Thyroid-stimulating Hormone Concentrations Research Articles

Features of the functioning of the hypothalamic-pituitary-thyroid axis in mice with Lewis carcinoma on the background of induced hyperthyroidism

Thyroid hormones (TH) influence the processes of cell proliferation and differentiation, but their role in the processes of carcinogenesis is contradictory. The purpose of the study. To study the effect of induced hyperthyroidism in mice of both sexes with intertwined Lewis carcinoma (LLC) on the activity of the hypothalamic-pituitary-thyroid axis (GGT). Materials and methods. The experimental model was mixed-sex mice of the C57BL/6 line with subcutaneously transplanted LLC on the background of induced hyperthyroidism (main group). Two control groups were used: control group I – mice with sodium liothyronine- induced hyperthyroidism and control group II – mice with subcutaneously transplanted LLC. On the 25th day after tumor transplantation, the level of thyrotropin- releasing hormone (TRH), thyroid- stimulating hormone (TSH), triiodothyronine (T3), total and free thyroxine (T4, FT4) was determined in the homogenates of GGT organs and in blood serum. Results. In female mice, hyperthyroidism caused an increase in the level of TRH in the hypothalamus and a decrease in TSH in the pituitary gland; in males, a decrease in TRH only in the hypothalamus. In control group II, euthyroid disorder syndrome developed: In mice of both sexes, serum levels of T4 and FT4 were found to decrease against the background of unchanged T3 levels and an increase in TSH content only in females. In the females of the main group, an increase in the level of TSH in the thyroid gland caused a decrease in T3 content in 73 % of animals against the background of normal T4 and elevated FT4 levels, in 27 % of females the T3 level increased. In males, in 73 % of the observations, the T3 level was increased against the background of high T4 and FT4 values and unchanged TSH levels. In the skin and LLC samples of the mice of the main group, an increase in T3 levels was noted. Conclusion. The growth of LLC against the background of hyperthyroidism is a process with multifactorial effects. High levels of T3 in blood serum and skin stimulated the proliferation of tumor cells, which led to the formation of subcutaneous tumors of a larger volume in the mice of the main group. Sex differences in the GGT response indicate different mechanisms that implement pathological processes.

Association of maternal mild hypothyroidism in the first and third trimesters with obstetric and perinatal outcomes: a prospective cohort study

BackgroundMild hypothyroidism, including subclinical hypothyroidism (SCH) and isolated maternal hypothyroxinemia (IMH), is fairly common in pregnant women, but its impact on pregnancy outcomes is less clear, especially mild hypothyroidism in late pregnancy. ObjectiveTo evaluate the impact of SCH and IMH in the first and third trimesters, respectively, on obstetric and perinatal outcomes. Study DesignThis large prospective study was conducted at the International Peace Maternity and Child Health Hospital (IPMCH) in Shanghai. 52,027 pregnant women who underwent the first-trimester antenatal screening at IPMCH were consecutively enrolled from January 2013 to December 2016. To evaluate the impact of maternal SCH and IMH in the first trimester on pregnancy outcomes, participants were divided into three groups according to thyroid function in the first trimester: first-trimester euthyroidism group (n= 33,130), first-trimester SCH group (n= 884), and first-trimester IMH group (n= 846). Then, to evaluate the impact of maternal SCH and IMH in the third trimester on pregnancy outcomes, the first-trimester euthyroidism group was subdivided into three groups according to thyroid function in the third trimester: third-trimester euthyroidism group (n= 30,776), third-trimester SCH group (n= 562), and third-trimester IMH group (n= 578). Obstetric and perinatal outcomes, including preterm birth (PTB), preeclampsia, gestational hypertension, gestational diabetes mellitus (GDM), large for gestational age (LGA), small for gestational age, macrosomia, cesarean section, and fetal demise were measured and compared between those in either SCH/IMH group and euthyroid group. Binary logistic regression was used to assess the association of SCH or IMH with these outcomes. Results34,860 pregnant women who had first (weeks 8–14) and third trimester (weeks 30–35) thyrotropin and free thyroxine concentrations available were included in the final analysis. Maternal SCH in the first trimester was linked to a lower risk of GDM (aOR 0.64, 95% CI 0.50–0.82) compared with the euthyroid group. However, third-trimester SCH is associated with heightened rates of PTB (aOR 1.56, 95%CI 1.10–2.20), preeclampsia (aOR 2.23, 95%CI 1.44–3.45), and fetal demise (aOR 7.00, 95%CI 2.07–23.66) compared with the euthyroid group. IMH in the first trimester increased risks of preeclampsia (aOR 2.14, 95% CI 1.53–3.02), GDM (aOR 1.45, 95%CI 1.21–1.73), LGA (aOR 1.64, 95%CI 1.41–1.91), macrosomia (aOR 1.85, 95%CI 1.49–2.31) and cesarean section (aOR 1.35, 95%CI 1.06–1.74), while IMH in the third trimester increased risks of preeclampsia (aOR 2.85, 95%CI 1.97–4.12), LGA (aOR 1.49, 95%CI 1.23–1.81) and macrosomia (aOR 1.60, 95%CI 1.20–2.13) compared with the euthyroid group. ConclusionThis study indicates that while first-trimester SCH did not elevate the risk for adverse pregnancy outcomes, third-trimester SCH was linked to several adverse pregnancy outcomes. IMH in the first and third trimesters was associated with adverse pregnancy outcomes, yet the impact varied by trimester. These results suggest the timing of mild hypothyroidism in pregnancy may be pivotal in determining its effects on adverse pregnancy outcomes and underscore the importance of trimester-specific evaluations of thyroid function.

