Free Triiodothyronine Concentrations Research Articles

Energy-Related Hormones in Raw and Retail Cow’s Milk and Possible Risk for Consumers

Abstract The study aimed to determine the concentration of energy-related hormones in cow’s milk and to consider them from a public health perspective. Fourteen Holstein cows were subjected to milk and blood sampling on the following days in lactation (DIL): 10, 30, 60, 90, 150, 180, 210, 250 and 280 to determine milk hormones, fat and protein content and blood biochemical parameters. For the same purpose, bulk-tank milk was sampled and samples of retail m ilk with 1.5% (CM1.5) and 3.2% (CM3.2) fat was purchased. Milk insulin-like growth factor-1 (IGF-1) values were significantly lower at 90, 150, 180, 210 and 250 and significantly higher at 10, 30 and 60 DIL than lactation average (LA). Milk insulin concentrations were significantly lower at 30, 60 and 90 and higher at 210, 250 and 280 DIL than LA. Free thyroxine (fT4) level in the milk was higher at 250 DIL, while milk free triiodothyronine (fT3) concentrations were lower at 30, 60, 90 and 280 DIL, and significantly higher at 10 and 180 DIL than respective LA. Milk cortisol levels were lower at 60 and 280 DIL than LA. All measured milk hormones were significantly lower in CM1.5 compared to CM3.2, bulk-tank milk and LA. An exception was the LA of IGF-1, which was significantly lower than the IGF-1 content in CM1.5. Blood biochemical parameters fluctuated evenly during lactation and were within the reference range. Hormone concentrations in cow’s milk fluctuate during lactation, giving milk an important role in the context of public health.

Relationship between thyroid function and sex hormones in female German shepherd dogs.

Several variables influence the serum concentration of thyroid hormones in dogs, including breed, age, drugs, and concurrent diseases. However, data regarding the interaction between thyroid function and the estrous stage of female dogs are limited. Estrous stage may influence thyroid function in German Shepherd dogs. Longitudinal, observational, non-randomized cohort study. The dogs were monitored during the complete estrous cycle, and different stages were determined by vaginal cytology. Two blood samples were collected at the beginning and end of each stage to analyze the following: total thyroxine (TT4), free thyroxine (fT4), total triiodothyronine (TT3), free triiodothyronine (fT3), canine thyrotropin (cTSH), progesterone, 17-β-estradiol, triglycerides, and cholesterol concentrations. Hematological and biochemical evaluations were performed at the beginning and end of the study period. Seventeen German Shepherds were included, of which 7 were bred during the study period. One dog was excluded for estrus interruption and another for suspected hypothyroidism. Serum concentrations of T4, fT4, and fT3 were negatively correlated with age. Total thyroxine demonstrated significant changes in serum concentrations between estrous stages, with higher concentrations in estrus and diestrus. Total thyroxine concentrations were positively correlated with progesterone concentrations and negatively correlated with 17-β-estradiol concentrations. Free thyroxine did not show significant variations but was positively correlated with progesterone concentrations. Canine TSH concentrations were positively correlated with 17-β-estradiol concentrations. No significant differences in thyroid hormones and cTSH concentrations were observed between diestrus during pregnancy and pseudopregnancy. Different stages of estrus can influence the measurement of TT4 in female dogs.

Changes in thyroid function levels in female patients with first-episode bipolar disorder.

