The sick euthyroid syndrome: changes in thyroid hormone serum parameters and hormone metabolism

Role of thyroid function in non-basal ganglia intracerebral hemorrhage prognosis

PURPOSE

Thyroid function disorders serve as unfavorable prognosis predictors for numerous diseases. However, their role in predicting intracerebral hemorrhage outcome is unclear. This study investigated the prognostic potential of thyroid function parameters for intracerebral hemorrhage.

METHODS

Admissions for intracerebral hemorrhage caused by hypertension were retrospectively enrolled to determine thyroid function levels. Patients were subjected to three month- and three year-follow up to assess short- and long-term prognosis, respectively.

RESULTS

Elevated levels of thyroxine and decreased levels of free triiodothyronine (fT3) are associated with unfavorable short-term prognosis in non-basal ganglia intracerebral hemorrhage patients. The levels of thyroid stimulating hormone and free tetraiodothyronine did not exhibit any significant change. This alteration in thyroid function was not observed in basal-ganglia intracerebral hemorrhage patients. Furthermore, the inclusion of thyroxine and fT3 enhanced the prognostic power of the traditional model (NIHSS only) in predicting short-term outcomes. Among patients 55 years or older, subgroup analyses results are consistent with previous findings. Additionally, our clinical model is also applicable towards predicting the long-term prognosis of non-basal ganglia intracerebral hemorrhage.

CONCLUSION

Thyroid function concentrations, especially the levels of thyroxine and fT3, could serve as key prognostic predictors for non-basal ganglia cerebral hemorrhage, especially among the middle-aged and elderly groups.

Cytokine Storm-Induced Thyroid Dysfunction in COVID-19: Insights into Pathogenesis and Therapeutic Approaches

Angiotensin-converting enzyme 2 receptors (ACE2R) are requisite to enter the host cells for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). ACE2R is constitutive and functions as a type I transmembrane metallo-carboxypeptidase in the renin-angiotensin system (RAS). On thyroid follicular cells, ACE2R allows SARS-CoV-2 to invade the thyroid gland, impose cytopathic effects and produce endocrine abnormalities, including stiff back, neck pain, muscle ache, lethargy, and enlarged, inflamed thyroid gland in COVID-19 patients. Further damage is perpetuated by the sudden bursts of pro-inflammatory cytokines, which is suggestive of a life-threatening syndrome known as a "cytokine storm". IL-1β, IL-6, IFN-γ, and TNF-α are identified as the key orchestrators of the cytokine storm. These inflammatory mediators upregulate transcriptional turnover of nuclear factor-kappa B (NF-κB), Janus kinase/signal transducer and activator of transcription (JAK/STAT), and mitogen-activated protein kinase (MAPK), paving the pathway for cytokine storm-induced thyroid dysfunctions including euthyroid sick syndrome, autoimmune thyroid diseases, and thyrotoxicosis in COVID-19 patients. Targeted therapies with corticosteroids (dexamethasone), JAK inhibitor (baricitinib), nucleotide analogue (remdesivir) and N-acetyl-cysteine have demonstrated effectiveness in terms of attenuating the severity and frequency of cytokine storm-induced thyroid dysfunctions, morbidity and mortality in severe COVID-19 patients. Here, we review the pathogenesis of cytokine storms and the mechanisms and pathways that establish the connection between thyroid disorder and COVID-19. Moreover, cross-talk interactions of signalling pathways and therapeutic strategies to address COVID-19-associated thyroid diseases are also discussed herein.

Relationship between serum thyroid hormone and interleukin-1b levels and postmortem tissue deiodinase activity in critically ill patients

Background

This study investigated the relationship between serum thyroid hormones and interleukin-1b (IL-1β) levels and postmortem tissue deiodinase activity in critically ill patients.

Methods

Serum thyroid hormones and IL-1β were measured on the 5th, 15th, and last day of 80 critically ill patients. Forty of these patients were non-survived, and liver and skeletal muscle were harvested to analyze type 1, 2, and 3 iodothyronine deiodinases (D1, D2, and D3) activity.

Thyroid Disorders

This article includes a review of information primary care physicians need to know direct their evaluation and treatment of thyroid disorders that include sick euthyroid, hyperthyroidism, hypothyroidism, and subclinical thyroid disorders.

Thyroid function tests during nonthyroidal illness syndrome and recovery in acutely ill dogs

BACKGROUND

Nonthyroidal illness syndrome (NTIS) can result in thyroid function test alterations that mimic hypothyroidism. The duration of NTIS-induced changes in dogs is not well-described.

OBJECTIVES

Document alterations in thyroid function tests during NTIS and recovery, and the time necessary for their resolution.

ANIMALS

From 103 dogs sampled, 25 euthyroid dogs with acute, resolvable illness having a low serum total thyroxine (TT4) concentration on admission were analyzed.

METHODS

Prospective observational study. Serum TT4 concentration was measured in 103 dogs within 4 hours of admission. If below the reference interval (RI), subsequent serum samples were obtained every 24 hours from admission until discharge (acute phase) and at 2 weeks and 4 weeks after discharge (recovery phase). Serum samples were submitted for batch measurement of serum TT4, free thyroxine (fT4), total 3,5,3'-triiodothyronine (TT3), and thyroid-stimulating hormone (TSH) concentrations.

RESULTS

In the cohort of dogs analyzed, serum TT4, TT3, and fT4 concentrations were below the RI in 100%, 80%, and 16% at admission; 20%, 80%, and 0% at discharge; 4%, 8%, and 0% at 2 weeks; and 0%, 0%, and 0% at 4 weeks, respectively. Serum TSH concentration was within the RI in 100% at admission and discharge, and above the RI in 4% and 12% at 2 weeks and 4 weeks, respectively.

CONCLUSIONS AND CLINICAL IMPORTANCE

Naturally occurring NTIS in dogs induces alterations in thyroid function tests during acute illness and recovery. Measurement of serum TT4 concentration 2 to 4 weeks after discharge or serum fT4 concentration by ED during illness is recommended for accurate assessment of thyroid function in acutely ill dogs.

Critically ill patients: Histopathological evidence of thyroid dysfunction

PURPOSE

Critical illness is characterized by severe biphasic physical and metabolic stress as result of systemic inflammatory response syndrome and/or multiple organ dysfunction syndrome, and is frequently associated with non-thyroidal illness. Purpose of this study is to better understand the cytomorphological basis of NTI by performing histopathological examinations of thyroid gland on autopsies of patients who died from critical illness.

METHODS

Histopathological examination of thyroid gland of 58 critically ill patients was performed in our hospital. The cases included 24 cases of burn injury, 24 cases of traumatic brain injury, and 10 cases of cerebral stroke. Thyroid samples obtained during autopsy were preserved in formol saline and stained with hematoxylin and eosin. The sections were visualized under light microscopy.

RESULTS

Out of 58 cases examined, 21 patients showed normal thyroid findings, and rest of the cases had unusual thyroid findings in the histopathological study. The principal finding was distortion of thyroid follicular architecture. Other findings include mononuclear cell infiltration, clumping of thyroglobulin, and exhaustion of thyroid follicles.

CONCLUSION

Critical illness produces metabolically damaging effects on thyroid gland, which functionally corresponds to a state of low T3 syndrome. These changes are more pronounced in BI and cerebral stroke than in TBI.

Low T3 syndrome is associated with 30-day mortality in adult patients with fulminant myocarditis

Background

Fulminant myocarditis (FM) is a critical disease with high early mortality. Low triiodothyronine syndrome (LT3S) was a strong predictor of poor prognosis of critical diseases. This study investigated whether LT3S was associated with 30-day mortality in FM patients.

Methods

Ninety-six FM patients were divided into LT3S (n=39, 40%) and normal free triiodothyronine (FT3) (n=57, 60%) groups based on serum FT3 level. Univariable and multivariable logistic regression analyses were performed to identify independent predictors of 30-day mortality. Kaplan-Meier curve was used to compare 30-day mortality between two groups. Receiver operating characteristic (ROC) curve and decision curve analysis (DCA) were used to assess the value of FT3 level for 30-day mortality prediction.

Results

Compared to normal FT3 group, LT3S group had higher incidence of ventricular arrhythmias, worse hemodynamics, worse cardiac function, more severe kidney impairment, and higher 30-day mortality (48.7% vs. 12.3%, P<0.001). In univariable analysis, LT3S (odds ratio [OR]:6.786, 95% confidence interval [CI]:2.472-18.629, P<0.001) and serum FT3 (OR:0.272, 95%CI:0.139-0.532, P<0.001) were significant strong predictors of 30-day mortality. After adjustment for confounders in multivariable analysis, LT3S (OR:3.409, 95%CI:1.019-11.413, P=0.047) and serum FT3 (OR:0.408, 95%CI:0.199-0.837, P=0.014) remained independent 30-day mortality predictors. The area under the ROC curve of FT3 level was 0.774 (cut-off: 3.58, sensitivity: 88.46%, specificity: 62.86%). In DCA, FT3 level showed good clinical-application value for 30-day mortality prediction.

Conclusion

In FM patients, LT3S could independently predict 30-day mortality. FT3 level was a strong 30-day mortality predictor and a potentially useful risk-stratification biomarker.