Characterization of a human thyroid microtissue model for testing thyroid disrupting chemicals.

Perturbation of thyroid hormone (T4) synthesis is known to cause numerous developmental, metabolic, and cognitive disorders in humans. Due to species differences in sensitivity to chemical exposures, there is a need for human-based in vitro approaches that recapitulate thyroid cellular architecture and T4 production when screening. To address these limitations, primary human thyrocytes, isolated from healthy adult donor tissues and cryopreserved at passage one (p'1) were characterized for cellular composition, 3D follicular architecture, and thyroglobulin (TG)/T4 expression and inhibition by prototype thyroid disrupting chemicals (TDC). Flow analysis of the post-thaw cell suspension showed >80% EpCAM-positive cells with 10%-50% CD90-positive cells. When seeded onto 96-well Matrigel®-coated plates and treated with bovine thyroid stimulating hormone (TSH), thyrocytes formed 3D microtissues during the initial 4-5 days of culture. The microtissues exhibited a stable morphology and size over a 14-day culture period. TG and T4 production were highest in microtissues when the proportion of CD90-positive cells, seeding density and thyroid stimulating hormone concentrations were between 10%-30%, 6K-12Kcells per well, and 0.03-1 mIU/mL, respectively. At maximal TG and T4 production levels, average microtissue diameters ranged between 50 and 200µm. The T4 IC50 values for two prototype TPO inhibitors, 6-propyl-2-thiouracil and methimazole, were ∼0.7µM and ∼0.5 µM, respectively, in microtissue cultures treated between days 9 and 14. Overall, p'1 cryopreserved primary human thyrocytes in 3D microtissue culture represent a promising new model system to prioritize potential TDC acting directly on the thyroid as part of a weight-of-evidence hazard characterization.

The time course of lactate and endocrine changes in dogs suffering from dog bite wounds.

The stress response after acute trauma in humans and animals has been well-recognised in the literature. However, data on temporal changes in endocrine parameters after acute trauma in previously healthy dogs are scant. To longitudinally track endocrine variables and lactate concentrations in dogs with canine bite wounds. Prospective study involving 20 dogs hospitalised after being bitten by another dog. Serum cortisol, thyroxine (total T4), thyrotropin (TSH), and lactate concentrations were measured on admission and every 8 hours after the recorded bite incident, for a 72-hour period. Median cortisol concentration was markedly elevated on admission (314.6 nmol/L; IQR 229.3-369.6) but returned to within the reference interval by 16 hours post-bite (99.5 nmol/L; IQR 48.7-225.4) and reached a nadir at 48 hours post-bite (38.5 nmol/L; IQR 32.1-115.9). Median total T4 concentration was within the reference interval on admission (20.6 nmol/L; IQR 12.7-27.9) but decreased below the reference interval by 8 hours (11.0 nmol/L; IQR 5.0-14.1) and reached a nadir 16 hours postbite (7.0 nmol/L; IQR 2.9-19.7), before gradually increasing after 64 hours to reach the reference range by 72 hours. The median TSH concentrations remained within the reference interval throughout the study period. Median lactate concentration was mildly elevated on admission (3.0 mmol/L; IQR 2.0-3.9). This study produced novel data on the temporal relationships of the hypothalamic-pituitary-adrenal and hypothalamicpituitary- thyroidal axes alterations after an acute traumatic insult in dogs.

Differences between non-obese and obese patients with hypertension according to gender

