Nonthyroidal illness syndrome and prolonged mechanical ventilation in patients admitted to the ICU

Association between serum TSH levels and all-cause mortality in critically ill patients

Thyroid dysfunction is common in critical illness and may influence prognosis. However, the value of TSH in patients with severe diseases remains unclear. The aim of this study was to investigate the association between TSH and the clinical prognosis of critically ill patients. Methods: This retrospective study identified patients who were admitted to the ICU in the Medical Information Mart for Intensive Care (MIMIC-IV) database (version 2.2). A total of 6432 patients were divided into four groups based on TSH quartiles (Q1, <0.92 mIU/L; Q2, 0.92-1.07 mIU/L; Q3, 1.07-3.10 mIU/L; Q4, >3.10 mIU/L). The clinical outcomes were defined as all-cause 7-, 30-, and 90-year mortality after ICU admission. Restricted cubic splines (RCSs) for nonlinear associations were generated to visualize the relationship between TSH levels and clinical outcomes. The survival differences among the four groups were also analyzed using Kaplan‒Meier curves and log rank tests. Univariable and multivariable Cox proportional hazards regression were further used to assess the association between TSH levels and clinical outcomes. Results: After multivariate adjustment, a U-shaped relationship was observed between TSH levels and all-cause 7-, 30-, and 90- mortality among patients with severe disease (all P < 0.05 for nonlinearity). The plot showed a risk reduction in the low range of TSH, which reached the lowest risk at approximately 2.9 μIU/mL and then increased thereafter. Compared with patients with Q3 TSH levels, those with Q1, Q2, and Q4 TSH levels had a significantly higher risk of all-cause 30-day mortality (Q1: hazard ratio, 1.28; 95% CI, 1.06-1.54; Q2: hazard ratio, 1.22; 95% CI, 1.01-1.48; Q4: hazard ratio, 1.25; 95% CI, 1.04-1.50). For all-cause 90-day mortality, only the Q4 group had a significantly higher mortality risk than the Q3 group (hazard ratio, 1.24; 95% CI, 1.07-1.44). In subgroup analyses, we found that Q1 TSH levels were associated with higher mortality risk in men and older (≥65 years) patients, while Q4 TSH had a greater risk in men and younger (<65 years) patients. Conclusions: TSH was significantly associated with all-cause 7-, 30-, and 90-day mortality in critically ill patients after admission to the ICU. TSH may serve as a valuable biomarker for risk stratification in critically ill patients.

To Be Frail or Not to Be Frail: This Is the Question-A Critical Narrative Review of Frailty

Many factors have contributed to rendering frailty an emerging, relevant, and very popular concept. First, many pandemics that have affected humanity in history, including COVID-19, most recently, have had more severe effects on frail people compared to non-frail ones. Second, the increase in human life expectancy observed in many developed countries, including Italy has led to a rise in the percentage of the older population that is more likely to be frail, which is why frailty is much a more common concern among geriatricians compared to other the various health-care professionals. Third, the stratification of people according to the occurrence and the degree of frailty allows healthcare decision makers to adequately plan for the allocation of available human professional and economic resources. Since frailty is considered to be fully preventable, there are relevant consequences in terms of potential benefits both in terms of the clinical outcome and healthcare costs. Frailty is becoming a popular, pervasive, and almost omnipresent concept in many different contexts, including clinical medicine, physical health, lifestyle behavior, mental health, health policy, and socio-economic planning sciences. The emergence of the new "science of frailty" has been recently acknowledged. However, there is still debate on the exact definition of frailty, the pathogenic mechanisms involved, the most appropriate method to assess frailty, and consequently, who should be considered frail. This narrative review aims to analyze frailty from many different aspects and points of view, with a special focus on the proposed pathogenic mechanisms, the various factors that have been considered in the assessment of frailty, and the emerging role of biomarkers in the early recognition of frailty, particularly on the role of mitochondria. According to the extensive literature on this topic, it is clear that frailty is a very complex syndrome, involving many different domains and affecting multiple physiological systems. Therefore, its management should be directed towards a comprehensive and multifaceted holistic approach and a personalized intervention strategy to slow down its progression or even to completely reverse the course of this condition.

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 as a predictor of poor outcomes in patients with follicular lymphoma

The aim of this study was to investigate the prognostic value of low T3 syndrome in follicular lymphoma (FL). A total of 221 FL patients with detailed serum thyroid hormone levels and other complete clinical data were enrolled. Baseline features associated with low T3 syndrome were analyzed and balanced by propensity score matching. Univariate and multivariate regression analyses were performed to determine independent risk factors for progression-free survival (PFS) and overall survival (OS). A receiver operating characteristic (ROC) curve was plotted, and the area under the curve (AUC) was calculated to assess the predictive accuracy of FL international prognostic index FLIPI-1/FLIPI-2 and low T3 syndrome. A total of 22 patients (10.0%) had low T3 syndrome at diagnosis, which was associated with poor PFS and OS in the rituximab era. It is an independent prognostic factor for PFS and OS. Low T3 syndrome and FLIPI-1/FLIPI-2 significantly increased the AUC of PFS and OS compared to FLIPI-1/FLIPI-2 alone. Low T3 is a risk factor for POD24. In conclusion, low T3 syndrome may be a good candidate for predicting the prognosis of CLL in future clinical practice. Our study demonstrates that low T3 syndrome is associated with poorer survival outcomes in FL patients.

Non-thyroidal Illness Syndrome (NTIS) is no independent predictor for mortality in ICU patients

BACKGROUND

Low T3-(/T4-) syndrome, also known as non-thyroidal Illness Syndrome (NTIS) describes a decrease in free serum thyroid hormones without a concomitant increase in TSH, frequently observed in critically ill patients. However, whether NTIS is only a metabolic adaption to stress in critically ill or plays a crucial role as an independent risk factor for ICU mortality, remains unknown. Our study aimed to evaluate NTIS as an independent risk factor for increased ICU mortality.

METHODS

All patients admitted to the interdisciplinary intensive care unit (ICU) at the University Hospital of Leipzig between 2008 and 2014 were retrospectively analyzed for thyroidal function. Baseline data, information on additional thyroid function tests, disease progression, hospital and ICU length of stay (LOS) and patient outcome were retrospectively analyzed from the hospitals digital information system. For statistical evaluation, univariate analysis, matched pairs analysis and multivariate logistic regression were conducted.

RESULTS

One thousand, seven hundred ninety patients were enrolled in the study, of which 665 showed NTIS. Univariate analysis revealed a positive association of NTIS with ICU- and hospital-LOS, need for mechanical ventilation, incidence of sepsis, acute respiratory distress syndrome, acute liver failure and increased ICU mortality. Results of matched pair analysis confirmed these findings. In multivariate logistic regression, NTIS was associated with an increased ICU-LOS, increased duration of mechanical ventilation, acute kidney injury and liver failure, but showed no independent association with increased ICU-mortality.

CONCLUSION

Duration of mechanical ventilation as well as incidence of acute kidney injury, sepsis and acute liver failure were detected as independent predictors of mortality in patients with NTIS. NTIS itself was no independent predictor of increased ICU-mortality.

