Thyroid hormones and cardiovascular disease

Abstract

Myocardial and vascular endothelial tissues have receptors for thyroid hormones and are sensitive to changes in the concentrations of circulating thyroid hormones. The importance of thyroid hormones in maintaining cardiovascular homeostasis can be deduced from clinical and experimental data showing that even subtle changes in thyroid hormone concentrations - such as those observed in subclinical hypothyroidism or hyperthyroidism, and low triiodothyronine syndrome - adversely influence the cardiovascular system. Some potential mechanisms linking the two conditions are dyslipidaemia, endothelial dysfunction, blood pressure changes, and direct effects of thyroid hormones on the myocardium. Several interventional trials showed that treatment of subclinical thyroid diseases improves cardiovascular risk factors, which implies potential benefits for reducing cardiovascular events. Over the past 2 decades, accumulating evidence supports the association between abnormal thyroid function at the time of an acute myocardial infarction (MI) and subsequent adverse cardiovascular outcomes. Furthermore, experimental studies showed that thyroid hormones can have an important therapeutic role in reducing infarct size and improving myocardial function after acute MI. In this Review, we summarize the literature on thyroid function in cardiovascular diseases, both as a risk factor as well as in the setting of cardiovascular diseases such as heart failure or acute MI, and outline the effect of thyroid hormone replacement therapy for reducing the risk of cardiovascular disease.

Hypothyroidism and the Heart

“…Though the mechanism is unclear, increased capillary permeability and reduced lymphatic drainage from the pericardial space have been suggested. 4 Hypothyroidism can also be associated with a decrease in insulin sensitivity due to downregulation of glucose transporters and direct effects on insulin secretion and clearance. …”

Funkcjonowanie seksualne i objawy depresyjne u młodych mężczyzn z niedoczynnością tarczycy leczonych terapią skojarzoną z zastosowaniem lewotyroksyny i liotyroniny

“…This may suggest that discrete abnormalities in the production and/or metabolism of hormones playing a role in the regulation of sexual functioning secondary to tissue hypothyroidism may, at least partially, explain the beneficial effect of levothyroxine/liothyronine combination therapy in our study. In line with this hypothesis, hypothyroid rats were characterised by a decreased number and impaired morphology of Leydig cells [25], while thyroid hormone supplementation increased testicular testosterone production [25,26]. Certainly, it cannot be ruled out that impaired desire may be a consequence of an effect on cardiovascular homeostasis and/or on nervous regulation of the sexual response [27,28].…”

“…Higher total scores indicate more severe depressive symptoms. Based on the overall BDI-II score, depressive symptoms are classified as minimal (0-13), mild (14)(15)(16)(17)(18)(19), moderate (20)(21)(22)(23)(24)(25)(26)(27)(28), or severe (29-63) [16].…”

The central hemodynamics assessment methods in thyrotoxicosis patients under inhaled anesthesia

“…Вираженість порушень серцево-судинної системи безпосередньо залежить від важкості тиреотоксикозу. Некомпенсо-ваний тиреотоксикоз не тільки погіршує якість жит-тя пацієнтів, але і значно підвищує ризик виконання операції, що дозволяє вважати його протипоказан-ням до плановому оперативному втручанню [5] і є підставою для обов'язкового проведення цілеспря-мованої допераційної підготовки. Згідно сучасних рекомендацій, немає підстав вважати, що оперативні втручання повинні бути відстрочені у пацієнтів з субклінічним гіпертиреозом [6] Серед засобів ане-стезіологічного забезпечення може бути використані різні методи місцевої та загальної анестезії з інту-бацією трахеї, що наведено в сучасній літературі [7].…”