Relationship between triiodothyronine and proinflammatory cytokines in chronic heart failure

Causal Association of Thyroid Signaling with C-Reactive Protein: A Bidirectional Mendelian Randomization

Methods

Based on the latest genome-wide association study summary data, bidirectional two-sample Mendelian randomization (MR) was employed to detect the causal relationship and effect direction between TSH, fT4, and CRP. Furthermore, in view of obesity being an important risk factor of CVD, obesity trait waist-hip ratio (WHR) and body mass index (BMI) were treated as the research objects in MR analyses for exploring the causal effects of TSH and fT4 on them, respectively.

Results

Genetically increased CRP was associated with increased TSH (β = -0.02, P = 0.011) and with increased fT4 (β = 0.043, P = 0.001), respectively, but there was no evidence that TSH or fT4 could affect CRP. In further analyses, genetically increased TSH was associated with decreased WHR (β = -0.02, P = 3.99e - 4). Genetically increased WHR was associated with decreased fT4 (β = -0.081, P = 0.002). Genetically increased BMI was associated with increased TSH (β = 0.03, P = 0.028) and with decreased fT4 (β = -0.078, P = 1.05e - 4). Causal associations of WHR and BMI with thyroid signaling were not supported by weighted median analysis in sensitivity analyses.

Conclusion

TSH and fT4 were increased due to the higher genetically predicted CRP. WHR was decreased due to the higher genetically predicted TSH. These findings will provide reference for the prevention and treatment of inflammation and metabolic syndrome.

T3 as predictor of mortality in any cause non-critically ill patients

BACKGROUND

Low T3 syndrome refers to a set of thyroid hormone metabolism alterations present in the disease state. A correlation between low T3 and poor clinical outcomes in the intensive care unit is more established. Nonetheless, studies on non-critically ill patients are few and controversial.

OBJECTIVE

To evaluate the prevalence and predictive value of low T3 levels on 30-day and 6-month mortality in non-critically ill patients. Secondary outcomes evaluated the length of hospital stay, overall mortality, and hospital readmission.

DESIGN

Prospective cohort study.

METHODS

A total of 345 consecutive patients from the Internal Medicine ward of a tertiary hospital in southern Brazil were included and followed from October 2018 to April 2019 (6 months). Levels of total serum T3 were measured weekly, from admission to discharge, and correlated with 30-day and 6-month mortality.

RESULTS

Prevalence of low T3 was 36.6%. Low T3 levels were associated with higher 30-day hospital mortality (15.1% vs 4.1%, P < 0.001) and higher 6-month overall mortality (31.7% vs 13.2%, P < 0.001). Total serum T3 at admission was an independent predictor of 30-day hospital mortality.

CONCLUSION

Low T3 levels are a prevalent condition among non-critically ill patients, and this condition is associated with poor clinical outcomes in this population. Total serum T3 levels, alone or in association with other predictive scores, were demonstrated to be an easy and valuable tool for risk stratification and should be further employed in this setting.

Thyroid hormone mediates cardioprotection against postinfarction remodeling and dysfunction through the IGF-1/PI3K/AKT signaling pathway

AIMS

Severe cardiovascular diseases, such as myocardial infarction or heart failure, can alter thyroid hormone (TH) secretion and peripheral conversion, leading to low triiodothyronine (T3) syndrome. Accumulating evidence suggests that TH has protective properties against cardiovascular diseases and that treatment with TH can effectively reduce myocardial damage after myocardial infarction (MI). Our aim is to investigate the effect of T3 pretreatment on cardiac function and pathological changes in mice subjected to MI and the underlying mechanisms.

MAIN METHODS

Adult male C57BL/6 mice underwent surgical ligation of the left anterior descending coronary artery (LAD) (or sham operation) to establish MI model. T3, BMS-754807 (inhibitor of insulin-like growth factor-1 receptor (IGF-1R)) or vehicle was administered before surgery.