Relationship among Low T3 Levels, Type 3 Deiodinase, Oxidative Stress, and Mortality in Sepsis and Septic Shock: Defining Patient Outcomes

Low T3 syndrome occurs frequently in patients with sepsis. Type 3 deiodinase (DIO3) is present in immune cells, but there is no description of its presence in patients with sepsis. Here, we aimed to determine the prognostic impact of thyroid hormones levels (TH), measured on ICU admission, on mortality and evolution to chronic critical illness (CCI) and the presence of DIO3 in white cells. We used a prospective cohort study with a follow-up for 28 days or deceased. Low T3 levels at admission were present in 86.5% of the patients. DIO3 was induced by 55% of blood immune cells. The cutoff value of 60 pg/mL for T3 displayed a sensitivity of 81% and specificity of 64% for predicting death, with an odds ratio of 4.89. Lower T3 yielded an area under the receiver operating characteristic curve of 0.76 for mortality and 0.75 for evolution to CCI, thus displaying better performance than commonly used prognostic scores. The high expression of DIO3 in white cells provides a novel mechanism to explain the reduction in T3 levels in sepsis patients. Further, low T3 levels independently predict progression to CCI and mortality within 28 days for sepsis and septic shock patients.

Study of Non-Thyroidal Illness Syndrome and Its Recovery in Critically Ill Patients at a Tertiary Care Centre in South India

Background and Objectives

Transient thyroid hormone alterations are common during critical illness and are termed non-thyroidal illness syndrome (NTIS). We studied the prevalence of NTIS in the ICU setting and its impact on predicting mortality and other outcomes and compared it to the Acute Physiology and Chronic Health Evaluation II (APACHE II) score.

Materials and Methods

The study included 119 consecutive patients admitted with a critical illness. APACHE II score was calculated. Total T3, total T4, TSH, free T3, and free T4 were measured at admission and after six weeks of discharge. NTIS and euthyroid groups were studied for ICU, hospital stays, mortality, readmission, and recovery. Predictors of mortality were compared between survivors and non-survivors.

Results

The mean age was 60.15 ± 14.50 years with M:F = 84 (71%):35 (29%). NTIS was observed in 84 (71%), low T3 being the most common abnormality in 53 (63%). The occurrence of NTIS was significantly higher among non-survivors (28/30, 93%) versus survivors (56/89, 63%) (P = 0.002). Non-survivors showed significantly lower T3, TSH, and FT3/FT4 ratios and higher readmissions. NTIS group showed significantly greater ICU stay (P = 0.02) and had higher readmission rates (P = 0.032). Baseline T3 had the greatest power to predict mortality. APACHE II score also correlated significantly with mortality (19.60 ± 10.58 vs 11.99 ± 6.80, P < 0.001). The area under the curve (0.677) for the T3 level was lower than the APACHE II score (0.760). After six weeks, 61% had recovered from NTIS.

Conclusions

NTIS was common amongst critically ill patients (71.5%), which reversed in 61% at six weeks. Low T3 was the most common abnormality and independently predicted mortality. Free T3/free T4 also significantly predicted mortality. The correlation between thyroid dysfunction and the severity of primary illness makes it an additional attractive low-cost marker of mortality.

Thyroxine changes in COVID-19 pandemic: A systematic review and meta-analysis

OBJECTIVE

COVID-19 infection may affect thyroid function. However, changes in thyroid function in COVID-19 patients have not been well described. This systematic review and meta-analysis assess thyroxine levels in COVID-19 patients, compared with non-COVID-19 pneumonia and healthy cohorts during the COVID-19 epidemic.

METHODS

A search was performed in English and Chinese databases from inception to August 1, 2022. The primary analysis assessed thyroid function in COVID-19 patients, comparing non-COVID-19 pneumonia and healthy cohorts. Secondary outcomes included different severity and prognoses of COVID-19 patients.

RESULTS

A total of 5873 patients were enrolled in the study. The pooled estimates of TSH and FT3 were significantly lower in patients with COVID-19 and non-COVID-19 pneumonia than in the healthy cohort (P < 0.001), whereas FT4 were significantly higher (P < 0.001). Patients with the non-severe COVID-19 showed significant higher in TSH levels than the severe (I² = 89.9%, P = 0.002) and FT3 (I² = 91.9%, P < 0.001). Standard mean differences (SMD) of TSH, FT3, and FT4 levels of survivors and non-survivors were 0.29 (P= 0.006), 1.11 (P < 0.001), and 0.22 (P < 0.001). For ICU patients, the survivors had significantly higher FT4 (SMD=0.47, P=0.003) and FT3 (SMD=0.51, P=0.001) than non-survivors.

CONCLUSIONS

Compared with the healthy cohort, COVID-19 patients showed decreased TSH and FT3 and increased FT4, similar to non-COVID-19 pneumonia. Thyroid function changes were related to the severity of COVID-19. Thyroxine levels have clinical significance for prognosis evaluation, especially FT3.

Biochemical indicators of euthyroid sick syndrome in critically ill children

OBJECTIVES

This study aimed to determine the prevalence and predictors of euthyroid sick syndrome (ESS) in pediatric intensive care, and to establish a link between thyroid function tests and mortality.

METHODS

Between January 2015 and March 2020, children admitted to our pediatric intensive care unit (PICU) and tested for free triiodothyronine (fT3), free thyroxine (fT4), and thyrotropin (TSH) levels were included. Patients with decreased fT3, with normal or decreased fT4, and normal or decreased TSH levels were assigned to the ESS group. The association between biochemical indicators and ESS, as well as the relationship between fT3 and mortality, were examined.

RESULTS

A total of 141 (36%) of 386 children included to study were classified in the ESS group. The ESS group had a higher rate of 28-day mortality (12 [8.5%] vs. 9 [3.7%]). Blood urea nitrogen (BUN), albumin, platelet, lactate, and pediatric index of mortality 3 [PIM3 (%)] were significantly associated with ESS (odds ratios in order: 1.024, 0.422, 0.729, 1.208, 1.013). Multivariate regression analysis showed that BUN, albumin, platelet, and lactate were independently associated with ESS progression. The area under curve (AUC [95%CI]) for fT3 was 0.644 (0.555-0.789) to detect mortality. Children with a fT3 level lower than 2.31 pg/mL had significantly higher 28-day mortality (log rank test, p=0.001).

CONCLUSIONS

Our study identified BUN, albumin, lactate, and platelet count as independent risk factors for ESS progression in children. Furthermore, our findings indicated a correlation between fT3 and mortality, which makes fT3 an ideal candidate to be included in mortality indices.

Opposite Effect of Thyroid Hormones on Oxidative Stress and on Mitochondrial Respiration in COVID-19 Patients

Background: Thyroid hormones (TH)s are master regulators of mitochondrial activity and biogenesis. Nonthyroidal illness syndrome (NTIS) is generally considered an adaptative response to reduced energy that is secondary to critical illness, including COVID-19. COVID-19 has been associated with profound changes in the cell energy metabolism, especially in the cells of the immune system, with a central role played by the mitochondria, considered the power units of every cell. Infection by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) affects and alters mitochondrial functions, both to influence its intracellular survival and to evade host immunity. Aim of the study: This study was undertaken to analyze the oxidative balance and mitochondrial respiration in COVID-19 patients with and without NTIS to elucidate the role that thyroid hormones (TH)s play in this context. Methods: In our cohort of 54 COVID-19 patients, admitted to our University Hospital during the COVID-19 pandemic, we evaluated the generation of reactive oxygen species (ROS) by measuring the serum levels of derivatives of reactive oxygen metabolites (dROMs), and we analyzed the antioxidant capacity by measuring the serum biological antioxidant potential (BAP). We then analyzed the mitochondrial respiration in peripheral blood mononuclear cells (PBMC)s of 28 of our COVID-19 patients, using the seahorse instrument (Agilent). Results were correlated with the serum levels of THs and, in particular, of FT3. In addition, the role of T3 on bioelectrical impedance analysis (BIA) and mitochondrial respiration parameters was directly evaluated in two COVID-19 patients with NTIS, in which treatment with synthetic liothyronine (LT3) was given both in vivo and in vitro. Results: In our COVID-19 patients with NTIS, the dROMs values were significantly lower and the BAP values were significantly higher. Consequently, the oxidative stress index (OSi), measured as BAP/dROMs ratio was reduced compared to that observed in COVID-19 patients without NTIS, indicating a protective role exerted by NTIS on oxidative stress. In our COVID-19 patients, the mitochondrial respiration, measured in PBMCs, was reduced compared to healthy controls. Those with NTIS showed a reduced maximal respiratory capacity and a reduced proton leak, compared to those with normal FT3 serum values. Such lowered mitochondrial respiratory capacity makes the cells more vulnerable to bioenergetic exhaustion. In a pilot study involving two COVID-19 patients with NTIS, we could reinforce our previous observation regarding the role of T3 in the maintenance of adequate peripheral hydroelectrolytic balance. In addition, in these two patients, we demonstrated that by treating their PBMCs with LT3, both in vitro and in vivo, all mitochondrial respiration parameters significantly increased. Conclusions: Our results regarding the reduction in the serum levels of the reactive oxygen species (ROS) of COVID-19 patients with NTIS support the hypothesis that NTIS could represent an adaptative response to severe COVID-19. However, beside this beneficial effect, we demonstrate that, in the presence of an acute reduction of FT3 serum levels, the mitochondrial respiration is greatly impaired, with a consequent establishment of a hypoenergetic state of the immune cells that may hamper their capacity to react to massive viral infection.

