Changes In Thyroid Hormone Levels Research Articles

Supplementation with selenium and coenzyme Q10 in an elderly Swedish population low in selenium — positive effects on thyroid hormones, cardiovascular mortality, and quality of life

BackgroundSelenium-dependent deiodinases play a central role in thyroid hormone regulation and metabolism. In many European countries, insufficient selenium intake may consequently lead to adverse effects on thyroid function. In this randomised placebo-controlled double-blind study, we examined the effect of supplementation with selenium and coenzyme Q10 on thyroid hormonal status, cardiovascular (CV) mortality and health-related quality of life (Hr-QoL).MethodsFree T3, free T4, reverse T3, and TSH were determined in 414 individuals at baseline, and the effect of selenium yeast (200 µg/day) and coenzyme Q10 (200 mg/day) supplementation on hormone concentrations, CV mortality and Hr-QoL was evaluated after 48 months using Short Form 36 (SF-36). Pre-intervention plasma selenium was low, mean 67 µg/L, corresponding to an estimated intake of 35 µg/day. Changes in concentrations of thyroid hormones following the intervention were assessed using T-tests, repeated measures of variance, and ANCOVA analyses.ResultsIn the total population, the group with the lowest selenium concentration at baseline presented with significantly higher levels of TSH and lower levels of fT3 as compared to subjects with the highest selenium concentration. Supplementation with selenium and coenzyme Q10 for 4 years significantly increased fT3 and rT3, decreased fT4, and diminished the increase in TSH levels compared with placebo treatment (p = 0.03, all). In the placebo group, TSH and fT4 values above the median were associated with an increase in 10-year CV mortality, as compared with the mortality rate among those with TSH and fT4 below the median (p < 0.04, both), with no difference in mortality rate according to TSH and fT4 levels in the active intervention group. Similarly, TSH > median and fT3 < median were associated with a decline in mental Hr-QoL measures vs. TSH < and fT3 > median in the placebo group during 4 years of follow-up, but this was wiped out in the active group.ConclusionsSupplementation with selenium and coenzyme Q10 had a beneficial effect on thyroid hormones with respect to CV mortality and Hr-QoL outcomes. The initial deficient selenium status was associated with an impaired thyroid function and the changes in thyroid hormone levels can be explained by increased activity of deiodinases. We conclude that a substantial part of the elderly study population might suffer from suboptimal thyroidal function with adverse clinical implications due to selenium deficiency.Trial registrationThis study was registered at ClinicalTrials.gov and has the identifier NCT01443780. Since it was not mandatory to register at the time the study began, the study has been registered retrospectively.

Thyroid Dysfunction Risk After Iodinated Contrast Media Administration: A Prospective Longitudinal Cohort Analysis.

Iodinated contrast media (ICM) is a common source of excess iodine in medical settings, given the common use of iodinated radiologic procedures. To determine the long-term risks of thyroid dysfunction following iodinated contrast administration in a prospective study. A longitudinal cohort study was conducted of patients in the U.S. Veterans Affairs medical system who received ICM. Serum thyroid function, thyroid antibody, and inflammatory markers were measured at baseline. Thyroid function tests were repeated at 1 month, 3 months, and every 6 months thereafter until 36 months. Risk of thyroid dysfunction and longitudinal changes in thyroid hormone levels were assessed using mixed effect models. There were 122 participants (median age, 70.0 [IQR 62.2-74.0] years; 98.4% male). At baseline, six subjects had subclinical thyroid dysfunction prior to ICM receipt. During median follow-up of 18 months, iodine-induced thyroid dysfunction was observed in 11.5% (14/122); six (4.9%) developed hyperthyroidism (including one with overt hyperthyroidism) and eight (6.6%) subclinical hypothyroidism. At last follow-up, ten of 20 subjects with thyroid dysfunction (14 new-onset cases and six with preexisting thyroid dysfunction) had persistent subclinical hyperthyroidism or hypothyroidism. There were also subtle changes in thyroid hormones observed longitudinally within the reference ranges in the overall cohort. There is a rare long-term risk of an excess iodine load on thyroid dysfunction even among individuals from an overall iodine-sufficient region, supporting the need for targeted monitoring following iodinated contrast administration.

Does an episode of diabetic ketoacidosis affect thyroid function tests in pediatric patients?