KEY FINDINGS

Compared with the MI group, the T3 pretreatment group exhibited significant attenuation of the myocardial infarct area, inhibition of cardiomyocyte apoptosis and fibrosis, and improved left ventricular function after MI. In addition, T3 exhibited an enhanced potency to stimulate angiogenesis and exert anti-inflammatory effects by reducing the levels of serum inflammatory cytokines after MI. However, all of these protective effects were inhibited by the IGF-1R inhibitor BMS-754807. Moreover, the protein expression of IGF-1/PI3K/AKT signaling-related proteins, such as IGF-1, IGF-1R, phosphorylated PI3K (p-PI3K) and p-AKT was significantly upregulated in MI mice that received T3 pretreatment, and BMS-754807 pretreatment blocked the upregulation of the expression of these signaling-related proteins.

SIGNIFICANCE

T3 pretreatment can protect the heart against dysfunction post-MI, which may be mediated by the activation of the IGF-1/PI3K/AKT signaling pathway.

Relationship of thyroid dysfunction with cardiovascular diseases: updated review on heart failure progression

Heart disease remains the leading cause of death globally. Heart failure (HF) is a clinical syndrome that results from impairment of the ability of the ventricle to fill with or eject blood. Over the past two decades, accumulated evidence has revealed the contribution of thyroid hormones to cardiovascular (CV) events, exerting their action through genomic and non-genomic pathways within the cardiomyocytes. The pivotal role of thyroid hormones in maintaining cardiac homeostasis has been observed in previous investigations which suggest that the CV system is adversely impacted by fluctuations in thyroid hormone levels, such as those that occur in hypothyroidism, hyperthyroidism, and low triiodothyronine syndrome (LT₃S). Thyroid dysfunction has direct effects on myocardial contractility, systolic and diastolic blood pressure, heart mass, heart rate, ejection fraction, and heart output, which may ultimately lead to HF. Recent clinical data have shown that thyroid hormone replacement therapy for hypothyroid patients appears to provide the potential for reducing CV events. Therefore, this review aims to address the impact of thyroid hormone dysfunction on pathophysiological mechanisms contributing to the development and progression of HF.

Thyroid Abnormalities in Heart Failure

The effects of hyperthyroidism and hypothyroidism on the heart and cardiovascular system are well documented. It has also been shown that various forms of heart disease including but not limited to congenital, hypertensive, ischemic, cardiac surgery, and heart transplantation cause an alteration in thyroid function tests including a decrease in serum liothyronine (T₃). This article discusses the basic science and clinical data that support the hypothesis that these changes pose pathophysiologic and potential novel therapeutic challenges.

Evidence for the important role of inflammation in xenotransplantation

There is increasing evidence of a sustained state of systemic inflammation after pig-to-nonhuman primate (NHP) xenotransplantation (that has been termed systemic inflammation in xenograft recipients [SIXR]). Increases in inflammatory markers, e.g., C-reactive protein, histones, serum amyloid A, D-dimer, cytokines, chemokines, and a decrease in free triiodothyronine, have been demonstrated in the recipient NHPs. The complex interactions between inflammation, coagulation, and the immune response are well-recognized, but the role of inflammation in xenograft recipients is not fully understood. The evidence suggests that inflammation can promote the activation of coagulation and the adaptive immune response, but the exact mechanisms remain uncertain. If prolonged xenograft survival is to be achieved, anti-inflammatory strategies (e.g., the administration of anti-inflammatory agents, and/or the generation of genetically-engineered organ-source pigs that are protected from the effect of inflammation) may be necessary to prevent, control, or negate the effect of the systemic inflammation that develops in xenograft recipients. This may allow for a reduction in the intensity of exogenous immunosuppressive therapy. If immunological tolerance to a xenograft is to be obtained, then control of inflammation may be essential.

