Relating circulating thyroid hormone concentrations to serum interleukins-6 and -10 in association with non-thyroidal illnesses including chronic renal insufficiency

Involvement of toxic metals and PCBs mixture in the thyroid and male reproductive toxicity: In silico toxicogenomic data mining

Toxicological research is mostly limited to considering the effects of a single substance, even though the real exposure of people is reflected in their daily exposure to many different chemical substances in low-doses. This in silico toxicogenomic study aims to provide evidence for the selected environmental (organo)metals (lead, cadmium, methyl mercury) + polychlorinated biphenyls mixture involvement in the possible alteration of thyroid, and male reproductive system function, and furthermore to predict the possible toxic mechanisms of the environmental cocktail. The Comparative Toxicogenomic Database, GeneMANIA online software, and ToppGene Suite portal were used as the main tools for toxicogenomic data mining and gene ontology analysis. The results show that 35 annotated common genes between selected chemicals and endocrine system diseases can interact on the co-expression level. Our study highlighted the disruption of the cytokines, the cell's response to oxidative stress, and the influence of the transcription factors as the potential core of toxicological mechanisms of the discussed mixture's effects. The connected toxicological effects of the tested mixture were abnormal sperm cells, a disrupted level of testosterone, and thyroid hormones. The core mechanisms of these effects were inflammation, oxidative stress, disruption of androgen receptor signaling, and the alteration of the FOXO3-Keap-1/NRF2-HMOX1-NQO1 pathway signaling most likely controlled by the co-expression of overlapped genes among used chemicals. This in silico research can be used as a potential core for the determination of biomarkers that can be monitored in future further in vitro and in vivo experiments.

Subclinical Hypothyroidism, Kidney, and Heart from Normal to Uremic Milieu

Thyroid hormone (TH) imbalances, particularly subclinical hypothyroidism (SCHT), are associated with chronic kidney disease (CKD) and end-stage kidney disease (ESKD). SCHT is more prevalent in CKD and ESKD patients than in the general population, and this condition increases the risk of cardiovascular disease (CVD) morbidity and mortality. The risk of CVD is higher in CKD and ESKD patients compared with the general population. Traditional and nontraditional risk factors, including TH abnormalities, contribute to the high CVD burden in CKD and ESKD patients. The review discusses the link between CKD and hypothyroidism, with a focus on SCHT, and the mechanisms that lead to CVD burden.

Investigating the Predictive Value of Thyroid Hormone Levels for Stroke Prognosis

Given the expansion of life expectancy, the aging of the population, and the anticipated rise in the number of stroke survivors in Europe with severe neurological consequences in the coming decades, stroke is becoming the most prevalent cause of functional disability. Therefore, the prognosis for a stroke must be timely and precise. Two databases (MEDLINE and Scopus) were searched to identify all relevant studies published between 1 January 2005 and 31 December 2022 that investigated the relationship between thyroid hormone levels and acute stroke severity, mortality, and post-hospital prognosis. Only full-text English-language articles were included. This review includes Thirty articles that were traced and incorporated into the present review. Emerging data regarding the potential predictive value of thyroid hormone levels suggests there may be a correlation between low T3 syndrome, subclinical hypothyroidism, and poor stroke outcome, especially in certain age groups. These findings may prove useful for rehabilitation and therapy planning in clinical practice. Serum thyroid hormone concentration measurement is a non-invasive, relatively harmless, and secure screening test that may be useful for this purpose.

Thyroid dysfunction in COVID-19 patients

PURPOSE

"Non thyroidal illness syndrome" (NTIS) or "euthyroid sick syndrome" (ESS) is a possible biochemical finding in euthyroid patients with severe diseases. It is characterized by a reduction of serum T₃ (fT3), sometimes followed by reduction of serum T₄ (fT4). The relationship between thyroid hormones levels and mortality is well known and different studies showed a direct association between NTIS and mortality. The sudden spread of the 2019 novel coronavirus (SARS-CoV 2) infection (COVID-19) and its high mortality become a world healthcare problem. Our aim in this paper was to investigate if patients affected by COVID-19 presented NTIS and the relationship between thyroid function and severity of this infection.

METHODS

We evaluated the thyroid function in two different groups of consecutive patients affected by COVID-19 with respect to a control group of euthyroid patients. Group A included patients hospitalized for COVID-19 pneumonia while patients requiring intensive care unit (ICU) for acute respiratory syndrome formed the group B. Group C identified the control group of euthyroid patients.

RESULTS

Patients from group A and group B showed a statistically significant reduction in fT3 and TSH compared to group C. In group B, compared to group A, a further statistically significant reduction of fT3 and TSH was found.

CONCLUSIONS

COVID-19 in-patients can present NTIS. FT3 and TSH serum levels are lower in patients with more severe symptoms.