The aim of our study was to investigate the changes in thyroid hormone levels during and after acute metabolic disorder in patients with diabetic ketoacidosis (DKA). Eighty five patients diagnosed with DKA were included in the study. Patients with control thyroid function test (TFT) values at admission (the first blood sample) and 1month later were included in the study. Thyroid function tests obtained during diabetic ketoacidosis and at the first month follow-up were compared. Euthyroidism and euthyroid sick syndrome were defined and grouped according to current guidelines. The mild and moderate groups, according to DKA classification, were combined and compared with the severe group. A significant increase was observed between the first admission and the control TFT values 1month later. However, there was no significant difference found in TFT between mild/moderate and severe groups taken at the time of DKA. Difference between two groups, euthyroid sick syndrome and euthyroid, was examined and the result that was different from the literature was the difference between TSH levels. We found that low FT4 levels were associated with higher HgbA1c, although the correlation was weak. Thyroid hormone levels may not reflect a thyroid disease during severe DKA attack. Therefore, it is unnecessary to check thyroid function tests.

In vitro and in vivo investigation of a thyroid hormone system-specific interaction with triazoles

Alterations in thyroid hormones (TH) and thyroid-stimulating hormone levels are frequently found following exposure to chemicals of concern. Dysregulation of TH levels can severely perturb physiological growth, metabolism, differentiation, homeostasis in the adult and developmental processes in utero. A frequently identified mode of action for this interaction is the induction of hepatic detoxification mechanisms (e.g. SULTs and UGTs), which lead to TH conjugation and elimination and therefore interfere with hormonal homeostasis, fulfilling the endocrine disruptors (EDs) definition. A short-term study in rats with dietary exposure to cyproconazole, epoxiconazole and prochloraz was conducted and hepatocyte hypertrophy, hepatic UGT activity and Phase 1/2 gene expression inductions were observed together with changes in TH levels and thyroid follicular hypertrophy and hyperplasia. To test for specific interaction with the thyroid hormone system, in vitro assays were conducted covering thyroidal I-uptake (NIS), TH transmembranal transport via MCT8 and thyroid peroxidase (TPO) function. Assays for iodothyronine deiodinases (DIO1–DIO3) and iodotyrosine deiodinase (DEHAL1) were included, and from the animal experiment, Dio1 and Dehal1 activities were measured in kidney and liver as relevant local indicators and endpoints. The fungicides did not affect any TH-specific KEs, in vitro and in vivo, thereby suggesting hepatic conjugation as the dominant MoA.

RELATIONSHIP BETWEEN MOOD DISORDERS AND THYROID CHANGES

The thyroid gland, located at the base of the neck, produces hormones that regulate the body's metabolism, growth and development. Changes in the levels of these hormones, such as hypothyroidism (low production) and hyperthyroidism (high production), can have a significant impact on mental health, influencing the development of mood disorders. Studies demonstrate a strong association between thyroid dysfunction and disorders such as depression and bipolar disorder. In hypothyroidism, depressive symptoms may include fatigue, mental sluggishness, anhedonia, and weight gain. In hyperthyroidism, anxiety, insomnia and irritability are more frequent. The bidirectional relationship between thyroid and mood is complex and involves several mechanisms. Changes in thyroid hormone levels can affect brain neurotransmission, especially serotonin and dopamine, neurotransmitters directly related to mood. Furthermore, the hypothalamic-pituitary-thyroid axis, responsible for thyroid hormonal regulation, can also be influenced by psychological factors such as stress. Objective: To carry out a systematic review of the literature to evaluate the relationship between mood disorders and thyroid changes, investigating the prevalence of mood disorders in individuals with thyroid diseases, the underlying pathophysiological mechanisms and the impact of hormone replacement on mental health. Methodology: The review followed the PRISMA checklist guidelines. The PubMed, Scielo and Web of Science databases were searched using the following descriptors: "mood disorders", "hypothyroidism", "hyperthyroidism", "thyroid" and "mental health". Articles published in the last 10 years were selected. Inclusion criteria: studies that evaluate the relationship between mood disorders and thyroid diseases; Human studies; Published in Portuguese, English or Spanish; Published in the last 10 years. Exclusion: Animal studies; Studies with inadequate methodological designs; Studies that do not evaluate the relationship between mood and thyroid. Results: 15 studies were selected. The review identified that the prevalence of mood disorders is significantly higher in individuals with thyroid disease than in the general population. Hypothyroidism is associated with depression, while hyperthyroidism is more related to anxiety. The pathophysiological mechanisms underlying the relationship between mood and thyroid are complex and involve changes in cerebral neurotransmission, the hypothalamic-pituitary-thyroid axis and the response to stress. Adequate hormone replacement for thyroid disease can significantly improve symptoms of mood disorders in many cases. Conclusions: The systematic review confirmed the strong association between mood disorders and thyroid changes. Thyroid dysfunction can be a risk factor for the development of mood disorders, and adequate hormone replacement can be an important therapeutic tool.