Low triiodothyronine syndrome and selenium deficiency - undervalued players in advanced heart failure? A single center pilot study

Background

The function of deiodinases – selenoproteins converting thyroid hormones may be disturbed by oxidative stress accompanying heart failure. Selenium (Se) may be used by glutathione peroxidase, leading to a lack of deiodinase and triiodothyronine (T3). The aim of the study was the evaluation of the prevalence and clinical significance of low T3 syndrome in heart failure and the assessment of the association of low fT3 and Se deficiency.

Methods

The study group consisted of 59 consecutive patients hospitalized due to decompensated HFrEF NYHA III or IV. Exclusion criteria were: thyroid dysfunction, severe systemic disease, treatment with amiodarone, steroids or propranolol. Group A included 9 patients with low free T3 (fT3) concentration below 3.1 pmol/L. Group B consisted of the remaining 50 patients with normal fT3 levels.

Results

The prevalence of low T3 syndrome was 15.3%. The prevalence of Se deficiency was 74.6%. We demonstrated correlations between fT3 and main clinical variables (i.e. NT-proBNP, LVEF, hsCRP), but we did not find correlation between fT3 and the Se level. Kaplan-Meier survival analysis showed lower survival probability in patients with low fT3 (p < 0.001).

Conclusions

Low T3 syndrome is frequently found in patients with HFrEF and is associated with a poor outcome. We did not identify any significant correlation between Se and fT3 level.

Cardioprotection and Thyroid Hormones in the Clinical Setting of Heart Failure

Ischemic heart disease is the main cause of morbidity and mortality worldwide and is becoming more widespread with population aging. Cardioprotection is a dynamic process characterized by mechanisms related to myocardial damage and activation of protective factors. Targeting these processes could be attractive as a new therapeutic strategy in the evolution of post-ischemic heart failure (HF). In this context, the role of thyroid hormone (TH)-mediated cardioprotection is supported by a number of findings regarding the modulation of neuroendocrine systems, inflammatory and oxidative stress status, pro-survival intracellular pathways, and epigenetic factors, its effects on cardiac angiogenesis, structure, and function and on the preservation of mitochondrial function and morphology, and its beneficial effects on cell growth and redifferentiation. Moreover, the numerous effects of TH on the heart involve genomic mechanisms, which include cardiac differentiation during the perinatal period and non-genomic action, directed toward the maintenance of cardiovascular homeostasis. This evidence suggests that there is an opportunity to treat HF patients with TH. This review is mainly focused on the clinical evidence of the role of the thyroid system in the complex setting of HF.

Functional Polymorphisms of the Type 1 and Type 2 Iodothyronine Deiodinase Genes in Autoimmune Thyroid Diseases

Graves' disease (GD) and Hashimoto's disease (HD) are major autoimmune thyroid diseases (AITDs), and their pathological conditions vary among patients. Type 1 iodothyronine deiodinase (D1) and type 2 iodothyronine deiodinase (D2) convert from thyroxine (T4) to triiodothyronine (T3). However, few findings have been described concerning the association between polymorphisms in D1 and D2 genes and AITD. Therefore, we genotyped D1 rs11206244, D2 rs225014, and rs12885300 polymorphisms in 134 GD patients, including 54 patients with intractable GD and 44 patients with GD in remission and 132 HD patients, including 57 patients with severe HD, 45 patients with mild HD, and 84 healthy controls using PCR-RFLP. In the D2 rs225014 polymorphism, the TT genotype, which was correlated with higher D2 activity, was less frequent in AITD, especially in HD, than in control subjects (P = 0.0032 and 0.0002, respectively). Moreover, they were also less frequent in HD than in GD (P = 0.0199). The TT genotype and T allele were less frequent in severe HD and mild HD than in control subjects (P = 0.0003, 0.0006, 0.0432, and 0.0427, respectively). In conclusion, the low frequency of the TT genotype D2 rs225014 polymorphism was associated with the development of AITD and severity of HD.

Thyroid hormones and cardiovascular disease

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.