Decreased triiodothyronine (T3) as a predictor for prolonged mechanical ventilation in critically ill patients with cardiac surgery

BACKGROUND

This study aimed to examine the correlation between thyroid hormone and prolonged mechanical ventilation (MV) in adult critically ill patients having undergone cardiac surgery.

METHODS

The present study refers to a retrospective, cohort study conducted at Nanjing First Hospital from March 2019 to December 2020. Patients receiving cardiac surgery and admitting to the Cardiovascular Intensive Care Unit (CVICU) in the study period were screened for potential inclusion. Demographic information, thyroid hormone and other laboratory measurements and outcome variables were recorded for analysis. Prolonged MV was defined as the duration of MV after cardiac surgery longer than 5 days. Thyroid hormones were assessed for the prognostic significance for prolonged MV.

RESULTS

One thousand eight hundred ninety-six patients who underwent cardiac surgery were screened for potential enrollment. Overall, 118 patients were included and analyzed in this study. Patients fell to the control (n = 64) and the prolonged MV group (n = 54) by complying with the duration of MV after cardiac surgery. The median value of total triiodothyronine (TT3) and free triiodothyronine (FT3) were 1.03 nmol/L and 3.52 pmol/L in the prolonged MV group before cardiac surgery, significantly lower than 1.23 nmol/L (P = 0.005) and 3.87 pmol/L, respectively in control (P = 0.038). Multivariate logistic regression analysis indicated that TT3 before surgery (pre-op TT3) had an excellent prognostic significance for prolonged MV (OR: 0.049, P = 0.012).

CONCLUSIONS

This study concluded that decreased triiodothyronine (T3) could be common in cardiac patients with prolonged MV, and it would be further reduced after patients undergo cardiac surgery. Besides, decreased T3 before surgery could act as an effective predictor for prolonged MV after cardiac surgery.

Non-thyroidal illness syndrome predicts outcome in adult critically ill patients: a systematic review and meta-analysis

We performed a systematic review and meta-analysis to comprehensively determine the prevalence and the prognostic role of non-thyroidal illness syndrome (NTIS) in critically ill patients. We included studies that assessed thyroid function by measuring the serum thyroid hormone (TH) level and in-hospital mortality in adult septic patients. Reviews, case reports, editorials, letters, animal studies, duplicate studies, and studies with irrelevant populations and inappropriate controls were excluded. A total of 6869 patients from 25 studies were included. The median prevalence rate of NTIS was 58% (IQR 33.2-63.7). In univariate analysis, triiodothyronine (T3) and free T3 (FT3) levels in non-survivors were relatively lower than that of survivors (8 studies for T3; standardized mean difference (SMD) 1.16; 95% CI, 0.41-1.92; I2 = 97%; P < 0.01). Free thyroxine (FT4) levels in non-survivors were also lower than that of survivors (12 studies; SMD 0.54; 95% CI, 0.31-0.78; I2 = 83%; P < 0.01). There were no statistically significant differences in thyrotropin levels between non-survivors and survivors. NTIS was independently associated with increased risk of mortality in critically ill patients (odds ratio (OR) = 2.21, 95% CI, 1.64-2.97, I2 = 65% P < 0.01). The results favor the concept that decreased thyroid function might be associated with a worse outcome in critically ill patients. Hence, the measurement of TH could provide prognostic information on mortality in adult patients admitted to ICU.

Nonthyroidal illness syndrome in acute pancreatitis patients: an 8-year cohort study

BACKGROUND

Nonthyroidal illness syndrome (NTIS) is common in critical illness and is associated with poor prognosis. The aim of this study was to find the prevalence, charateristics, and prognosis of NTIS and its correlation with outcomes in AP patients.

METHODS

A retrospective review of AP patients with a diagnosis of NTIS from Jan 2012 to September 2020 was performed. The serum thyroidal hormone (TH) disturbances, as well as the demographic characteristics and clinical outcomes of the study patients, were collected and analyzed.

RESULTS

Over the eight years, 183 included AP patients were diagnosed as NTIS, constituting an incidence of 64.7%. Patients with NTIS were admitted with worse condition based on the higher APACHE II score, SOFA score, Balthazar's CT score, CRP and lower albumin than euthyroid patients. Also, these patients had a longer ICU duration (3, 2-10 vs 2, 0-3, days, P = 0.039) and tended to be more likely to develop infected pancreatic necrosis (IPN) (15.3% vs 6.3%, P = 0.087) and gastrointestinal fistula (6% vs 0%, P = 0.082) than euthyroid patients. Free triiodothyronine (FT3) was found the best performance in predicting death compared by other well-recognized biomarkers.

CONCLUSION

NTIS is common in AP patients within 7 days after the onset of the disease. NTIS is associated with the worse characteristics at admission and poor outcome during the course. FT3 should be investigate as a potential biomarker in the prediction of death in AP patients.

Nonthyroidal Illness Syndrome: To Treat or Not to Treat? Have We Answered the Question? A Review of Metanalyses

BACKGROUND AND OBJECTIVE

Nonthyroidal Illness Syndrome (NTIS) occurs in approximately 70% of patients admitted to Intensive Care Units (ICU)s and has been associated with increased risk of death. Whether patients with NTIS should receive treatment with thyroid hormones (TH)s is still debated. Since many interventional randomized clinical trials (IRCT)s were not conclusive, current guidelines do not recommend treatment for these patients. In this review, we analyze the reasons why TH treatment did not furnish convincing results regarding possible beneficial effects in reported IRCTs.

METHODS

We performed a review of the metanalyses focused on NTIS in critically ill patients. After a careful selection, we extracted data from four metanalyses, performed in different clinical conditions and diseases. In particular, we analyzed the type of TH supplementation, the route of administration, the dosages and duration of treatment and the outcomes chosen to evaluate the results.

RESULTS

We observed a marked heterogeneity among the IRCTs, in terms of type of TH supplementation, route of administration, dosages and duration of treatment. We also found great variability in the primary outcomes, such as prevention of neurological alterations, reduction of oxygen requirements, restoration of endocrinological and clinical parameters and reduction of mortality.