[The impact of low T3 syndrome on the prognosis of patients with newly diagnosed multiple myeloma]

Objective: This study aimed to examine the relationship between low T3 syndrome (LT3S) and the prognosis of newly diagnosed multiple myeloma (NDMM) patients. Methods: A retrospective examination of 211 NDMM patients treated at the Department of Hematology, Jiangsu Provincial People's Hospital from July 2009 to December 2020 was performed, and all patients received thyroid function testing to determine if they had LT3S. We investigated the relationship between LT3S and clinical features, as well as its impact on MM prognosis. Results: Of the 211 patients, 119 were males, and 92 were females, with a median age of 60 (33-86) years. Patients with LT3S had significantly higher levels of β(2)-microglobulin, C-reactive protein, and blood creatinine compared to those with normal T3 levels. They also had lower levels of hemoglobin, platelets, and serum albumin, as well as more advanced ISS stages (P<0.001) . Patients with LT3S had shorter progression-free survival (PFS) (16 months vs 30 months, P=0.003) and overall survival (OS) (57 months vs 75 months, P=0.004) than patients without LT3S. LT3S was found to be a standalone unfavorable factor in multivariate analysis, LT3S was an independent unfavorable factor in predicting both PFS (HR=2.114, 95% CI 1.271-3.516, P=0.004) and OS (HR=2.231, 95% CI 1.088-4.577, P=0.029) . Conclusions: Low T3 syndrome was an independent unfavorable prognostic predictor for NDMM.

Early detection of thiamine deficiency by non-thyroidal illness syndrome in a hemodialysis patient

An 88-year-old male patient on maintenance hemodialysis (HD) therapy experienced gradual losses in appetite and liveliness during the course of 1 month. Physical examinations revealed no abnormalities. However, blood testing indicated non-thyroidal illness syndrome (NTIS) typically observed in patients with severe illness, with serum levels of thyroid stimulating hormone, free triiodothyronine, and free thyroxine of 0.17 μIU/mL, < 1.0 pg/mL, and 0.23 ng/dL, respectively. Brain magnetic resonance imaging to exclude the possibility of central hypothyroidism unexpectedly displayed slight abnormalities inside of the thalami that were characteristic of Wernicke's encephalopathy. Additional examination disclosed low serum thiamine of 20 ng/mL. Thiamine injections of 100 mg at every HD treatment rapidly restored his appetite, liveliness, and NTIS findings. HD patients are at a particularly high risk of thiamine deficiency (TD) and associated severe symptoms due to losses of thiamine during HD sessions. However, its non-specific initial symptoms, including decreases in appetite and liveliness, as well as undetectability in routine blood tests complicate early detection, resulting in underdiagnosis and more severe outcomes. In the present case, TD manifested only as non-specific symptoms and was ultimately revealed by the presence of NTIS, which was resolved with thiamine supplementation. Thus, NTIS might assist in the early detection of TD as an initial sign in HD patients.

FT3 to FT4 Conversion Ratio May Be an Independent Prognostic Factor in Pancreatic Cancer Patients

Preclinical evidence suggests that T4 can promote tumor growth while T3 can act conversely; therefore, the fT3 and fT4 concentrations should affect overall survival (OS) in cancer patients. The objective of the study was to look for an association between thyroid hormone concentrations in peripheral blood and OS in the pancreatic adenocarcinoma (PDAC) patients group. We included, retrospectively, 15 PDAC patients, without thyroid dysfunction under treatment, who underwent radical surgery, with no prior history of anticancer therapy. TSH, fT3, and fT4 concentrations were determined in blood samples taken preoperatively. We found that the fT3/fT4 ratio categorized into two groups (<0.22 vs. ≥0.22) dichotomized the study population into poor and good prognosis subgroups (log-rank p = 0.03; OS medians, respectively: 3 and 14 months), being a statistically significant predictor both in uni- and multivariate Cox regression analysis. We conclude that the importance of fT4 into fT3 conversion means not just its standard metabolic effects as the final products of thyroid gland activity. We hypothesize that it is linked to the progression of pancreatic malignancies, either via thyroid hormone receptors or indirectly, by interaction with cancer cells product.

Low T3 syndrome is associated with peripheral neuropathy in patients with type 2 diabetes mellitus

INTRODUCTION/AIMS

Diabetic peripheral neuropathy (DPN) is one of the most common chronic complications of diabetes mellitus. Diabetic patients often have thyroid dysfunction. The aim of this study was to investigate the association between low triiodothyronine (T3) syndrome and DPN in patients with type 2 diabetes mellitus (T2DM).

METHODS

A retrospective review was performed of 928 patients with T2DM for whom data was available for clinical manifestations and nerve conduction studies (NCS), and of 134 non-diabetic controls. The composite Z scores of conduction velocity and amplitude were calculated. Low T3 syndrome was defined as T3 levels below the lower limit of the reference interval.

RESULTS

Among the patients with T2DM, 632 (68.1%) had DPN, and a larger proportion of these patients presented with low T3 syndrome than patients without DPN. After adjusting for potential confounders, low T3 syndrome was independently associated with the occurrence of DPN (odds ratio [OR] = 2.049, 95% confidence interval [CI] 1.319-3.181, p = .001) and the severity of DPN (OR = 1.597, 95% CI 1.030-2.476, p = .036). Adding the criterion of low T3 syndrome improved the prognostic performance of the traditional model (age + gender + diabetic duration + glycated hemoglobin [HbA1c]) for predicting DPN.

DISCUSSION

Low T3 syndrome is associated with a higher risk and increased severity of DPN in patients with T2DM. These findings suggest that low T3 syndrome could be a predictor for risk stratification in patients with T2DM.

Low triiodothyronine syndrome is associated with stroke-associated pneumonia

OBJECTIVE

Stroke-associated pneumonia (SAP) is the most common early consequence in patients suffering from an acute ischaemic stroke (AIS). The purpose of this study was to explore the possible relationship between low triiodothyronine (T3) syndrome and SAP in stroke patients.

METHODS

This study recruited 2460 consecutive AIS patients. SAP was defined according to the modified Centers for Disease Control and Prevention criteria for hospital-acquired pneumonia. The thyroid hormones levels were measured within 24 h after admission. Low T3 syndrome was characterized as T3 below the lower limit of the reference interval accompanied by normal TSH levels.

RESULTS

Among the total patients, 336 (13.7%) patients were diagnosed with SAP. SAP in individuals with low T3 syndrome was substantially greater (p < .001) as compared to those without low T3 syndrome. After adjusting for possible confounders, low T3 syndrome (adjusted odds ratio [aOR] = 1.59; 95% confidence interval [CI], 1.20-2.09; p = .001) remained significant in our logistic model. Patients with low T3 syndrome had a higher risk of severe SAP (aOR = 2.17, 95% confidence interval [CI] 1.38-3.44; p = .001).

CONCLUSION

Low T3 syndrome, independent of recognized risk factors, is a possible risk factor for in-hospital SAP, which can help clinicians in the early detection and treatment of high-risk patients.

Effect of levothyroxine supplementation in extremely low birth weight infants with transient hypothyroxinemia of prematurity

This study aimed to determine the short- and/or long-term outcomes of levothyroxine replacement therapy in extremely low birth weight (ELBW) infants with transient hypothyroxinemia of prematurity (THOP). The medical records of 335 ELBW infants with THOP were reviewed retrospectively to identify whether levothyroxine treatment affects short- and/or long-term outcomes at a corrected age of 2 years. The infants were arbitrarily grouped based on thyroxine (T4) (free T4 [fT4]) levels into group 1 (n = 142), which included infants with T4 (fT4) levels < 2.5 (0.5) ng/dl, and group 2 (n = 193), which included those with T4 (fT4) levels ranging from ≥ 2.5 (0.5) ng/dl to < 4.5 (0.9) ng/dl. Levothyroxine replacement therapy was not associated with beneficial short- or long-term outcomes in ELBW infants with THOP. Short-term outcomes, such as mortality and composite morbidities, and long-term outcomes, such as failure to achieve catch-up height at a corrected age of 2 years, were significantly higher in group 1 than in group 2, regardless of levothyroxine treatment status. Levothyroxine replacement therapy is not associated with short-or long-term advantages in ELBW infants with THOP. This study suggests that the severity of THOP may be the major determinant of adverse outcomes in ELBW infants with THOP, rather than levothyroxine treatment.

The Changes of Thyroid Function and Related Factors in Critical Patients without Thyroid Illness in ICU: A Retrospective Cross-Sectional Study

Objective

To retrospectively analyze the changes of thyroid function and related factors in critical patients with non-thyroid illness, hoping to find some indicators for the further examination of the thyroid function in the intensive care unit situation.

Methods

The clinical data of 52 patients admitted to the ICU of Fuzhou First Hospital in Fujian Province, China, from May 2018 to March 2019 were collected. Patients were allocated into the central hypothyroidism group (CH group, n = 21) and the low T3 syndrome group (LT3S group, n = 31) based on thyroid function. All related medical data were collected, and the correlations between variables were identified using Spearman's or Pearson's rank correlation coefficients.