The identification of molecular biomarkers for bipolar disorder is anticipated to greatly improve the diagnosis and treatment of this disease. The objective of this case-control study is to determine whether the blood thyroid hormone levels in bipolar disorder patients are associated with different types of first onset. From August 1, 2020 to July 31, 2021 a total of 120 female patients diagnosed with bipolar disorder and hospitalized at Qingdao Mental Health Center were recruited as the case group, including 60 patients with depression as their first onset (depression first-episode group, DF) and 60 with mania/hypomania as their first onset (mania/hypomania first-episode group, M/HF). A group of 60 healthy adult females matching general demographic data, such as race and age, were selected as the control group. Blood samples were taken from both groups to measure serum triiodothyronine (T3), thyroxine (T4), free triiodothyronine (FT3), free thyroxine (FT4), and thyroid stimulating hormone (TSH) concentrations. The duration of current onset in the M/HF group was significantly less than that in the DF group (23.1 ± 20.2 vs. 125.2 ± 41.0 days). About 27% of patients in the M/HF group had thyroid abnormalities, in contrast to 60% in the DF group. The blood T3 and T4 levels in both the M/HF group and the DF group, as well as the TF3 levels in the DF group, were significantly lower as compared to control. The M/HF group had significantly higher T3 and FT3 levels than the DF group. The blood T3 levels were inversely correlated with the Young's Mania Scale score and the Hamilton Depression Scale score in both the M/HF and DF groups. Thyroid dysfunction resulting in reduced levels of blood thyroid levels may be involved in the disease progression of bipolar disorder, and correlated with the clinical symptoms in patients with depression or mania as the first episode.

Thyroid-Related Hormones Changes Predict Changes in Anthropometric Measures and Incidence of Obesity in Chinese Euthyroid Persons.

The purpose of this study was to investigate the correlation of thyroid-related hormones changes within the reference range with the changes in anthropometric measures and incidence of obesity. The study included 4850 subjects with normal thyroid-related hormones at baseline and at follow-up. We evaluated the relationship of changes in thyroid-related biomarkers with anthropometric measures changes and incidence of obesity. In euthyroid persons, changes in serum thyroid stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxine (FT4) concentrations and FT3/FT4 ratio were independent predictors of changes in body mass index (BMI) and waist circumference (WC) in men, changes in serum FT3 and FT4 concentrations and FT3/FT4 ratio were independent predictors of changes in BMI and WC in women. Every single unit increment in ΔFT3/FT4 was accompanied by a 7.144 and 7.572 times risk of having obesity in men and women, respectively. Every single unit decrement in ΔFT4 was accompanied by a 21.0% and 26.9% lower risk of having obesity in men and women, respectively. In conclusion, in euthyroid individuals, changes in thyroid-related hormones were associated with anthropometric measures changes and incidence of obesity.

Effects of sub-chronic exposure to microcystin-LR on the endocrine system of male rats

Microcystins (MCs) can cause reproductive and developmental toxicity and disrupt endocrine homeostasis in mammals. In the present study, male, Sprague-Dawley (SD) rats were administrated 3 or 30 μg MC-LR/kg, body mass (bm) per day via intraperitoneal (i.p.) injections for 6 weeks. Effects of MC-LR on histology, hormone concentrations, gene transcriptional profiles and protein expressions along the hypothalamic-pituitary-adrenal (HPA), ‐gonad (HPG) and -thyroid (HPT) axes were assessed. Sub-chronic administration with MC-LR caused histological damage to hypothalamus, pituitary, adrenal, testes and thyroid and affected relative masses of pituitary, adrenal and testes. The HPA axis was activated and serum concentrations of corticotropin-releasing hormone (CRH), adrenocorticotropic hormone (ACTH) and corticosterone (CORT) were significantly augmented. Along the HPG axis, serum concentrations of gonadotropin-releasing hormone (GnRH) and dihydrotestosterone (DHT) were diminished, while concentrations of luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone (T) and estradiol (E2) were augmented. For the HPT axis, only concentrations of free tetra-iodothyronine (fT4) were significantly diminished, while concentrations of thyrotropin-releasing hormone (TRH), thyroid-stimulating hormone (TSH) or free tri-iodothyronine (fT3) were not significantly changed. Also, several genes and proteins related to synthesis of steroid hormones were significantly altered. Findings of the present study illustrate that MC-LR can cause endocrine-disrupting effects through the disruption of synthesis and secretion of hormones along the HPA, HPG and HPT axes and negative feedback regulation. Also, there could be crosstalk among HPA, HPG and HPT axes. These findings elucidate mechanisms of endocrine-disrupting effects of MCs.