Brain to periphery in acute ischemic stroke: Mechanisms and clinical significance

The social and public health burdens of ischemic stroke have been increasing worldwide. In addition to focal brain damage, acute ischemic stroke (AIS) provokes systemic abnormalities across peripheral organs. AIS profoundly alters the autonomic nervous system, hypothalamic-pituitary-adrenal axis, and immune system, which further yield deleterious organ-specific consequences. Poststroke systemic pathological alterations in turn considerably contribute to the progression of ischemic brain injury, which accounts for the substantial impact of systemic complications on stroke outcomes. This review provides a comprehensive and updated pathophysiological model elucidating the systemic effects of AIS. To address their clinical significance and inform stroke management, we also outline the resulting systemic complications at particular stages of AIS and highlight the mechanisms. Future therapeutic strategies should attempt to integrate the treatment of primary brain lesions with interventions for secondary systemic complications, and should be tailored to patient individualized characteristics to optimize stroke outcomes.

Thyroid hormone status in patients with impaired kidney function

PURPOSE

We aimed to investigate the prevalence of thyroid hormone abnormalities and the relationship between free triiodothyronine (fT3), thyroid stimulating hormone (TSH) and free thyroxine (fT4) serum levels with kidney function and proteinuria in 4108 subsequent patients admitted to a Nephrology Clinic at a tertiary Medical Centre.

METHODS

All patients were categorized based on their estimated glomerular filtration rate (eGFR) as follows: normal-eGFR ≥ 60 ml/min, mild kidney impairment-30 ≤ eGFR < 60 ml/min, and severe kidney impairment-eGFR < 30 ml/min.

RESULTS

Subjects with normal eGFR presented a laboratory constellation of hypothyroidism in 3.38% and "low-T3 syndrome" in 8.28%, while subjects with severe kidney impairment were diagnosed with hypothyroidism in 2.82% and "low-T3 syndrome" in 22.9%. Multivariate regression analysis showed that eGFR was a strong independent predictor of serum fT3 levels in patients with eGFR < 60 ml/min. Impaired kidney function was associated with low fT4 and fT3 but not TSH. Our findings showed an inverse correlation of fT3 and fT4 levels and proteinuria range. FT4 inversely correlated with the extent of proteinuria in all subgroups of patients. In contrast, the inverse correlation of fT3 serum levels and proteinuria disappeared in patients with eGFR < 60 ml/min.

CONCLUSION

In a large cohort of inpatients, the prevalence of low-T3 syndrome was 2.5 times higher in patients with advanced kidney disease, compared to those with normal kidney function. In advanced CKD, both eGFR and proteinuria were strongly correlated with thyroid hormones. Therefore, close screening of the "thyroid profile" in patients with any stage of CKD, especially to those with proteinuria, might be warranted.

[Association of non-thyroidal illness syndrome with interleukin-6 and interleukin-10 in critically ill children with sepsis]

OBJECTIVE

To study the incidence rate of non-thyroidal illness syndrome (NTIS) in critically ill children with or without sepsis and the association of NTIS with interleukin-6 (IL-6) and interleukin-10 (IL-10).

METHODS

A retrospective analysis was performed on the medical data of 97 children with sepsis (sepsis group) and 80 non-sepsis children with bacterial infection (non-sepsis group). The correlations of IL-6 and IL-10 with the thyroid function parameters triiodothyronine (T3), thyroxine (T4), and thyroid stimulating hormone (TSH) were analyzed.

RESULTS

There were no significant differences in age and sex between the sepsis and non-sepsis groups (P>0.05). Compared with the non-sepsis group, the sepsis group had a significantly higher Sequential Organ Failure Assessment score, a significantly longer length of hospital stay, and a significantly higher rate of use of ventilator (P<0.05). As for inflammation markers, the sepsis group had significantly higher levels of C-reactive protein, procalcitonin, and IL-6 than the non-sepsis group (P<0.05). As for thyroid function parameters, the sepsis group had significantly lower levels of T3, T4, free T3, free T4, and TSH than the non-sepsis group (P<0.05). Compared with the non-sepsis group, the sepsis group had significantly higher incidence rates of NTIS, low T3 and T4, and low TSH (P<0.001). The correlation analysis revealed that IL-6 level was not correlated with T3, T4, and TSH levels in children with or without sepsis (P>0.05), but the pooled analysis of the two groups showed that IL-6 level was negatively correlated with T3 and T4 levels (P<0.001).

CONCLUSIONS

Children with sepsis have a higher incidence rate of NTIS than those without sepsis. The high level of IL-6 may be associated with the development of NTIS.

[Association of non-thyroidal illness syndrome with interleukin-6 and interleukin-10 in critically ill children with sepsis]

OBJECTIVE

To study the incidence rate of non-thyroidal illness syndrome (NTIS) in critically ill children with or without sepsis and the association of NTIS with interleukin-6 (IL-6) and interleukin-10 (IL-10).