Abstract Introduction In recent years, obesity has escalated markedly, emerging as a one of major worldwide health issue. The frequency of obesity in both adults and children is rising at an alarming rate, leading to severe consequences for public health. The World Health Organization (WHO) reports that as much as 13% of the global population is grappling with obesity. Numerous research studies have established that obesity not only heightens the risk of cardiovascular diseases (CVD) including hypertension, coronary heart disease, and heart failure, but also exacerbates complications in individuals already suffering from these conditions. Purpose The aim of this study was to retrospectively analyze the differences between non-obese and obese patients admitted to the cardiology department due to hypertension according to gender. Methods We performed a retrospective analysis of 486 medical records of patients who had been admitted to the Institute of Heart Diseases of the University Clinical Hospital in Wroclaw (Poland) between January 2017 and June 2021. The study group was divided in two ways. The division of patients was into one of two groups based on the following cut-off BMI values: non-obese (BMI < 30) and obese (BMI ≥ 30). The study was conducted following the principles of the Declaration of Helsinki and approved by the independent Bioethics Committee of Wroclaw Medical University, protocol no. KB-837/2022. The significance level for all statistical tests was set to 0.05. R 4.3.0. was used for computations. Results Women accounted for 53% of the study group and were significantly older than men (64.7±12.8 vs. 60.5±11.8, p=0.466). Women with obesity had significantly higher triglycerides (TG), high-sensitivity C-reactive protein and thyroid-stimulating hormone concentrations and significantly lower high-density lipoprotein (HDL) concentrations than women who were not affected by obesity. Men with obesity had significantly higher TG levels, lower HDL levels, more more frequent to have diabetes (DM) and less frequent stroke in the past compared to men without obesity. (Table 1 and 2) Conclusions This study highlights important differences between patients with hypertension without and with obesity, with notable gender differences. Women with obesity showed differences only in laboratory test results, while men with obesity showed differences in laboratory test results and comorbidities. These findings emphasize the need for gender-specific management strategies and research in hypertension and obesity, underscoring the distinct cardiovascular risks associated with obesity in both genders.

Towards Personalized TSH Reference Ranges: A Genetic and Population-Based Approach in Three Independent Cohorts.

Background: Serum thyroid-stimulating hormone (TSH) measurement is the diagnostic cornerstone for primary thyroid dysfunction. There is high inter-individual but limited intra-individual variation in TSH concentrations, largely due to genetic factors. The currently used wide population-based reference intervals may lead to inappropriate management decisions. Methods: A polygenic score (PGS) including 59 genetic variants was used to calculate genetically determined TSH reference ranges in a thyroid disease-free cohort (n = 6,834). Its effect on reclassification of diagnoses was investigated when compared to using population-based reference ranges. Next, results were validated in a second independent population-based thyroid disease-free cohort (n = 3,800). Potential clinical implications were assessed in a third independent population-based cohort including individuals without thyroid disease (n = 26,321) as well as individuals on levothyroxine (LT4) treatment (n = 1,132). Results: PGS was a much stronger predictor of individual TSH concentrations than FT4 (total variance in TSH concentrations explained 9.2-11.1% vs. 2.4-2.7%, respectively) or any other nongenetic factor (total variance in TSH concentrations explained 0.2-1.8%). Genetically determined TSH reference ranges differed significantly between PGS quartiles in all cohorts, while the differences in FT4 concentrations were absent or only minor. Up to 24.7-30.1% of individuals, previously classified as having subclinical hypo- and hyperthyroidism when using population-based TSH reference ranges, were reclassified as euthyroid when genetically determined TSH reference ranges were applied. Individuals in the higher PGS quartiles had a higher probability of being prescribed LT4 treatment compared to individuals from the lower PGS quartiles (3.3% in Q1 vs. 5.2% in Q4, Pfor trend =1.7 × 10-8). Conclusions: Individual genetic profiles have the potential to personalize TSH reference ranges, with large effects on reclassification of diagnosis and LT4 prescriptions. As the currently used PGS can only predict approximately 10% of inter-individual variation in TSH concentrations, it should be further improved when more genetic variants determining TSH concentrations are identified in future studies.

Development of an animal model of hypothyroxinemia during pregnancy in Wistar rats

AbstractBackgroundHypothyroxinemia is a subclinical thyroid hormone deficiency in which the mother has inadequate levels of T4 during pregnancy. The fetus relies entirely on the mother's T4 hormone level for early neurodevelopment. Isolated maternal hypothyroxinemia (IMH) in the first trimester of pregnancy can lead to lower intelligence, lower motor scores, and a higher risk of mental illness in descendants. Here, we focus on the autism‐like behavior of IMH offspring.MethodsThe animals were administered 1 ppm of propylthiouracil (PTU) for 9 weeks. Then, the concentrations of T3, T4, and thyroid‐stimulating hormone (TSH) were detected using enzyme‐linked immunosorbent assay (ELISA) to verify the developed animal model of IMH. We performed four behavioral experiments, including the marble burying test, open‐field test, three‐chamber sociability test, and Morris water maze, to explore the autistic‐like behavior of 40‐day‐old offspring rats.ResultsThe ELISA test showed that the serum T3 and TSH concentrations in the model group were normal compared with the negative control group, whereas the T4 concentration decreased. In the behavioral experiments, the number of hidden marbles in the offspring of IMH increased significantly, the frequency of entering the central compartment decreased, and the social ratio decreased significantly.ConclusionThe animal model of IMH was developed by the administration of 1 ppm of PTU for 9 weeks, and there were autistic‐like behavior changes such as anxiety, weakened social ability, and repeated stereotyping in the IMH offspring by 40 days.