CONCLUSIONS

NTIS is a frequent finding in critical ill patients. Despite several available IRCTs, it is still unclear whether NTIS should be treated or not. New primary endpoints should be identified to adequately validate the efficacy of TH treatment and to obtain a clear answer to the question raised some years ago.

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.

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.

Thyroid Disfunction in Critically Ill COVID-19 Patients. Relationship with In-Hospital Mortality

The incidence of thyroid disfunction has not been analyzed in critically ill COVID-19 patients. Our objective was to analyze the relationship of the thyroid profile and in-hospital mortality in critically ill COVID-19 patients. This was a prospective single-center study involving critically ill COVID-19 patients admitted to the ICU of a tertiary University Hospital. Thyroid hormones were measured through drawing blood samples from a central venous catheter at ICU admission and on the fifth day. A multiple logistic regression analysis was performed to analyze the variables associated with mortality. The ability of the different thyroid hormones to predict in-hospital mortality was evaluated by calculating the receiver operating characteristics (ROCs) and the area under the curve (AUC). A total of 78 patients were included in the study at ICU admission; 72 had their thyroid profile measured at day 5. In-hospital mortality reached 29.5%. Multiple logistic regression analysis showed that variables associated with mortality were age and prior beta-blocker therapy at ICU admission and age fT4 at day 5. The AUC for in-hospital mortality predictions of fT4 at day 5 was 0.69. Thyroid responses are commonly observed in critically ill COVID-19 patients. fT4 at day 5 after ICU admission was associated with mortality.

Association between Thyroid Dysfunction and Intensive Care Unit-Acquired Weakness: A Case-Control Study

Background

Thyroid disorders may decrease the threshold for developing myopathy. Nonthyroidal illness syndrome (NTIS) is a common form of thyroid dysfunction in critically ill patients who are prone to the development of intensive care unit-acquired weakness (ICUAW). We therefore tested the hypothesis that patients with abnormalities in thyroid function are at a higher risk of developing ICUAW.

Methods

We assessed blood samples from patients admitted to the ICU for ≥7 days for thyroid functions. Patients were classified into 4 categories (euthyroid, hyperthyroid, hypothyroid, and NTIS). Patients were then evaluated daily for ICUAW development. Patients with ICUAW were considered as cases, whereas patients who did not develop ICUAW served as controls. We compared demographic and clinical variables, such as APACHE II score; length of ICU stay; free T3 (FT3), free T4, and thyroid-stimulating hormone levels; incidence of the four categories of thyroid function; and other risk factors for ICUAW. Logistic regression was used to determine independent risk factors for ICUAW.

Results

This case-control study included 114 patients: 57 cases (ICUAW) and 57 controls. FT3 levels were significantly lower in the cases (2.13 ± 0.96 mU/L) than in controls (2.69 ± 1.07 mU/L; P=0.004). There were no significant differences between cases and controls regarding the incidence of all categories of thyroid function. In univariate analysis, five independent variables had P < 0.25 (sepsis, vasopressors, mechanical ventilation duration, NTIS, and FT3 levels). Among these variables, multiple regression showed that only FT3 level (CI = 0.157-0.82, P=0.015) was an independent risk factor.

Conclusion

The study revealed an inverse association between ICUAW incidence and FT3 levels.

The Association of TSH and Thyroid Hormones With Lymphopenia in Bacterial Sepsis and COVID-19

CONTEXT

Lymphopenia is a key feature of immune dysfunction in patients with bacterial sepsis and coronavirus disease 2019 (COVID-19) and is associated with poor clinical outcomes, but the cause is largely unknown. Severely ill patients may present with thyroid function abnormalities, so-called nonthyroidal illness syndrome, and several studies have linked thyrotropin (thyroid stimulating hormone, TSH) and the thyroid hormones thyroxine (T4) and 3,5,3'-triiodothyronine (T3) to homeostatic regulation and function of lymphocyte populations.

OBJECTIVE

This work aimed to test the hypothesis that abnormal thyroid function correlates with lymphopenia in patients with severe infections.

METHODS

A retrospective analysis of absolute lymphocyte counts, circulating TSH, T4, free T4 (FT4), T3, albumin, and inflammatory biomarkers was performed in 2 independent hospitalized study populations: bacterial sepsis (n = 224) and COVID-19 patients (n = 161). A subgroup analysis was performed in patients with severe lymphopenia and normal lymphocyte counts.

RESULTS

Only T3 significantly correlated (ρ = 0.252) with lymphocyte counts in patients with bacterial sepsis, and lower concentrations were found in severe lymphopenic compared to nonlymphopenic patients (n = 56 per group). Severe lymphopenic COVID-19 patients (n = 17) showed significantly lower plasma concentrations of TSH, T4, FT4, and T3 compared to patients without lymphopenia (n = 18), and demonstrated significantly increased values of the inflammatory markers interleukin-6, C-reactive protein, and ferritin. Remarkably, after 1 week of follow-up, the majority (12 of 15) of COVID-19 patients showed quantitative recovery of their lymphocyte numbers, whereas TSH and thyroid hormones remained mainly disturbed.

CONCLUSION

Abnormal thyroid function correlates with lymphopenia in patients with severe infections, like bacterial sepsis and COVID-19, but future studies need to establish whether a causal relationship is involved.

Thyroid hormone concentrations in severely or critically ill patients with COVID-19

OBJECTIVE

COVID-19 is a new coronavirus infectious disease. We aimed to study the characteristics of thyroid hormone levels in patients with COVID-19 and to explore whether thyroid hormone predicts all-cause mortality of severely or critically ill patients.

METHODS

The clinical data of 100 patients with COVID-19, who were admitted to Wuhan Tongji Hospital from February 8 to March 8, 2020, were analyzed in this retrospective study. The patients were followed up for 6-41 days. Patients were grouped into non-severe illness and severe or critical illness, which included survivors and non-survivors. Multivariate Cox proportional hazards analysis was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause mortality in association with continuous and the lower two quartiles of thyroid hormone concentrations in severely or critically ill patients.

RESULTS

The means of free T3 (FT3) were 4.40, 3.73 and 2.76 pmol/L in non-severely ill patients, survivors and non-survivors, respectively. The lower (versus upper) two quartiles of FT3 was associated with all-cause mortality HR (95% CI) of 9.23 (2.01, 42.28). The HR (95% CI) for all-cause mortality in association with continuous FT3 concentration was 0.41 (0.21, 0.81). In the multivariate-adjusted models, free T4 (FT4), TSH and FT3/FT4 were not significantly related to all-cause mortality. Patients with FT3 less than 3.10 pmol/L had increased all-cause mortality.

CONCLUSION

FT3 concentration was significantly lower in patients with severe COVID-19 than in non-severely ill patients. Reduced FT3 independently predicted all-cause mortality of patients with severe COVID-19.

Mortality Risk Profiling of Staphylococcus aureus Bacteremia by Multi-omic Serum Analysis Reveals Early Predictive and Pathogenic Signatures

Staphylococcus aureus bacteremia (SaB) causes significant disease in humans, carrying mortality rates of ∼25%. The ability to rapidly predict SaB patient responses and guide personalized treatment regimens could reduce mortality. Here, we present a resource of SaB prognostic biomarkers. Integrating proteomic and metabolomic techniques enabled the identification of >10,000 features from >200 serum samples collected upon clinical presentation. We interrogated the complexity of serum using multiple computational strategies, which provided a comprehensive view of the early host response to infection. Our biomarkers exceed the predictive capabilities of those previously reported, particularly when used in combination. Last, we validated the biological contribution of mortality-associated pathways using a murine model of SaB. Our findings represent a starting point for the development of a prognostic test for identifying high-risk patients at a time early enough to trigger intensive monitoring and interventions.

