos.

Fra-1 Expression in Malignant and Benign Thyroid Tumor

BACKGROUND: The differential diagnosis of thyroid nodules is very important in deciding the treatment modality and the fine needle aspiration is the best diagnostic method. But, there are some limitations in use because of inadequate test materials and difficulty in interpreting. According to the study of oncogene and tumor suppressor gene about the origin of thyroid tumor, expression of Fra-1, one of AP-1 complex, is increased in thyroid neoplasm, though not present in the normal tissue. So, there is a possibility that it will be used as a method for the differential diagnosis of thyroid nodules. We tried to know whether presence or absence of Fra-1 expression can be used as a diagnostic method in differential diagnosis of thyroid nodules using the immunohistochemical (IHC) staining method. METHOD: In 4 types of thyroid tumor that were confirmed by histologic diagnosis after operation (18 cases of adenomatous goiter, 16 cases of follicular adenoma, 30 cases of papillary cancer, 10 cases of follicular cancer), IHC staining method was performed to evaluate the expression of Fra-1. RESULT: In papillary and follicular thyroid cancers, the expression of Fra-1 was stronger than in benign thyroid tumor, but there was no difference in Fra-1 expression between the two types of carcinoma. Weak expression of Fra-1 was observed in all cases of follicular adenoma, though it was weaker than in carcinoma, and it was also weakly expressed only in some cases (33%) of adenomatous goiter. CONCLUSION: The expression of Fra-1 was stronger in thyroid cancer than in benign thyroid tumor, but it was impossible to differentiate thyroid cancer from benign thyroid tumor by presence or absence of Fra-1 expression using IHC staining method.

Evaluation of a new direct radioimmunoassay for serum thyroid peroxidase and thyroglobulin antibodies.

The measurement of serum TPO Ab and Tg Ab by a new direct sensitive RIA in this study are quantitative and provided a convenient system. When compared to the commonly used PH technique for TM Ab and Tg Ab, this RIA determination appears to be more sensitive than by PH, since it enabled detection of TPO Ab and/or Tg Ab in sera that were negative by PH. Thus, this RIA determination should be more widely used in a clinical laboratory.