Life-threatening amiodarone-induced thyrotoxicosis – Personalized approach to radical treatment

ObjectiveAmiodarone is an iodine-rich molecule and an effective antiarrhythmic drug. It is a first-line treatment for patients with life-threatening ventricular arrhythmias and for prevention in patients at high risk. The use of amiodarone may cause serious adverse effects such as pharmacotherapy-resistant, life-threatening amiodarone-induced thyrotoxicosis (AIT)leading to rapid deterioration of the patient's condition.According to the European Thyroid Association (ETA) guidelines, emergency thyroidectomy is the first-line treatment option in these cases. ; however, is not always feasible in the clinical setting due to the high anesthetic risk.We aimed to assess the clinical course and results of urgent thyroidectomy and 131-I therapy in patients with severe AIT with worsening of cardiac status. MethodsRetrospective analysis of the clinical course and outcomes of life-threatening AIT refractory to pharmacotherapy in patients hospitalized at a tertiary endocrinology center between 2014 and 2022. ResultsAn electronic database search identified 75 patients hospitalized for severe AIT. At the time of AIT diagnosis, median Thyroid-stimulating hormone (TSH) concentration was 0.001 mIU/L (range 0.001–0.35), fT4 63.2 pmol/L (range 9.0 - >100), and fT3 10.2 pmol/L (range 3.8–49.3). All patients received optimal conservative treatment. Among them, 20 required urgent radical therapy due to worsening arrhythmias and/or AIT-related heart failure. In this group, 6 patients died before any radical treatment was applied, 6 underwent total thyroidectomy, while 8 patients were successfully treated with 131-I (in 6 cases after rhTSH stimulation). The median dose of 131-I used for the therapy was 784MBq (range 627–860). The decision to treat with 131-I despite low but detectable 131-I uptake (median value 6 %) was made in cases of significant contraindications to anesthesia due to refractory ventricular arrhythmias, exacerbation of severe heart failure unresponsive to cardiac treatment, myocardial infarction during AIT course, massive pulmonary embolism. ConclusionThe decision regarding the optimal time and type of radical treatment of AIT refractory to pharmacotherapy is critical for patients management and should not be delayed. Urgent therapy with 131-I may be an effective therapeutic option in patients who are unsuitable for thyroidectomy due to the high risk of anesthesia.

Impact of Subclinical Hypothyroidism on Lipid Profile in Jeddah: A Retrospective Cohort Study.

Background Patients with subclinical hypothyroidism (SCH) have a high serum concentration of thyroid-stimulating hormone (TSH), whereas their serum-free thyroxine concentrations are normal. Lipid metabolism is regulated in large part by thyroid hormones. It could be connected to a changed lipid profile. This study aimed to evaluate the relationship between SCH and alterations in the lipid profile. Methodology Data from 99 patients with SCH and 109 euthyroid cases were collected from King Abdulaziz Medical City, Jeddah, Saudi Arabia, from 2016 to 2022. Patients older than 18 years were included in the study. The groups were matched in terms of gender, age, and body mass index. SCH was defined as a TSH value of 4.5 to 10 mIU/L, and normal T4 as 5 to 18 μg/dL. Control cases had a normal TSH ranging from 0.45 to 4.5 mIU/L. The total serum cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, and triglyceride (TG) levels in both groups were examined and the results were recorded. Results In comparison to the control group, SCH patients had greater median glycated hemoglobin (HbA1C) (p = 0.001) and lower median vitamin D levels (p = 0.004) before therapy. Before therapy, SCH patients also showed considerably lower HDL levels and significantly higher LDL and TG levels (p < 0.001). Conclusions There is a substantial correlation between SCH and reduced HDL and vitamin D levels. It was linked to increased TG, LDL, and HbA1c levels. Only vitamin D and LDL were pathologically high. Treatment with levothyroxine raised total and LDL cholesterol levels. Future research should look into the affordability of treating SCH.

Retrospective Cross-Sectional Study of the Relationship of Thyroid Volume and Function with Anthropometric Measurements, Body Composition Analysis Parameters, and the Diagnosis of Metabolic Syndrome in Euthyroid People Aged 18-65.

Background and Objectives: The thyroid is a key endocrine gland for the regulation of metabolic processes. A body composition analysis (BCA) is a valuable complement to the assessment of body mass index, which is derived only from body weight and height. This cross-sectional retrospective study aimed to investigate the relationships between thyroid volume (TV) and thyroid function parameters, anthropometric measurements, BCA parameters, and the presence of metabolic syndrome (MetS) in adults without clinically overt thyroid disease. Material and Methods: This study involved 45 people (females: 57.8%; MetS: 28.9%) hospitalized for planned diagnostics without signs of acute illness or a deterioration of their health and without thyroid disease, who underwent thyroid ultrasound scans, biochemical tests to assess their thyroid function, MetS assessments, anthropometric measurements, and BCAs using the bioelectrical impedance method. Results: The TV was significantly larger in people with MetS compared to people without MetS. The TV was significantly higher and the serum thyrotropin (TSH) concentration was significantly lower in overweight and obese people than in normal and underweight people. The free triiodothyronine (FT3) serum concentration and TV were correlated with waist circumference and some parameters of the BCA, and the FT3 concentration was also correlated with the body mass index, waist-hip ratio, and waist-height ratio. No significant correlations were found between the FT4 and TSH and the results of the anthropometric and BCA measurements. Conclusions: Even in a population of euthyroid patients without clinically overt thyroid disease, there were some significant relationships between the volume and function of the thyroid gland and the results of their anthropometric parameters, BCAs, and the presence of MetS features.