Association of exposure to perfluoroalkyl substances (PFAS) and phthalates with thyroid hormones in adolescents from HBM4EU aligned studies

BackgroundPerfluoroalkyl substances (PFAS) and phthalates are synthetic chemicals widely used in various types of consumer products. There is epidemiological and experimental evidence that PFAS and phthalates may alter thyroid hormone levels; however, studies in children and adolescents are limited. AimTo investigate the association of exposure to PFAS and phthalate with serum levels of thyroid hormones in European adolescents. MethodsA cross-sectional study was conducted in 406 female and 327 male adolescents (14–17 years) from Belgium, Slovakia, and Spain participating in the Aligned Studies of the HBM4EU Project (FLEHS IV, PCB cohort, and BEA, respectively). Concentrations of perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), perfluorononanoic acid (PFNA), free thyroxine (FT4), free triiodothyronine (FT3), and thyroid-stimulating hormone (TSH) were measured in sera from study participants, and urinary metabolites of six phthalates (DEP, DiBP, DnBP, BBzP, DEHP, and DiNP) and the non-phthalate plasticizer DINCH® were quantified in spot urine samples. Associations were assessed with linear regression and g-computational models for mixtures. Effect modification by sex was examined. ResultsIn females, serum PFOA and the PFAS mixture concentrations were associated with lower FT4 and higher FT3 levels; MEP and the sums of DEHP, DiNP, and DINCH® metabolites (∑DEHP, ∑DiNP, and ∑DINCH) were associated with higher FT4; ∑DEHP with lower FT3; and the phthalate/DINCH® metabolite mixture with higher FT4 and lower FT3. In males, PFOA was associated with lower FT4 and the PFAS mixture with higher TSH levels and lower FT4/TSH ratio; MEP and ∑DiNP were associated with higher FT4; and MBzP, ∑DEHP, and the phthalate/DINCH® metabolite mixture with lower TSH and higher FT4/TSH. PFOA, mono-(2-ethyl-5-hydroxyhexyl) phthalate (OH-MEHP), mono-(2-ethyl-5-oxohexyl) phthalate (oxo-MEHP), and monocarboxyoctyl phthalate (MCOP) made the greatest contribution to the mixture effect. ConclusionsResults suggest that exposure to PFAS and phthalates is associated with sex-specific differences in thyroid hormone levels in adolescents.

Mediation by Thyroid Hormone in the Relationships Between Gestational Exposure to Methylmercury and Birth Size

Our previous studies have linked gestational methylmercury exposure, originating from seafood, to changes in maternal thyroid hormones and infant birth size in a Swedish birth cohort. Herein we aimed to determine associations between maternal thyroid hormones and infant birth size and elucidate if maternal hormones could mediate the relationship between methylmercury and lower birth size. In 515 women, without known thyroid disease, we assessed metal exposure by erythrocyte mercury concentrations (mainly methylmercury, reflecting exposure over the past months) in early third trimester measured with inductively coupled plasma-mass spectrometry. Plasma concentrations of total and free thyroxine (tT4 and fT4) and triiodothyronine (tT3 and fT3), and thyroid-stimulating hormone (TSH) were measured at an accredited clinical laboratory. In multivariable-adjusted linear regression models, maternal tT3 (per 1 nmol/L increase) was positively associated with birth weight (B: 125 g; 95% CI 36, 214) and length (B: 0.59 cm; 95% CI 0.21, 0.97). Maternal fT4 was inversely associated with birth weight (B: − 33 g; 95% CI − 57, − 9.5), driven by obese women (n = 76). Causal mediation analyses suggested that a doubling of erythrocyte mercury (> 1 µg/kg; n = 374) was associated with a mean tT3-mediated decrease in birth weight of 11 g (95% CI − 25, − 1.6) and in birth length of 0.1 cm (95% CI − 0.12, − 0.01), both equivalent to about 12% of the total effect. To conclude, tT3 was positively associated with infant birth size. Reduced tT3 levels appeared to mediate a minor part of the inverse association between methylmercury exposure and birth size.