METHODS

A retrospective analysis was performed on the medical data of 97 children with sepsis (sepsis group) and 80 non-sepsis children with bacterial infection (non-sepsis group). The correlations of IL-6 and IL-10 with the thyroid function parameters triiodothyronine (T3), thyroxine (T4), and thyroid stimulating hormone (TSH) were analyzed.

RESULTS

There were no significant differences in age and sex between the sepsis and non-sepsis groups (P>0.05). Compared with the non-sepsis group, the sepsis group had a significantly higher Sequential Organ Failure Assessment score, a significantly longer length of hospital stay, and a significantly higher rate of use of ventilator (P<0.05). As for inflammation markers, the sepsis group had significantly higher levels of C-reactive protein, procalcitonin, and IL-6 than the non-sepsis group (P<0.05). As for thyroid function parameters, the sepsis group had significantly lower levels of T3, T4, free T3, free T4, and TSH than the non-sepsis group (P<0.05). Compared with the non-sepsis group, the sepsis group had significantly higher incidence rates of NTIS, low T3 and T4, and low TSH (P<0.001). The correlation analysis revealed that IL-6 level was not correlated with T3, T4, and TSH levels in children with or without sepsis (P>0.05), but the pooled analysis of the two groups showed that IL-6 level was negatively correlated with T3 and T4 levels (P<0.001).

CONCLUSIONS

Children with sepsis have a higher incidence rate of NTIS than those without sepsis. The high level of IL-6 may be associated with the development of NTIS.

Low Tri-iodothyronine Syndrome Is Associated With Cognitive Impairment in Patients With Acute Ischemic Stroke: A Prospective Cohort Study

OBJECTIVE

Low tri-iodothyronine (T3) syndrome is a predictor of poor prognosis in patients with stroke. Poststroke cognitive impairment (PSCI) is a common and important complication after stroke. The association between low T3 syndrome and PSCI is unclear. We aimed to explore the potential relationship between low T3 syndrome and PSCI in the acute phase of ischemic stroke at a 1-month follow-up visit.

METHODS

In total, 314 ischemic stroke patients were consecutively enrolled in the study and followed up at 1 month. Thyroid hormones were measured within 24 hours after admission. Cognitive function was evaluated by the Mini-Mental State Exam (MMSE) 1 month after acute ischemic stroke. Cognitive impairment was defined as an MMSE score of less than 27. Cognitive impairment severity was categorized as severe, mild, or none (MMSE score <23, 23-26, or ≥27, respectively).

RESULTS

According to the MMSE score, 182 participants (58.0%) had cognitive impairment 1 month after stroke. Patients with low T3 syndrome were more prone to have cognitive impairment than patients with normal levels of T3 (p < 0.001). After adjusting for potential confounders in our logistic model, low T3 syndrome was independently associated with PSCI (odds ratio 4.319, 95% confidence interval 1.553-12.013, p = 0.005).

CONCLUSION

Low T3 syndrome in the acute phase of ischemic stroke was associated with a higher prevalence of 1-month PSCI, independently of established risk factors.

Thyroid Allostasis-Adaptive Responses of Thyrotropic Feedback Control to Conditions of Strain, Stress, and Developmental Programming

The hypothalamus-pituitary-thyroid feedback control is a dynamic, adaptive system. In situations of illness and deprivation of energy representing type 1 allostasis, the stress response operates to alter both its set point and peripheral transfer parameters. In contrast, type 2 allostatic load, typically effective in psychosocial stress, pregnancy, metabolic syndrome, and adaptation to cold, produces a nearly opposite phenotype of predictive plasticity. The non-thyroidal illness syndrome (NTIS) or thyroid allostasis in critical illness, tumors, uremia, and starvation (TACITUS), commonly observed in hospitalized patients, displays a historically well-studied pattern of allostatic thyroid response. This is characterized by decreased total and free thyroid hormone concentrations and varying levels of thyroid-stimulating hormone (TSH) ranging from decreased (in severe cases) to normal or even elevated (mainly in the recovery phase) TSH concentrations. An acute versus chronic stage (wasting syndrome) of TACITUS can be discerned. The two types differ in molecular mechanisms and prognosis. The acute adaptation of thyroid hormone metabolism to critical illness may prove beneficial to the organism, whereas the far more complex molecular alterations associated with chronic illness frequently lead to allostatic overload. The latter is associated with poor outcome, independently of the underlying disease. Adaptive responses of thyroid homeostasis extend to alterations in thyroid hormone concentrations during fetal life, periods of weight gain or loss, thermoregulation, physical exercise, and psychiatric diseases. The various forms of thyroid allostasis pose serious problems in differential diagnosis of thyroid disease. This review article provides an overview of physiological mechanisms as well as major diagnostic and therapeutic implications of thyroid allostasis under a variety of developmental and straining conditions.

