The cardiac growth process (hypertrophy) is a crucial phenomenon conserved across a wide array of species and is critically involved in the maintenance of cardiac homeostasis. This process enables an organism to adapt to changes in systemic demand and occurs due to a plethora of responses, depending on the type of signal or stimuli received. The growth of cardiac muscle cells in response to environmental conditions depends on the type, strength and duration of stimuli, and results in adaptive physiological responses or non-adaptive pathological responses. Thyroid hormones (TH) have a direct effect on the heart and induce a cardiac hypertrophy phenotype, which may evolve to heart failure. In this review, we summarize the literature on TH function in the heart by presenting results from experimental studies. We discuss the mechanistic aspects of TH associated with cardiac myocyte hypertrophy, increased cardiac myocyte contractility and electrical remodeling, as well as the associated signaling pathways. In addition to classical crosstalk with the sympathetic nervous system (SNS), emerging work pointing to the new endocrine interaction between TH and the renin-angiotensin system (RAS) is also explored. Given the inflammatory potential of the angiotensin II peptide, this new interaction may open the door for new therapeutic approaches which target the key mechanisms responsible for TH-induced cardiac hypertrophy.
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M L M Barreto-Chaves, N Senger, M R Fevereiro, A C Parletta, and A P C Takano
Ursula M M Costa, Carla R P Oliveira, Roberto Salvatori, José A S Barreto-Filho, Viviane C Campos, Francielle T Oliveira, Ivina E S Rocha, Joselina L M Oliveira, Wersley A Silva, and Manuel H Aguiar-Oliveira
GH and its principal mediator IGF1 have important effects on metabolic and cardiovascular (CV) status. While acquired GH deficiency (GHD) is often associated with increased CV risk, the consequences of congenital GHD are not known. We have described a large group of patients with isolated GHD (IGHD) due to a homozygous mutation (c.57+1G>A) in the GH releasing hormone receptor gene, and shown that adult GH-naïve individuals have no evidence of clinically evident premature atherosclerosis. To test whether subclinical atherosclerosis is anticipated in untreated IGHD, we performed a cross-sectional study of 25 IGHD and 27 adult controls matched for age and gender. A comprehensive clinical and biochemical panel and coronary artery calcium scores were evaluated by multi-detector tomography. Height, weight, IGF1, homeostasis model assessment of insulin resistance, creatinine and creatininekinase were lower in the IGHD group. Median and interquartile range of calcium scores distribution was similar in the two groups: IGHD 0(0) and control 0(4.9). The vast majority of the calcium scores (20 of 25 IGHD (80%) and 18 of 27 controls (66.6%)) were equal to zero (difference not significant). There was no difference in the calcium scores classification. None of IGHD subjects had minimal calcification, which were present in four controls. Three IGHD and four controls had mild calcification. There were two IGHD individuals with moderate calcification and one control with severe calcification. Our study provides evidence that subjects with congenital isolated lifetime and untreated severe IGHD do not have accelerated subclinical coronary atherosclerosis.
Peter D Mark, Mikkel Andreassen, Claus L Petersen, Andreas Kjaer, and Jens Faber
The aim of this study was to investigate structure and function of the heart in subclinical hyperthyroidism (SH) before and after obtaining euthyroidism by radioactive iodine treatment, using high precision and observer-independent magnetic resonance imaging (MRI) technology.
Cardiac MRI was performed before and after euthyroidism was obtained by radioactive iodine treatment in 12 otherwise healthy patients (11 women and one man, mean age 59 years, range 44–71 years) with a nodular goiter and SH, and compared with eight healthy controls investigated at baseline. Cardiac data were expressed as an index, as per body surface area, except for heart rate (HR) and ejection fraction.
Post-treatment cardiac MRI was performed in median 139 days after a normalized serum TSH value had been recorded. During treatment, serum TSH increased from (median (range)) 0.01 (0.01–0.09) to 0.88 (0.27–3.99) mU/l. Patients with untreated SH had increased resting HR (P<0.01) as well as cardiac index (cardiac output as per body surface area) (P<0.01) compared with controls. Obtaining euthyroidism resulted in a significant decrease in left ventricular mass index (LVMI) of 2.7 g/m2 (P=0.034), in HR of 8 bpm (P=0.001), and in cardiac index of 0.24 l/min per m2 (P=0.017).
Normalization of thyroid function by radioactive iodine treatment of SH resulted in significant reductions in clinically important heart parameters such as LVMI, HR, and cardiac index. SH should be regarded as a condition in which aggressive treatment should be considered to protect cardiac function.