Helicobacter pylori infection increase the risk of subclinical hyperthyroidism in middle-aged and elderly women independent of dietary factors: Results from the Tianjin chronic low-grade systemic inflammation and health cohort study in China.

Prospective studies on the association between Helicobacter pylori (H. pylori) infection and subclinical hyperthyroidism are limited. We, therefore, designed a large-scale cohort study to explore the association between H. pylori infection and the risk of subclinical hyperthyroidism in women. This prospective cohort study investigated 2,713 participants. H. pylori infection was diagnosed with the carbon 13 breath test. Subclinical hyperthyroidism was defined as serum thyroid-stimulating hormone levels are low or undetectable but free thyroxine and tri-iodothyronine concentrations are normal. Propensity score matching (PSM) analyses and Cox proportional hazards regression models were used to estimate the association between H. pylori infection and subclinical hyperthyroidism. A total of 1,025 PS-matched pairs of H. pylori infection women were generated after PSM. During 6 years of follow-up, the incidence rate of subclinical hyperthyroidism was 7.35/1,000 person-years. After adjusting potential confounding factors (including iodine intake in food and three main dietary patterns score), the multivariable hazard ratio (HR; 95% confidence intervals) of subclinical hyperthyroidism by H. pylori infection was 2.49 (1.36, 4.56). Stratified analyses suggested a potential effect modification by age, the multivariable HR (95% confidence intervals) was 2.85 (1.45, 5.61) in participants aged ≥ 40 years and 0.70 (0.08, 6.00) in participants aged < 40 years (P for interaction = 0.048). Our prospective study first indicates that H. pylori infection is significantly associated with the risk of subclinical hyperthyroidism independent of dietary factors among Chinese women, especially in middle-aged and older individuals.Clinical Trial Registration:https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000031137, identifier UMIN000027174.

Low Free Triiodothyronine as a More Sensitive Predictor of Survival Than Total Testosterone among Dialysis Men.

Some endocrine disorders, previously considered benign, may be related to a poorer prognosis for patients with renal failure. Both low serum free triiodothyronine (fT3) and low total testosterone (TT) concentrations have been considered as predictors of death in dialysis patients, but the results of studies are inconsistent. In our study, we evaluated the relationships of the serum thyroid hormone levels and the total testosterone levels with survival in male dialysis patients. Forty-eight male dialysis patients, 31 on hemodialysis (HD) and 17 on peritoneal dialysis (PD), aged 61.4 ± 10.0, 59.2 ± 12.2 years, respectively, were included in the study. Serum thyroid hormones and total testosterone were measured. During the 12-month follow-up, nine all-cause deaths were recorded. The concentrations of fT3 were significantly lower in those who died than in the survivors (p = 0.001). We did not observe any statistically considerable differences between the group of men who died and the rest of the participants in terms of the total serum testosterone concentration (p = 0.350). Total testosterone positively correlated with fT3 (r = 0.463, p = 0.009) in the HD group. In the group of male dialysis patients, the serum concentration of fT3 had a better prognostic value in terms of survival than the total testosterone. A linear relationship between the fT3 levels and testosterone levels in men undergoing hemodialysis may confirm the hypothesis that some of the hormonal changes observed in chronic kidney disease (CKD) may have a common cause.

Effect of Thyroxine on the Structural and Dynamic Features of Cardiac Mitochondria and Mitophagy in Rats.

This work investigated the effect of thyroxine on the biogenesis and quality control system in rat heart mitochondria. In hyperthyroid rats, the concentrations of free triiodothyronine and thyroxine increased severalfold, indicating the development of hyperthyroidism in these animals. The electron microscopy showed 58% of cardiac mitochondria to be in a swollen state. Some organelles were damaged and had a reduced number of cristae. Multilamellar bodies formed from cristae/membranes were found in the vacuolated part of the mitochondria. The hyperthyroidism caused no changes to mitochondrial biogenesis in the investigated animals. At the same time, the levels of mitochondrial dynamics proteins OPA1 and Drp1 increased in the hyperthyroid rats. The administration of thyroxine to the animals led to a decrease in the amount of PINK1 and Parkin in heart tissue. The data suggest that excess thyroid hormones lead to changes in mitochondrial dynamics and impair Parkin-dependent mitophagy in hyperthyroid rat heart.

