Thyroid Hormones and Cardiovascular Function and Diseases

Razvi, Salman; Jabbar, Avais; Pingitore, Alessandro; Danzi, Sara; Biondi, Bernadette; Klein, Irwin; Peeters, Robin P.; Zaman, Azfar; Iervasi, Giorgio

doi:10.1016/j.jacc.2018.02.045

Cited by 334 publications

(350 citation statements)

References 145 publications

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“…Although the cause of CVD is multifactorial, one of its causes has been recently recognised as being attributed to SCH, which incidence increases with advancement of age 4,5 . The thyroid hormones exert their effects through their receptors α and β located in the myocardial and vascular endothelial tissues and modulate their cardiovascular function 6‐8 . Minor changes in thyroid hormone levels could have an adverse impact on the cardiometabolic effects in the body that include increases in serum cholesterol and glucose levels, endothelial dysfunction through decreased availability of nitric oxide (NO), causing arterial stiffness and increase in peripheral vascular resistance and blood pressure (BP), all being significant risk factors for CVD and HF 9‐13 .…”

Section: Introductionmentioning

confidence: 99%

The current debate over treatment of subclinical hypothyroidism to prevent cardiovascular complications

Chrysant

2020

Int J Clin Pract

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Background Subclinical hypothyroidism (SCH) is an asymptomatic condition associated with increased thyroid‐stimulating hormone (TSH) >4 mIU/L with normal thyroxine (T4) and triidothyronine (T3) levels. It is more common in older subjects and especially in women with an overall incidence of 10%. Objective Because the normal TSH levels increase with age up to 7.5 mIU/L in older people, several studies have reported either no benefits whereas others have reported the benefits of treatment. These studies have caused a great debate over the treatment of SCH, especially in older subjects. Therefore, the objective of this study was to review the current evidence over this debate by reviewing the recent literature on the subject to discern whether treatment of SCH is necessary and under what circumstances. Methods To get a better perspective on the current debate over treatment of SCH, a focused Medline search of the English language literature was conducted from 2012 to 2019 using the terms, hypothyroidism, subclinical, dyslipidaemia, cardiovascular disease, heart failure and 38 papers with pertinent information were selected. Results The analysis of results from these papers indicated that the normal levels of TSH are increasing with the advancement of age from 4 mIU/L up to 7.5 mIU/L for patients ≥75 years of age. Also, several of reviewed studies have shown no benefits of treatment whereas, others have shown definite benefits of treatment with levothyroxine supplementation on the clinical and metabolic effects of SBH with reductions in CVD, HF and mortality. The treatment is more effective in younger persons and less so in older persons. Conclusions Based on the overall evidence, treatment of SCH is indicated in younger persons with a TSH level >4.0 mIU/L. In older subjects, treatment should be individualised and based on the presence of symptoms, the level of TSH, and initiated at TSH levels ≥10 mIU/L and at low doses to avoid adverse cardiovascular effects from overtreatment.

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Section: Introductionmentioning

confidence: 99%

The current debate over treatment of subclinical hypothyroidism to prevent cardiovascular complications

Chrysant

2020

Int J Clin Pract

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“…Thus, thyroid hormones influence the production and breakdown of steroid hormones (5), the metabolism of carbohydrates (6,7), fats (8), and proteins (9). Also, thyroid hormones specifically affect the development of the brain (10), heart rate (11,12), pulmonary blood irrigations (13), but also some processes of the immune system (14). Growth, development and reproduction of the body are influenced by thyroid hormones (15,16).…”

Section: Introductionmentioning

confidence: 99%

Interaction of levothyroxine with bovine serum albumin: a spectroscopic assay

Sandu

Chilom

David

et al. 2020

Preprint

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The binding mechanism and affinity of the interaction between levothyroxine (LT4) and bovine serum albumin (BSA) were investigated, both in solution using UV-Vis, Fourier-transform infrared spectroscopy (FT-IR), fluorescence and fluorescence resonance energy transfer (FRET), as well as by Surface Plasmon Resonance (SPR) with BSA confined to a gold-coated chips. Quenching of BSA fluorescence by LT4 combined with UV-Vis spectroscopy shows a ground-state complex formation that may be accompanied by a nonradiative energy transfer process. FT-IR revealed the changes induced by LT4 in the secondary structure of BSA molecules, due to the partial unfolding of BSA native structure upon LT4 binding. Scatchard approach allowed the determination of the binding constant K b (5.12 x 10 6 M -1 ) and the equilibrium dissociation constant K d (19.5 x 10 -6 M) which suggest a moderate binding, as well as the thermodynamic parameters, which correspond to an enthalpic process (-51.99 kJ mol -1 ), driven mainly by hydrogen bonds and van der Waals forces. Using SPR, first, the confinement of BSA onto the chip gold surface was optimized towards LT4 binding. Second, the binding affinity of LT4 with BSA was characterized using the Hill-Langmuir equation, which led to a moderate binding affinity (apparent K d = 67.6 x 10 -6 M). As preliminary results, both fluorescence quenching and SPR can be used as a stepping stone for the development of a spectroscopic biosensor for LT4 detection, with a limit of detection as low as 0.23 x 10 -6 M. SIGNIFICANCEMost cellular and tissue functions are influenced by thyroid hormones, such as thyroxine (T4). Thus, these hormones influence the metabolism of various biomolecules and are related to a wide variety of medical conditions, of which, the best therapy is the hormone replacement using LT4 medicine. Therefore, the monitoring LT4 levels in the human body while undergoing LT4 treatment is of particular importance. Here we investigated the binding mechanism and affinity between LT4 and bovine serum albumin (BSA), one of the transporter proteins, by spectroscopic (UV-Vis, FTIR, fluorescence) and optical (SPR) methods. Although LT4-BSA binding was driven mainly by hydrogen and van der Waals bonds with moderate affinity, we found that fluorescence can be used for LT4 detection in nanomolar range. Keywords: RTICLEFIGURE 1 (A) The UV spectrum of LT4 diluted in HEPES buffer solution, pH 7.4. (B) The absorbance of LT4 at pH in the range of 5.35 and 9.40, measured at 240 nm. (C) The representation of the 1 st derivative of the absorbance.FIGURE 2 (A)FT-IR curves of LT4 and BSA-LT4 between the 3,000 -2,800 cm −1 , corresponding to the NH2 stretching in LT4 is shifted from 2,954 cm-1 to 2,920 cm-1 in the BSA-LT4 complex; the peak from 2836 cm -1 in LT4 is completely attenuated in the BSA-LT4 complex; curve-fitted amide I band between the 1,700 -1,600 cm −1 for: (B) free BSA and (C) BSA-LT4. The amide I band is represented in black and the curves for the secondary structure elements are: blue for α helix, magenta ...