Lack of associations between thyroid dysfunction and obstructive sleep apnea-hypopnea syndrome: A meta-analysis.

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is a comprehensive syndrome with endocrine and metabolic complications. This review aims to explore the correlation between thyroid hormone levels and the severity of OSAHS in patients. The protocol for this meta-analysis has been registered on PROSPERO. Searches were carried out from the inception of the databases to July 18, 2023, utilizing 6 databases (PubMed, CNKI, EMBASE, Web of Science, Cochrane Library, China Biology Medicine, and Wanfang). Standardized mean difference (SMD) and correlation coefficients were used as the effect size measures. Additionally, random effects or fixed effects models were used for pooled analysis. Moreover, data were statistically evaluated with the help of STATA 11.0 and R 4.1.3. This study included 23 articles that satisfied the pre-defined criteria. The prevalence of hypothyroidism and subclinical hypothyroidism in OSAHS patients was 6% and 8%, whereas hyperthyroidism had a prevalence of 2%. Moreover, thyroid hormone levels in OSAHS individuals exhibited no significant difference relative to healthy subjects. Subgroup analysis based on disease severity also established no significant changes in thyroid hormone levels between OSAHS individuals and controls. There was no significant correlation between the Apnea-Hypopnea Index (AHI) and free triiodothyronine (FT3), serum thyroid stimulating hormone (TSH), and free thyroxine (FT4) levels. The prevalence of thyroid dysfunction is relatively low in OSAHS individuals. Thyroid hormone levels show no significant difference between OSAHS patients and healthy subjects. Furthermore, there is no significant correlation between AHI and serum TSH, FT3, and FT4 levels. Based on existing data, the relationship between OSAHS and thyroid function remains controversial, and further in-depth research is warranted to validate the connection and elucidate the underlying mechanisms.

Effects of perchlorate and exogenous T4 exposures on body condition and endochondral ossification of Rana chensinensis tadpoles

Perchlorate, as an endocrine-disrupting chemical (EDC), is largely produced and used in the military, fireworks, fertilizers, and other industries and widely exists in water. Although perchlorate is known to destroy the normal function of thyroid hormones (THs) in amphibians and interfere with their growth and development, the impact of TH levels caused by sodium perchlorate (NaClO4) on endochondral ossification and skeletal development is poorly investigated, and the underlying molecular mechanism has not been clarified. The present study aimed to explore the potential effects of NaClO4 and exogenous thyroxine (T4) on the skeletal development of Rana chensinensis tadpoles and elucidate the related molecular mechanisms. Our results showed that histological changes occurred to the femur and tibia-fibula of tadpoles raised in 250 μg/L NaClO4 and 5 μg/L exogenous T4, and the length of their hindlimbs was significantly reduced. In addition, exogenous T4 exposure significantly interfered with the expression of Dio3, TRβ, MMP9, MMP13, and Runx2, inhibiting the endochondral ossification process. Therefore, we provide robust evidence that the changes in TH levels caused by NaClO4 and exogenous T4 will adversely affect the endochondral ossification and skeletal development of R. chensinensis tadpoles.

Study On Association of Thyroid Hormone and Intensive Care Unit Mortality in Central India.

Thyroid dysfunction has been linked to mortality in patients hospitalized in the intensive care unit (ICU). We aim tostudy the thyroid hormone level changes in critically ill ICU patients and predict mortality based on thyroid hormone levels. Thisprospective observational study was conducted on 80 consecutive patients aged over 18yrs, from November 2021 to May 2022,in patients admitted to ICU at Chirayu medical college and Hospital, Bhopal, and followed up during their ICU stay. Samples weretested for T3, T4, and TSH on day 1 and day 7. In our study of 80 participants, 46(57.5%) were male, and 34(42.5%) were female.About 32 (40%) were non-survivors. The significance value (P value) of T3 levels on day 1 was 0.083, and on day 7 was 0.001; T4levels on day 1 were 0.85, and on day 7 was 0.001. Similarly, the significance of TSH levels on day 1 was 0.085, and on day 7 was0.001. Day 1 levels of T3 are significantly correlated with APACHE II Score, and Day 7 levels of T3, T4, and TSH significantlycorrelated with APACHE II scores in predicting the outcome of the patients with the higher significance of T3 compared to T4and TSH. Our study showed that low T3 level during critical illness increases mortality risk. Thyroid profiles can be used inpredicting mortality and as an independent factor in predicting the outcome of ICU patients.