Results

The Acute Physiology and Chronic Health Evaluation (APACHE) II score in the CH group and the LT3S group were 20.6 ± 3.6 and 19.3 ± 3.6, respectively, measured within 24 hours following hospital admission. The mean value of thyroid-stimulating hormone (TSH) in the CH group (0.3 ± 0.3 IU/mL) was significantly lower than that in the LT3S group (1.7 ± 0.9 IU/mL), P < 0.001. Fasting plasma glucose (FPG) level in the CH group was significantly higher than that in the LT3S group (10.3 ± 5.0 mmol/L vs 6.8 ± 2.5 mmol/L, P = 0.002).

Conclusion

Central hypothyroidism may exist in critically ill patients and may be associated with elevated fasting plasma glucose levels; accordingly, it should be included as part of patient assessment. When FPG is higher than 6.4mmol/L on admission, thyroid function should be actively examined.

Thyroid Hormone Levels Help to Predict Outcome of Critically Ill Patients Undergoing Early Neurological Rehabilitation

The present study was aimed at examining thyroid hormones and other clinical factors to improve the accuracy of outcome prediction among critically ill patients undergoing early neurological rehabilitation. Patients consecutively admitted to an intensive or intermediate care unit were screened for eligibility. Serum levels of free triiodothyronine (fT3), free thyroxine (fT4), and thyroid-stimulating hormone (TSH) were collected during the first three days after admission. The Glasgow Outcome Scale (GOS) was defined as the primary outcome measure. Thyroid hormone levels and other clinical factors were entered into a binary logistic regression model to predict a good outcome at the end of early rehabilitative treatment. 395 patients (268 males) with a median age of 62 years (IQR = 52 − 76) and a median disease duration of 19 days (IQR = 13 − 28) were included in the study. Most patients (80%) had decreased fT3 values. Patients with low fT3 were admitted earlier to the rehabilitation facility and had more severe impairment upon admission compared to patients with fT3 values within the normal range. Both decreased fT3 and TSH levels were associated with an unfavorable outcome (GOS ≤ 3), but only TSH proved to be an independent predictor in multivariate analyses (OR = 1.11; 95%CI = 1.02 − 1.22). These data suggest that decreased fT3 and TSH levels upon admission may predict an unfavorable outcome at the end of early rehabilitative treatment. Thus, thyroid hormone levels are not only important during acute treatment but also in prolonged critical illness.

Evaluation of the Thyroid Characteristics and Correlated Factors in Hospitalized Patients with Newly Diagnosed Type 2 Diabetes

BACKGROUND

Diabetes mellitus (DM) and thyroid dysfunction (TD) are two closely associated disorders. The objective of the present study was to investigate the thyroid status and the relationships between thyroid hormones, diabetic complications and metabolic parameters in hospitalized patients with newly diagnosed type 2 DM (T2DM).

METHODS

This was an observational cross-sectional study, conducting on 340 patients with newly diagnosed T2DM who were admitted to ward of endocrinology department and 120 matched individuals without diabetes. Anthropometric, clinical and biochemical data were collected. Spearman correlation coefficients were calculated to evaluate the correlations between thyroid hormones and other variables. Factors associated with diabetic nephropathy (DN) was analyzed with multivariate logistic regression.

RESULTS

Levels of free triiodothyronine (FT3), free thyroxine (FT4) and thyroid stimulating hormone (TSH) were significantly lower in patients with T2DM as compared to control group without diabetes. The prevalence of TD was 21.2% in patients with diabetes, higher than that in controls (4.2%). The low T3 syndrome was the most frequent TD, shown in 14.7% of patients. The presence of diabetic complications DN, diabetic ketosis or ketoacidosis), metabolic and demographic factors, including age, glycemic control and insulin resistance were factors significantly associated with levels of thyroid hormones. FT3 level was inversely correlated with the level of urinary total protein (mg/24h) and the presence of DN. Multivariate analysis indicated low FT3 level as a strong independent risk factor (OR = 0.364, P = 0.001) for DN.

CONCLUSION

TD is not rarely seen in hospitalized patients with newly diagnosed T2DM. Diabetic complications and diabetes-related metabolic and demographic factors are related to thyroid hormone levels. Decreased FT3 is strongly correlated with the presence of DN.

The Association Between Low T3 Syndrome and Survival in Patients With Newly Diagnosed Multiple Myeloma: A Retrospective Study

Objective: The correlation between low triiodothyronine (T3) syndrome and shorter survival in malignant tumor patients has been increasingly reported. The objective of the present study was to investigate the association between low T3 syndrome and survival in multiple myeloma (MM) patients. Methods: A total of 201 newly diagnosed MM patients were included in this retrospective study. All participants were divided into 2 groups based on serum free T3 (FT3) level: low T3 syndrome group (FT3 < 2.3 pg/mL) and non-low T3 syndrome group (FT3 ≥ 2.3 pg/mL). Baseline clinical characteristics, overall survival (OS) and progression free survival (PFS) were analyzed. Results: 80 (39.8%) patients had low T3 syndrome. Patients with low T3 syndrome had significantly lower blood hemoglobin and albumin, higher creatinine and β2-microglobulin (β2-MG), higher neutrophil/lymphocyte and (neutrophil + monocyte)/lymphocyte ratio, and more advanced ISS and R-ISS stages (all P < .05). Serum FT3 level was positively associated with blood hemoglobin and albumin, and negatively correlated with β2-MG, creatinine, neutrophil/lymphocyte ratio, and (neutrophil + monocyte)/lymphocyte ratio (all P < .05). Patients with low T3 syndrome had significantly inferior OS time and PFS time (both P < .001). In multivariate Cox analysis, low T3 syndrome was found to be an independent factor associated with OS (P < .001) and PFS (P = .002). Receiver operator characteristic curve analyses showed that FT3 was a predictive marker for death during the entire follow-up period (the area under the curve [AUC] = 0.720, P < .001) and during 1 year (AUC = 0.747, P < .001). Conclusion: Low T3 syndrome might be useful for predicting survival in patients with newly diagnosed MM.

Free triiodothyronine (T3) is negatively associated with fasting ghrelin serum levels in a population sample of euthyroid subjects

PURPOSE

Ghrelin is an orexigenic peptide hormone secreted in times of stress and hunger. It is deeply involved in the regulation of metabolism and energy homeostasis, promoting energy intake and inhibiting energy expenditure on a metabolic level. In this regard, it has in many ways antagonistic effect on the thyroid hormones, which increase metabolism and thus energy expenditure. While there is reasonable evidence of a negative association between ghrelin and hormones of the hypothalamic-pituitary-thyroid (HPT-) axis from studies in patients with thyroid dysfunction and small intervention studies, large-scale studies in healthy subjects are lacking. Therefore, we studied the relationship between total ghrelin serum levels and serum levels of the thyroid hormones in a large sample of euthyroid subjects.

METHODS

Total ghrelin, thyroid-stimulating hormone (TSH), free thyroxine (fT4) and free triiodothyronine (fT3) were determined after an overnight fast in 1666 subjects participating in a population-based cross-sectional study ('LIFE') including 10,000 adults. 1012 subjects were included in this analysis. Multiple linear regression analyses were performed.

RESULTS

FT3 was negatively associated with serum ghrelin; total sample: β = - 0.0001, p < 0.001; men: β = - 0.0002, p = 0.013; women: β = - 0.0001, p = 0.010, adjusted for age, BMI, alcohol consumption, serum levels of TSH and fT4 and smoking status. No associations were found between ghrelin serum levels and serum levels of fT4 or TSH.

CONCLUSION

This is to date the largest study investigating the relationship between total serum ghrelin and thyroid hormones. The results point to a complex interaction and should initiate further research.

Frequency of Euthyroid Sick Syndrome Before and After Renal Transplantation in Patients with End Stage Renal Disease and Its Association with Oxidative Stress

OBJECTIVE

In this study, we aimed to evaluate the frequency of euthyroid sick syndrome (ESS) before and after renal transplantation in patients with end-stage renal disease (ESRD), and its association with oxidative stress (OS) by evaluating thiol-disulfide levels.

METHODS

Free triiodothyronine (fT3), free thyroxine (fT4) thyroid stimulating hormone (TSH), and thiol and disulfide levels were recorded before and after renal transplantation in patients with ESRD. ESS was diagnosed in patients with unresponsive TSH to low fT3 and/or fT4 levels.

RESULTS

A total of 121 patients were included in the study. Of these, 69 (57%) were males and 52 (43%) were females. The mean age was 45 ± 12.61 years. ESS was detected in 39 (32%) of 121 patients. Of 39 patients, 24 (61%) had ESS before transplantation and 15 (39%) after transplantation. Sixteen of 24 (66.7%) patients with ESS before transplantation reached normal thyroid functions after transplantation. In post transplantation period, patients with ESS had significantly higher urea and creatinine (p = 0.025 and p = 0.009, respectively) compared to patients without ESS. Furthermore, thiol-disulfide levels of 20 patients with ESS at any time compared with 68 patients without ESS. It was found that native thiol and total thiol were significantly lower in patients with ESS (p = 0.025 and p = 0.044, respectively).

CONCLUSION

The present study is an initial evaluation of the OS and antioxidant status in the etiology of ESS in patients with renal transplantation. These patients have markedly low levels of antioxidant products, which support the possible role of OS in ESS.