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“…[1][2][3] As far we know, several physiological systems work to control cardiovascular homeostases, such as the neuroendocrine, kidneys and adrenal glands. [4][5][6][7] From all mechanisms already known, it is important to highlight specific factors, such as the atrial (ANP) and brain (BNP) natriuretic peptides. 8,9 Natriuretic peptides (NP) play an important homeostatic role in cardiocirculatory hemodynamics through their action on the renal function.…”

Section: Introductionmentioning

confidence: 99%

Acute Effect of Different Types of Exercise on Natriuretic Peptides of Wistar Rats

Pianca

Neto

Silva

et al. 2019

Rev Bras Med Esporte

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Introduction: The study of the effects of different types of physical exercise on cardiovascular physiology is increasing in the literature. The many mechanisms of hemodynamic control include the atrial release of natriuretic peptides. Although extensive evidence demonstrates their acute effects and the increase in their plasma concentration, it is not known whether both atria respond in a similar way to both types of natriuretic peptide in response to different types of exercise. Objective: To compare the acute responses of different exercise types in the atrial (ANP) and brain (BNP) natriuretic peptides of both atrial cardiomyocytes of Wistar rats. Methods: Animals were divided into control (CG), aerobic (AG), resistance (RG) and combined (ARG). The RG performed six climbs, with a load equivalent to 60% of body weight. The AG ran on a treadmill at a speed of 12m/min for 60 minutes. The ARG exercise consisted of three consecutive ladder climbs, followed by 30 minutes of running. Results: First, the right atrium released more ANP and BNP during all types of exercise; second, the resistance exercise released the most ANP and BNP in both atria; third, in the right atrium, aerobic and combined workouts released more small and medium ANP granules while resistance exercise released larger BNP granules; and fourth, in the left atrium, aerobic exercise released more ANP granules while resistance and combined exercise released larger ANP and BNP granules. Conclusion: All types of exercise induce partial release of natriuretic peptide granules, with greater response to resistance exercise. Furthermore, a particular and different response could be seen in both types of atria in the release of ANP and BNP. Level of evidence II; Therapeutic studies -Investigation of treatment results. RESUMOIntrodução: O estudo dos efeitos de diferentes tipos de exercício físico na fisiologia cardiovascular está aumentando na literatura. Os muitos mecanismos de controle hemodinâmico incluem a liberação atrial de peptídeos natriuréticos. Embora amplas evidências demonstrem seus efeitos agudos e o aumento na sua concentração plasmática, não se sabe se ambos os átrios respondem de maneira semelhante aos dois tipos de peptídeos natriuréticos em resposta a diferentes tipos de exercício. Objetivo: Comparar as respostas agudas de diferentes tipos de exercícios nos peptídeos natriuréticos atrial (ANP) e cerebral (BNP) de ambos os cardiomiócitos atriais dos ratos Wistar. Métodos: Os animais foram divididos em: controle (GC), aeróbico (GA), resistência (GR) e combinado (GAR). O GR realizou seis escaladas com uma carga equivalente a 60% do peso corporal. O GA correu em esteira a uma velocidade de 12 m/min durante 60 minutos. O exercício do GAR consistiu em subir a escada três vezes consecutivas, seguido de 30 minutos de corrida. Resultados: Primeiro, o átrio direito liberou mais ANP e BNP durante todos os tipos de exercícios; Segundo, o exercício de resistência liberou mais ANP e BNP em ambos os átrios; Terceiro, no átrio direito, os exercícios aeróbic...

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Thyroid Hormones and Cardiovascular Function and Diseases

Cited by 334 publications

References 145 publications

The current debate over treatment of subclinical hypothyroidism to prevent cardiovascular complications

The current debate over treatment of subclinical hypothyroidism to prevent cardiovascular complications

Interaction of levothyroxine with bovine serum albumin: a spectroscopic assay

Acute Effect of Different Types of Exercise on Natriuretic Peptides of Wistar Rats

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