Distinct Features of Nonthyroidal Illness in Critically Ill Patients With Infectious Diseases

Nonthyroidal illness (NTI), often observed in critically ill patients, arises through diverse alterations in the hypothalamus-pituitary-thyroid (HPT) axis. However, the causal relationship between underlying disease and NTI diversity in critically ill patients is poorly understood.The aim of this study was to examine NTI severity and adverse outcomes in critically ill patients with respect to their underlying disease(s).The medical records of 616 patients admitted to the intensive care unit (ICU) between January 2009 and October 2014 were retrospectively reviewed. Patients with known diseases or taking medications that affect thyroid function were excluded. All-cause mortality (ACM) and length of stay (LOS) in the ICU were assessed as adverse outcomes.The enrolled patients (n = 213) were divided into the following 4 groups according to the severity of NTI at the nadir of their thyroid function test (TFT): normal (n = 11, 5.2%), mild NTI (n = 113, 53.1%), moderate NTI (n = 78, 36.6%), and severe NTI (n = 11, 5.2%). There was no significant difference between the groups in terms of age and gender. NTI severity showed a significantly strong association with ACM (P < 0.0001) and a significant positive association with LOS in the ICU (P = 0.031). After adjusting for age, gender, and current medications affecting TFT, increasing NTI severity led to increased ACM (odds ratio = 3.101; 95% confidence interval = 1.711-5.618; P < 0.0001). Notably, the prevalence of moderate-to-severe NTI was markedly higher in patients with infectious disease than in those with noninfectious disease (P = 0.012). Consistent with this, serum C-reactive protein levels were higher in patients with moderate-to-severe NTI (P = 0.016).NTI severity is associated with increased ACM, LOS, and underlying infectious disease. Future studies will focus on the biological and clinical implications of infectious disease on the HPT axis.

Comparison and relationship of thyroid hormones, IL-6, IL-10 and albumin as mortality predictors in case-mix critically ill patients

OBJECTIVE

To compare the ability of thyroid hormones, IL-6, IL-10, and albumin to predict mortality, and to assess their relationship in case-mix acute critically ill patients.

METHODS

APACHE II scores and serum thyroid hormones (FT3, FT4, and TSH), IL-6, IL-10, and albumin were obtained at EICU admission for 79 cases of mix acute critically ill patients without previous history of thyroid disease. Patients were followed for 28 days with patient's death as the primary outcome. All mean values were compared, correlations assessed with Pearson' test, and mortality prediction assessed by multivariate logistic regression and ROC.

RESULTS

Non survivors were older, with higher APACHE II score (p=0.000), IL-6 (p<0.05), IL-10 (p=0.000) levels, and lower albumin (p=0.000) levels compared to survivors at 28 days. IL-6 and IL-10 had significant negative correlation with albumin (p=0.001) and FT3 (p ⩽ 0.05) respectively, while low albumin had a direct correlation with FT3 (p<0.05). In the mortality prediction assessment, IL-10, albumin and APACHE II were independent morality predictors and showed to have a good (0.70-0.79) AUC-ROC (p<0.05). Despite that the entire cohort showed low FT3 serum levels (p=0.000), there was not statistical difference between survivors and non-survivors; neither showed any significance as mortality predictor.

CONCLUSIONS

IL-6 and IL-10 are correlated with Low FT3 and hypoalbuminemia. Thyroid hormones assessed at EICU admission did not have any predictive value in our study. And finally, high levels of IL-6 and IL-10 in conjunction with albumin could improve our ability to evaluate disease's severity and predict mortality in the critically ill patients. When use in combination with APACHE II scores, our model showed improved mortality prediction.

Effects of long-term dietary nitrate supplementation in mice

Background

Inorganic nitrate (NO3-) is a precursor of nitric oxide (NO) in the body and a large number of short-term studies with dietary nitrate supplementation in animals and humans show beneficial effects on cardiovascular health, exercise efficiency, host defense and ischemia reperfusion injury. In contrast, there is a long withstanding concern regarding the putative adverse effects of chronic nitrate exposure related to cancer and adverse hormonal effects. To address these concerns we performed in mice, a physiological and biochemical multi-analysis on the effects of long-term dietary nitrate supplementation.

Design

7 week-old C57BL/6 mice were put on a low-nitrate chow and at 20 weeks-old were treated with NaNO₃ (1 mmol/L) or NaCl (1 mmol/L, control) in the drinking water. The groups were monitored for weight gain, food and water consumption, blood pressure, glucose metabolism, body composition and oxygen consumption until one group was reduced to eight animals due to death or illness. At that point remaining animals were sacrificed and blood and tissues were analyzed with respect to metabolism, cardiovascular function, inflammation, and oxidative stress.