Thyroid hormones concentration in portal and peripheral blood in patients with pancreatic cancer: Preliminary study

BACKGROUND

The prognostic value of D-dimers concentration in portal blood in patients with pancreatic cancer has been established in several studies. Thyroid hormones and their receptors, especially T3 also seems to have a specific role in process of neoplasia and metastatic spread.

OBJECTIVE

The aim of the study was to look for changes of thyroid hormones concentration between portal and peripheral blood.

METHODS

We included prospectively 8 patients with pancreatic cancer, without liver dysfunction, qualified to surgical treatment. D-dimers, THS, fT3, fT4 concentration was determined in blood samples from portal and peripheral vein taken intraoperatively.

RESULTS

The difference and quotient of portal and peripheral concentration of D-dimers, THS, fT3 and fT4 was calculated (D-dimer-; THS-; fT3-; fT4-d and -q). The level of D-dimers measured in portal blood was > 2700 ng/mL in 3 patients. The peripheral fT3 level was significantly higher In high portal D-dimers group. FT3 change coefficients showed strong statistically significant negative correlation with portal D-dimer concentration level.

CONCLUSIONS

We suggest that fT3 or its receptors can influence progression of pancreatic malignancies. The results of this study are also a new evidence that both fT3 and portal D-dimers are biologically linked to intensity of local neoplastic process. Nevertheless, deeper knowledge about portal circulation probably constitute missing part in understanding nature of pancreatic neoplasia. Investigations both on larger group and in the field of basic sciences are needed.

Higher Prevalence of Non-thyroidal-Illness Syndrome in Elderly Male Patients With Active Helicobacter pylori Infection

Objective: It is currently unclear whether the Helicobacter pylori (H. pylori) infection leads to associated alterations in thyroid functions and thyroidal illnesses. This study aims to analyse this relationship in an elderly male cohort over a five-year period.

Design: A case retrospective study.

Methods: A longitudinal study was designed to collect subjects (≥65 years old) receiving both a thyroid examination and H. pylori infection status determined by ¹³C-urea breath test in 2013 at our unit. Subjects were followed every 1 to 2 years until December 2017 for laboratory results, visits to outpatient clinics/emergency departments etc. Blood tests and thyroid ultrasonography were performed to determine thyroid function and morphology.

Results: 356 male subjects with mean age 78.5 ± 9.8 years were included. Active H. pylori infection was positive in 88 subjects (24.7%). Thyroid function tests and ultrasonography showed similar patterns between H. pylori positive and negative groups. Non-thyroidal-illness syndrome (NTIS) was diagnosed in 30/210 (14%) patients who experienced acute illnesses and hospitalization over five-year follow-up. Notably, NTIS demonstrated significantly higher prevalence in the H. pylori positive group compared to the negative group (17.1 vs. 5.6%, P = 0.001). Multivariate analysis showed that when age, APACHE II score and hemoglobin levels were adjusted, H. pylori status still has significant interrelationship with NTIS (OR = 3.497, P = 0.003).

Conclusions: There is a positive association between chronic active H. pylori infection and NTIS prevalence in this elderly male cohort. Further studies are needed to elucidate the role of H. pylori infection on NTIS in elderly male patients.

Thyroid dysfunction may be associated with poor outcomes in patients with COVID-19

BACKGROUND

Coronavirus disease (COVID-19) has resulted in considerable morbidity and mortality worldwide. Thyroid hormones play a key role in modulating metabolism and the immune system. However, the prevalence of thyroid dysfunction (TD) and its association with the prognosis of COVID-19 have not yet been elucidated. In this study, we seek to address this gap and understand the link between TD and COVID-19.

METHODS

Herein, we enrolled patients who were hospitalized with COVID-19 and had normal or abnormal thyroid function test results at the West Court of Union Hospital in Wuhan, China, between 29 January and February 26, 2020. We carried out follow up examinations until April 26, 2020. Data on clinical features, treatment strategies, and prognosis were collected and analyzed. TD was defined as an abnormal thyroid function test result, including overt thyrotoxicosis, overt hypothyroidism, subclinical hypothyroidism, subclinical hyperthyroidism, and euthyroid sick syndrome.

RESULTS

A total of 25 and 46 COVID-19 patients with and without TD, respectively, were included in the study. COVID-19 patients with TD had significantly higher neutrophil counts and higher levels of C-reactive protein, procalcitonin, lactate dehydrogenase, serum creatine kinase, aspartate transaminase, and high-sensitive troponin I and a longer activated partial thromboplastin time but lower lymphocyte, platelet, and eosinophil counts. A longitudinal analysis of serum biomarkers showed that patients with TD presented persistently high levels of biomarkers for inflammatory response and cardiac injury. COVID-19 patients with TD were more likely to develop a critical subtype of the disease. Patients with TD had a significantly higher fatality rate than did those without TD during hospitalization (20% vs 0%, P = 0.002). Patients with TD were more likely to stay in the hospital for more than 28 days than were those without TD (80% vs 56.52%, P = 0.048).

CONCLUSIONS

Our preliminary findings suggest that TD is associated with poor outcomes in patients with COVID-19.

Serum thyroxine and thyrotropin concentrations decrease with severity of nonthyroidal illness in cats and predict 30-day survival outcome

Background

In cats, nonthyroidal illness affects serum thyroid hormone concentrations. Serum thyroxine (T₄) and triiodothyronine (T₃) concentrations commonly decrease, whereas free T₄ (fT₄) concentrations vary unpredictably. Limited information exists regarding effects on serum thyrotropin (thyroid‐stimulating hormone [TSH]) concentrations in cats with nonthyroidal illness syndrome (NTIS).

Objectives

To characterize alterations in thyroid function that develop in cats with NTIS and to correlate these alterations with severity and outcome of the nonthyroidal illness.

Animals

Two hundred and twenty‐two cats with NTIS and 380 clinically normal cats of similar age and sex.

Methods

Prospective, cross‐sectional study. All cats had serum T₄, T₃, free T₄, and TSH concentrations measured. Cats were grouped based on illness severity and 30‐day survival.

Results

Cats with NTIS had lower serum T₄ and T₃ concentrations than did normal cats (P < .001). Serum fT₄ and TSH concentrations did not differ between groups. Serum T₄, T₃, and fT₄ concentrations progressively decreased with increasing disease severity (P < .001). The 56 cats that died had lower T₄, T₃, and TSH concentrations than did the 166 survivors, with no difference in fT₄ concentration. Multivariable logistic regression modeling indicated that serum T₄ and TSH concentrations both predicted survival (P < .02).

Conclusions and Clinical Importance

Cats with NTIS commonly develop low serum T₄, T₃, and TSH concentrations, the prevalence and extent of which increases with disease severity. Clinicians should consider evaluating thyroid function in cats with severe NTIS, because doing so could help determine probability of successful treatment responses before investing considerable time, effort, and finances in addressing the underlying disease.

Incidence of low-triiodothyronine syndrome in patients with septic shock

OBJECTIVE

Low levels of thyroid hormones have been associated with poor clinical outcomes. This metabolic situation, designated euthyroid sick syndrome, has been interpreted as a state of adaptation to different pathological processes, characterized by the decrease in plasma triiodothyronine. The present study seeks to determine the incidence of this disorder in patients with septic shock and its relationship with other severity indices and clinical outcomes.

METHODS

This prospective analytical study evaluated patients admitted to the intensive care unit with septic shock between April 2018 and July 2019. Variables associated with septic shock and thyroid profile were recorded at the time of the septic shock diagnosis and 7, 14, and 21 days later.

RESULTS

A total of 27 patients who met the inclusion criteria were analyzed. The incidence of an altered thyroid axis was 96.3%, with a mortality at 28 days of 36.7%. Patients without hormonal alteration did not present negative outcomes. Among those with low triiodothyronine, 42.3% recovered their thyroid function within 28 days, in whom mortality was 0%; 57.7% did not recover their thyroid function, in whom mortality was 66.7%. Those whose thyroid axis was altered and who did not normalize its function required more doses of vasoactives and had deteriorated lactate clearance.

CONCLUSION

Patients with septic shock have a high incidence of alteration of the thyroid axis, and this dysfunction is associated with higher mortality.

Severe hyperthyroidism without symptoms due to nonthyroidal illness in a child with acute hepatitis: case report and literature review

While liver enzyme changes are frequently reported in hyperthyroidism, liver dysfunction itself can lead to alterations in thyroid hormone metabolism. However, the exact relationship between hyperthyroidism and liver dysfunction is unclear. We report an 11-year-old boy presenting with acute hepatitis of unknown etiology, who was incidentally found to have asymptomatic biochemical hyperthyroidism. Despite significant total and free T4 elevation, clinical evidence of thyrotoxicosis was absent. Thyroid I-123 uptake was also reduced. Additional testing revealed slight T3 elevation and significant rT3 elevation. Graves' and Hashimoto's thyroiditis testing was negative. We hypothesize that the biochemical hyperthyroidism was due to transient thyroiditis. Although an etiology for the boy's hepatitis was never determined, and an undiagnosed infectious etiology causing subacute thyroiditis was considered, subsequent testing showing positive thyroid peroxidase antibodies, suggesting autoimmune Hashimoto's thyroiditis as the likely cause of the hyperthyroidism. We believe, furthermore, that the absence of symptoms was the result of concurrent nonthyroidal illness resulting in the biochemical findings of slight T3 elevation and significant rT3 increase despite significant T4 elevation.

