Low triiodothyronine syndrome is associated with stroke-associated pneumonia

Low triiodothyronine is associated with high risk of malnutrition and poor functional status in subacute stroke patients

BACKGROUND AND AIMS

Stroke patients may exhibit low thyroid hormone (TH) levels and disease-related malnutrition, both potentially affecting clinical status; their relationships remain unexplored. This study aimed to evaluate TH concentrations in subacute stroke patients and investigate the relationships between TH levels, nutritional risk, and functional status.

METHODS AND RESULTS

Early subacute stroke patients admitted to a rehabilitation unit were assessed using various nutritional screening tools (Geriatric Nutritional Risk Index-GNRI, Prognostic Nutritional Index-PNI, and Controlling Nutritional Status-CONUT score) and with the Global Leadership Initiative on Malnutrition (GLIM) criteria. Thyroid-Stimulating Hormone (TSH), free Tetraiodothyronine-Thyroxine (fT4) and free Triiodothyronine (fT3) levels were determined. Functional and cognitive status was evaluated using different scales. Associations between altered THs and nutritional status were examined through univariate/multivariate analyses and ROC analyses. Among 264 patients (age 72.0 ± 10.5 yrs), significant correlations emerged between fT3 and nutritional risk and functional tests (mostly p < 0.001). The prevalence of high nutritional risk determined by GNRI, PNI and CONUT increased from higher to lower fT3 tertiles. Lower fT3 levels were observed in patients at high nutritional risk and with GLIM-based malnutrition. fT3 exhibited reasonable predictive power for high nutritional risk (particularly PNI: AUC 0.769, 95%CI 0.702-0.836, p < 0.001). Multivariate logistic regression identified nutritional risk (p < 0.001) and time from stroke onset as predictors of low fT3 values.

CONCLUSION

Altered fT3 levels in early subacute stroke patients correlate with high nutritional risk and poor functional status. Low fT3 values upon admission for stroke rehabilitation may serve as a further parameter to be considered in patients at high nutritional risk.

Euthyroid sick syndrome predicts the risk of ischemic stroke-associated pneumonia in the acute stage of ischemic stroke: a nested case-control study

Objective

Ischemic stroke-associated pneumonia (iSAP) affects about 10% of acute ischemic stroke patients during hospitalization. Current prediction scales for iSAP are insufficient. Identifying early biomarkers for stroke-associated pneumonia is crucial for improving patient outcomes. This study aimed to investigate the predictive value of euthyroid sick syndrome (ESS) for iSAP in acute-stage of ischemic stroke patients.

Methods

We studied 1767 acute ischemic stroke patients within one week of symptom onset, categorizing them into an infection group (iSAP, n=376) and control group (control, n=1391). COX regression analysis was used to identify the potential risk and protected factors. Kaplan-Meier time-event curves and Log-Rank tests were performed to differentiate infection time in patients with ESS or normal T3 group.

Results

The iSAP group had higher rates of risk factors like older age, atrial fibrillation, COPD, and ESS, along with elevated levels of WBC, CRP,and FT4 levels (all P < 0.001). Conversely, iSAP patients had lower GCS scores, eGFR, TSH, T3, FT3 (all P < 0.001) and T4 levels (P = 0.005) upon admission. No significant differences were observed in sex, smoking history, hypertension, diabetes, or LDL-C levels (P > 0.05). COX regression analysis identified age, KWST scores, leukocyte count, CRP, and ESS (all P < 0.001) as significantly correlated with iSAP. ROC analysis revealed ESS as a predictor with sensitivity of 35.64% and specificity of 87.92% for SAP prediction, like atrial fibrillation and higher than COPD and eGFR.

Conclusion

ESS at admission predicts a higher risk of stroke-associated pneumonia in acute-stage of ischemic stroke.

Risk factors for stroke-related pneumonia in patients with ischaemic stroke: A systematic evaluation and meta-analysis

BACKGROUND

Stroke-associated pneumonia (SAP) is a frequent and severe complication occurring within the first week after a stroke, particularly in ischemic stroke (IS) patients. SAP is primarily driven by stroke-induced immune suppression, dysphagia, and impaired consciousness, leading to aspiration and subsequent pneumonia. Its incidence ranges from 3.9 % to 12 %, making it a leading cause of mortality and morbidity in stroke survivors. Despite previous studies identifying risk factors such as age, and dysphagia, the results have often been inconsistent due to methodological differences and the inclusion of both ischemic and hemorrhagic stroke patients.

OBJECTIVE

This study aims to provide a comprehensive and targeted analysis of SAP risk factors specific to IS patients through a systematic review and meta-analysis, with the goal of enhancing clinical risk assessment and prevention strategies.

METHODS

This study searched eight databases-PubMed, EMBASE, Web of Science, Cochrane Library, CNKI, VIP, CBM, and Wanfang-for literature on risk factors for SAP in IS patients, with a timeframe of January 1, 2014, to April 6, 2024. Using Revman 5.4, the odds ratio values and 95 % confidence intervals for each collected risk factor were combined and analysed to explore the risk factors for the development of SAP in patients with ischemic stroke.