Effects of dietary Silybum marianum powder on growth performance, egg and carcass characteristics, immune response, intestinal microbial population, haemato-biochemical parameters and sensory meat quality of laying quails

The study aimed to assess the effects of different dietary Silybum marianum (SM, milk thistle) powder levels on growth performance, productivity, immunity, small intestine, haemato-biochemical parameters, meat quality, and egg and carcass characteristics of laying quails. The experimental subjects consisted of one hundred and eight 43-day-old quails divided into 3 treatments (0, 0.75, and 1.50% SM) with 4 replicates each. The egg characteristics and growth performance of the quails were evaluated. Quails were euthanized for evaluation of carcasses, microbiota, and sensory characteristics of meat. Blood samples were analyzed for haematology and biochemical profile. SM at 0.75% and 1.50% significantly (P < 0.05) increased feed intake, enhanced egg characteristics (number, weight, width, length, volume, weight of egg yolk, and eggshell thickness), jejunum and ileum length, spleen weight, lactobacillus population, sensory characteristics of meat, red blood cell (RBC), hemoglobin, erythrocytic indices, concentration of albumin, globulin and thyroid stimulating hormone (TSH). SM at 0.75% and 1.50% decreased (P < 0.05) carcass weight (abdominal fat, heart, neck, and pancreas), feed conversion ratio (FCR) based on eggs produced, percentages of heterophils and lymphocytes, concentration of lactate dehydrogenase, population of coliforms clostridia, and Escherichia coli. Aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and creatine kinase were not significantly (P > 0.05) altered by 0.75% and 1.50% SM. SM at both levels (0.75% and 1.50%) may improve growth, egg characteristics, immune response, intestinal morphology and microbiota, meat quality and erythropoiesis, and also lead to decreased cholesterol in laying quails. Economics can be improved, too. The authors recommend adding 1.0% of SM to quail diet.

The Effect of Mediterranean Diet on Thyroid Gland Activity.

The main goal of this research was to determine whether there is a correlation between adherence to the Mediterranean diet (assessed by the Mediterranean Diet Serving Score (MDSS)) and parameters indicating thyroid gland activity, such as concentration of thyroid-stimulating hormone (TSH), thyroid hormones (free triiodothyronine (fT3), free thyroxine (fT4)), thyroglobulin (Tg), antibodies to thyroid proteins (thyroglobulin antibodies (TgAb) and thyroid peroxidase antibodies (TPOAb)), and calcitonin (CT) in plasma and serum samples. An additional objective was to investigate whether there are differences in the values of the MDSS among clinical groups (euthyroid individuals, euthyroid individuals with positive TgAb and/or TPOAb, and hypothyroid and hyperthyroid participants). This cross-sectional study included 4620 participants over 18 years of age from the islands of Korčula and Vis, and the mainland city of Split. The MDSS was assessed from a food frequency questionnaire (FFQ). MDSS values were significantly higher in females compared to males and showed a positive association with the age of the participants. There was no significant difference in the MDSS values among the examined clinical groups. In the group of subjects with euthyroidism, a significant positive association was found between fT3 and the MDSS, while in the group of subjects with subclinical hypothyroidism, a significant positive association was observed between the MDSS and both fT3 and fT4. CT levels were also positively associated with the MDSS. Considering the significant positive association of the MDSS and both fT3 and fT4 levels in patients with subclinical hypothyroidism, the results of this study could be used to create guidelines for selecting an appropriate, potentially protective diet for these patients.