Effects of High Doses of Sodium Metavanadate on the Thyroid Status in Rats

Introduction: The widespread use of vanadium in the metallurgical industry leads to its high content in the workplace air, which poses a threat to human health both in the workforce and the community. Vanadium accumulates in many organs and has a toxic effect; yet, studies of its effects on the thyroid gland are scarce and narrowly focused. This study is aimed at establishing the effect of vanadium on the functioning of the thyroid gland. Objective: To establish thyroid status in rats after a single intraperitoneal injection of sodium metavanadate. Materials and methods: Twenty-six male Wistar rats aged 3 months weighing more than 200 g were divided into a control group (10 animals) exposed to distilled water and two exposure groups (V11 and V18) of eight animals each intraperitoneally exposed to 11 and 18 mg of sodium metavanadate per kg of body weight, respectively. Serum levels of the thyroid-stimulating hormone, total and free thyroxine and triiodothyronine were determined by enzyme immunoassay. Results: We observed that the high single exposure dose of sodium metavanadate caused significant changes in thyroid hormone levels. Administration of sodium metavanadate at the dose of 11 mg/kg b.w. induced an increase in the levels of total and free thyroxine but a decrease in the ratio of total triiodothyronine to total thyroxine compared with the controls. Administration of a higher dose of the compound (18 mg/kg b.w.) increased the levels of free triiodothyronine, free thyroxine, the ratio of free triiodothyronine to total triiodothyronine, and the ratio of free thyroxine to total thyroxine compared with the controls. We also noted the differences in health effects between the exposure groups, such as a higher level of free triiodothyronine and higher ratios of free triiodothyronine to total triiodothyronine and of free thyroxine to total thyroxine in the V11 exposure group. Conclusions: Our findings show that a single intraperitoneal injection of sodium metavanadate at high doses of 11 and 18 mg/kg b.w. suppresses thyroid function and induces hypothyroidism, even 14 days after administration.

Investigation the impact of liraglutide on the thyroid function tests

Aim: Liraglutide is a once-daily glucagon-like peptide-1 receptor agonist (GLP‑1 RA) which is an incretin hormone secreted from intestinal L cells in response to nutritional intake and stimulates glucose-dependent insulin secretion, decreases hepatic glucagon secretion, slows gastric emptying, provides a feeling of satiety and is the first GLP‑1 RA to be indicated for weight loss treatment for obesity. The impact of liraglutide on thyroid function tests is unknown and to the best of our knowledge, there are no studies on this regard. Our aim is to compare thyroid function tests, other biochemical and hemogram parameters before and 6 months after liraglutide treatment.&#x0D; Material and Methods: The patients, 18-65 years old, who used liraglutide for at least 6 months due to obesity treatment between January 2021 and January 2023 in Burdur State Hospital were included.&#x0D; Results: There were 51 patients (39 female, 12 male) using liraglutide without thyroid disease during the study period. Twelve patients discontinued liraglutide use before the 6th month of treatment was completed. Weight, body mass index (BMI), fasting plasma glucose (FPG), hemoglobin A1C (HbA1c), low-density lipoprotein (LDL), triglyceride and thyroid-stimulating hormone (TSH) values were significantly lower at the 6th month of treatment. Free thyroxine (FT4) and free triiodothyronine (FT3) values were similar. and there was no difference other biochemical and hemogram parameters between before and 6 months after treatment&#x0D; Conclusion: We found a significant decrease in TSH values and improvement in metabolic parameters, but no change in thyroid hormone levels.

Developmental and environmental modulation of fecal thyroid hormone levels in wild Assamese macaques (Macaca assamensis).