Thyroid hormone: relevance to xenotransplantation

BACKGROUND

It has been well documented that the level of serum/plasma free triiodothyronine (fT3) falls rapidly following brain death or during certain surgical procedures, for example, heart surgery carried out on cardiopulmonary bypass. The level in patients following cardiopulmonary bypass usually recovers within 2 days.

METHODS

We have measured serum fT3 in healthy naïve baboons (n = 31), healthy naïve monkeys (n = 5), and after pig-to-baboon heterotopic heart xenotransplantation (xenoTx) (Group 1, n = 9), orthotopic liver xenoTx (Group 2, n = 10), artery patch xenoTx (Group 3, n = 9), and in monkey-to-monkey heterotopic heart alloTx (Group 4, n = 5).

RESULTS

The mean level of fT3 in healthy naïve baboons was 3.1 ± 0.9 pg/ml and in healthy naïve monkeys was 2.6 ± 0.3 pg/ml. Following pig heart, liver, and artery patch xenoTx and monkey heart alloTx, there was an immediate rapid fall in fT3 level. Recovery of fT3 was more rapid in Groups 3 and 4 than in Groups 1 and 2. In Group 1, within 4 days fT3 had recovered, but only to the lower limit of normal range, where it remained throughout follow-up (for up to 42 days). In Group 2, no recovery was seen during the 7 days of follow-up. In immunosuppressed baboons with pig patch grafts that received IL-6R blockade (n = 2), the fT3 tended to rise higher than in those that received no IL-6R blockade (n = 6).

CONCLUSIONS

Following operative procedures, there is a dramatic fall in serum fT3 levels. The persistent low level of fT3 after pig heart and liver xenoTx may be associated with a continuing inflammatory state. We suggest that consideration should be given to the replacement of T3 therapy to maintain normal fT3 levels, particularly in nonhuman primates undergoing orthotopic pig heart or liver xenoTx.

Relationship and prognostic importance of thyroid hormone and N-terminal pro-B-Type natriuretic peptide for patients after acute coronary syndromes: a longitudinal observational study

Background

Altered thyroid function and increased rates of N-terminal pro-B-Type natriuretic peptide (NT-pro-BNP) are highly prevalent in coronary artery disease (CAD) patients with heart failure, and are associated with unfavorable prognosis. This study was undertaken to examine the relationship and prognostic impact of thyroid hormones, inflammatory biomarkers, and NT-pro-BNP on long-term outcomes in patients after acute coronary syndrome (ACS).

Methods

The study comprised of 642 patients (age 58 ± 10 years, 77 % male) attending an in-patient cardiac rehabilitation program after experiencing ACS. Patients were evaluated for demographic, clinical and CAD risk factors as well as thyroid hormones (e.g., fT3, fT4 level, fT3/fT4 ratio), inflammatory biomarkers (hs-CRP, IL-6) and NT-pro-BNP levels. Data on fT3/fT4 ratio and NT-pro-BNP levels were not normally distributed and were natural-log transformed (ln). Both all-cause (cumulative) and cardiac-related mortality were considered the primary outcomes of interest.

Results

According to the Cox model, age, NYHA class, (ln)NT-pro-BNP levels (HR 1.53, 95 % CI 1.13–2.07), fT4 level (HR 1.15, 95 % CI 1.04–1.27), and (ln)fT3/fT4 ratio (HR 0.08, 95 % CI 0.02–0.32) were the most important predictors of all-cause mortality among CAD patients after ACS. Similarly, age, NYHA class, (ln)NT-pro-BNP levels (HR 1.62, 95 % CI 1.11–2.36), fT4 (HR 1.15, 95 % CI 1.02–1.29) and (ln)fT3/fT4 ratio (HR 0.10, 95 % CI 0.02–0.55) independently predicted cardiac-related mortality. Kaplan-Meier analyses provided significant prognostic information with the highest risk for all-cause mortality in the low cut off measures of fT3/fT4 ratio <0.206 and NT-pro-BNP ≥290.4 ng/L (HR 2.03, 95 % CI 1.39–2.96) and fT4 level >12.54 pg/ml (HR = 2.34, 95 % CI 1.05–5.18). There was no association between hs-CRP, IL-6 and mortality in CAD patients after ACS.