Nese Cinar and Alper Gurlek
Adipose tissue secretes a variety of active biological substances, called adipocytokines, that act in an autocrine, paracrine, and endocrine manner. They have roles in appetite control, thermogenesis, and thyroid and reproductive functions. All these molecules may lead to local and generalized inflammation, mediating obesity-associated vascular disorders including hypertension, diabetes, atherosclerosis, and insulin resistance. Thyroid dysfunction is associated with changes in body weight, thermogenesis, and energy expenditure. The connections between cardiovascular risk factors such as dyslipidemia, impaired glucose tolerance, insulin resistance, atherosclerosis, and thyroid dysfunction have been reported in several studies. The adipocytokines serve as causative or protective factors in the development of these disorders in the states of thyroid dysfunction. Abnormal levels of adipocytokines (adiponectin (ADP), leptin, resistin, vaspin, and visfatin) in hypo- and hyperthyroidism have been reported with controversial results. This review aims to update the implication of novel adipokines ADP, vaspin, and visfatin in thyroid dysfunction.
Yusaku Mori, Hiroyuki Shimizu, Hideki Kushima, Tomomi Saito, Munenori Hiromura, Michishige Terasaki, Masakazu Koshibu, Hirokazu Ohtaki, and Tsutomu Hirano
Nesfatin-1 is a novel anorexic peptide hormone that also exerts cardiovascular protective effects in rodent models. However, nesfatin-1 treatment at high doses also exerts vasopressor effects, which potentially limits its therapeutic application. Here, we evaluated the vasoprotective and vasopressor effects of nesfatin-1 at different doses in mouse models. Wild-type mice and those with the transgene nucleobindin-2, a precursor of nesfatin-1, were employed. Wild-type mice were randomly assigned to treatment with vehicle or nesfatin-1 at 0.2, 2.0 or 10 μg/kg/day (Nes-0.2, Nes-2, Nes-10, respectively). Subsequently, mice underwent femoral artery wire injury to induce arterial remodeling. After 4 weeks, injured arteries were collected for morphometric analysis. Compared with vehicle, nesfatin-1 treatments at 2.0 and 10 μg/kg/day decreased body weights and elevated plasma nesfatin-1 levels with no changes in systolic blood pressure. Furthermore, these treatments reduced neointimal hyperplasia without inducing undesirable remodeling in injured arteries. However, nesfatin-1 treatment at 0.2 μg/kg/day was insufficient to elevate plasma nesfatin-1 levels and showed no vascular effects. In nucleobindin-2-transgenic mice, blood pressure was slightly higher but neointimal area was lower than those observed in littermate controls. In cultured human vascular endothelial cells, nesfatin-1 concentration-dependently increased nitric oxide production. Additionally, nesfatin-1 increased AMP-activated protein kinase phosphorylation, which was abolished by inhibiting liver kinase B1. We thus demonstrated that nesfatin-1 treatment at appropriate doses suppressed arterial remodeling without affecting blood pressure. Our findings indicate that nesfatin-1 can be a therapeutic target for improved treatment of peripheral artery disease.
Angelo Maria Patti, Kalliopi Pafili, Nikolaos Papanas, and Manfredi Rizzo
Hormonal changes during pregnancy can trigger gestational diabetes (GDM), which is constantly increasing. Its main characteristic is pronounced insulin resistance, but it appears to be a multifactorial process involving several metabolic factors; taken together, the latter leads to silent or clinically evident cardiovascular (CV) events. Insulin resistance and central adiposity are of crucial importance in the development of metabolic syndrome, and they appear to correlate with CV risk factors, including hypertension and atherogenic dyslipidaemia. Hypertensive disease of pregnancy (HDP) is more likely to be an accompanying co-morbidity in pregnancies complicated with GDM. There is still inconsistent evidence as to whether or not co-existent GDM and HDP have a synergistic effects on postpartum risk of cardiometabolic disease; however, this synergism is becoming more accepted since both these conditions may promote endothelial inflammation and early atherosclerosis. Regardless of the presence or absence of the synergism between GDM and HDP, these conditions need to be dealt early enough, in order to reduce CV morbidity and to improve health outcomes for both women and their offspring.
Isabel M Abreu, Eva Lau, Bernardo de Sousa Pinto, and Davide Carvalho
Previous studies suggested that subclinical hypothyroidism has a detrimental effect on cardiovascular risk factors, and that its effective treatment may have a beneficial impact on overall health. The main purpose of this review and meta-analysis was to assess whether subclinical hypothyroidism treatment is of clinical relevance, based on cardiovascular risk parameters correction. A systemic research of the literature using MEDLINE tool was performed to identify the relevant studies. Only placebo-controlled randomized control trials were included. A quantitative analysis was also performed. This systematic review and meta-analysis of randomized placebo-controlled trials assess the different impact of levothyroxine vs placebo treatment. A significant decrease in serum thyroid-stimulating hormone and total and low-density lipoprotein cholesterol was obtained with levothyroxine therapy (66, 9 and 14%, respectively) and, although modest, this could be significant in terms of reduction of the incidence of coronary artery disease. Other significant results of lipid parameters were not obtained. This systematic review provides a strong evidence-based data in favour of specific changes and beneficial effects of levothyroxine treatment.