Results

Animals were supplemented for 17 months before final sacrifice. Body composition, oxygen consumption, blood pressure, glucose tolerance were measured during the experiment, and vascular reactivity and muscle mitochondrial efficiency measured at the end of the experiment with no differences identified between groups. Nitrate supplementation was associated with improved insulin response, decreased plasma IL-10 and a trend towards improved survival.

Conclusions

Long term dietary nitrate in mice, at levels similar to the upper intake range in the western society, is not detrimental.

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Long term dietary nitrate supplementation for 17 months in mice.

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Nitrate treatment in the upper range in the western society diet, has no adverse health effects.

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Chronic nitrate intake in mice improves fasting insulin and insulin response.

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Cardiovascular and inflammatory parameters were unchanged after long-term dietary nitrate treatment.

Low T3 syndrome in canine babesiosis associated with increased serum IL-6 concentration and azotaemia

Low triiodothyronine (T3) syndrome, also named euthyroid sick syndrome or non-thyroidal illness syndrome, has been recognized in canine babesiosis caused by Babesia rossi, where it manifested by lowering of the serum thyrotropin (TSH), total thyroxin (TT4) and free thyroxin (FT4) concentrations. This syndrome has also been observed in critical diseases in humans and animals, and the severity of the disease is considered an important factor in lowering of thyroid hormone concentrations. Interleukin-6 (IL-6) plays a role in the development of low T3 syndrome by causing a decrease in deiodinases 1 and 2 activity and increased activity of deiodinase 3, enzymes involved in the conversion of thyroxin (T4) to T3. The purpose of this study was to compare the concentrations of serum thyroid hormones and TSH between healthy dogs and dogs with babesiosis, and to determine correlations between serum IL-6 concentration and serum total T3 (TT3), TT4, FT4, and TSH concentrations, and the level of azotaemia in dogs with babesiosis. The concentrations of IL-6, TT3, TT4, FT4, TSH, urea and creatinine were determined in 13 dogs with canine babesiosis caused by Babesia canis and in 10 healthy dogs. The results of this study showed decreases in TT3, TT4, FT4, and TSH and increases in IL-6, urea and creatinine concentrations in affected dogs in comparison to healthy dogs. The concentration of IL-6 was negatively correlated with TT3 and TSH concentrations and the TT3 concentration was negatively correlated with serum urea and creatinine concentrations. This study showed low T3 syndrome in canine babesiosis, which was confirmed by the determination of the T3 concentration, and demonstrates that in canine babesiosis the T3 concentration is associated with IL-6 concentration.

Thyroid functional disease: an under-recognized cardiovascular risk factor in kidney disease patients

Thyroid functional disease, and in particular hypothyroidism, is highly prevalent among chronic kidney disease (CKD) and end-stage renal disease (ESRD) patients. In the general population, hypothyroidism is associated with impaired cardiac contractility, endothelial dysfunction, atherosclerosis and possibly higher cardiovascular mortality. It has been hypothesized that hypothyroidism is an under-recognized, modifiable risk factor for the enormous burden of cardiovascular disease and death in CKD and ESRD, but this has been difficult to test due to the challenge of accurate thyroid functional assessment in uremia. Low thyroid hormone levels (i.e. triiodothyronine) have been associated with adverse cardiovascular sequelae in CKD and ESRD patients, but these metrics are confounded by malnutrition, inflammation and comorbid states, and hence may signify nonthyroidal illness (i.e. thyroid functional test derangements associated with underlying ill health in the absence of thyroid pathology). Thyrotropin is considered a sensitive and specific thyroid function measure that may more accurately classify hypothyroidism, but few studies have examined the clinical significance of thyrotropin-defined hypothyroidism in CKD and ESRD. Of even greater uncertainty are the risks and benefits of thyroid hormone replacement, which bear a narrow therapeutic-to-toxic window and are frequently prescribed to CKD and ESRD patients. In this review, we discuss mechanisms by which hypothyroidism adversely affects cardiovascular health; examine the prognostic implications of hypothyroidism, thyroid hormone alterations and exogenous thyroid hormone replacement in CKD and ESRD; and identify areas of uncertainty related to the interplay between hypothyroidism, cardiovascular disease and kidney disease requiring further investigation.

The Evaluation of Dipeptidyl Peptidase (DPP)-IV, α-Glucosidase and Angiotensin Converting Enzyme (ACE) Inhibitory Activities of Whey Proteins Hydrolyzed with Serine Protease Isolated from Asian Pumpkin (Cucurbita ficifolia)

In the present study, whey protein concentrate (WPC-80) and β-lactoglobulin were hydrolyzed with a noncommercial serine protease isolated from Asian pumpkin (Cucurbita ficifolia). Hydrolysates were further fractionated by ultrafiltration using membranes with cut-offs equal 3 and 10 kDa. Peptide fractions of molecular weight lower than 3 and 3-10 kDa were further subjected to the RP-HPLC. Separated preparations were investigated for their potential as the natural inhibitors of dipeptidyl peptidase (DPP-IV), α-glucosidase and angiotensin converting enzyme (ACE). WPC-80 hydrolysate showed higher inhibitory activities against the three tested enzymes than β-lactoglobulin hydrolysate. Especially high biological activities were exhibited by peptide fractions of molecular weight lower than 3 kDa, with ACE IC50 <0.64 mg/mL and DPP-IV IC50 <0.55 mg/mL. This study suggests that peptides generated from whey proteins may support postprandial glycemia regulation and blood pressure maintenance, and could be used as functional food ingredients in the diet of patients with type 2 diabetes.