Conclusions

Thyroid hormones (i.e., fT4 level and fT3/fT4 ratio) together with NT-pro-BNP level may be valuable and simple predictors of long-term outcomes of CAD patients after experiencing ACS.

Role of the Thyroid System in the Dynamic Complex Network of Cardioprotection

Cardioprotection is a common goal of new therapeutic strategies in patients with coronary artery disease and/or left ventricular dysfunction. Myocardial damage following ischaemia/reperfusion injury lead to left ventricular adverse remodelling through many mechanisms arising from different cell types in different myocardial districts, namely the border and remote zone. Cardioprotection must face this complex, dynamic network of cooperating units. In this scenario, thyroid hormones can represent an effective therapeutic strategy due to the numerous actions and regulating mechanisms carried out at the level of the myocytes, interstitium and the vasculature, as well as to the activation of different pro-survival intracellular pathways involved in cardioprotection.

Effects of triiodothyronine replacement therapy in patients with chronic stable heart failure and low-triiodothyronine syndrome: a randomized, double-blind, placebo-controlled study

Objectives

The present study assessed the changes in functional, biochemical, and echocardiographic measures following long‐term liothyronine therapy in heart failure (HF) patients with low‐triiodothyronine (T3) syndrome (LT3S).

Methods

In the present placebo‐controlled, double‐blind study, adult patients with clinically stable New York Heart Association functional class I–III systolic HF and LT3S receiving standard HF therapy were randomly assigned 1:1 to receive oral liothyronine or placebo for 6 weeks. Low‐T3 syndrome was defined as a serum free T3 of less than the lower limit of normal (<2.4 pg/mL) with normal thyroid‐stimulating hormone (thyrotropin) and free thyroxin values.

Results

Fifty patients, including 39 (78%) men with a mean ± standard deviation age of 60 ± 15 years were included. The 6‐min walk distance increased in the liothyronine group by 93 ± 16 m and in the placebo group by 67 ± 28 m, resulting in a treatment effect of 26 m (P = 0.003). A higher decrease of high‐sensitivity C‐reactive protein level was seen in the liothyronine group than in the placebo group (P = 0.009). Liothyronine markedly decreased serum N‐terminal pro‐brain natriuretic peptide level compared with the placebo (P = 0.01). A significant increase was also seen in the left ventricular ejection fraction by liothyronine as compared with the placebo (<0.001).

Conclusion

Triiodothyronine replacement by chronic liothyronine therapy seems to safely benefit stable HF patients with LT3S receiving optimal HF medications.

Thyroid hormone and heart failure: from myocardial protection to systemic regulation

Heart failure (HF) is an intriguing model of chronic disease. It starts as an organ disorder developing, in its progression, into a systemic disease in which the dysfunction of other organs plays a relevant clinical and prognostic impact. Furthermore, continuous activation of systemic pathways plays a role in disease progression, switching their effect from protective to harmful. In this combination of organ dysfunction and systemic derangement, thyroid hormone (TH) have an important regulative impact from cardiovascular to systemic level and from molecular/cellular processes to clinical setting. Whether it is accepted to include TH and thyroid stimulating hormone assessment in the clinical HF course, the next challenge will be to ascertain the benefit of TH replacement therapy in HF patients, taking into consideration the type of hormone to administer, dosage and treatment schedule.

A meta-analysis of proinflammatory cytokines in chronic heart failure

BACKGROUND

Previous studies suggested that inflammation was involved in chronic heart failure (CHF), but their sample sizes were small.