Prevalence of thyroid dysfunction in women with dysfunctional uterine bleeding in Kano, North-Western Nigeria

Context: Thyroid hormones play a key role in the menstrual and reproductive functions of women. Thyroid dysfunction is marked by a large number of menstrual aberrations. Objective: To determine the incidence of thyroid dysfunction in dysfunctional uterine bleeding (DUB) and its correlation with menstrual patterns. Materials and Methods: The study population consisted of 64 DUB patients aged between 19 and 45 years and an equal number of age-matched women with a normal menstrual cycle. Plasma concentrations of thyroid-stimulating hormone (TSH), free thyroxine (T4), and free triiodothyronine (T3) of the participants were measured. Laboratory analyses were conducted on Elecsys 2010 immunology analyzer. Statistical analysis was performed with Microsoft Excel software, and the data were transferred into IBM SPSS version 21.0 for processing. A P-value of <0.05 was considered significant. Results: Among the 64 women with DUB, 21.9% had thyroid dysfunction, of which 14.1% had overt hypothyroidism, 6.2% had subclinical hypothyroidism, and 1.5% had overt hyperthyroidism. The main menstrual complaint among hypothyroid DUB patients was menorrhagia. The only presentation in hyperthyroidism was oligomenorrhea. Conclusion: The prevalence of abnormal thyroid function in this study was high; therefore, screening of DUB patients for thyroid function abnormalities is suggested.

Graves' Disease in Children: An Update.

Graves' disease (GD) is the most common cause of hyperthyroidism in children. A common GD symptom is a goiter. The usual biochemical profile in children with GD is a decreased thyroid hormone stimulating hormone (TSH) level and high free thyroxine (FT4) and free triiodothyronine (FT3) concentrations. The presence of thyroid receptor antibodies (TRAb) is the most important specific immunological sign for diagnosing GD. The treatment choices for pediatric GD are anti-thyroid drugs (ATDs), radioiodine, and thyroidectomy, but the risks and benefits of each modality are different. Management recommendations include the first-line use of a prolonged course of ATDs for at least 3 years and potentially 5 years or more. Rituximab and Teprotumumab are new novel alternative medications for the treatment of adult patients with GD and Graves' orbitopathy respectively, but evidence of the efficacy and safety of these drugs in pediatric patients with GD is lacking.

Reference Intervals of Thyroid Hormones During Pregnancy Established by Three Statistical Methods.

Monitoring the thyroid hormones during pregnancy is of great importance for fetal growth and development. Throughout the whole pregnancy, there is constant fluctuation in the thyroid hormone reference intervals (RIs). The purpose of this study is to determine method- and trimester-specific RIs for thyroid-stimulating hormone, free thyroxine, and free triiodothyronine in pregnant women in China. In this study, 2,167 women with normal pregnancies (first trimester, n = 299; second trimester, n = 1,032; third trimester, n = 836) and 4,231 healthy nonpregnant women subjects were recruited. Serum thyroid-stimulating hormone (TSH), free thyroxine (fT4), and free triiodothyronine (fT3) concentrations were measured using electrochemiluminescence immunoassays in Abbott Alinity i analyzer. Following the exclusion of outliers, the RIs were determined using three statistical techniques: the non-parametric method, the Hoffmann method, and the Q-Q plot method. Pregnant women's levels of these three thyroid hormones differ markedly from those of healthy non-pregnant women. In addition, the concentrations of these three hormones change considerably over the course of the three phases of pregnancy. The Q-Q plot method offered more comparable RIs with the non-parametric method in healthy non-pregnant women than the Hoffmann method. Three statistical techniques were used to construct the trimester-specific RIs of thyroid hormones in pregnant women, and there was little difference between them all. The RIs by the non-parametric and Q-Q plot methods indicated closer RIs, and the RIs by the Hoffmann approach were higher and wider than those by the other two methods. For thyroid hormones, trimester-specific RIs are required. The RIs determined by non-parametric and Q⁃Q plot indirect calculation could be used as the alternative method.