Elevated arterial stiffness and diastolic dysfunction in subclinical hypothyroidism

BACKGROUND

Thyroid hormone is associated with arterial stiffness and left ventricular diastolic function in hypothyroid disease. The relationship of thyroid hormone level to cardio-ankle vascular index (CAVI) and left ventricular diastolic function, however, remains unclear in subjects with subclinical hypothyroidism.

METHODS AND RESULTS

We conducted a cross-sectional study of 83 patients with untreated subclinical hypothyroidism and compared them with 83 randomly selected controls from health check-ups. Log N-terminal prohormone of brain natriuretic peptide (NT-proBNP), C-reactive protein (CRP), and arterial stiffness were measured. In addition, we measured early diastolic mitral annular velocity (E') in 43 participants with subclinical hypothyroidism and in 40 controls. When compared with the control group, patients with subclinical hypothyroidism had higher logNT-proBNP (1.9±0.5 vs. 1.7±0.3pg/ml, P<0.05), CRP (0.22±0.04 vs. 0.09±0.06mg/dl, P<0.05), and CAVI (8.8±1.7 vs. 7.8±1.4, P<0.001) and lower E' (5.8±1.7 vs. 7.5±2.1cm/s, P<0.001). CAVI was significantly associated with logNT-proBNP, CRP and E' in the subclinical hypothyroidism group.

CONCLUSIONS

High logNT-proBNP was associated with a raised CAVI in patients with subclinical hypothyroidism. Subclinical hypothyroidism may be a risk factor for cardiovascular events related to arterial stiffening and left ventricular diastolic dysfunction.

Ischemic stroke functional outcomes are independently associated with C-reactive protein concentrations and cognitive outcomes with triiodothyronine concentrations: a pilot study

Elevated concentrations of C-reactive protein (CRP) and decreased concentrations of triiodothyronine (T3) were shown to predict poor outcomes in patients with stroke. However, the prognostic value of CRP and T3 has not been studied simultaneously in relation to stroke functional and cognitive outcomes despite of close interaction between inflammatory markers and thyroid function. We evaluated the association of thyroid hormone and CRP concentrations with immediate outcomes after ischemic stroke. Eighty-eight ischemic stroke patients on admission to the stroke unit were evaluated for clinical stroke severity (Scandinavian stroke scale or SSS) and concentrations of thyroid-stimulating hormone, free thyroxin, free T3, and CRP. Functional outcome (modified Rankin scale) and cognitive outcome (Mini mental state examination) were evaluated at discharge. Greater ln CRP concentrations (r = -0.35, p = 0.001), but not thyroid hormone concentrations, correlated with score on the SSS. In univariate analyses lower free T3 concentrations and higher CRP concentrations were associated with poor functional and poor cognitive outcomes. After adjustment for clinical stroke severity, higher CRP concentrations (β = 0.18, p = 0.04) remained associated with worse functional outcome and lower free T3 concentrations with worse cognitive outcome (β = 0.23, p = 0.03). In sum, clinical stroke severity is associated with elevated CRP concentration. Higher CRP concentration is independently associated with worse functional outcomes and lower free T3 concentration with worse cognitive outcomes at discharge. T3 and CRP can be important biomarkers in patients with acute ischemic stroke.

Nonthyroidal illness and the cardiorenal syndrome

The cardiorenal syndrome represents a final common pathway for renal and congestive heart failure and heralds a poor prognosis. Factors that link the failing heart and the failing kidneys--the so-called cardiorenal connectors--are, therefore, of clinical and therapeutic interest. Alterations in the levels and function of thyroid hormones that fit the spectrum of nonthyroidal illnesses could be considered to be cardiorenal connectors as both renal failure and heart failure progress with the development of nonthyroidal illness. In addition, circumstantial evidence suggests that nonthyroidal illness can induce deterioration in the function of the heart and the kidneys via multiple pathways. As a consequence, these reciprocal associations could result in a vicious cycle of deterioration that likely contributes to increased mortality. In this Review, we describe the evidence for a pathophysiological role of nonthyroidal illness in the cardiorenal syndrome. We also discuss the available data from studies that have investigated the efficacy of thyroid hormone replacement therapy in patients with renal failure and the rationale for interventional trials to examine the effects of normalization of the thyroid hormone profile in patients with renal failure and congestive heart failure.