Thyroid hormones are key modulators of development, as well as mediators of environmental conditions, by regulating developmental processes and metabolism in primates. Hormone measurement in noninvasively collected samples, that is, feces and urine, is a valuable tool for studying the endocrine function of wildlife, and recent studies have demonstrated the feasibility of measuring thyroid hormones in fecal samples of zoo-housed and wild nonhuman primates. Our study aimed to (i) validate the measurement of immunoreactive fecal total triiodothyronine (IF-T3) in wild Assamese macaques (Macaca assamensis) and (ii) to investigate its developmental changes and its response to environmental changes, including stress responses, in immature individuals. Fecal samples and environmental parameters were collected from individuals of three social groups of wild Assamese macaques living at Phu Khieo Wildlife Sanctuary, Northeastern Thailand. Our study confirmed the methodological feasibility and biological validity of measuring IF-T3 in this population. Specifically, the biological validation demonstrated higher IF-T3 levels in immatures compared to adults, and higher levels in females during late gestation compared to the preconception stage. Our analysis of IF-T3 levels in developing immature macaques revealed a significant increase with age. Furthermore, we found a positive association between IF-T3 and immunoreactive fecal glucocorticoid levels, an indicator of the physiological stress response. Neither minimum temperature nor fruit abundance predicted variation in IF-T3 levels in the immatures. Our findings indicate the possibility for differing effects of climatic factors and food availability on thyroid hormone level changes in immature versus adult animals and in wild compared to experimental conditions. Overall, our study provides the basis for further investigations into the role of thyroid hormones in shaping species-specific traits, growth, and overall primate development.

Hypothyroidism in induction chemotherapy of children with acute lymphoblastic leukaemia: A single-centre study.

Hypothyroidism as a long-term complication in cancer survivors has been an issue, but few studies have focused on changes in thyroid hormone levels during chemotherapy for leukaemia. This retrospective study was conducted to assess the characteristics of children with acute lymphoblastic leukaemia (ALL) and hypothyroidism during induction chemotherapy and to investigate the prognostic value of hypothyroidism in ALL. Patients with a detailed thyroid hormone profile at ALL diagnosis were enrolled. Hypothyroidism was defined as low serum levels of free tetraiodothyronine (FT4) and/or free triiodothyronine (FT3). The Kaplan-Meier method was used to create survival curves, and multivariate Cox regression analysis was used to screen prognostic factors associated with progression-free survival (PFS) and overall survival (OS). There were 276 children eligible for the study, and 184 patients (66.67%) were diagnosed with hypothyroidism, including 90 cases (48.91%) with functional central hypothyroidism and 82 cases (44.57%) with low T3 syndrome. Hypothyroidism was correlated with the dosages of L-Asparaginase (L-Asp) (P = .004) and glucocorticoids (P = .010), central nervous system (CNS) status (P = .012), number of severe infections (grade 3, 4 or 5) (P = .026) and serum albumin level (P = .032). Hypothyroidism was an independent prognostic factor for PFS in ALL children (P = .024, 95% CI: 1.1-4.1). We conclude that hypothyroidism is commonly present in ALL children during induction remission, which is related to chemotherapy drugs and severe infections. Hypothyroidism was a predictor of poor prognosis in childhood ALL.

Thyroid hormone decreasing after mechanical thrombectomy for cerebral infarction (P3-5.018)

<h3>Objective:</h3> The aim of this study wasto clarify the changes in thyroid hormone levels in the acute phase and the effects of the iodine contrast agent on thesehormones. <h3>Background:</h3> Mechanical thrombectomy (MT) is an established treatment for large vessel occlusion in patients with cerebral infarction. The use of iodine contrast agent decreases thyroid hormone levels via the so-called Wolff-Chaikoff effect. Low triiodothyronine (T3) syndrome caused by a severe illness status can contribute to decreased thyroid hormones. Reportedly, a low T3 level is associated with poor prognosis in patients with cerebral infarction. <h3>Design/Methods:</h3> This was a single-center, prospective, and single-arm trial. Thyroid stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxine (FT4) were tested on admission and 24 h postoperatively in patients who were approved for MT. <h3>Results:</h3> A total of 37 patients were screened during the study period and 31 patients were enrolled. Significant decreases were observed in TSH (<i>P</i> &lt; 0.001) and FT3 (<i>P</i> &lt; 0.001) levels 24 h after MT. Moreover, there was a correlation between the decrease ratio of change in FT3 levels and the amount of iodine contrast agent used per body surface area (<i>r</i> = 0.43, <i>P</i> = 0.019), while no such correlations were detected for TSH and FT4. <h3>Conclusions:</h3> We demonstrated that decrease in TSH and FT3 levels in the acute phase after MT and that FT3 levels were associated with the amount of iodine contrast agent used. <b>Disclosure:</b> Dr. Kobayashi has nothing to disclose.