Acute exposure to microcystins affects hypothalamic-pituitary axes of male rats

Microcystins (MCs) produced by some cyanobacteria can cause toxicity in animals and humans. In recent years, growing evidence suggests that MCs can act as endocrine disruptors. This research systematically investigated effects of microcystin-LR (MC-LR) on endocrine organs, biosynthesis of hormones and positive/negative feedback of the endocrine system in rats. Male, Sprague-Dawley rats were acutely administrated MC-LR by a single intraperitoneal injection at doses of 45, 67.5 or 90 μg MC-LR/kg body mass (bm), and then euthanized 24 h after exposure. In exposed rats, histological damage of hypothalamus, pituitary, adrenal, testis and thyroid were observed. Serum concentrations of corticotropin-releasing hormone (CRH), adrenocorticotropic hormone (ACTH) and corticosterone (CORT), expressions of genes and proteins for biosynthesis of hormones were lesser, which indicated an overall suppression of the hypothalamus-pituitary-adrenal (HPA) axis. Along the hypothalamus-pituitary-gonadal (HPG) axis, lesser concentrations of gonadotropin-releasing hormone (GnRH) and testosterone (T), but greater concentrations of luteinizing hormone (LH), follicle-stimulating hormone (FSH) and estradiol (E2) were observed. Except for greater transcription of cyp19a1 in testes, transcriptions of genes and proteins for T and E2 biosynthesis along the HPG axis were lesser. As for the hypothalamus-pituitary-thyroid (HPT) axis, after MCs treatment, greater concentrations of thyroid-stimulating hormone (TSH), but lesser concentrations of free tri-iodothyronine (fT3) were observed in serum. Concentrations of free tetra-iodothyronine (fT4) were greater in rats dosed with 45 μg MCs/kg, bm, but lesser in rats dosed with 67.5 or 90 μg MCs/kg, bm. Transcripts of genes for biosynthesis of hormones and receptors along the HPT axis and expressions of proteins for biosynthesis of tetra-iodothyronine (T4) and tri-iodothyronine (T3) in thyroid were significantly altered. Cross-talk among the HPA, HPG and HPT axes probably occurred. It was concluded that MCs caused an imbalance of positive and negative feedback of hormonal regulatory axes, blocked biosynthesis of key hormones and exhibited endocrine-disrupting effects.

Ambient air pollution and thyroid function in Spanish adults. A nationwide population-based study (Di@bet.es study)

BackgroundRecent reports have suggested that air pollution may impact thyroid function, although the evidence is still scarce and inconclusive. In this study we evaluated the association of exposure to air pollutants to thyroid function parameters in a nationwide sample representative of the adult population of Spain.MethodsThe Di@bet.es study is a national, cross-sectional, population-based survey which was conducted in 2008-2010 using a random cluster sampling of the Spanish population. The present analyses included 3859 individuals, without a previous thyroid disease diagnosis, and with negative thyroid peroxidase antibodies (TPO Abs) and thyroid-stimulating hormone (TSH) levels of 0.1-20 mIU/L. Participants were assigned air pollution concentrations for particulate matter <2.5μm (PM2.5) and Nitrogen Dioxide (NO2), corresponding to the health examination year, obtained by means of modeling combined with measurements taken at air quality stations (CHIMERE chemistry-transport model). TSH, free thyroxine (FT4), free triiodothyronine (FT3) and TPO Abs concentrations were analyzed using an electrochemiluminescence immunoassay (Modular Analytics E170 Roche).ResultsIn multivariate linear regression models, there was a highly significant negative correlation between PM2.5 concentrations and both FT4 (p<0.001), and FT3 levels (p<0.001). In multivariate logistic regression, there was a significant association between PM2.5 concentrations and the odds of presenting high TSH [OR 1.24 (1.01-1.52) p=0.043], lower FT4 [OR 1.25 (1.02-1.54) p=0.032] and low FT3 levels [1.48 (1.19-1.84) p=<0.001] per each IQR increase in PM2.5 (4.86 μg/m3). There was no association between NO2 concentrations and thyroid hormone levels. No significant heterogeneity was seen in the results between groups of men, pre-menopausal and post-menopausal women.ConclusionsExposures to PM2.5 in the general population were associated with mild alterations in thyroid function.