RESULTS

A total of 25 studies were included, involving 4,251,064 patients and 153,431 SAP patients. We identified 68 potential risk factors for SAP in IS patients from 25 studies, with detailed analysis performed on 13 factors. The remaining factors were not included in the combined analysis due to insufficient supporting literature (fewer than five studies). Out of 13 risk factors, 11 were determined to be associated with the occurrence of SAP, including age, gender, smoking, diabetes, swallowing disorders, with a timeframe of January 1, 2014, to April 6, 2024. chronic lung disease, consciousness disorders, a high NIHSS score, elevated white blood cell count, elevated CRP, and nasogastric tube.

CONCLUSION

This study identified major risk factors for SAP in IS patients, confirming some existing factors in current assessment scales, such as advanced age, impaired consciousness, and dysphagia. Additionally, new risk factors were identified, including nasogastric tube use, and diabetes. These findings will help improve risk assessment tools, facilitate early identification of SAP risk factors, and prevent SAP occurrence, thereby improving outcomes for IS patients.

REGISTRATION

This systematic review according to the Preferred Reporting Items for Systematic Evaluation and Meta-Analysis (PRISMA) guidelines [1] and is registered in PROSPERO (Registration No: CRD42024548441).

Thyroid hormones and stroke, the gap between clinical and experimental studies

Despite plenty of human studies on changes in thyroid hormones after stroke and some animal studies that assessed the effects of thyroid hormone administration on stroke, conclusive evidence for clinical application is lacking. This review aimed to determine the consistency of the results between clinical and preclinical studies. This article reviewed the PubMed, Embase, web of Knowledge, and Google Scholar databases up to June 2023 using the MeSH terms "stroke, cerebral ischemia, cerebral infarction, brain ischemia, brain infarction, triiodothyronine (T3), tetraiodothyronine (T4), thyroxine (T4), and thyroid hormone". The results of clinical and preclinical studies related to T3 substantially confirm each other. That is, in most human studies lower T3 was associated with poor outcomes, and in experimental studies, T3 administration also had therapeutic effects. However, the results of experimental studies related to T4 could not support those of clinical studies. There seem to be some conflicts between experimental and human studies, especially regarding changes and effects of T4 after stroke. The gap between experimental and clinical studies may lead to non-applicable results, wasting time and money, and unnecessary killing of animals.

Low T3 syndrome as a predictor of poor prognosis in peripheral T-cell lymphomas

PURPOSE

The purpose of the study was to evaluate the prognostic value of low T3 syndrome in peripheral T-cell lymphomas (PTCLs).

METHODS

One hundred and seventy-four patients of newly diagnosed PTCLs were enrolled in the study. We performed statistical analysis based on the clinical data collected.

RESULTS

Thirty-Six (20.69%) patients had low T3 syndrome at first admission. Results suggested that the patients with higher score of ECOG PS, International Prognostic Index (IPI) and Prognostic Index for T-cell lymphoma (PIT), bone marrow involvement and lower level of albumin tended to develop low T3 syndrome. The median progression-free survival (PFS) and overall survival (OS) were 10 months and 36 months, respectively, for all patients. Pre-existing low T3 syndrome was in correlation with worse PFS and OS. Patients with low T3 syndrome showed worse PFS (4 months vs 13 months, P = 0.0001) and OS (7 months vs 83 months, P < 0.0001) than patients without low T3 syndrome. IPI and PIT, respectively, combined with low T3 syndrome improved the ability to predict OS and PFS of PTCLs.

CONCLUSIONS

The study indicated that low T3 syndrome may be a good candidate for predicting prognosis of peripheral T-cell lymphomas.

Cardiovascular and Neuronal Consequences of Thyroid Hormones Alterations in the Ischemic Stroke

Ischemic stroke is one of the leading global causes of neurological morbidity and decease. Its etiology depends on multiple events such as cardiac embolism, brain capillaries occlusion and atherosclerosis, which ultimately culminate in blood flow interruption, incurring hypoxia and nutrient deprivation. Thyroid hormones (THs) are pleiotropic modulators of several metabolic pathways, and critically influence different aspects of tissues development. The brain is a key TH target tissue and both hypo- and hyperthyroidism, during embryonic and adult life, are associated with deranged neuronal formation and cognitive functions. Accordingly, increasing pieces of evidence are drawing attention on the consistent relationship between the THs status and the acute cerebral and cardiac diseases. However, the concrete contribution of THs systemic or local alteration to the pathology outcome still needs to be fully addressed. In this review, we aim to summarize the multiple influences that THs exert on the brain and heart patho-physiology, to deepen the reasons for the harmful effects of hypo- and hyperthyroidism on these organs and to provide insights on the intricate relationship between the THs variations and the pathological alterations that take place after the ischemic injury.