Reversibility of thyroid hormone system-disrupting effects on eye and thyroid follicle development in zebrafish (Danio rerio) embryos.

Early vertebrate development is partially regulated by thyroid hormones (THs). Environmental pollutants that interact with the TH system (TH system disrupting chemicals; THSDCs) can have massively disrupting effects on this essential phase. Eye development of fish is directly regulated by THs and can, therefore, be used as a thyroid-related endpoint in endocrine disruptor testing. To evaluate the effects of THSDC-induced eye malformations during early development, zebrafish (Danio rerio) embryos were exposed for 5 days post fertilization (dpf) to either propylthiouracil, a TH synthesis inhibitor, or tetrabromobisphenol A, which interacts with TH receptors. Subsequently, one half of the embryos were exposed further to the THSDCs until 8 dpf, while the other half of the embryos was raised in clean water for 3 days to check for reversibility of effects. Continued THSDC exposure altered eye size and pigmentation and induced changes in the cellular structure of the retina. This correlated with morphological alterations of thyroid follicles as revealed by use of a transgenic zebrafish line. Interestingly, effects were partly reversible after a recovery period as short as 3 days. Results are consistent with changes in TH levels measured in different tissues of the embryos, e.g., in the eyes. Results show that eye development in zebrafish embryos is very sensitive to THSDC treatment, but able to recover quickly from early exposure by effective repair mechanisms. This article is protected by copyright. All rights reserved. Environ Toxicol Chem 2023;00:0-0. © 2023 SETAC.

Association of SNP localized near &lt;i&gt;DIO2&lt;/i&gt; gene with hormonal profiles of the thyroid axis and fertility indicators in black-and-white cows

Thyroid hormones can affect the reproductive function of cows through the regulation of various metabolic pathways. The activity of the thyroid system is under the control of three types of deiodinases (DIO). In cattle, there are several genetic variants for the DIO1 and DIO3 genes, but there is no information on the polymorphism of the DIO2 gene.Purpose: to conduct a search for genetic variants for SNPs in the DIO2 gene and in nearby regions and investigate their association with prepartum and postpartum thyroid profiles and reproductive performance in dairy cows.Materials and methods. Black-and-white cows of calving 2-4 were used in the experiments. Before calving and after calving, blood was taken from the animals to determine the concentration of hormones by ELISA. The assessment of the luteal activity of the ovaries was performed on the basis of an ultrasound study and the content of progesterone in the blood. Genotyping was performed on 48 samples of cow DNA using a Bovine GGP 150K biochip.Results. No SNPs present on the Bovine GGP 150K chip were found within the target gene. The SNP Bovine- HD1000026761, localized upstream of the DIO2 gene, was selected for research, with a frequency of genotypes being 45.83% (AA), 47.92% (AG), and 6.25% (GG). In cows with the AA and AG genotypes, a decrease of 1.4 times (p&lt;0.01) in the blood concentration of total thyroxine (T4) 2 weeks before calving, compared with that for 4 weeks, and its further decrease by 1.5 -1.9 times (p&lt;0.001-p&lt;0.05) by the 1st week of lactation were found. From the 6th to the 2nd week before parturition, this indicator was 1.5–1.6 times higher (p&lt;0.001–p&lt;0.05) in individuals with the AG genotype than in ones with the AA genotype. In animals with the AG genotype, a decrease in the blood concentration of reverse T3 (1.4 times, p&lt;0.05) between the 4th week before calving and the 1st week of lactation was revealed. At the same time, this concentration was relatively constant in the animals of the other two groups. Furthermore, in animals with the AG genotype, the content of rT3 in the blood was 1.3 times lower than in animals with the AA genotype from the 3rd to the 7th week of lactation. In cows with a heterozygous genotype, the T4/T3 ratio increased 2.1 times (p&lt;0.001) between the 2nd week before calving and the 1st week after calving, and then decreased 2.2 times (p&lt;0.001) to the 3rd week. After 1 week of lactation, this ratio was 1.9 times higher (p&lt;0.001) than in animals with the AA genotype. Meanwhile, the frequency of occurrence of individuals with the shortest period of recovery of the ovarian function and open days period was the lowest in the group with the AA genotype.Conclusions. The data obtained indicate that the SNP BovineHD1000026761, located upstream of the DIO2 gene, is associated with long-term changes in thyroid hormone levels in the prepartum and postpartum periods.