Importance of Thyroid Hormone level and Genetic Variations in Deiodinases for Patients after Acute Myocardial Infarction: A Longitudinal Observational Study

This study aimed to examine the influence of thyroid hormone (TH) levels and genetic polymorphisms of deiodinases on long-term outcomes after acute myocardial infarction (AMI). In total, 290 patients who have experienced AMI were evaluated for demographic, clinical characteristics, risk factors, TH and NT-pro-BNP. Polymorphisms of TH related genes were included deiodinase 1 (DIO1) (rs11206244-C/T, rs12095080-A/G, rs2235544-A/C), deiodinase 2 (DIO2) (rs225015-G/A, rs225014-T/C) and deiodinase 3 (DIO3) (rs945006-T/G). Both all-cause and cardiac mortality was considered key outcomes. Cox regression model showed that NT-pro-BNP (HR = 2.11; 95% CI = 1.18– 3.78; p = 0.012), the first quartile of fT3, and DIO1 gene rs12095080 were independent predictors of cardiac-related mortality (HR = 1.74; 95% CI = 1.04–2.91; p = 0.034). The DIO1 gene rs12095080 AG genotype (OR = 3.97; 95% CI = 1.45–10.89; p = 0.005) increased the risk for cardiac mortality. Lower fT3 levels and the DIO1 gene rs12095080 are both associated with cardiac-related mortality after AMI.

Predictive value of thyroxine for prognosis in pediatric septic shock: a prospective observational study

Background Thyroid hormone plays an important role in the adaptation of metabolic function to critically ill. The relationship between thyroid hormone levels and the outcomes of septic shock is still unclear. The aim of this study was to assess the predictive value of thyroid hormone for prognosis in pediatric septic shock. Methods We performed a prospective observational study in a pediatric intensive care unit (PICU). Patients with septic shock were enrolled from August 2017 to July 2019. Clinical and laboratory indexes were collected, and thyroid hormone levels were measured on PICU admission. Results Ninety-three patients who fulfilled the inclusion criteria were enrolled in this study. The incidence of nonthyroidal illness syndrome (NTIS) was 87.09% (81/93) in patients with septic shock. Multivariate logistic regression analysis showed that T4 level was independently associated with in-hospital mortality in patients with septic shock (OR: 0.965, 95% CI: 0.937-0.993, p = 0.017). The area under receiver operating characteristic (ROC) curve (AUC) for T4 was 0.762 (95% CI: 0.655-0.869). The cutoff threshold value of 58.71 nmol/L for T4 offered a sensitivity of 61.54% and a specificity of 85.07%, and patients with T4 < 58.71 nmol/L showed high mortality (60.0%). Moreover, T4 levels were negatively associated with the pediatric risk of mortality III scores (PRISM III), lactate (Lac) level in septic shock children. Conclusions Nonthyroidal illness syndrome is common in pediatric septic shock. T4 is an independent predictor for in-hospital mortality, and patients with T4 < 58.71 nmol/L on PICU admission could be with a risk of hospital mortality.

Nonthyroidal Illness Syndrome Across the Ages

In conditions of acute illness, patients present with reduced plasma T3 concentrations without a concomitant rise in TSH. In contrast, plasma concentrations of the inactive hormone rT3 increase, whereas plasma concentrations of T4 remain low-normal. This constellation of changes, referred to as nonthyroidal illness syndrome (NTIS), is present across all ages, from preterm neonates and over-term critically ill infants and children to critically ill adults. Although the severity of illness strongly correlates with the severity of the NTIS phenotype, the causality of this association remains debated, and pathophysiological mechanisms remain incompletely understood. In the acute phase of illness, NTIS appears to be caused predominantly by an increased peripheral inactivation of thyroid hormones, in which reduced nutritional intake plays a role. Current evidence suggests that these acute peripheral changes are part of a beneficial adaptation of the body to reduce expenditure of energy and to activate the innate immune response, which is important for survival. In contrast, in more severely ill and prolonged critically ill patients, an additional central suppression of the thyroid hormone axis alters and further aggravates the NTIS phenotype. Recent studies suggest that this central suppression may not be adaptive. Whether treatment of this central component of NTIS in prolonged critically ill patients, with the use of hypothalamic releasing factors, improves outcome remains to be investigated in large randomized control trials.

Effects of Short-Term Fasting and Different Overfeeding Diets on Thyroid Hormones in Healthy Humans

Background: A greater decrease in 24-hour energy expenditure (EE) during fasting and a smaller increase in 24-hour EE during low-protein overfeeding (metabolic "thrifty" phenotype) predict weight gain. As thyroid hormones (TH) are implicated in energy intake and metabolism, we assessed whether: (i) TH concentrations are altered by 24-hour fasting or overfeeding diets with varying protein content and (ii) diet-related changes in TH correlate with concomitant changes in EE. Methods: Fifty-eight euthyroid healthy subjects with normal glucose regulation underwent 24-hour dietary interventions including fasting, eucaloric feeding, and five overfeeding diets in a crossover design within a whole-room indirect calorimeter to measure the 24-hour EE. Overfeeding diets (200% of energy requirements) included three diets with 20% protein, one diet with 3% protein (low-protein overfeeding diet [LPF]: 46% fat), and one diet with 30% protein (high-protein overfeeding diet [HPF]: 44% fat, n = 51). Plasma free thyroxine (fT4), free triiodothyronine (fT3), and fibroblast growth factor 21 (FGF21) concentrations were measured after overnight fast the morning of and after each diet. Results: On average, fT4 increased by 8% (+0.10 ng/dL, 95% confidence interval [CI 0.07-0.13], p < 0.0001) and fT3 decreased by 6% (-0.17 pg/mL [CI -0.27 to -0.07], p = 0.001) after 24-hour fasting, whereas both fT4 and fT3 decreased by 5% (-0.07 ng/dL [CI -0.11 to -0.04], p < 0.0001) and 4% (-0.14 pg/mL [CI -0.24 to -0.04], p = 0.008) following HPF, respectively. Greater decreases in fT3 after HPF are associated with larger decreases in FGF21 (r = 0.40, p = 0.005). Following LPF, the mean fT3 increased by 6% (+0.14 pg/mL [CI 0.05-0.2], p = 0.003) with no change in fT4 (p = 0.7). No changes in TH were observed after normal-protein overfeeding diets (all p > 0.1). No associations were observed between TH concentrations and diet-related changes in 24-hour EE during any diet (all p > 0.07). Conclusions: Acute (200%) short-term (24 hours) changes in food intake induce small changes in TH concentrations only after diets with low (0% fasting and 3% protein overfeeding) or high (30% protein overfeeding) protein content. The fT3-FGF21 association after high-protein overfeeding suggests a role for TH in inhibiting FGF21 secretion by the liver during protein excess. These results indicate that TH are involved in protein metabolism; however, they do not mediate the short-term EE response to diets that characterize the metabolic phenotypes and determine the individual susceptibility to weight gain.

Low triiodothyronine syndrome is associated with hemorrhagic transformation in patients with acute ischaemic stroke

Hemorrhagic transformation (HT) is a severe complication occurring in acute ischemic stroke (AIS) patients. We explored the association between low triiodothyronine (T3) syndrome and HT in AIS patients. A total of 208 consecutive participants with HT and 208 age- and sex-matched stroke patients without HT were enrolled in this study. HT was diagnosed by follow-up imaging assessment, and was radiologically classified as hemorrhagic infarction (HI) type 1 or 2 or parenchymal hematoma (PH) type 1 or 2. HT was also classified into asymptomatic or symptomatic. The incidence of low T3 syndrome was significantly higher among patients who developed HT than among those without HT. Moreover, the more severe the HT, the lower the detected T3 levels. Multivariate-adjusted binary logistic regression showed that low T3 syndrome was an independent risk factor for HT and symptomatic HT in AIS patients. Low T3 syndrome was also significantly associated with a higher risk of PH, but not with the risk of HI. Thus, low T3 syndrome was independently associated with the risk of HT, symptomatic HT, and severe HT (PH) in AIS patients, which suggests monitoring T3 could be a useful means of preventing HT in patients with ischemic stroke.

Incidence and severity of transient hypothyroxinaemia of prematurity associated with survival without composite morbidities in extremely low birth weight infants

This study investigated the incidence of transient hypothyroxinaemia of prematurity (THOP) associated with survival without composite morbidities and the predictability of THOP severity in extremely low birth weight infants (ELBWIs). We retrospectively reviewed the medical records of 546 ELBWIs who underwent initial thyroid function tests within 14 postnatal days, with 156 ELBWIs from 2000 to 2005 (period I) and 390 from 2006 to 2013 (period II). The infants were stratified into 23–24, 25–26 and 27–28 weeks’ gestation subgroups within each period; the initial thyroxine (T4) level, mortality, clinical characteristics and composite morbidities, including bronchopulmonary dysplasia, intraventricular haemorrhage, necrotizing enterocolitis, and retinopathy of prematurity were analysed. The predictive value of the initial T4 level, Apgar score at 5 min, and clinical risk index for babies II (CRIB II) score for estimating mortality and survival with or without composite morbidities was assessed. Comparing period II and period I, the incidence of THOP was significantly decreased along with significantly increased survival without composite morbidities in ELBWIs at 25–28 weeks’ gestation. The severity of THOP showed significant associations with mortality and composite morbidities. The initial T4 level was most effective for predicting outcome compared with Apgar and CRIB II scores.