MARKERS OF LIPID AND PROTEIN OXIDATION IN THE BLOOD OF WOMEN AND MEN WITH AUTOIMMUNE HASHIMOTO'S THYROIDITIS

Purpose: The aim of this study was to analyze changes in markers of oxidative stress (lipid peroxidation and oxidative modification of proteins) and the total antioxidant activity in the blood of women and men with autoimmune Hashimoto's thyroiditis (HT). Methodology. This study was carried out in a group of 153 individuals. The group of women participating in the study consisted of 109 individuals (71.24%), while the group of men consisted of 44 individuals (28.76%). All persons were divided into two groups: 1) euthyroidism (n = 64; men – n = 18, and women – n = 46); and 2) Hashimoto's autoimmune thyroiditis with subclinical hypothyroidism (n = 89; men – n = 26, and women – n = 63). The functioning of the thyroid gland was additionally verified by measuring the concentration of thyrotropin (TSH), free triiodothyronine (fT3), free tetraiodothyronine (thyroxine, fT4), and antibodies against thyroid peroxidase (anti-TPO). The concentration of thyrotropin, triiodothyronine, free thyroxine and the concentration of antibodies against thyroperoxidase in human serum were determined using the electrochemiluminescence method "ECLIA" on the immunological analyzer Elecsys Cobas e 411 (Hitachi, Japan). In each group of women and men with euthyroidism and Hashimoto's autoimmune thyroiditis with subclinical hypothyroidism, the 2-thiobarbituric acid reactive substances (TBARS), carbonyl derivatives of protein oxidative modification (OMP), and total antioxidant capacity (TAC) were determined. Scientific novelty. Statistically significant changes in levels of oxidative stress markers were not observed. In women with HT, elevated TBARS levels with simultaneously increased TAC levels in the plasma and erythrocytes were observed. Additionally, levels of aldehydic and ketonic derivatives of oxidative modification of proteins in the blood of women with HT were lower compared to the women with the euthyroid state. In men with HT, levels of markers of oxidative stress (except TAC levels in the plasma) were lower compared to those obtained in men with the euthyroid state. Conclusions. Hashimoto's thyroiditis with subclinical hypothyroidism does not have a direct influence on levels of biomarkers of lipid and protein oxidation. The results obtained in the current study highlight the need for future investigations of biomarkers of lipid and protein oxidation, especially depending on the duration of this disease.

Статеві та клініко-інструментальні паралелі рівнів ліпопротеїн(а) в пацієнтів з дуже високим серцево-судинним ризиком

In recent years it has been established that elevated levels of Lp(a) are an independent genetic risk factor for the development of atherosclerotic cardiovascular diseases and aortic stenosis, however, issues of gender and age characteristics remain controversial.The aim of study was to analyze the gender characteristics of the relationship between Lp(a) levels and atherogenic changes in the lipid spectrum of the blood, clinical and instrumental characteristics, taking into account damage to the aortic valve and the results of coronary angiography in patients with stable coronary heart disease. Materials and methods. The 106 patients with chronic coronary heart disease (CAD) were examined. The average age of the subjects was 55.00±1.0 years (95% CI 51.11-58.89), among them: 78 men and 28 women.The entire cohort of patients was divided depending on the Lp(a) levels: 1group (n=58) with a Lp(a) level less than 50 mg/dl; 2 group (n=20) with Lp(a) level 50-100 mg/dl; 3 group (n=8) with Lp(a) level 101-150 mg/dl and 4 group (n=20) with Lp(a) level more than 150 mg/dl.Research methods included: 1. General clinical examination; 2. Laboratory characteristics of lipid (with determination of Lp(a)) and carbohydrate metabolism, as well as standard biochemical parameters; 3. Instrumental examination (electrocardiography, echocardiography, ultrasound peripheral vessels examination, coronary angiography); 4. Mathematical and statistical processing of the results obtained.Results and conclusions. In patients with CAD verified by clinical-instrumental and coronary angiographic criteria, it is noted that Lp(a) levels in women are on average significantly higher (P&lt; 0.05) than in men and increase with the onset of menopause.Close correlations have not been recorded between Lp(a) in mg/dL and total cholesterol, LDL cholesterol and non-HDL cholesterol, as well as the concentrations of glucose, glycosylated hemoglobin, serum creatinine, and the concentration of thyroid-stimulating hormone (TSH).Determined that in patients with documented atherosclerotic lesions of the coronary arteries against the Lp(a) levels above 100 mg/dl, there is a greater need for coronary revascularization. A close relationship is observed between the increase in Lp(a) levels and the percentage of detection of aortic stenosis, which confirms the pathogenetic role of this lipoprotein in the formation of this acquired aortic valve disease.

Acute moderate normobaric hypoxia does not modify circulating thyroid hormone concentrations induced by 1 h of head-out cold-water immersion.

This study tested the hypothesis that acute moderate normobaric hypoxia augments circulating thyroid hormone concentrations during and following 1 h of cold head-out water immersion (HOWI), compared with when cold HOWI is completed during normobaric normoxia. In a randomized crossover single-blind design, 12 healthy adults (27 ± 2 yr, 2 women) completed 1 h of cold (22.0 ± 0.1°C) HOWI breathing either normobaric normoxia ([Formula: see text] = 0.21) or normobaric hypoxia ([Formula: see text] = 0.14). Free and total thyroxine (T3) and triiodothyronine (T4), and thyroid-stimulating hormone (TSH) concentrations were measured in venous blood samples obtained before (baseline), during (15-, 30-, and 60 min), and 15 min following HOWI (post-), and were corrected for changes in plasma volume. Arterial oxyhemoglobin saturation and core (rectal) temperature were measured continuously. Arterial oxyhemoglobin saturation was lower during hypoxia (90 ± 3%) compared with normoxia (98 ± 1%, P < 0.001). Core temperature fell from baseline (normoxia: 37.2 ± 0.4°C, hypoxia: 37.2 ± 0.4°C) to post-cold HOWI (normoxia: 36.4 ± 0.5°C, hypoxia: 36.3 ± 0.5°C, P < 0.001) in both conditions but did not change differently between conditions (condition × time: P = 0.552). Circulating TSH, total T3, free T4, total T3, and free T4 concentrations demonstrated significant main effects of time (all P ≤ 0.024), but these changes did not differ between normoxic and hypoxic conditions (condition × time: all P ≥ 0.163). These data indicate that acute moderate normobaric hypoxia does not modify the circulating thyroid hormone response during 1 h of cold HOWI.NEW & NOTEWORTHY Acute head-out cold (22°C) water immersion (HOWI) decreased core temperature and increased thermogenesis. This thermogenic response was paralleled by the activation of the hypothalamic-pituitary-thyroid axis, as evidenced by changes in thyroid hormones. However, cold HOWI in combination with moderate normobaric hypoxia did not modify the thermogenic nor the circulating thyroid hormone response. This finding suggests that hypoxia-induced alterations in thyroid hormone concentrations are unlikely to acutely contribute to adaptations resulting from repeated cold-water exposures.