Challenges in Thyroid Function Testing: Interferences and Clinical Implications

In recent decades, significant advancements have been made in the methodologies used for evaluating thyroid dysfunctions. These advancements include the development of radioimmunoassays, immunometric assays, and liquid chromatography coupled with mass spectrometry. The main thyroid function tests include thyroid-stimulating hormone (TSH) and the measurement of triiodothyronine (T3) and thyroxine (T4), including their total and free fractions. Over time, different generations of TSH tests have been developed, starting from radioimmunoassays to immunometric assays, and more recently, tests utilizing fluorophores and chemiluminescent molecules. The third-generation tests are currently the most widely used due to their high sensitivity and specificity. Thyroid-stimulating hormone is preferred as the initial test for evaluating thyroid function since it has a log-linear relationship with free T4 levels, enabling the identification of subclinical hypothyroidism and subclinical hyperthyroidism. The reference range for normal TSH levels is typically between 0.45 and 4.5 mIU/L. However, there can be variations in TSH levels based on factors such as sex, age, and ethnicity. Specific reference values may be required for certain populations, such as the elderly, pregnancy, and neonates. In the elderly, an increase in TSH levels is expected. In the neonatal period, TSH levels are high after birth and take a few weeks to normalize. During pregnancy, various physiological changes occur, leading to alterations in thyroid hormones to meet fetal demands. Laboratory interferences in thyroid hormone assays must be considered to ensure accurate results. Biotin interference can lead to falsely low TSH and falsely high free T3 and T4 levels. Macro-thyrotropin can cause elevated TSH levels with normal thyroid hormone levels. Heterophilic antibodies can also cause false results. Additionally, the evaluation of autoantibodies and markers used in thyroid cancer follow-up needs special attention. Patients experiencing conditions like trauma, particularly in severe cases, may undergo changes in thyroid hormone levels, even without having a specific thyroid disease, which is called low triiodothyronine syndrome. In conclusion, it is essential to be aware of potential laboratory interferences and consider individual variations to ensure accurate interpretation and appropriate management of patients.

Pomegranate (Punica granatum) peel alleviates lithium-induced alterations in the thyroid gland of rats by modulating apoptosis and oxidative stress.

Lithium carbonate (LC) is known to alter thyroid gland function. Pomegranate (PG) is a fruit with multiple antioxidant and antiapoptotic properties. Here, we studied the effect of PG on LC-induced morphological and functional alterations in the thyroid glands of rats. Rats were divided into four groups: control, lithium, lithium-PG, and PG. After 8 weeks, the rats were sacrificed, the levels of thyroid hormones and oxidative stress markers were estimated, and thyroid tissues were subjected to histological, immunohistochemical, and ultrastructural evaluations. Compared to the control group, the lithium group showed significant changes in thyroid hormone levels, greater expression of the oxidant marker malondialdehyde, and lower expression of the antioxidant marker superoxide dismutase (SOD). Most of these changes improved upon PG treatment. Histological evaluation of the thyroid in the lithium group showed disorganization and follicle involution. Additionally, the periodic acid Schiff staining intensity and SOD immunoreactivity declined significantly, whereas the collagen fiber content and Bax immunoreactivity increased. The follicular ultrastructure showed marked distortion. These changes were mitigated upon PG treatment. In conclusion, PG alleviated the morphological and functional changes in the thyroid glands induced by LC by modulating apoptosis and oxidative stress.