Prognostic Value of Thyroid Hormone FT3 in General Patients Admitted to the Intensive Care Unit

Low plasma triiodothyronine (T3) concentration indicates nonthyroidal illness syndrome (NTIS), which might be associated with a poor outcome in patients in the intensive care unit (ICU). This study evaluated the relationship between NTIS and prognostic indicators in patients admitted to the ICU and examined the fT3 cut-off points that could be associated with 28-day mortality. This prospective observational study included patients admitted to the ICU of The Third Hospital of Hebei Medical University from February to November 2018. The baseline variables and the occurrence of low free T3 (FT3) were collected. The patients were divided into the NTIS (FT3 < 3.28) and non-NTIS groups. Among 305 patients, 118 (38.7%) were in the NTIS group. FT3 (P < 0.001) and FT4 (P = 0.001) were lower, while the 28-day mortality rate (P < 0.001) and hospitalization expenses in ICU (P = 0.001) were higher in the NTIS group. The univariable analyses identified NTIS, FT3, free thyroxine/FT3, APACHEII, sequential organ failure score, duration of mechanical ventilation, creatinine, oxygenation index, white blood cells, albumin, age, and brain natriuretic peptide as being associated with 28-day mortality (all P < 0.05). The cut-off value of FT3 for 28-day mortality was 2.88 pmol/L. The 28-day mortality rate and hospitalization expenses in the ICU were higher in patients with NTIS. NTIS was independently associated with 28-day mortality.

Low Free T3 Is Associated With Worse Outcomes in Patients in the ICU Requiring Invasive Mechanical Ventilation

OBJECTIVE

Critical illness causes a decrease in serum free triiodothyronine (T₃) levels. This condition, known as nonthyroidal illness syndrome (NTIS), is associated with poor outcomes. The association of NTIS and outcomes in patients in the intensive care unit (ICU) requiring mechanical ventilation has not been well studied. This study aimed to determine the impact of NTIS on the outcomes of these patients.

METHODS

This prospective study included 162 patients in the ICU who underwent mechanical ventilation. Serum free T₃ levels were tested on the day of initiation of mechanical ventilation. The rates of in-hospital mortality and ventilator-free days (VFDs) at day 28 after the initiation of mechanical ventilation were compared between patients with low (<2.3 pg/mL) and normal (≥2.3 pg/mL) free T₃ levels. Patients who died while on mechanical ventilation were assigned a VFD of 0.

RESULTS

Low T₃ was present in 60% of study patients. The in-hospital mortality rate of the entire cohort was 39%, and the mean and median VFDs at day 28 were 13.5 and 21 days, respectively. Compared to patients with normal free T₃, patients with low free T₃ had higher in-hospital mortality (52% vs 19%, P < .001) and less mean and median VFDs at day 28 (10.7 vs 18 and 0 vs 23, respectively. P < .001 for both mean and median VFDs).

CONCLUSIONS

The presence of low T₃ due to NTIS in patients in the ICU requiring mechanical ventilation is associated with poor outcomes.

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.

Impact of thyroid hormones on asthma in older adults

Objective

Thyroid hormones affect airway contraction, but the specific effects of thyroid hormones on airways are controversial.

Methods

We divided 78 advanced-age men with asthma into 3 groups: type I respiratory failure (RF1), type II respiratory failure (RF2), and no respiratory failure (NRF). Pulmonary function was measured after asthma stabilization.

Results

The free triiodothyronine (FT3) level was significantly higher in the RF1 than RF2 group, but the free thyroxine (FT4), total thyroxine (TT4), and thyroid-stimulating hormone (TSH) levels were not significantly different. In the RF1, RF2, and NRF groups, the correlation coefficients between FT3 and the forced expiratory volume in1 s (FEV₁) were 0.317, 0.627, and 0.213; those between FT3 and the FEV₁/forced vital capacity (FVC) ratio were 0.287, 0.412, and 0.156; those between FT4 and FEV₁ were 0.214, 0.231, and 0.167; and those between FT4 and the FEV₁/FVC ratio were 0.211, 0.215, and 0.218, respectively. In the RF1 and RF2 groups, the correlation coefficients between the sum activity of peripheral deiodinases (SPINA-GD) and the FEV₁/FVC ratio were 0.164 and 0.421, and those between SPINA-GD and FEV₁ were 0.284 and 0.491, respectively.

Conclusion

The correlation between FT3 and pulmonary function is likely caused by changes in thyroid enzymology.

Predictors for euthyroid sick syndrome and its impact on in-hospital clinical outcomes in high-risk patients undergoing coronary artery bypass grafting

Objective:

The purpose of this cohort study was to investigate the independent relationship between euthyroid sick syndrome and in-hospital outcomes in high-risk patients undergoing isolated coronary artery bypass grafting, and we also examined the direct correlation between pre- or intra-operative variables and the incidence of coronary artery bypass grafting–associated euthyroid sick syndrome.

Methods:

The present study enrolled high-risk patients undergoing coronary artery bypass grafting from 1 January 2017 to 31 December 2017 in Beijing Anzhen hospital, including 387 (58.7%) patients with coronary artery bypass grafting–associated euthyroid sick syndrome and 272 (41.3%) patients without coronary artery bypass grafting–associated euthyroid sick syndrome.

Results:

The mean age of euthyroid sick syndrome group was significantly older than that of no euthyroid sick syndrome group (65.9 ± 7.5 vs 60.9 ± 9.6, p < 0.0001). Compared with the control group, significantly higher proportions of patients with euthyroid sick syndrome had presented with the following clinical characteristics at hospital admission: moderate and poor left ventricular ejection fraction (42.9% vs 28.7%, p < 0.0001), higher euroscore II (9.2 ± 4.1 vs 8.0 ± 3.9, p < 0.0001). Multivariate logistic regression analysis on the total patients revealed that the independent risk factors for coronary artery bypass grafting–associated euthyroid sick syndrome were advanced age (odds ratio = 1.07, 95% confidence interval = 1.05-1.09, p < 0.0001), higher euroscore II (odds ratio = 1.06, 95% confidence interval = 1.01-1.11, p = 0.013), and moderate and poor left ventricular ejection fraction (odds ratio = 2.26, 95% confidence interval = 1.61-3.18, p < 0.0001). Furthermore, euthyroid sick syndrome was independently correlated with an increased risk of in-hospital major adverse cardiovascular and cerebral events (odds ratio = 3.40, 95% confidence interval = 1.64-7.02, p = 0.001) and post-infection (odds ratio = 8.11, 95% confidence interval = 3.97-16.57, p < 0.0001) Besides, we also confirmed coronary artery bypass grafting–associated euthyroid sick syndrome was associated with Sequential Organ Failure Assessment maximum greater than 11 (odds ratio = 2.98, 95% confidence interval = 1.90-4.65, p < 0.0001), which predicted an in-hospital death rate of 95%, independently.

Conclusion:

Coronary artery bypass grafting–associated euthyroid sick syndrome exerted detrimental effects on short-term clinical outcomes in high-risk patients undergoing isolated coronary artery bypass grafting. Advanced age, higher euroscore II, and moderate and poor left ventricular ejection fraction were independent risk factors for coronary artery bypass grafting–associated euthyroid sick syndrome.

Thyroid Hormones in Critical Illness

Thyroid hormone is integral for normal function, yet during illness, circulating levels of the most active form (triiodothyronine [T3]) decline. Whether this is an adaptive response in critical illness or contributes to progressive disease has remained controversial. This review outlines the basis of thyroid hormone changes during critical illness and considers the evidence regarding T3 replacement.