Total thyroxine, triiodothyronine, and thyrotropin concentrations during acute nonthyroidal illness and recovery in dogs.

Acute illness can result in changes in serum total thyroxine (tT4), total triiodothyronine (tT3), and thyrotropin (TSH) concentrations in euthyroid dogs defined as nonthyroidal illness syndrome, but longitudinal evaluation of these hormones during the recovery phase is lacking. To longitudinally evaluate serum tT4, tT3, and TSH concentrations during the acute phase and recovery from acute illness in dogs. Nineteen euthyroid client-owned dogs hospitalized for acute illness at a veterinary teaching hospital. Prospective longitudinal study. Serum tT4, tT3, and TSH concentrations were measured at the admission (T0), at last day of hospitalization (T1), and during the recovery phase at 3, 7, 14, and 21 days after the discharge (T2, T3, T4, and T5), respectively. tT4 and tT3 were below the reference interval (RI) at T0 in 3 (16%) and 18 (95%) dogs, respectively; tT4 normalized in all dogs early in the recovery phase, while low tT3 persisted at the end of the study in 16 (83%) dogs. Median TSH concentrations were increased at T5 compared with T1 (0.19 ng/mL [range 0.03-0.65] vs 0.11 ng/mL [range (0.05-0.26)], mean difference = 0.09 ng/mL; P = .03). Five (26%) dogs had TSH above the RI at least at 1 time point during the recovery phase. None of the dogs had concurrent low tT4 and high TSH during the study. In euthyroid dogs acute illness can interfere with evaluation of thyroid function up to 21 days during the recovery phase. Thyroid testing should be avoided or postponed in these dogs.

Protective Effect of Prunella vulgaris L. Whole Plant or Spicas Water Extracts on Hyperthyroidism with Liver-yang Hyperactivity Syndrome

Background: Prunella vulgaris L. (Lamiaceae) is a perennial medicinal plant commonly used to treat thyroid dysfunction, infectious hepatitis, and mastitis in north-east Asia and Europe. In China, there has been a historical change in the medicinal use of P. vulgaris from the use of whole plants to the use of the spicas. Purpose: This study aimed to evaluate the protective effects of whole plant P. vulgaris water extracts and spicas on hyperthyroidism with liver-yang hyperactivity syndrome and to preliminarily explain the mechanism of action of these water extracts. Methods: Rats were induced with aconite decoction and levothyroxine and treated with P. vulgaris whole plant and spicas water extract for 28 days at the same time. Body weight, food intake, and rectal temperature were monitored. The serum thyroid function indicators thyroid stimulating hormone (TSH), thyroid hormone-free triiodothyronine (FT3) and free thyroxine (FT4), liver function index alanine aminotransferase (ALT) and aspartate aminotransferase (AST), oxidative damage index malondialdehyde (MDA), and superoxide dismutase (SOD) were detected. Liver and thyroid tissues were taken for sectioning and observation. The liver inflammatory factors human tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were detected by immunohistochemistry, and the expression levels of the apoptotic proteins caspase-3 and B-cell lymphoma-2 (Bcl-2) were detected. Results: Both P. vulgaris whole plant and spica water extract groups exhibited markedly reduced FT3 and FT4 contents, increased the TSH content, and decreased ALT and AST activities. Furthermore, these agents improve thyroid and liver lesion tissue; reduce MDA content; increase SOD activity; reduce IL-6, TNF-α, and caspase-3 expression; and increase Bcl-2 expression. Conclusion: The whole plant and spicas water extracts of P. vulgaris have obvious protective effects on hyperthyroidism and hyperactivity in liver yang, and the protective effect of the water extract of spicas is greater than that of the whole plant water extract.