ODP507 PREVALENCE OF CARDIOVASCULAR DISEASE IN PATIENTS WITH SUBCLINICAL HYPOTHYROISIM

Abstract Introduction Thyroid hormones play an essential role in maintaining cardiovascular homeostasis. Experimental studies have revealed that subtle changes in thyroid hormone levels, as observed in subclinical hypothyroidism, have adverse effects on the cardiovascular system due to predisposition to endothelial dysfunction, dyslipidemia and direct effects of thyroid hormones on the myocardium. We conducted a retrospective cohort study to elicit the role of subclinical hypothyroidism as an independent risk factor for cardiovascular diseases. Methods We conducted a retrospective analysis of 3 years of the National Inpatient Sample (NIS) database, 2016 to 2018. Study populations were selected using ICD-10 diagnosis code. Discharge-level weight analysis was used to produce a national estimate. We conducted multivariate regression analysis to calculate odds ratio with STATA 17. Results During the study period, 106,970,745 study population met the inclusion criteria and 37,215 of subclinical hypothyroidism (SCH) patients were discharged. SCH patients tended to be more female (63.48% v 56.40%), older (mean age 58.22± 0.25 v 49.48 ± 0. 01), diabetic (24.84% v 21.47%) and obese (18.63% v 13.54%). Prevalence of hyperlipidemia and hypertension were similar in both SCH and non-SCH groups (3.75% v 3.24% and 29. 09% v 29.35% each). Caucasian patients were predominant in both groups with similar ethnicity distribution (62.26% v 64.96%). 3.56% of SCH patient had acute coronary artery syndromes (ACS), whereas 2.78% of non-SCH patients developed the ACS. For the patients without history of heart failure (HF), 2.54% of SCH patients developed new onset of HF, whereas 1.11% of non-SCH patients developed HF. After adjusting for age, sex, race and comorbid burden, SCH is not associated with ACS (p = 0.375) or Afib (p= 0.74) but associated with elevated risk for new onset of HF (OR 1.88, 1.62–2.18, p &amp;lt; 0. 0001). Conclusion Our study shows that subclinical hypothyroidism is not associated with higher rates of ACS or Atrial fibrillation, however it is associated with statistically significant higher risk of new onset HF. Further research needs to be done to determine subclinical hyperthyroidism as a potential risk factor for HF and assess the benefit of lower threshold for treating subclinical hypothyroidism in preventing or delaying the onset of HF in patients with associated cardiac risk factors. Presentation: No date and time listed

Thyroid hormone levels in Alzheimer disease: a systematic review and meta-analysis.

Thyroid hormone (TH) disturbances are perceived to contribute to cognitive impairment and dementia. However, there is no consensus on the association between TH levels and Alzheimer Disease (AD). In this study, we aimed to compare serum and cerebrospinal fluid (CSF) TH levels in AD patients to controls by performing a meta-analysis. We systematically searched online databases for papers comparing CSF or serum TH levels in AD patients to controls, and performed a meta-analysis on the extracted data. Out of 1604 records identified, 32 studies were included. No significant difference in serum TSH (standardized mean difference (SMD): -0.03; 95% confidence interval (CI): -0.22-0.16), total T4 (SMD: 0.10; 95% CI: -0.29-0.49), and free T4 (SMD: 0.25; 95% CI: -0.16-0.69) levels were observed. However, there was significantly lower serum total T3 (SMD: -0.56; 95%CI: -0.97 to -0.15) and free T3 (SMD: -0.47; 95%CI: -0.89 to -0.05) levels in AD group compared to controls. Subgroup analyses on studies including only euthyroid patients did not show any significant difference in either of the thyroid hormone levels. Also, no significant difference in CSF total T4 and total T3/total T4 ratios but significantly lower CSF total T3 (SMD: -2.45; 95% CI: -4.89 to -0.02) in AD group were detected. Serum total and free T3 and CSF total T3 levels are significantly lower in AD patients compared to controls. The temporality of changes in thyroid hormone levels and AD development should be illustrated by further longitudinal studies.

Relationship between thyroid function and Major Depressive Disorder (MDD): an integrative literature review

Thyroid function is closely associated with neuropsychological functions, including mental status and cognitive functions. Subclinical hypothyroidism (HSC) is defined as a condition with elevated levels of thyroid stimulating hormone (TSH) and normal levels of free thyroxine (T4). Although the role played by thyroid hormones in the pathophysiology of mental disorders is unclear, it has been suggested that small changes in thyroid hormone levels, even within the normal range, may be related to altered brain function in depression. Currently, there are 2 explanatory hypotheses: serotonin deficit and noradrenaline deficit in the central nervous system caused by hormonal disorders. It is important to emphasize that the thyroid-psychic pathway is bidirectional, therefore, both thyroid alterations can cause depressive symptoms or exacerbate a previous psychiatric pathology, and depression can promote thyroid disorders, the latter being less frequent. Thus, the role of thyroid function in depressive illness is unclear. