scholarly journals The impact of thyroid hormone dysfunction on ischemic heart disease

2019 ◽  
Vol 8 (5) ◽  
pp. R76-R90 ◽  
Author(s):  
Madalena von Hafe ◽  
João Sergio Neves ◽  
Catarina Vale ◽  
Marta Borges-Canha ◽  
Adelino Leite-Moreira

Thyroid hormones have a central role in cardiovascular homeostasis. In myocardium, these hormones stimulate both diastolic myocardial relaxation and systolic myocardial contraction, have a pro-angiogenic effect and an important role in extracellular matrix maintenance. Thyroid hormones modulate cardiac mitochondrial function. Dysfunction of thyroid axis impairs myocardial bioenergetic status. Both overt and subclinical hypothyroidism are associated with a higher incidence of coronary events and an increased risk of heart failure progression. Endothelial function is also impaired in hypothyroid state, with decreased nitric oxide-mediated vascular relaxation. In heart disease, particularly in ischemic heart disease, abnormalities in thyroid hormone levels are common and are an important factor to be considered. In fact, low thyroid hormone levels should be interpreted as a cardiovascular risk factor. Regarding ischemic heart disease, during the late post-myocardial infarction period, thyroid hormones modulate left ventricular structure, function and geometry. Dysfunction of thyroid axis might even be more prevalent in the referred condition since there is an upregulation of type 3 deiodinase in myocardium, producing a state of local cardiac hypothyroidism. In this focused review, we summarize the central pathophysiological and clinical links between altered thyroid function and ischemic heart disease. Finally, we highlight the potential benefits of thyroid hormone supplementation as a therapeutic target in ischemic heart disease.

2013 ◽  
Vol 168 (2) ◽  
pp. 1568-1569 ◽  
Author(s):  
Dimitris Tousoulis ◽  
Eirini Toli ◽  
Antigoni Miliou ◽  
Nikolaos Papageorgiou ◽  
Charalambos Antoniades ◽  
...  

2021 ◽  
Vol 53 (07) ◽  
pp. 453-460
Author(s):  
Kai Guo ◽  
Hongwei Ling ◽  
Xiaoyan Zhou ◽  
Changjiang Ying

AbstractThyrotropin receptor antibodies (TRAbs) play a significant role in the course of hepatic dysfunction (HDF) in patients with Graves’ disease (GD). However, few studies have considered the factors that influence the relationships among TRAbs, thyroid hormone levels, and hepatic function in subjects with newly diagnosed GD. Here we investigated the associations of TRAbs with thyroid hormones and hepatic function and assessed potential factors that can influence these associations among patients with GD. A total of 368 patients newly diagnosed with GD were collected in this cross-sectional study. Patients who had received antithyroid drugs, radioactive iodine, or surgery were excluded. Levels of TRAbs and thyroid hormones and hepatic function were recorded. Linear and binary logistic regression analysis models were applied to investigate associations among these variables after adjusting for confounding characteristics. There was a significant difference in TRAbs indices between the HDF and normal hepatic function groups (p <0.05). After adjusting for confounders, the relationship between TRAbs and thyroid hormones was nonlinear, showing a curve with an initial positive slope and a subsequent flattening (p <0.05). Higher TRAbs were associated with HDF [odds ratio (OR) 1.036, 95% confidence interval (CI) 1.018–1.053 per 1-IU/l increase]. These associations were modified by age, but not by gender, smoking status, Graves’ orbitopathy, thyroid-peroxidase antibody levels, or thyroglobulin antibody levels. In younger patients, increasing TRAbs were correlated with higher thyroid hormones and HDF (OR 1.034, 95% CI 1.017–1.052) per1-IU/l increase). In older patients, TRAbs were not correlated with thyroid hormones or HDF (OR 1.024, 95% CI 0.993–1.056) per 1-IU/l increase. Age can affect the impact of TRAbs on thyroid hormone levels and hepatic function in GD. TRAb measurement can have good predictive value in younger patients.


1990 ◽  
Vol 127 (1) ◽  
pp. 59-67 ◽  
Author(s):  
G. R. Buzzell ◽  
A. Menendez-Pelaez ◽  
R. A. Hoffman ◽  
M. K. Vaughan ◽  
R. J. Reiter