Relevance of TSH evaluation in elderly in-patients with non-thyroidal illness

BACKGROUND

Non-thyroidal illness (NTI) is frequent in hospitalized patients. Its recovery is characterized by a raise in TSH levels. However, the clinical significance of high TSH levels at admission in hospitalized elderly patients with NTI remains uncertain.

AIM

To explore the relevance of baseline TSH evaluation in hospitalized elderly patients with NTI.

METHODS

We examined the participants with NTI (n = 123) from our previous study (Sforza, 2017). NTI was defined as: low T3 (< 80 ng/dL) and normal or low total T4 in the presence of TSH values between 0.1 and 6.0 mU/L. Thyroid function tests were performed on day 1 and day 8 of the hospital stay. Positive TSH changes (+ ΔTSH) were considered when the day-8 TSH value increased more than the reference change value for TSH (+ 78%). Multiple logistic regression was used to evaluate the independent association of baseline TSH, sex, clinical comorbidities (by ACE-27) and medications with + ΔTSH.

RESULTS

Out of 123 patients (77 ± 8 years, 52% female), 34 showed a + ΔTSH. These patients had a lower TSH at admission (p < 0.001) and intra-hospital mortality (p = 0.003) than the others. In multiple logistic regression, TSH > 2.11 mU/L at baseline was associated with reduced odds to show + ΔTSH [odds ratio (95 CI) 0.29 (0.11-0.75); p = 0.011] in a model adjusted by age, sex and ACE-27.

DISCUSSION

Inappropriately higher TSH levels at admission in hospitalized elderly patients were associated with a reduced ability to raise their TSH levels later on. The present results confront the idea that TSH levels at admission are irrelevant in this clinical context.

The prognostic value of total T3 after acute cerebral infarction is age-dependent: a retrospective study on 768 patients

BACKGROUND

Serum triiodothyronine (T3) concentration was reported to be associated with the prognosis after acute ischemic stroke. The aim of this study was to evaluate the effect of age on the prognostic value of thyroid-related hormones after an acute ischemic stroke.

METHODS

This was a retrospective study involving the review of 1072 ischemic stroke patients who had been consecutively admitted to the hospital within 72 h of symptom onset. Total triiodothyronine (T3), total thyroxine (T4), free T3, free T4, and thyroid-stimulating hormone (TSH) were assessed to determine their values for predicting functional outcome at the first follow-up clinic visits, which usually occurred 2 to 4 weeks after discharge from the hospital.

RESULTS

A total of 768 patients were finally included in the study and divided into two age groups: a younger group (age < 65 years) and an older group (age ≥ 65 years). On univariate analysis, four factors-lower total T3, free T3 concentrations, higher scores on the National Institute of Health Stroke Scale (NIHSS) and the presence of atrial fibrillation-were associated with poor functional outcomes in both groups. In addition, older age, female gender, higher free T4, and lower TSH levels were also associated with poor function in the older group. On multiple logistic regression analysis, higher NIHSS scores (odds ratio [OR] =1.95; 95% confidence interval [CI], 1.66-2.30; P ≤ .001) and lower total T3 concentrations (OR = 0.06; 95% CI, 0.01-0.68; P = .024) remained independently associated with poor functional outcome in the older group. However, the independent association with poor function of lower total T3 was not confirmed in the younger group.

CONCLUSIONS

The prognostic value of low total T3 is age-associated and more meaningful in an older population.

Thyroid Hormone, Thyroid Hormone Metabolites and Mast Cells: A Less Explored Issue

Mast cells are primary players in immune and inflammatory diseases. In the brain, mast cells are located at the brain side of the blood brain barrier (BBB) exerting a crucial role in protecting the brain from xenobiotic invasion. Furthermore, recent advances in neuroscience indicate mast cells may play an important role in glial cell-neuron communication through the release of mediators, including histamine. Interestingly, brain mast cells contain not only 50% of the brain histamine but also hormones, proteases and lipids or amine mediators; and cell degranulation may be triggered by different stimuli activating membrane bound receptors including the four types of histaminergic receptors. Among hormones, mast cells can store thyroid hormone (T3) and express membrane-bound thyroid stimulating hormone receptors (TSHRs), thus suggesting from one side that thyroid function may affect mast cells function, from the other that mast cell degranulation may impact on thyroid function. In this respect, the research on hormones in mast cells is scarce. Recent pharmacological evidence indicates the existence of a non-genomic portion of the thyroid secretion including thyroid hormone metabolites. Among which the 3,5 diiodothyronine (3,5-T2), 3-iodothyroanamine (T1AM) and 3-iodothyroacetic acid (TA1) are the most studied. All these compounds are endogenously occurring and found to be increased in inflammatory-based diseases involving mast cells. T1AM and TA1 induce, as T3, neuroprotective effects and itch but also hyperalgesia in rodents with a mechanism largely unknown but mediated by the release of histamine. Due to the rapid onset of their effectiveness they may trigger histamine release from a cell where it is “ready-to-be released,” i.e., mast cells. Following a very thin path which passes through old experimental and clinical evidence, at the light of novel acquisitions on endogenous T3 metabolites, we aim to stimulate the attention on the possibility that mast cell histamine may be the connector of a novel (neuro) endocrine pathway linking the thyroid with mast cells.

Low Value of Thyroid Testing in the Pediatric Inpatient Setting

OBJECTIVES

Our objective was to assess the frequency of pediatric inpatient thyroid testing, frequency of detection of abnormal results, and apparent impact on patient management.

METHODS

This is a retrospective study of admissions from July 2015 to June 2016 at a large urban children's hospital. Chart review was conducted on all hospitalized pediatric patients who underwent thyroid testing. We used a normal range of 0.5 to 5.0 μIU/mL for thyroid-stimulating hormone (TSH) and 1.0 to 2.0 ng/dL for free thyroxine (FT4), except for neonates for whom we used the higher reference ranges specified by the hospital laboratory.

RESULTS

Thyroid testing occurred in 1202 (5.7%) of 20 907 hospitalizations; 79.3% had combined thyroid function tests (TFTs) with TSH + FT4 being most common, and 20.6% had TSH only. Combined TFTs were ordered routinely by psychiatry and frequently by endocrine, gastrointestinal, cardiology, and neurology services, but many cases had no identified reason for testing. Of the 205 abnormal tests (17.1%), the most common abnormalities in the combined TFTs group were normal FT4 and increased TSH (35.4%) (76% of which were between 5 and 10 μIU/mL), normal FT4 and TSH 0.1 to 0.5 μIU/mL (33.1%), and high FT4 but normal TSH (14.3%). Patients with new-onset type 1 diabetes had borderline low or high TSH in about 20% of cases, but all abnormalities resolved at outpatient follow-up. Overall, 8 patients (0.66%) were started on levothyroxine.

CONCLUSIONS

Pediatric inpatient thyroid testing is relatively common at our institution, and although results are often abnormal, they do not point to thyroid disease that has contributed to the reason for hospitalization and do not identify patients in urgent need of starting therapy.

Rare case of meningococcal sepsis-induced testicular failure, primary hypothyroidism and hypoadrenalism: Is there a link?

Severe illness can lead to multiple transient endocrinopathies. In adult patients, neuroendocrine alterations include sick euthyroid syndrome, an increase in corticosteroid levels, increase in prolactin levels, decreased insulin growth factor 1 levels and hypogonadism. We report the case of a 24-year-old man with meningococcal sepsis with multiple end-organ complications who developed persistent non-autoimmune hypothyroidism, adrenal insufficiency and primary hypogonadism all requiring hormone replacement. While adrenal insufficiency as part of the Waterhouse-Friderichsen syndrome is well described, reports of primary hypothyroidism and persistent primary hypogonadism in severe illness are exceedingly rare. Multiple combined endocrinopathies as in this case have not been reported previously. This case highlights the necessity of screening for endocrine abnormalities in severe illness and the need for treatment if persistent. It also raises a novel concept of meningococcal sepsis causing multiple endocrinopathies possibly via disseminated intravascular coagulopathy-related ischaemic damage.

Low FT3 is a valuable predictor of severe acute pancreatitis in the emergency department

OBJECTIVE

To investigate the relationship between serum levels of thyroid hormones and disease severity at the early stage of acute pancreatitis (AP).

METHODS

Cohort data from 172 patients with AP attending the Emergency Department of our hospital from 2012 to 2017 were retrospectively reviewed and analyzed. Patients were categorized into mild (MAP), moderately severe (MSAP) and severe AP (SAP) groups based on the disease severity. The MSAP and SAP groups were combined into a non-MAP group for analysis. The predictive values of C-reactive protein (CRP) levels, Ranson score, APACHE II score and serum thyroid hormone levels were analyzed.