Myrtille Fouché, Yves Bouffard, Mary-Charlotte Le Goff, Johanne Prothet, François Malavieille, Pierre Sagnard, Françoise Christin, Davy Hayi-Slayman, Arnaud Pasquer, Gilles Poncet, Thomas Walter, and Thomas Rimmelé
Only few descriptions of intraoperative carcinoid syndrome (ioCS) have been reported. The primary objective of this study was to describe ioCS. A second aim was to identify risk factors of ioCS. We retrospectively analysed patients operated for small-bowel neuroendocrine tumour in our institution between 2007 and 2015, and receiving our preventive local regimen of octreotide continuous administration. ioCS was defined as highly probable in case of rapid (<5 min) arterial blood pressure changes ≥40%, not explained by surgical/anaesthetic management and regressive ≥20% after octreotide bolus injection. Probable cases were ioCS which did not meet all criteria of highly-probable ioCS. Suspected ioCS were detected on the anaesthesia record by an injection of octreotide due to a manifestation which did not meet the criteria for highly-probable or probable ioCS. A total of 81 patients (liver metastases: 59, prior carcinoid syndrome: 49, carcinoid heart disease: 7) were included; 139 ioCS occurred in 45 patients: 45 highly probable, 67 probable and 27 suspected. ioCs was hypertensive (91%) and/or hypotensive (29%). There was no factor, including the use of vasopressors, significantly associated with the occurrence of an ioCS. All surgeries were completed and one patient died from cardiac failure 4 days after surgery. After preoperative octreotide continuous infusion, ioCS were mainly hypertensive. No ioCS risk factors, including vasopressor use, were identified. No intraoperative carcinoid crisis occurred, suggesting the clinical relevance of a standardized octreotide prophylaxis protocol.
Susanna Cirera, Sophia G Moesgaard, Nora E Zois, Nathja Ravn, Jens P Goetze, Signe E Cremer, Tom Teerlink, Páll S Leifsson, Jesper L Honge, J Michael Hasenkam, and Lisbeth H Olsen
Non-ischemic mitral regurgitation (MR) is primarily caused by myxomatous mitral valve (MV) disease leading to adaptive remodeling, enlargement, and dysfunction of the left ventricle. The aim of this study was to examine the regulation of plasma markers and several cardiac key genes in a novel porcine model of non-ischemic MR.
Methods and results
Twenty-eight production pigs (Sus scrofa) were randomized to experimental MR or sham surgery controls. MR was induced by external suture(s) through the posterior MV leaflet and quantified using echocardiography. The experimental group was subdivided into mild MR (mMR, MR=20–50%, n=10) and moderate/severe MR (sMR, MR >50%, n=6) and compared with controls (CON, MR ≤10%, n=12). Eight weeks postoperatively, follow-up examinations were performed followed by killing. Circulating concentrations of pro-atrial natriuretic peptide (proANP), l-arginine, asymmetric dimethylarginine, and symmetric dimethylarginine (SDMA) were measured. MV, anterior papillary muscle, and left ventricular free wall tissues were collected to quantify mRNA expression of eNOS (NOS3), iNOS (NOS2), MMP9, MMP14, ANP (NPPA), BNP (NPPB), and TGFB1, 2, and 3 and five microRNAs by quantitative real-time PCR. Pigs with sMR displayed markedly increased plasma proANP and SDMA concentrations compared with both controls and mMR (P<0.05). The expression of all genes examined differed significantly between the three localizations in the heart. miR-21 and miR-133a were differently expressed among the experimental groups (P<0.05).
Plasma proANP and SDMA levels and tissue expression of miR-21 and miR-133a are associated with severity of chronic MR in an experimental porcine model.
Jing Hong, Wen-Yue Liu, Xiang Hu, Fei-Fei Jiang, Ze-Ru Xu, Fang Li, Fei-Xia Shen, and Hong Zhu
A prolonged heart rate-corrected QT interval (QTc) has been associated with peripheral artery disease (PAD) in the general population. However, no study to date has identified a link between prolonged QTc and the severity of PAD in patients with diabetes mellitus and foot ulcers (DFUs). This study aimed to investigate this relationship.
This multicenter study enrolled 281 patients with DFUs. The severity of PAD was classified into no severe PAD group (without stenosis or occlusion) and severe PAD group (with stenosis or occlusion) based on duplex ultrasonography. The association of prolonged QTc with severe PAD was evaluated in a multivariable mixed-effect logistic regression model, with the hospital as a random effect. Directed acyclic graphs were used to drive the selection of variables to fit the regression model.
Patients with severe PAD had longer QTc than those without. Based on the multivariable mixed-effect logistic regression model, a prolonged QTc was positively associated with severe PAD (odds ratio (OR) = 2.61; 95% CI: 1.07–6.35) and severe DFUs (Wagner grade score ≥ 3) (OR = 2.87; 95% CI: 1.42–5.81).
A prolonged QTc was associated with severe PAD in patients with DFUs. Further research is required to ascertain whether the association is causal.