Circulating free triiodothyronine concentration is positively associated with β-cell function in euthyroid patients with obesity and type 2 diabetes.

ObjectiveTo investigate the relationship between thyroid hormone concentrations and β-cell function in euthyroid patients with obesity and type 2 diabetes.MethodsWe performed a single-center cross-sectional study of 254 patients with type 2 diabetes mellitus aged ≥40 years. The participants were allocated to an obesity group or non-obesity group on the basis of their body mass index (BMI). Their β-cell function was assessed by measuring C-peptide concentration during a 75-g oral glucose tolerance test (OGTT); and their serum free triiodothyronine (FT3), free thyroxine (FT4) and thyroid-stimulating hormone concentrations were measured.ResultsThe serum FT3 concentration and the C-peptide concentrations at five time points of the OGTT were significantly higher in the obesity group than in the non-obesity group. FT3 was positively associated with the β-cell function of the obesity group, but not that of the non-obesity group, in multiple linear regression analysis, after adjustment for potential confounding factors. Serum FT3 concentration was also significantly associated with indices of obesity (BMI, waist circumference, body fat percentage, fat mass, fat mass/height 2 and visceral fat area).ConclusionsObesity-associated high serum FT3 concentrations might affect β-cell function in euthyroid patients with obesity and type 2 diabetes.

Thyroid Function, Inflammatory Response, and Glucocorticoids in COVID-19.

The ongoing COVID-19 pandemic calls for extensive research on various medical topics. Since the beginning of the pandemic, multiple studies investigated the impact of SARS CoV-2 on thyroid function. However, crucial data, such as trend progression over time or influence of commonly used drugs, might still be missing. We checked the thyroid function in 174 patients with PCR-confirmed COVID-19. Our research covered three separate time points of hospitalization (days 1, 4, and 10). We did not exclude patients treated with glucocorticoids but, instead, compared them with patients not treated with steroids. We correlated the results of thyroid function tests with markers of systemic inflammation. We checked if abnormal thyroid function can predict unfavorable outcomes defined as combined primary endpoint and/or secondary endpoints; the combined primary endpoint was the occurrence of death, mechanical ventilation, non-invasive ventilation, vasopressor infusion, or prolonged hospital stay, and the secondary endpoint was any of the listed events. In general, 80.46% of evaluated patients displayed abnormalities in thyroid function tests over at least one time point throughout the observation. We noticed a high prevalence of features typical for thyroid dysfunction in non-thyroidal illness (NTI). Free triiodothyronine (fT3) concentration was significantly lower in the group requiring glucocorticoids. Patients displaying abnormal thyroid function were statistically more likely to meet the predefined combined primary endpoint. We found that fT3 measured at admission could be perceived as an independent predictor of endpoint completion for all analyzed groups. Thyroid involvement is common in COVID-19. Our study supports the idea of thyroid function abnormalities being important clinical tools and allowing early recognition of possible detrimental outcomes of the disease.

Sublethal effects of acrylamide on thyroid hormones, complete blood count and micronucleus frequency of vertebrate model organism (Cyprinus carpio)