ABSTRACT This study tested the hypothesis that activity of the enzyme N-acetyltransferase (NAT) in the Harderian gland of the Syrian hamster is regulated both by androgens and by hormones of the pituitary-thyroid axis. To test the effects of castration and hypothyroidism, intact or castrated male hamsters were given either tap water or methimazole in their drinking water for 3 weeks. Methimazole suppresses iodination of thyroglobulin, thereby decreasing circulating levels of thyroid hormones and increasing TSH levels. Hypothyroidism or castration caused elevated or depressed Harderian gland NAT activities respectively, compared with euthyroid controls. When castration and hypothyroidism were combined, the animals exhibited high NAT activity compared with castrated euthyroid males. To test the effects of castration and hyperthyroidism, male hamsters were given daily injections of thyroxine (T4) or diluent and were either castrated or left intact for 4 weeks. Intact animals given T4 had depressed Harderian NAT activity; serum thyroid hormone levels were elevated and TSH levels were depressed compared with those of intact controls. Castrated animals had depressed NAT activity below that of intact controls; serum thyroid hormone levels were normal but TSH levels were depressed. Castrated animals given T4 injections had NAT activity similar to that of euthyroid castrated hamsters; thyroid hormone levels were elevated but TSH levels were similar to those seen in euthyroid castrated hamsters. In another experiment, both T4 and tri-iodothyronine (T3) were equally effective in decreasing NAT activity in intact males. To determine the effects of the removal of pituitary influences, male hamsters were hypophysectomized. NAT activity in the Harderian glands of these animals was reduced compared with intact controls. Injection of T4 in hypophysectomized male hamsters did not alter NAT activity from that of hypophysectomized hamsters. Female hamsters given methimazole for 3 weeks had elevated Harderian NAT activity compared with controls. Injection of T4 or T3 for 4 weeks led to significantly reduced Harderian gland NAT activity compared with untreated controls. This response to thyroid hormones was the same, whether T4 or T3 was used. These results can be explained by androgens stimulating Harderian NAT activity, as has been suggested by previous published reports, and by NAT activity being inhibited by thyroid hormones or stimulated by TSH. Journal of Endocrinology (1990) 127, 59–67


2021 ◽  
Vol 22 (12) ◽  
pp. 6521
Author(s):  
Mirjana Babić Babić Leko ◽  
Ivana Gunjača ◽  
Nikolina Pleić ◽  
Tatijana Zemunik

Thyroid hormones are necessary for the normal functioning of physiological systems. Therefore, knowledge of any factor (whether genetic, environmental or intrinsic) that alters the levels of thyroid-stimulating hormone (TSH) and thyroid hormones is crucial. Genetic factors contribute up to 65% of interindividual variations in TSH and thyroid hormone levels, but many environmental factors can also affect thyroid function. This review discusses studies that have analyzed the impact of environmental factors on TSH and thyroid hormone levels in healthy adults. We included lifestyle factors (smoking, alcohol consumption, diet and exercise) and pollutants (chemicals and heavy metals). Many inconsistencies in the results have been observed between studies, making it difficult to draw a general conclusion about how a particular environmental factor influences TSH and thyroid hormone levels. However, lifestyle factors that showed the clearest association with TSH and thyroid hormones were smoking, body mass index (BMI) and iodine (micronutrient taken from the diet). Smoking mainly led to a decrease in TSH levels and an increase in triiodothyronine (T3) and thyroxine (T4) levels, while BMI levels were positively correlated with TSH and free T3 levels. Excess iodine led to an increase in TSH levels and a decrease in thyroid hormone levels. Among the pollutants analyzed, most studies observed a decrease in thyroid hormone levels after exposure to perchlorate. Future studies should continue to analyze the impact of environmental factors on thyroid function as they could contribute to understanding the complex background of gene–environment interactions underlying the pathology of thyroid diseases.


2011 ◽  
Vol 14 (6) ◽  
pp. 384 ◽  
Author(s):  
Vladimir V. Lomivorotov ◽  
Sergey M. Efremov ◽  
Vladimir A. Shmirev ◽  
Dmitry N. Ponomarev ◽  
Vladimir N. Lomivorotov ◽  
...  