OBJECTIVE

To summarise the clinical cytokine data systematically and emphasise the importance of proinflammatory cytokines in the pathogenesis of CHF, we conducted a meta-analysis of relevant literatures.

METHODS

Articles about cytokines and CHF were searched in Pubmed, EMBASE, Cochrane Library, Chinese National Knowledge Infrastructure and Chinese Wanfang Database. The pooled effects were measured by weighted mean difference (MD) and 95% CI, which were calculated by RevMan 5.1 software.

RESULTS

Finally, a total of 28 studies were included. Compared with normal control subjects, concentrations of tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6), IL-1β and C reactive protein (CRP) in the peripheral blood in CHF patients are significantly increased. The overall MDs with 95% CIs for TNF-α, IL-6, CRP and IL-1β were 2.59 pg/ml (2.14∼3.05, p<0.00001), 5.49 pg/mL (4.68∼6.29, p<0.00001), 11.45 mg/dL (7.68∼15.23, p<0.00001) and 0.11 pg/mL (0.09∼0.14, p<0.00001). The mortality of elevated IL-6 group was significantly higher than control group (OR=6.73, 95% CI 2.39∼18.93, p=0.0003).

CONCLUSIONS

Concentrations of TNF-α, IL-6, IL-1β and CRP are significantly higher in CHF patients than in control subjects. Proinflammatory cytokines play an import role in the pathogenesis of CHF.

Thyroid disease and the cardiovascular system

Thyroid hormones, specifically triiodothyronine (T3), have significant effects on the heart and cardiovascular system. Hypothyroidism, hyperthyroidism, subclinical thyroid disease, and low T3 syndrome each cause cardiac and cardiovascular abnormalities through both genomic and nongenomic effects on cardiac myocytes and vascular smooth muscle cells. In compromised health, such as occurs in heart disease, alterations in thyroid hormone metabolism may further impair cardiac and cardiovascular function. Diagnosis and treatment of cardiac disease may benefit from including analysis of thyroid hormone status, including serum total T3 levels.

Concurrent evolution of cancer cachexia and heart failure: bilateral effects exist

Cancer cachexia is defined as a multifactorial syndrome of involuntary weight loss characterized by an ongoing loss of skeletal muscle mass and progressive functional impairment. It is postulated that cardiac dysfunction/atrophy parallels skeletal muscle atrophy in cancer cachexia. Cardiotoxic chemotherapy may additionally result in cardiac dysfunction and heart failure in some cancer patients. Heart failure thus may be a consequence of either ongoing cachexia or chemotherapy-induced cardiotoxicity; at the same time, heart failure can result in cachexia, especially muscle wasting. Therefore, the subsequent heart failure and cardiac cachexia can exacerbate the existing cancer-induced cachexia. We discuss these bilateral effects between cancer cachexia and heart failure in cancer patients. Since cachectic patients are more susceptible to chemotherapy-induced toxicity overall, this may also include increased cardiotoxicity of antineoplastic agents. Patients with cachexia could thus be doubly unfortunate, with cachexia-related cardiac dysfunction/heart failure and increased susceptibility to cardiotoxicity during treatment. Cardiovascular risk factors as well as pre-existing heart failure seem to exacerbate cardiac susceptibility against cachexia and increase the rate of cardiac cachexia. Hence, chemotherapy-induced cardiotoxicity, cardiovascular risk factors, and pre-existing heart failure may accelerate the vicious cycle of cachexia-heart failure. The impact of cancer cachexia on cardiac dysfunction/heart failure in cancer patients has not been thoroughly studied. A combination of serial echocardiography for detection of cachexia-induced cardiac remodeling and computed tomography image analysis for detection of skeletal muscle wasting would appear a practical and non-invasive approach to develop an understanding of cardiac structural/functional alterations that are directly related to cachexia.