Abstract Objectives Acrylamide, a widely used chemical in industry, clinical laboratory and waste treatment plants, is considered a carcinogen in humans. The present study examined the hormonal, hematologic, and genotoxic responses in the invertebrate model common carp Cyprinus carpio after exposure to sublethal acrylamide. Methods Fish were exposed to acrylamide at 10 and 50 mg/L for 96 h, along with the respective control group. Serum levels of cortisol and thyroid hormones were measured using diagnostic ELISA direct immunoenzymatic kits. For micronucleus (MN) frequency assay, thin smears of the peripheral blood of fish were prepared. Results Serum levels of cortisol in both treatment groups considerably increased, which proposed that acrylamide caused a stress reaction of acrylamide exposed fish (p&lt;0.05). Fish demonstrated significant decreases in triiodothyronine (T3), free thyroxine (FT4), and free triiodothyronine (FT3) concentrations in a dose-dependent manner after acrylamide exposure (p&lt;0.05). However, serum thyroxine (T4) concentrations did not alter significantly in the treatment groups. Mean MN frequencies of fish erythrocytes increased significantly in acrylamide exposed groups suggesting that acrylamide is genotoxic in common carp (p&lt;0.05). The hematocrit, hemoglobin, and erythrocyte numbers of carp increased significantly in exposure groups (p&lt;0.05). Conclusions These results suggested that acrylamide can significantly affect the hemopoietic system. Furthermore, this study confirmed that the widespread use of acrylamide, even in sublethal concentrations, could affect the survival of non-target organisms, especially fish, in aquatic environments.

DEACARIZATION-ASSOCIATED DYNAMICS OF GLUCOCORTICOIDS AND THYROID HORMONE IN HENS AFTER DERMANYSSOSIS

The study of the sanogenetic mechanism implementation and the adaptation of the body to extreme factors at the same time are hot topics for modern biology, physiology, and parasitology, as well as for poultry industry. Poultry is exposed to a whole range of extreme stress factors in the industrial sector. A special group is biological stressors, in particular, hematophagous ectoparasites D. gallinae. Studies conducted on High-Line laying hens on an industrial poultry farm showed that the cortisol concentration increased significantly in their blood by 3.6 (p&lt;0.001) in dermanyssosis as compared to the control values. At the same time, the free triiodothyronine concentration in the experimental birds was significantly lower by 14.5% (p&lt;0.001) as compared to the control. After the poultry building deacarization with the working emulsion 5% D-Cyphenothrin Emulsion of the drug, changes were detected in the hormonal supply of the hens from the experimental group. Thus, after dermanyssosis, they found an increase in the activity of follicular cells of the thyroid gland and a decrease tendency in the function of the adrenal glands that produces cortisol as compared to the control group. The described changes in the hormonal supply of the experimental hens’ organism indicate the activation of biophysiochemical recovery mechanisms of the birds’ organism and a tendency to optimize their homeostasis.

Low free triiodothyronine levels are associated with frail phenotype in hospitalized inpatients with cirrhosis

Objective Frailty is a prevalent complication predicting morbidity and mortality in cirrhosis. However, the association between thyroid hormone levels and frailty in cirrhotics remains elusive. Therefore we aimed to evaluate the relationship between thyroid hormone and frail phenotype in euthyroid patients with cirrhosis. Methods A total of 214 adult cirrhotic inpatients were divided into two groups according to Frailty Index. Concentrations of free triiodothyronine (FT3), free thyroxine (FT4) and thyroid stimulating hormone (TSH) were compared. An analysis of the receiver operating characteristic (ROC) curve was implemented to determine the best cut-off for frailty. Multiple logistic regression was used to assess the association between FT3 and frailty. Results ROC analysis indicated that the optimal cut-off to stratify frailty was FT3 <3.03 pmol/L with an area under the curve of 0.673 (95% CI: 0.582-0.764, p = 0.002), sensitivity of 81.8% and specificity of 51.9%. Patients with FT3 <3.03 pmol/L exhibited higher incidence of Child-Pugh class B/C, elevated model for end-stage liver disease score, higher creatinine, lower sodium as well as higher incidence of frailty (23.7 vs 6.0%, p < 0.001). A negative correlation was observed between FT3 values and Frailty Index (r = -0.220, p = 0.001). FT3 remained an independent risk factor for frailty after adjusting for age, Child-Pugh class, creatinine, sodium and alanine aminotransferase. Conclusion In our current study, FT3 <3.03 pmol/L were significantly associated with increased risk for frailty. Measuring FT3, a readily available biomarker, may be useful for identifying frail phenotype in euthyroid patients with cirrhosis.