Prevalence of hyperthyroidism and hypothyroidism in liver transplant recipients and associated risk factors

The prevalence of hyperthyroidism and hypothyroidism and associated risk factors are unknown in liver transplant recipients. We aimed to determine the prevalence of hyperthyroidism and hypothyroidism and associated risk factors in liver transplant recipients and to compare it with controls from the general population. As part of the Danish Comorbidity in Liver Transplant Recipients (DACOLT) Study, all Danish liver transplant recipients over the age of 20 were invited for measurements of concentrations of thyrotropin and thyroid hormones. The prevalence of hyperthyroidism and hypothyroidism was compared to age- and sex-matched controls from the Copenhagen General Population Study. Using logistic regression adjusted for age, sex, smoking, and body-mass index, we investigated potential risk factors. We recruited 489 liver transplant recipients and 1808 controls. Among liver transplant recipients, 14 (2.9%) had hyperthyroidism compared with 21 (1.2%) of controls (adjusted odds ratio [aOR] 2.24, 95% confidence interval [CI] 1.05–4.75, P = 0.04), while 42 (5.7%) had hypothyroidism compared with 139 (7.7%) of controls (aOR 0.68, 95% CI 0.43–1.08, P = 0.10). Female sex, and autoimmune hepatitis and primary sclerosing cholangitis as causes of transplantation were associated with hyperthyroidism after adjustments. Age, female sex, and autoimmune liver diseases as cause of transplantation were associated with hypothyroidism after adjustments. DACOLT is registered in ClinicalTrials.gov (NCT04777032).

Analysis of Serum Free Thyroxine Concentrations in Healthy Term Neonates Underlines Need for Local and Laboratory-Specific Reference Interval: A Systematic Review and Meta-Analysis of Individual Participant Data.

Background: Initial evaluation of the hypothalamus-pituitary-thyroid axis is done by measuring serum free thyroxine (fT4) and thyrotropin concentrations. For correct interpretation of these measurements, reliable age-specific reference intervals (RIs) are fundamental. Since neonatal fT4 RIs conforming to the Clinical and Laboratory Standards Institute guidelines are not available for all assays, we set out to create literature-based uniform age-specific neonatal fT4 RIs that may be used for every assay. Methods: For meta-analysis of individual participant fT4 concentrations, we systematically searched MEDLINE and Embase (search date December 6, 2023; PROSPERO registration CRD42016041871). We searched for studies reporting fT4 concentrations in healthy term newborns aged 2-27 days, born to mothers without thyroid disease in iodine-sufficient regions. Authors were invited to supply data. Due to standardization differences between assays, data could not be combined for meta-analysis directly, and we attempted to normalize the data using two distinct methods. Results: We obtained 4206 fT4 concentrations from 20 studies that used 13 different assays from 6 manufacturers. First, we set out to normalize fT4 data using the mean and standard deviation of (assay-specific) adult RIs. fT4 concentrations were transformed into Z-scores, assuming a normal distribution. Using a linear mixed-effects model (LMM), we still found a significant difference between fT4 concentration across studies (p < 0.001), after this normalization. As a second approach, we normalized the fT4 concentrations using data from a method/assay comparison study. We used the relationship between the Cobas assay and the other assays as a reference point to convert all values to Cobas values. However, this method also failed to produce consistent results, with significant differences between the normalized data (LMM p < 0.001). Conclusions: We conclude that our attempts at normalizing fT4 assay results were unsuccessful. Confounders related to our unsuccessful analysis may be assay related and/or biological. These findings have significant implications for patient care, since relying on RIs from literature may result in erroneous interpretation of results. Therefore, we strongly recommend to establish local RIs for accurate interpretation of serum fT4 concentrations in neonates.

Takotsubo syndrome outcomes predicted by thyroid hormone signature: insights from cluster analysis of a multicentre registry

Recently, abnormal thyroid function was shown to be common in patients with Takotsubo syndrome (TTS), being classified into "endocrine-type" and "stress-type" responses. The aim of this study was to investigate the association between thyroid homeostasis and TTS in a larger international registry. In total 288 patients with TTS were enrolled through the GEIST multicentre registry from Germany, Italy and Spain. Thyrotropin (TSH), free T4 (FT4) and free T3 (FT3) concentrations were analysed at admission. Data were collected both retrospectively and prospectively from 2017 onwards. Primary endpoints included in-hospital and all-cause fatality, determined by cluster analysis using an unsupervised machine learning algorithm (k-medoids). Three clusters were identified, classifying TTS with low (TSLT), high (TSHT) and normal (TSNT) thyroid output, based on TSH and FT4 levels in relation to the median thyroid's secretory capacity (SPINA-GT). Although TSH and FT4 concentrations were similar among survivors and non-survivors, these clusters were significantly associated with patient outcomes. In the longitudinal Kaplan-Meier analysis including in- and out-of-hospital survival, the prognosis related to concentrations of TSH, FT4, and FT3 as well as SPINA-GT, deiodinase activity (SPINA-GD) and clusters. Patients in the TSHT cluster and with cardiogenic shock had a lower initial left ventricular ejection fraction (LVEF). This study suggests that thyroid hormones may impact the evolution and prognosis of TTS. The findings indicate that thyroid-derived biomarkers may help identify high-risk patients and pave the way for novel personalized and preventive therapeutic options. This research was not funded by any public, commercial, or not-for-profit agencies.