<p><b>Background:</b> The aim of the present study was to investigate the cardioprotective effects of the perioperative use of N(2)-L-alanyl-L-glutamine (GLN) in patients with ischemic heart disease (IHD) who undergo their operations under cardiopulmonary bypass (CPB).</p><p><b>Methods:</b> This double-blind, placebo-controlled, randomized study included 50 patients who underwent cardiac surgery with CPB. Exclusion criteria were a left ventricular ejection fraction <50%, diabetes mellitus, <3 months since the onset of myocardial infarction, and emergency surgery. Patients in the study group (n = 25) received 0.4 g/kg GLN (Dipeptiven, 20% solution) per day. Patients in the control group (n = 25) were administered a placebo (0.9% NaCl). The primary end point was the dynamics of troponin I at the following stages: (1) prior to anesthesia, (2) 30 minutes after CPB, (3) 6 hours after CPB, (4) 24 hours after surgery, and (5) 48 hours after surgery. Secondary end points included measurements of hemodynamics with a Swan-Ganz catheter.</p><p><b>Results:</b> On the first postoperative day after the surgery, the median troponin I level was significantly lower in the study group than in the placebo group: 1.280 ng/mL (interquartile range [IQR], 0.840-2.230 ng/mL) versus 2.410 ng/mL (IQR, 1.060-6.600 ng/mL) (<i>P</i> = .035). At 4 hours after cardiopulmonary bypass (CPB), the median cardiac index was higher in the patients in the study group: 2.58 L/min per m<sup>2</sup> (IQR, 2.34-2.91 L/min per m<sup>2</sup>) versus 2.03 L/min per m<sup>2</sup> (IQR, 1.76-2.32 L/min per m<sup>2</sup>) (<i>P</i> = .002). The median stroke index also was higher in the patients who received GLN: 32.8 mL/m<sup>2</sup> (IQR, 27.8-36.0 mL/m<sup>2</sup>) versus 26.1 mL/m<sup>2</sup> (IQR, 22.6-31.8 mL/m<sup>2</sup>) (<i>P</i> = .023). The median systemic vascular resistance index was significantly lower in the study group than in the placebo group: 1942 dyn�s/cm<sup>5</sup> per m<sup>2</sup> (IQR, 1828-2209 dyn�s/cm<sup>5</sup> per m<sup>2</sup>) versus 2456 dyn�s/cm<sup>5</sup> per m<sup>2</sup> (IQR, 2400-3265 dyn�s/cm<sup>5</sup> per m<sup>2</sup>) (<i>P</i> = .001).</p><p><b>Conclusion:</b> Perioperative administration of GLN during the first 24 hours has cardioprotective effects in IHD patients following CPB. This technique enhances the troponin concentration at 24 hours after surgery and is associated with improved myocardial function.</p>


2017 ◽  
pp. 89-94
Author(s):  
Ke Toan Tran ◽  
Thi Thuy Hang Nguyen

Objective: To determine pulmonary vascular resistance (PVR) by echocardiography - Doppler and to find correlation between pulmonary vascular resistance with left ventricular EF, PAPs, TAPSE, tissue S-wave of the tricuspid valve in patients with ischemic heart disease. Subjects and Methods: We studied on 82 patients with ischemic heart disease and EF<40% including 36 females, 46 males. Patients were estimated for pulmonary vascular resistance, EF, PAPs, TAPSE, tissue S-wave of the tricuspid valve by echocardiographyDoppler. Results: 64.6% of patients are increased PVR, average of PVR is 3.91 ± 1.85 Wood units and it is increasing with NYHA severity. There are negative correlations between pulmonary vascular resistance with left ventricular ejection fraction (r = - 0.545; p <0.001), TAPSE index (r= -0.590; p <0.001) and tissue S-wave of the tricuspid valve (r = -0.420; p <0.001); positive correlation with systolic pulmonary artery pressure (r = 0.361, p = 0.001), Conclusions: Increased PVR is the primary mechanism for pulmonary hypertension and right heart failure in patients with left heart disease. Determination of PVR in patients with left ventricular dysfunction by echocardiography is important in clinical practice. Key words: Echocardiography-Doppler; Pulmonary vascular resistance; ischemic heart disease


2021 ◽  
Vol 10 (11) ◽  
pp. 2284
Author(s):  
Diana Gurzău ◽  
Alexandra Dădârlat-Pop ◽  
Bogdan Caloian ◽  
Gabriel Cismaru ◽  
Horaţiu Comşa ◽  
...  

Left bundle branch block is not a benign pathology, and its presence requires the identification of a pathological substrate, such as ischemic heart disease. Left bundle branch block appears to be more commonly associated with normal coronary arteries, especially in women. The objectives of our study were to describe the particularities of left bundle branch block in women compared to men with ischemic heart disease. Result: We included seventy patients with left bundle branch block and ischemic heart disease, with a mean age of 67.01 ± 8.89 years. There were no differences in the profile of risk factors, except for smoking and uric acid. The ventricular depolarization (QRS) duration was longer in men than women (136.86 ± 8.32 vs. 132.57 ± 9.19 msec; p = 0.018) and also men were observed to have larger left ventricular diameters. Left bundle branch block duration was directly associated with ventricular diameters and indirectly associated with left ventricular ejection fraction value, especially in women (R = −0.52, p = 0.0012 vs. R = −0.50, p = 0.002). In angiography, 80% of women had normal epicardial arteries compared with 65.7% of men; all these patients presented with microvascular dysfunction. Conclusion: The differences between the sexes were not so obvious in terms of the presence of risk factors; instead, there were differences in electrocardiographic, echocardiographic, and angiographic aspects. Left bundle branch block appears to be a marker of microvascular angina and systolic dysfunction, especially in women.


2021 ◽  
Vol 77 (18) ◽  
pp. 2581
Author(s):  
Andrea Teira Calderon ◽  
Adrián Margarida ◽  
Ignacio Santiago ◽  
Indira Cabrera ◽  
Sofia Gonzalez Lizarbe ◽  
...  

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