RESULTS

In total, 76 (44.2%), 85 (49.4%) and 11 (6.4%) patients were included in the MAP, MSAP and SAP groups, respectively. The free triiodothyronine (FT3) levels were significantly lower in the combined non-MAP group than in the MAP group. The tetraiodothyronine (T4) levels were significantly lower in the SAP group than in the MAP and MSAP groups (P = 0.002). Logistic regression analysis revealed that a low FT3 level was an independent risk factor for the incidence of non-MAP (P = 0.004). The area under the receiver operating characteristic curve and sensitivity of FT3 were 0.729 and 88.2%, respectively, which were higher than those of CRP, Ranson and APACHE II scores.

CONCLUSION

Monitoring FT3 levels in the early stage of AP is helpful for evaluating disease severity and predicting the incidence of non-MAP, making it a useful tool for guiding AP treatment.

Low T3 syndrome as a predictor of poor prognosis in chronic lymphocytic leukemia

Low triiodothyronine (T3) state is associated with poor prognosis in critical acute and prolonged illness. However, the information on thyroid dysfunction and cancer is limited. The aim of our study was to evaluate the prognostic value of low T3 syndrome in chronic lymphocytic leukemia (CLL). Two hundred and fifty-eight patients with detailed thyroid hormone profile at CLL diagnosis were enrolled. Low T3 syndrome was defined by low free T3 (FT3) level accompanied by normal-to-low free tetraiodothyronine (FT4) and thyroid-stimulating hormone (TSH) levels. A propensity score-matched method was performed to balance the baseline characteristics. Multivariate Cox regression analyses screened the independent prognostic factors related to time-to-first-treatment (TTFT) and cancer-specific survival (CSS). Area under the curve (AUC) assessed the predictive accuracy of CLL-International Prognostic Index (IPI) together with low T3 syndrome. The results showed that 37 (14.34%) patients had low T3 syndrome, which was significantly associated with unfavorable TTFT and CSS in the propensity-matched cohort, and it was an independent prognostic indicator for both TTFT and CSS. Serum FT3 level was positively related to protein metabolism and anemia, and inversely related to inflammatory state. Patients with only low FT3 demonstrated better survival than those with synchronously low FT3 and FT4, while those with synchronously low FT3, FT4 and TSH had the worst clinical outcome. Low T3 syndrome together with CLL-IPI had larger AUCs compared with CLL-IPI alone in TTFT and CSS prediction. In conclusion, low T3 syndrome may be a good candidate for predicting prognosis in future clinical practice of CLL.

Diagnosis and management of treatment-refractory hypothyroidism: an expert consensus report

There is a frequently encountered subset of hypothyroid patients who are refractory to standard thyroid hormone replacement treatment and require unexpectedly high doses of levothyroxine. In addition to clinical situations where hypothyroid patients are non-compliant, or where there is the possibility of excipient-induced disease exacerbation (gluten/celiac disease), therapeutic failure may be due to impaired absorption of the administered drug. The common approach to managing patients with unusual thyroxine needs is to escalate the dose of levothyroxine until targeted TSH levels are achieved. This approach can increase the risk for prolonged exposure to supratherapeutic doses of levothyroxine, which increase the chances of adverse outcomes. Repeated adjustments of levothyroxine can also escalate the costs of treatment, as frequent office visits and laboratory tests are required to determine and maintain the desired dose. Clinicians should take a systematic approach to managing patients whom they suspect of having treatment-refractory hypothyroidism. This may include searching for, and adjusting, occult medical conditions and/or other factors that may affect the absorption of levothyroxine, before up-titrating the dose of traditional levothyroxine therapy. Depending on the underlying pathology, another approach that may be considered is to try alternative formulations of levothyroxine that are less susceptible to intolerance issues related to excipients, or, in some cases, to malabsorption. The early discovery of these factors via a thoughtful patient work-up may avoid unnecessary thyroid medication adjustments and their consequences for both patients and clinicians.

Low T3 syndrome is a strong prognostic predictor in diffuse large B cell lymphoma

The aim of this study was to evaluate the prognostic effect of low triiodothyronine (T3) syndrome on patients with diffuse large B cell lymphoma (DLBCL). A hundred and eighty-eight patients with detailed thyroid hormone levels at diagnosis of DLBCL were enrolled. Low T3 syndrome was defined as a low serum free T3 (FT3) level with low or normal serum free tetraiodothyronine (FT4) and thyroid stimulating hormone levels. Multivariate Cox regression analysis was used to screen prognostic factors associated with progression-free survival (PFS) and overall survival (OS). Receiver-operator characteristic curves and the corresponding areas under the curve were calculated to assess the predictive accuracy of International Prognostic Index (IPI) and low T3 syndrome. Twenty-four patients were diagnosed with low T3 syndrome, which was associated with worse PFS and OS in the rituximab era. It was an independent prognostic factor for PFS and OS, especially for those with IPI 0-2, extranodal sites ≤1 and stage III-IV. Synchronously low FT3 and FT4 had poorer survival outcome compared to only low FT3 and adding criterion of low T3 syndrome improved the prognostic capacity of IPI for predicting PFS and OS in DLBCL. Low T3 syndrome was found to be a strong prognostic predictor in DLBCL.

Evaluation of activity of hypothalamo-pituitary-gonadal axis in postmenopausal women suffering from severe acute illness

Background & objectives:

Postmenopausal women constitute an ideal model for studying the extent of hypothalamo-pituitary gonadal (HPG) axis suppression in critical illness as the gonadotropins are normally high and non-cyclical in them. The objective was to assess the impact of acute severe illness in postmenopausal women on the HPG axis and the activities of the hypothalamo-pituitary-adrenal (HPA), the hypothalamo- pituitary-thyroid (HPT) axes; and levels of serum prolactin, by comparison between critically ill postmenopausal women and otherwise healthy postmenopausal women.

Methods:

Thirty five consecutive postmenopausal women older than 60 yr admitted to medical intensive care with a Simplified Acute Physiology Score II (SAPS II) more than 30 were included. On day five of their in-hospital stay, blood samples were collected for oestradiol, luteinizing hormone (LH), follicle stimulating hormone (FSH), cortisol, androstenedione, prolactin and thyroid profile. Thirty five apparently healthy postmenopausal women were selected as controls.

Results:

Levels of LH, FSH, thyrotropin, free thyroxin (fT₄) and free tri-iodothyronine (fT₃) were lower while oestradiol, cortisol and dehydroepiandrosterone were higher among patients in comparison to healthy controls. Prolactin levels were similar in patients and controls. Among sick patients both FSH and fT₄ showed a negative correlation (P<0.05) with the SAPS II score.

Interpretation & conclusions:

In critically ill postmenopausal women, paradoxically elevated oestrogen levels despite gonadotropin suppression suggests a non-ovarian origin. Prolactin remained unaltered in patients despite their illness, possibly reflecting atrophy of lactotrophs in menopause.

Hypothyroidism and reversible kidney dysfunction: an essential relationship to recognize

OBJECTIVE

To report 3 cases of reversible hypothyroidism-induced kidney dysfunction and review the interaction between these commonly encountered, yet seemingly disparate, conditions.

METHODS

We describe the clinical course and laboratory and physical findings of 3 patients who presented with kidney dysfunction that improved after initiating thyroid hormone replacement therapy. We also review similar cases in the literature and discuss the pathophysiologic mechanisms.

RESULTS

A 68-year-old male presented with classical signs and symptoms of hypothyroidism, including fatigue, confusion, and gait imbalance. Physical exam showed bradycardia, thyromegaly, slow mentation, and cracked, thin skin; he was found to have decreased kidney function. Second, a 42-year-old previously healthy female presented with bilateral hand swelling and elevated serum creatinine with an otherwise unremarkable physical exam. The third patient was a 72-year-old male with advanced heart failure on amiodarone and stage 3 chronic kidney disease who presented with fatigue, acute kidney injury, and lower extremity edema. In all cases, serum creatinine and thyroid-stimulating hormone (TSH) were elevated at presentation (1.4-3.0 mg/dL and 94.1-184 mIU/L respectively), and free thyroxine (T4) was low (undetectable-0.4 ng/dL). The initiation or increased dose of levothyroxine normalized serum creatinine to baseline within 2 to 10 months.

CONCLUSION

Hypothyroidism and kidney dysfunction are both commonly encountered clinical entities, but the interplay between the thyroid gland and kidneys may be infrequently recalled, causing the reversible relationship between these 2 disorders to be missed.

Treatment for non-thyroidal illness syndrome in advanced chronic kidney disease: a single-blind controlled study

AIM

Non-thyroidal illness syndrome (NTIS) is common among patients with advanced chronic kidney disease (CKD) and is strongly associated with poor prognosis. However, it remains unclear in how to correct this disorder and this study aimed to evaluate the effectiveness of sodium bicarbonate (SB) and N-acetyl-cysteine (NAC) for correcting NTIS status.

METHODS

Patients with CKD stage 3-4 were single-blind, placebo-controlled treated with placebo, SB, or NAC for 18 weeks. The primary end points were the correction of NTIS and the occurrence of end-stage renal disease (ESRD). The secondary point was the change in estimated glomerular filtration rate (eGFR) after the follow-up.