Relationship between disease severity and thyroid function in Chinese patients with euthyroid sick syndrome

Euthyroid sick syndrome (ESS) is commonly observed in various acute and chronic illness as risk factor for mortality in patients with severe diseases, with lower triiodothyronine (T3) and free triiodothyronine (fT3).To explore the relationship between disease severity and thyroid function in critically ill Chinese patients with ESS.A total of 51 patients admitted to intensive care unit were examined to determine acute physiology and chronic health assessment II (APACHE II) scores within 24 hours of admission; thyroid function tests (TSH, fT3, fT4, tT3, tT4) and rT3 levels were determined on the second day. Based on the test results, patients were divided into euthyroid (n = 13), decreased fT3 or fT4 (n = 17), and decreased TSH (n = 21) groups. APACHE II scores and thyroid function were compared between the 3 groups. Furthermore, the relationship between the severity of disease and euthyroid sick syndrome was assessed.Out of 51 patients, 38 were men and 13 were women [mean age (± SD): 60.39 (± 19.32) years; range, 15-88 years]. APACHE II scores and rT3 levels were increased in all the 3 groups (P > .05). APACHE II scores showed a positive correlation with rT3 (P = .004, r = 0.379).Critically ill Chinese patients with ESS have a poor health state. Higher rT3 values are associated with severe disease.

Prognostic Value of Thyroid Profile in Critical Care Condition

BACKGROUND

Patients suffering from critical illness admitted to the Intensive Care Unit (ICU) exhibit alterations in their thyroid hormone levels, collectively termed as euthyroid sick syndrome or nonthyroidal illness syndrome. Our study was conducted to determine the correlation between these changes in thyroid hormone levels and the prognosis of ICU-admitted patients.

METHODS

A total of 270 ICU-admitted patients without previous history of thyroid disorder were included in the study. We recorded their baseline characteristics, acute physiology and chronic health evaluation (APACHE-II) score, thyroid hormone levels, lactate, and other parameters on admission. ICU mortality was the primary outcome. We analyzed the ability of each parameter to predict mortality in the participants. Further, we also evaluated whether the combination of thyroid hormone levels with APACHE-II score could improve the mortality prediction.

RESULTS

The mean age of the study population was 38.99 ± 18.32 years. A total of 81 patients (30%) expired during their ICU treatment. Both fT3 and fT4 levels were lower in nonsurvivors compared to survivors. Among the thyroid hormones, fT3 had the highest predictive value for ICU mortality, as seen by the largest area under the curve (AUC) value (0.990 ± 0.007) which was even greater than AUC of APACHE-II score (0.824 ± 0.051) and fT4 (0.917 ± 0.049). Univariate logistic regression analysis showed that fT3 (β = 140.560) had the highest predictive potential for ICU mortality compared with APACHE-II score (β = 0.776), fT4 (β = 17.62) and other parameters. Multivariate logistic regression analysis revealed that the combination of fT3 and APACHE-II (R² = 0.652) was superior in predicting mortality than APACHE-II alone (R² = 0.286).

CONCLUSION

We observed that fT3 was the strongest predictor of ICU mortality compared to all other parameters included in our study. Further, the combination of fT3 levels and APACHE-II scores provided for a higher probability for predicting mortality in ICU patients.

Changes in thyroid hormone concentrations during neonatal extracorporeal membrane oxygenation

OBJECTIVE

Thyroid hormone concentrations can be disturbed during critical illness. Our aim was to determine changes in thyroid hormone concentrations during neonatal extracorporeal membrane oxygenation (ECMO).

STUDY DESIGN

We included 21 ECMO-treated neonates. Age-specific s.d. scores (SDS) of free and total thyroxine (FT4; TT4), reverse and total triiodothyronine (rT3; TT3), thyroid-stimulating hormone (TSH) and thyroxine-binding globulin (TBG) were determined at six fixed time-points. Data were analyzed using general linear models.

RESULTS

At baseline, mean SDS FT4 (-0.78, 95% CI: -1.37 to -0.19), TT4 (-1.97, 95% CI: -2.76 to -1.18), TT3 (-0.88, 95% CI: -1.13 to -0.63), TSH (-2.14, 95% CI: -2.93 to -1.35) and TBG (-3.52, 95% CI: -4.55 to -2.50) were low with high mean SDS rT3 (0.53, 95% CI: 0.28 to 0.78). One hour after start ECMO, TT4, TSH and TBG had further declined; 12 h after start ECMO TT3 had declined (all P<0.05). After this decline, mean SDS TSH increased to the baseline level 12 h after start ECMO (-2.50, 95% CI: -3.22 to -1.79), and was higher than baseline 48 h after start ECMO (-0.56, 95% CI: -1.29 to 0.17). This TSH increase was followed by increases in TT4 and TT3. FT4 remained constant within the normal range during ECMO.

CONCLUSIONS

Thyroid hormone concentrations before ECMO were suggestive of non-thyroidal illness syndrome (NTIS). During ECMO, increases in TSH, TT4 and TT3 after an initial decline possibly reflect spontaneous restoration of the hypothalamic-pituitary-thyroid axis. FT4 remained constant within the normal range. This suggests that thyroxine therapy is not required during ECMO.

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.

Two-step thyroid screening strategy in the critical patient

BACKGROUND

Thyroid function biochemical tests are known for their usefulness in prognosis of long-term critical patients, although current data are controversial regarding the clinical benefit of both free triiodothyronine and thyroxine as prognostic thyroid markers during the first 48h after Intensive Care Unit (ICU) admission.

METHODS

The aim of this study was to evaluate the usefulness of two strategies for thyroid function assessment in the first 48h after admission at the ICU. The usefulness of a two-step biochemical thyroid strategy (initial isolated TSH determination, followed by subsequent fT4 and fT3) was compared with a complete one-step biochemical profile (TSH+fT4+fT3).

RESULTS

No significant differences were found between the rates of thyroid dysfunction detection when using both strategies (2.8% vs. 2.4%; p=0.71). Using the two-step strategy and a 2.5μUI/mL cut-off value for TSH, sensitivity and negative predictive value were 100%. Among patients with an altered fT3 only, mortality was 14% if TSH≤2.5μUI/mL, whereas it was 7% if TSH>2.5μUI/mL (p=0.008).

CONCLUSIONS

For patients with critical illness, the early two-step thyroid screening strategy (starting with an isolated TSH determination between 24 and 48h after admission) led to a saving of 50% in fT4 and fT3 tests, with a false-negative rate of 1.3%. This represents an improved diagnostic approach, hence avoiding the performance of unnecessary complementary biochemical measurements.

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.

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.

Role of enteral nutrition in nonthyroidal illness syndrome: a retrospective observational study

BACKGROUND

The nonthyroidal illness syndrome (NTIS) is prevalent among patients with enterocutaneous fistula and is associated with poor outcomes. The present study aimed to explore the role of enteral nutrition (EN) therapy on thyroid function among patients with enterocutaneous fistula and NTIS.

METHODS

We conducted a retrospective observational study among patients with enterocutaneous fistula between January 2013 and April 2014. All enrolled patients received EN therapy. Thyroid function and other parameters were measured.

RESULTS

After administration of 4 weeks of EN therapy, NTIS was resolved in 66 patients (Group A), while it persisted in 14 patients (Group B). The overall treatment success rate was 82.50 %. There were no significant differences between groups A and B at baseline for all parameters, except for the time from admission to start of EN therapy. The logistic analysis revealed that the time from admission to start of EN therapy was a significant independent indicator for achieving resolution of NTIS in our cohort.

CONCLUSIONS

This retrospective observational cohort study demonstrated that EN therapy can aid in the resolution of NTIS among patients with enterocutaneous fistula. These findings confirm the benefit of EN in the treatment of enterocutaneous fistula.