Association between the serum concentration of triiodothyronine with components of metabolic syndrome, cardiovascular risk, and diet in euthyroid post-menopausal women without and with metabolic syndrome

PURPOSE

To determine the association between the serum concentration of triiodothyronine (T3) with components of metabolic syndrome (MetS), cardiovascular risk (CVR), and diet in euthyroid post-menopausal women without and with MetS.

METHODS

A cross-sectional study was performed in 120 voluntary women of an indigenous population from Tlaxcala-México. Euthyroid status was assessed measuring the serum concentration of thyrotropin (TSH) and thyroid hormones, while that of estradiol was measured to confirm the postmenopausal condition. MetS was diagnosed using the American Heart Association/National Heart, Lung, and Blood Institute Scientific Statement (AHA/NHLBI) criterion. Estimation of CVR was calculated based on the Framingham scale. Diet components were evaluated based on survey applications. Correlations, logistic regression analyses, ANOVA or Kruskall-Wallis, and chi-square tests were used to determine significant differences (P ≤ 0.05) between women without MetS and women with MetS having different serum concentrations of T3.

RESULTS

Triiodothyronine was positively correlated with insulin but negatively correlated with glucose, high-density lipoprotein cholesterol (HDL-C), and CVR. Compared to women without MetS, women with MetS and low-normal T3 concentration showed a high risk for hyperglycemia and moderate/high risk for CVR. In contrast, a high-normal T3 concentration increased the risk to have a big waist circumference, a high concentration of HDL-C, and insulin resistance. Diet analysis showed a high grade of malnutrition in women from all groups. The intake of calories was positively affected by the T3 concentration, albeit it did not affect the extent of malnutrition.

CONCLUSIONS

In contrast to concentrations of TSH, total thyroxin (T4), and free T4, the concentration of serum T3 was strongly correlated with cardio-metabolic variables in euthyroid postmenopausal women. In comparison to women without MetS, a high-normal serum concentration of T3 in women with MetS is positively associated with reduced glycaemia and CVR but negatively related to body mass index (BMI), insulin, insulin resistance, and HDL-C. Although the analyzed population had a nutritional deficiency, both calories and iron intake were positively affected by the T3 concentration. Our results suggest the necessity of health programs monitoring T3 in old people in order to treat hyperglycemia, cardio-metabolic components, and the ageing anorexia.

Impact of triiodothyronine and N-terminal pro-B-type natriuretic peptide on the long-term survival of critically ill patients with acute heart failure

We assessed the prognostic implications of low triiodothyronine (T3) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels in critically ill patients with acute heart failure. We acquired data for 144 critical care patients with acute decompensated heart failure, of which 106 were included in this study. Plasma thyroid hormones and NT-proBNP levels were determined within 48 hours of admission. We assessed these measures for predicting all-cause and cardiac mortalities. At a mean follow-up period of 25 ± 31 months, the all-cause mortality rate was 51% (54 of 106) and the cardiac mortality rate was 70% (38 of 54). A multivariate Cox regression model showed that log-transformed NT-proBNP levels (log NT-proBNP; hazard ratio [HR] 2.90, 95% confidence interval [CI] 1.38 to 6.08, p = 0.005) and T3 levels (HR 0.98, 95% CI 0.96 to 0.99, p = 0.008) were associated with all-cause mortality, and log NT-proBNP (HR 3.70, 95% CI 1.28 to 10.71, p = 0.02) and T3 (HR 0.98, 95% CI 0.96 to 0.99, p = 0.01) were associated with cardiac mortality. Based on cut-off values for NT-proBNP (10,685 pg/ml) and T3 (52.3 ng/dl), Kaplan-Meier analyses provided significant prognostic information with the highest risk for all-cause mortality in the low T3 (≤52.3 ng/dl)/high NT-proBNP (>10,685 pg/ml) group (HR 8.54, 95% CI 4.19 to 17.40, p <0.0001). In conclusion, T3 levels appear to be independent predictors for both all-cause and cardiac mortalities among critical ill patients with heart failure, and high NT-proBNP and low T3 levels predict a worse long-term outcome.