RESULTS

The Kaplan-Meier survival analysis showed significant lower correcting ratio of NTIS in control group compared with SB group [Hazard ratio (HR) 0.19, 95 % confidence interval (CI) 0.04-0.89, p = 0.035] and NAC group (HR 0.09, 95 % CI 0.02-0.38, p = 0.001), and increased ESRD risk in control group than in SB group (HR 1.97, 95 % CI 1.02-3.84, p = 0.045) and NAC group (HR 5.50, 95 % CI 2.23-13.57, p < 0.001). The Cox regression analysis demonstrated significantly different effectiveness of placebo, SB and NAC on NTIS correction and ESRD risk, p < 0.05, respectively. Variance analysis displayed a greater reduction in eGFR in controls than in SB (p = 0.044) and NAC group (p < 0.001).

CONCLUSION

SB and NAC are effective in promoting the recovery from NTIS status and delaying the deterioration of renal function in advanced CKD patients.

The Thyroid Hormone Inactivating Enzyme Type 3 Deiodinase is Present in Bactericidal Granules and the Cytoplasm of Human Neutrophils

Neutrophils are important effector cells of the innate immune system. Thyroid hormone (TH) is thought to play an important role in their function. Intracellular TH levels are regulated by the deiodinating enzymes. The TH-inactivating type 3 deiodinase (D3) is expressed in infiltrating murine neutrophils, and D3 knockout mice show impaired bacterial killing upon infection. This suggests that D3 plays an important role in the bacterial killing capacity of neutrophils. The mechanism behind this effect is unknown. We aimed to assess the presence of D3 in human neutrophils, and determine its subcellular localization using confocal and electron microscopy, because this could give important clues about its function in these cells. D3 appeared to be present in the cytoplasm and in myeloperoxidase containing azurophilic granules and as well as lactoferrin containing specific granules within human neutrophils. This subcellular localization did not change upon activation of the cells. D3 is observed intracellularly during neutrophil extracellular trap formation, followed by a reduction of D3 staining after release of the neutrophil extracellular traps into the extracellular space. At the transcriptional level, human neutrophils expressed additional essential elements of TH metabolism, including TH transporters and TH receptors. Here, we demonstrate the presence and subcellular location of D3 in human neutrophils for the first time and propose a model, in which D3 plays a role in the bacterial killing capacity of neutrophils either through generation of iodide for the myeloperoxidase system or through modulation of intracellular TH bioavailability.

Inflammation severely alters thyroid hormone signaling in the central nervous system during experimental allergic encephalomyelitis in rat: Direct impact on OPCs differentiation failure

Differentiation of oligodendrocyte precursor cells (OPCs) into myelinating oligodendrocytes is severely impaired by inflammatory cytokines and this could lead to remyelination failure in inflammatory/demyelinating diseases. Due to the role of thyroid hormone in the maturation of OPCs and developmental myelination, in this study we investigated (i) the possible occurrence of dysregulation of thyroid hormone signaling in the CNS tissue during experimental neuroinflammation; (ii) the possible impact of inflammatory cytokines on thyroid hormone signaling and OPCs differentiation in vitro. The disease model is the experimental allergic encephalomyelitis in female Dark-Agouti rats, whereas in vitro experiments were carried out in OPCs derived from neural stem cells. The main results are the following: (i) a strong upregulation of cytokine mRNA expression level was found in the spinal cord during experimental allergic encephalomyelitis; (ii) thyroid hormone signaling in the spinal cord (thyroid hormone receptors; deiodinase; thyroid hormone membrane transporter) is substantially downregulated, due to the upregulation of the thyroid hormone inactivating enzyme deiodinase 3 and the downregulation of thyroid hormone receptors, as investigated at mRNA expression level; (iii) when exposed to inflammatory cytokines, deiodinase 3 is upregulated in OPCs as well, and OPCs differentiation is blocked; (iv) deiodinase 3 inhibition by iopanoic acid recovers OPCs differentiation in the presence on inflammatory cytokines. These data suggest that cellular hypothyroidism occurs during experimental allergic encephalomyelitis, possibly impacting on thyroid hormone-dependent cellular processes, including maturation of OPCs into myelinating oligodendrocytes. GLIA 2016;64:1573-1589.

The Role of Hypothalamic NF-κB Signaling in the Response of the HPT-Axis to Acute Inflammation in Female Mice

A large proportion of critically ill patients have alterations in the hypothalamus-pituitary-thyroid (HPT) axis, collectively known as the nonthyroidal illness syndrome. Nonthyroidal illness syndrome is characterized by low serum thyroid hormone (TH) concentrations accompanied by a suppressed central component of the HPT axis and persistent low serum TSH. In hypothalamic tanycytes, the expression of type 2 deiodinase (D2) is increased in several animal models of inflammation. Because D2 is a major source of T3 in the brain, this response is thought to suppress TRH expression in the paraventricular nucleus via increased local bioavailability of T3. The inflammatory pathway component RelA (the p65 subunit of nuclear factor-κB) can bind the Dio2 promoter and increases D2 expression after lipopolysaccharide (LPS) stimulation in vitro. We aimed to determine whether RelA signaling in tanycytes is essential for the LPS-induced D2 increase in vivo by conditional elimination of RelA in tanycytes of mice (RelA(ASTKO)). Dio2 and Trh mRNA expression were assessed by quantitative in situ hybridization 8 or 24 hours after saline or LPS injection. At the same time points, we measured pituitary Tshβ mRNA expression and serum T3 and T4 concentrations. In RelA(ASTKO) mice the LPS-induced increase in Dio2 and decrease in Trh mRNA levels in the hypothalamus were reduced compared with the wild-type littermates, whereas the drop in pituitary Tshβ expression and in serum TH concentrations persisted. In conclusion, RelA is essential for the LPS-induced hypothalamic D2 increase and TRH decrease. The central changes in the HPT axis are, however, not required for the down-regulation of Tshβ expression and serum TH concentrations.

Low T3 syndrome is a strong predictor of poor outcomes in patients with community-acquired pneumonia

Low T3 syndrome was previously reported to be linked to poor clinical outcomes in critically ill patients. The aim of this study was to evaluate the predictive power of low T3 syndrome for clinical outcomes in patients with community-acquired pneumonia (CAP). Data for 503 patients were analyzed retrospectively, and the primary end point was 30-day mortality. The intensive care unit (ICU) admission rate and 30-day mortality were 8.3% and 6.4% respectively. The prevalence of low T3 syndrome differed significantly between survivors and nonsurvivors (29.1% vs 71.9%, P < 0.001), and low T3 syndrome was associated with a remarkable increased risk of 30-day mortality and ICU admission in patients with severe CAP. Multivariate logistic regression analysis produced an odds ratio of 2.96 (95% CI 1.14–7.76, P = 0.025) for 30-day mortality in CAP patients with low T3 syndrome. Survival analysis revealed that the survival rate among CAP patients with low T3 syndrome was lower than that in the control group (P < 0.01). Adding low T3 syndrome to the PSI and CURB-65 significantly increased the areas under the ROC curves for predicting ICU admission and 30-day mortality. In conclusion, low T3 syndrome is an independent risk factor for 30-day mortality in CAP patients.

Abnormalities of Thyroid Hormone Metabolism during Systemic Illness: The Low T3 Syndrome in Different Clinical Settings

Thyroid hormone abnormalities are common in critically ill patients. For over three decades, a mild form of these abnormalities has been described in patients with several diseases under outpatient care. These alterations in thyroid hormone economy are a part of the nonthyroidal illness and keep an important relationship with prognosis in most cases. The main feature of this syndrome is a fall in free triiodothyronine (T3) levels with normal thyrotropin (TSH). Free thyroxin (T4) and reverse T3 levels vary according to the underlying disease. The importance of recognizing this condition in such patients is evident to physicians practicing in a variety of specialties, especially general medicine, to avoid misdiagnosing the much more common primary thyroid dysfunctions and indicating treatments that are often not beneficial. This review focuses on the most common chronic diseases already known to present with alterations in serum thyroid hormone levels. A short review of the common pathophysiology of the nonthyroidal illness is followed by the clinical and laboratorial presentation in each condition. Finally, a clinical case vignette and a brief summary on the evidence about treatment of the nonthyroidal illness and on the future research topics to be addressed are presented.

Alteration of Thyroid-Related Hormones within Normal Ranges and Early Functional Outcomes in Patients with Acute Ischemic Stroke

This study evaluated the prognostic value of thyroid-related hormones within normal ranges after acute ischemic stroke. This was a retrospective study and we reviewed 1072 ischemic stroke patients consecutively admitted within 72 h after symptom onset. Total triiodothyronine (T3), total thyroxine (T4), free T3, free T4, and thyroid-stimulating hormone (TSH) were assessed to determine their values for predicting functional outcome at the first follow-up clinic visits, which usually occurred 2 to 4 weeks after discharge from the hospital. 722 patients were finally included. On univariate analysis, poor functional outcome was associated with presence of atrial fibrillation as the index event. Furthermore, score of National Institutes of Health Stroke Scale (NIHSS), total T4, free T4, and C-reactive protein at admission were significantly higher in patients with poor functional outcome, whereas free T3 and total T3 were significantly lower. On multiple logistic regression analysis, lower total T3 concentrations remained independently associated with poor functional outcome [odds ratio (OR), 0.10; 95% confidence interval (CI), 0.01-0.84; P = 0.035]. The only other variables independently associated with poor functional outcome were NIHSS scores. In sum, lower total T3 concentrations that were within the normal ranges were independently associated with poor short-term outcomes.