Thyroid function in critically ill patients

Patients in the intensive care unit (ICU) typically present with decreased concentrations of plasma tri-iodothyronine, low thyroxine, and normal range or slightly decreased concentration of thyroid-stimulating hormone. This ensemble of changes is collectively known as non-thyroidal illness syndrome (NTIS). The extent of NTIS is associated with prognosis, but no proof exists for causality of this association. Initially, NTIS is a consequence of the acute phase response to systemic illness and macronutrient restriction, which might be beneficial. Pathogenesis of NTIS in long-term critical illness is more complex and includes suppression of hypothalamic thyrotropin-releasing hormone, accounting for persistently reduced secretion of thyroid-stimulating hormone despite low plasma thyroid hormone. In some cases distinguishing between NTIS and severe hypothyroidism, which is a rare primary cause for admission to the ICU, can be difficult. Infusion of hypothalamic-releasing factors can reactivate the thyroid axis in patients with NTIS, inducing an anabolic response. Whether this approach has a clinical benefit in terms of outcome is unknown. In this Series paper, we discuss diagnostic aspects, pathogenesis, and implications of NTIS as well as its distinction from severe, primary thyroid disorders in patients in the ICU.

Euthyroid sick syndrome in children with diabetic ketoacidosis

OBJECTIVES

To investigate characteristics of euthyroid sick syndrome (ESS) in children with diabetic ketoacidosis (DKA).

METHODS

This retrospective study was carried out between May 2010 and April 2013 at the Pediatric Department of Shandong Provincial Hospital, Shandong University, Shandong, China. Diabetic ketoacidosis children were divided into 2 groups: euthyroidism (group one, n=30) and ESS (group 2, n=40). C-peptide, glycosylated hemoglobin (HbA1c), bicarbonate, anion gap (AG), free triiodothyronine (FT3), free thyroxine (FT4), and thyrotropin (TSH) levels were measured before and after 7 days of insulin treatment. Daily blood glucose (BG) profiles were recorded.

RESULTS

Glycosylated hemoglobin, AG, the mean daily BG, and fasting blood glucose levels were higher, and bicarbonate, FT3, FT4, and TSH levels were lower in group 2 than in group one (all p&lt;0.05). Free triiodothyronine (r=-0.593, p&lt;0.001) and FT4 (r=-0.402, p=0.001) were negatively correlated with HbA1c. Free triiodothyronine (r=-0.438, p&lt;0.001) and FT4 (r=-0.505, p&lt;0.001) were negatively correlated with AG, and FT3 (r=0.503, p&lt;0.001) and FT4 (r=0.448, p&lt;0.001) were positively correlated with bicarbonate.

CONCLUSION

Diabetic ketoacidosis children with ESS have poor diabetic control. Free thyroid hormones are associated with the severity of DKA.

Non-thyroidal illness in the ICU: a syndrome with different faces

BACKGROUND

Critically ill patients typically present with low or low-normal plasma thyroxine, low plasma triiodothyronine (T3), increased plasma reverse T3 (rT3) concentrations, in the absence of a rise in thyrotropin (TSH). This constellation is referred to as nonthyroidal illness syndrome (NTI). Although it is long known that the severity of NTI is associated with risk of poor outcomes of critical illness, the causality in this association has not been well investigated.

SUMMARY

In this narrative review, the different faces of NTI during critical illness are highlighted. Acute alterations are dominated by changes in thyroid hormone binding, peripheral thyroid hormone uptake, and alterations in the expression and activity of the type-1 and type-3 deiodinases. It was recently shown that at least part of these acute changes are brought about by concomitant macronutrient restriction, and this part appears adaptive and beneficial. However, the face of the NTI in the prolonged phase of critical illness is different, when patients are fully fed but continue to depend on intensive medical care. In that prolonged phase of illness, hypothalamic thyrotropin releasing hormone (TRH) expression is suppressed and explains reduced TSH secretion and whereby reduced thyroidal hormone release. During prolonged critical illness, and in the presence of adequate nutrition, several tissue responses could be interpreted as compensatory to low thyroid hormone availability, such as increased expression of monocarboxylate transporters, upregulation of type-2 deiodinase activity, and increased sensitivity at the receptor level. Infusing hypothalamic releasing factors in these prolonged critically ill patients can reactivate the thyroid axis and induce an anabolic response.

CONCLUSIONS

It is clear that the name "NTI" during critical illness refers to a syndrome with different faces. Tolerating the early "fasting response" to critical illness and its concomitant changes in thyroid hormone parameters appears to be wise and beneficial. This thus applies to the NTI present in the majority of the patients treated in intensive care units. However, the NTI that occurs in prolonged critically ill patients appears different with regard to both its causes and consequences. Future studies should specifically target this selected population of prolonged critically ill patients, and, after excluding iatrogic drug interferences, investigate the effect on outcome of treatment with hypothalamic releasing factors in adequately powered randomized controlled trials.

Can non-thyroid illness syndrome predict mortality in lung cancer patients? A prospective cohort study

This study aims to evaluate the incidence of non-thyroid illness syndrome (NTIS) among patients diagnosed as lung cancer and its association with the stage of the disease, Eastern Cooperative Oncology Group (ECOG) performance score, nutritional parameters, and survival. We enrolled 120 patients that 71 of them with newly diagnosed and staged non-small cell lung cancer and 49 of them small-cell lung cancer. The cases were examined for thyroid function tests, ECOG performance score, and nutritional evaluation before treatment. Also, cases were evaluated for their overall survival rates. NTIS was identified in 30 (42 %) of the 71 non-small cell lung cancer patients and 22 (44 %) of the 49 small-cell lung cancer patients. NTIS was more frequent among advanced stage of cases. Serum albumin level, cholesterol level, lymphocyte level, and body mass index were detected to be significantly low and ECOG performance score was significantly high in cases with NTIS when compared to cases without NTIS. NTIS was found to be negatively correlated with body mass index, ECOG performance score, and serum albumin level, and it was positively correlated with disease stage. NTIS was detected significantly as a poor prognostic factor for lung cancer. NTIS was frequently seen in cases with non-small cell lung cancer and small-cell lung cancer. NTIS can be used as a predictor of poor prognosis for lung cancer patients.

Thyroid hormones and antioxidant systems: focus on oxidative stress in cardiovascular and pulmonary diseases

In previous works we demonstrated an inverse correlation between plasma Coenzyme Q₁₀ (CoQ₁₀) and thyroid hormones; in fact, CoQ₁₀ levels in hyperthyroid patients were found among the lowest detected in human diseases. On the contrary, CoQ₁₀ is elevated in hypothyroid subjects, also in subclinical conditions, suggesting the usefulness of this index in assessing metabolic status in thyroid disorders. A Low-T3 syndrome is a condition observed in several chronic diseases: it is considered an adaptation mechanism, where there is a reduction in pro-hormone T4 conversion. Low T3-Syndrome is not usually considered to be corrected with replacement therapy. We review the role of thyroid hormones in regulation of antioxidant systems, also presenting data on total antioxidant capacity and Coenzyme Q₁₀. Published studies suggest that oxidative stress could be involved in the clinical course of different heart diseases; our data could support the rationale of replacement therapy in low-T3 conditions.

The identification of thyroid dysfunction in surgical sepsis

BACKGROUND

Studies have documented a correlation between hypothyroxinemia and mortality in critically ill patients; however, there are limited data in sepsis. The objective of this study was to assess baseline thyroid function studies and their association with mortality in surgical sepsis. We hypothesized that the relatively decreased levels of free thyroxine (T4), decreased levels of triiodothyronine (T3), and increased thyrotropin-stimulating hormone levels would be associated with mortality.

METHODS

This was a retrospective review of prospectively collected data in a surgical intensive care unit. Data evaluated included patient demographics, baseline thyroid function studies, and mortality. Patients were categorized as having sepsis, severe sepsis, or septic shock. A value of p < 0.05 was considered significant.

RESULTS

Within 24 months, 231 septic patients were accrued. The mean age was 59 ± 3 years, and 43% were male. Thirty-nine patients were diagnosed as having sepsis, 131 as having severe sepsis, and 61 as having septic shock. There were no statistically significant differences between the T3, free T4, or thyrotropin-stimulating hormone levels at baseline and the different categorizations of sepsis.T4 levels were increased in all patients but to a significantly lesser extent in those who died. Similarly, T3 levels were significantly decreased in patients who died.

CONCLUSION

In surgical sepsis, decreased T3 levels at baseline are associated with mortality. These data do not support the administration of levothyroxine (T4) because it is already elevated and would preferentially be converted to reverse T3 (inactive) in critical illness; however, replacement with liothyronine (T3) might be rational.

LEVEL OF EVIDENCE

Epidemiologic study, level III.

Thyroid hormone levels as a predictor of mortality in intensive care patients: A comparative prospective study

BACKGROUND

Mortality rates of intensive care patients are quite high. The aim of this study was to determine the role, as well as to compare the value of several markers in predicting mortality in intensive care patients. Patient-wise, this is the largest study of its kind and the first that attempts to correlate the degree of thyroid hormone suppression with elevations in procalcitonin (PCT) levels.

PATIENTS AND METHODS

In this study, a total of 417 patients were included in the final analysis, 235 of which were men (56%), and 182 were women (44%). Predictors of mortality that were investigated include age, APACHE II score, PCT, free triiodo-L-thyronine (fT3), free tetraiodothyronine/thyroxine (fT4) and thyroid stimulating hormone/thyrotropin (TSH).

RESULTS

High APACHE II score and low PCT levels, as well as suppression of fT3, fT4 and TSH levels were all found to be associated with higher mortality in our intensive care patients (p < 0.001). Suppression of thyroid hormones was also found to be reciprocally correlated with high APACHE II scores and PCT levels (p < 0.05).

CONCLUSION

Calculation of APACHE II score as well as measurement of PCT, fT3, fT4 and TSH levels may all be useful as predictors of mortality in intensive care patients.

Relationship between thyroid function and ICU mortality: a prospective observation study

Introduction

Although nonthyroidal illness syndrome is considered to be associated with adverse outcome in ICU patients, the performance of thyroid hormone levels in predicting clinical outcome in ICU patients is unimpressive. This study was conducted to assess the prognostic value of the complete thyroid indicators (free triiodothyronine (FT3), total triiodothyronine; free thyroxine, total thyroxine, thyroid-stimulating hormone and reverse triiodothyronine) in unselected ICU patients.

Methods

A total of 480 consecutive patients without known thyroid diseases were screened for eligibility and followed up during their ICU stay. We collected each patient's baseline characteristics, including the Acute Physiology and Chronic Health Evaluation II (APACHE II) score and thyroid hormone, N-terminal pro-brain natriuretic peptide (NT-proBNP) and C-reactive protein (CRP) levels. The primary outcome was ICU mortality. Potential predictors were analyzed for possible association with outcomes. We also evaluated the ability of thyroid hormones together with APACHE II score to predict ICU mortality by calculation of net reclassification improvement (NRI) and integrated discrimination improvement (IDI) indices.

Results

Among the thyroid hormone indicators, FT3 had the greatest power to predict ICU mortality, as suggested by the largest area under the curve (AUC) of 0.762 ± 0.028. The AUC for FT3 level was less than that for APACHE II score (0.829 ± 0.022) but greater than that for NT-proBNP level (0.724 ± 0.030) or CRP level (0.689 ± 0.030). Multiple regression analysis revealed that FT3 level (standardized β = -0.600, P = 0.001), APACHE II score (standardized β = 0.912, P < 0.001), NT-proBNP level (standardized β = 0.459, P = 0.017) and CRP level (standardized β = 0.367, P = 0.030) could independently predict primary outcome. The addition of FT3 level to APACHE II score gave an NRI of 54.29% (P < 0.001) and an IDI of 36.54% (P < 0.001). The level of FT3 was significantly correlated with NT-proBNP levels (r = -0.344, P < 0.001) and CRP levels (r = -0.408, P < 0.001).

Conclusion

In unselected ICU patients, FT3 was the most powerful and only independent predictor of ICU mortality among the complete indicators. The addition of FT3 level to the APACHE II score could significantly improve the ability to predict ICU mortality.

Beyond low plasma T3: local thyroid hormone metabolism during inflammation and infection

Decreased serum thyroid hormone concentrations in severely ill patients were first reported in the 1970s, but the functional meaning of the observed changes in thyroid hormone levels, together known as nonthyroidal illness syndrome (NTIS), remains enigmatic. Although the common view was that NTIS results in overall down-regulation of metabolism in order to save energy, recent work has shown a more complex picture. NTIS comprises marked variation in transcriptional and translational activity of genes involved in thyroid hormone metabolism, ranging from inhibition to activation, dependent on the organ or tissue studied. Illness-induced changes in each of these organs appear to be very different during acute or chronic inflammation, adding an additional level of complexity. Organ- and timing-specific changes in the activity of thyroid hormone deiodinating enzymes (deiodinase types 1, 2, and 3) highlight deiodinases as proactive players in the response to illness, whereas the granulocyte is a novel and potentially important cell type involved in NTIS during bacterial infection. Although acute NTIS can be seen as an adaptive response to support the immune response, NTIS may turn disadvantageous when critical illness enters a chronic phase necessitating prolonged life support. For instance, changes in thyroid hormone metabolism in muscle during critical illness may be relevant for the pathogenesis of myopathy associated with prolonged ventilator dependence. This review focuses on NTIS as a timing-related and organ-specific response to illness, occurring independently from the decrease in serum thyroid hormone levels and potentially relevant for disease progression.

Acute kidney injury on ventilator initiation day independently predicts prolonged mechanical ventilation in intensive care unit patients

PURPOSE

The purpose of this study is to identify the predictors for prolonged mechanical ventilation (PMV) of more than 21 days among intensive care unit (ICU) patients.

MATERIAL AND METHODS

A retrospective observational study was conducted in a respiratory ICU from December 2008 to November 2009. The outcome measurement was the occurrence of PMV. Acute kidney injury (AKI) was identified and defined as an increase in the serum creatinine level of 50% or greater from baseline.

RESULTS

Of 154 patients enrolled, 41 patients (26.6%) had PMV. Patients with PMV showed higher Acute Physiology and Chronic Health Evaluation II scores, lower serum albumin levels, and more AKI on mechanical ventilation (MV) initiation day compared with the non-PMV patients. Patients with PMV were significantly associated with longer MV duration before the day of readiness for weaning (DRW) and a higher rapid shallow breathing index on DRW. In a multivariate regression analysis, the independent risk factors for PMV were AKI on MV initiation day (odds ratio [OR], 5.630; 95% confidence interval [CI], 1.378-22.994; P = .016), longer MV duration before DRW (OR, 1.289; 95% CI, 1.158-1.435; P < .001), and higher rapid shallow breathing index on DRW (OR, 1.012; 95% CI, 1.003-1.021; P = .010).

CONCLUSIONS

Acute kidney injury on MV initiation day is an independent risk factor for PMV of more than 21 days, which may be helpful for clinicians to refine their management of these ICU patients early.