Association of serum triiodothyronine with B-type natriuretic peptide and severe left ventricular diastolic dysfunction in heart failure with preserved ejection fraction

There are well-documented changes in thyroid hormone metabolism that accompany heart failure (HF). However, the frequency of thyroid hormone abnormalities in HF with preserved ejection fraction (HFpEF) is unknown, and no studies have investigated the association between triiodothyronine (T(3)) and markers of HF severity (B-type natriuretic peptide [BNP] and diastolic dysfunction [DD]) in HFpEF. In this study, 89 consecutive patients with HFpEF, defined as symptomatic HF with a left ventricular ejection fraction >50% and a left ventricular end-diastolic volume index <97 ml/m(2), were prospectively studied. Patients were dichotomized into 2 groups on the basis of median T(3) levels, and clinical, laboratory, and echocardiographic data were compared between groups. Univariate and multivariate linear regression analyses were performed to determine whether BNP and DD were independently associated with T(3) level. We found that 22% of patients with HFpEF had reduced T(3). Patients with lower T(3) levels were older, were more symptomatic, more frequently had hyperlipidemia and diabetes, and had higher BNP levels. Severe (grade 3) DD, higher mitral E velocity, shorter deceleration time, and higher pulse pressure/stroke volume ratio were all associated with lower T(3) levels. T(3) was inversely associated with log BNP (p = 0.004) and the severity of DD (p = 0.039). On multivariate analysis, T(3) was independently associated with log BNP (β = -4.7 ng/dl, 95% confidence interval -9.0 to -0.41 ng/dl, p = 0.032) and severe DD (β = -16.3 ng/dl, 95% confidence interval -30.1 to -2.5 ng/dl, p = 0.022). In conclusion, T(3) is inversely associated with markers of HFpEF severity (BNP and DD). Whether reduced T(3) contributes to or is a consequence of increased severity of HFpEF remains to be determined.

Thyroid hormone and cardiac repair/regeneration: from Prometheus myth to reality?

Nature's models of repair and (or) regeneration provide substantial evidence that a natural healing process may exist in the heart. The potential for repair and (or) regeneration has been evolutionarily conserved in mammals, and seems to be restricted to the early developmental stages. This window of regeneration is reactivated during the disease state in which fetal gene reprogramming occurs in response to stress. Analogies exist between the damaged and developing heart, indicating that a regulatory network that drives embryonic heart development may control aspects of heart repair and (or) regeneration. In this context, thyroid hormone (TH), which is a critical regulator of the maturation of the myocardium, appears to have a reparative role later in adult life. Changes in TH - thyroid hormone receptor (TR) homeostasis govern the return of the injured myocardium to the fetal phenotype. Accordingly, TH can induce cardiac repair and (or) regeneration by reactivating developmental gene programming. As a proof of concept in humans, TH is found to be an independent determinant of functional recovery and mortality after myocardial infarction. The potential of TH to regenerate and (or) repair the ischemic myocardium is now awaited to be tested in clinical trials.

A low fT3 level as a prognostic marker in patients with acute myocardial infarctions

OBJECTIVE

To investigate the association between low free triiodothyronine (fT3) levels and the severity and prognosis of patients with acute myocardial infarction.

METHODS

A total of 501 patients with acute myocardial infarctions were enrolled in our study. The circulating levels of thyroid hormones and clinical parameters were assayed. The patients were categorized into either the low fT3 group or the normal fT3 group according to the fT3 level on admission. All patients underwent a follow-up for 10±2 months for mortality from any cause and the occurrence of any adverse major cardiac events (MACE).

RESULTS

There were 171 patients in the low fT3 group (fT3<3.5 pmol/L) and 330 patients in the normal fT3 group (≥3.5 pmol/L). During the follow-up period, 33 patients died (6.6%) and the overall survival rates were 86.0% and 97.3% in patients with a low fT3 level and a normal fT3 level, respectively. The rates of MACE were 66.7% and 45.5% in the patients with and those without low fT3 levels, respectively. Using a multivariable Cox proportional hazards model, the fT3 level was found to be the most important predictor of cumulative death and MACE (hazard ratio [HR] for death: 0.142, p<0.001 and HR for major adverse cardiac events: 0.748, p=0.007). A Kaplan-Meier analysis revealed that those patients with low fT3 levels had higher rates of MACE and death.

CONCLUSION

A low fT3 level, a common phenomenon in patients with acute myocardial infarctions, is a strong predictor of short-term and long-term poor prognoses in patients with acute myocardial infarctions.

Triiodothyronine and brain natriuretic peptide: similar long-term prognostic values for chronic heart failure

Although low levels of free triiodothyronine and high levels of brain natriuretic peptide have been shown as independent predictors of death in chronic heart failure patients, few studies have compared their prognostic values. The aim of this prospective study was to measure free triiodothyronine and brain natriuretic peptide levels and to compare their prognostic values among such patients.A total of 334 patients (mean age, 62 ± 13 yr; 218 men) with ischemic and nonischemic dilated cardiomyopathy were included in the study. The primary endpoint was a major cardiac event.During the follow-up period, 92 patients (28%) experienced a major cardiac event. Mean free triiodothyronine levels were lower and median brain natriuretic peptide levels were higher in patients with major cardiac events than in those without. A significant negative correlation was found between free triiodothyronine and brain natriuretic peptide levels. Receiver operating characteristic curve analysis showed that the predictive cutoff values were < 2.12 pg/mL for free triiodothyronine and > 686 pg/mL for brain natriuretic peptide. Cumulative survival was significantly lower among patients with free triiodothyronine < 2.12 pg/mL and among patients with brain natriuretic peptide > 686 pg/mL. In multivariate analysis, the significant independent predictors of major cardiac events were age, free triiodothyronine, and brain natriuretic peptide.In the present study, free triiodothyronine and brain natriuretic peptide had similar prognostic values for predicting long-term prognosis in chronic heart failure patients. These results also suggested that combining these biomarkers may provide an important risk indicator for patients with heart failure.

Relationship between triiodothyronine and proinflammatory cytokines in chronic heart failure

Cytokines and thyroid hormones are involved in the biochemical changes associated to heart failure (HF).

AIM

Aims of the study were to investigate: plasma circulating levels of the cytokines Interleukine-6 (IL-6) TNF alpha and C reactive protein (CRP) in patients with stable HF in relation to the severity of left ventricular dysfunction; the relationship between these inflammatory markers and thyroid hormones.

METHODS

One-hundred and sixty-six patients (121 males, age 64+/-12), with non-ischemic cardiomyopathy, were admitted to the Institute of Clinical Physiology for progressive deterioration of symptoms. Forty-eight healthy subjects (30 males, age range 26-75 years) were also enrolled as control group (Group N). High sensitivity (hs)-IL-6 and hs-TNFalpha were quantified using solid phase sandwich ELISA kits. Hs-CRP was measured by Immulite System.

RESULTS

In the whole population (HF and N), the association between inflammatory markers and age resulted statistically significant only for IL-6 serum concentration (p<0.001) but not for TNFalpha and CRP. IL-6 and TNFalpha were strongly higher in the HF in comparison with N (p<0.001) while CRP showed a less significant difference (p<0.05). Whole population showed a negative association between IL-6 and EF% and between CRP and EF% (respectively p<0.01, r=-0.23; p<0.05, r=0.19). Comparing normal subjects with two classes of patients, respectively with EF>35% and EF<35%, we clearly observed the progressive enhancement of the inflammatory markers. Considering normal subjects, patients without and with low T3 syndrome, IL-6 and TNFalpha increased progressively from normal to patients with fT3<2 pg/ml (p<0.01 and p<0.01) while CRP only respect to the group with low T3 syndrome (p<0.01). The inflammatory markers were all inversely correlated with FT3 levels.

CONCLUSION

Because low FT3 serum concentration represents a negative prognostic index, it is likely that impairment of T3 production and enhanced inflammation represent pathogenic mechanisms linked to HF progression.

Sex-specific pediatric percentiles for ventricular size and mass as reference values for cardiac MRI: assessment by steady-state free-precession and phase-contrast MRI flow

BACKGROUND

Cardiac MRI is important in the treatment of children with congenital heart disease, but sufficient normative data are lacking. For ventricular volumes and mass, we sought to deliver reference centiles and to investigate sex effects.

METHODS AND RESULTS

We included 114 healthy children and adolescents, uniformly distributed spanning an age range of 4 to 20 years, as required by the Lambda-Mu-Sigma method to achieve a percentile distribution, thus avoiding arbitrary age categories. Subjects underwent axial volumetry (1.5-T scanner) using standardized 2D steady-state free-precession and flow protocols. Percentiles were computed for age 8 to 20 years (99 subjects) because breath-holds were more consistent in this group. When indexed for body surface area or height, the centile curves of ventricular volumetric parameters showed allometric increase until adolescence, when a plateau was reached, with values comparable to published adult reference data. In contrast, ventricular mass centiles increased without plateau. There was a significant sex difference, with centiles reflecting larger values in boys than in girls (P<0.05) when ventricular volumes were indexed to body surface area or height but not when indexed to weight (exception: mass). There was excellent agreement of axial and short-axis volumetry and of volumetric and flow-derived stroke volumes.

CONCLUSIONS

Percentiles for ventricular volumes and mass in healthy children have been established to serve as reference values in pediatric heart disease. Significant sex differences were noted when indexing volumes to body surface area or height. Unisex centiles related to weight may be considered for chamber volumes albeit not for mass.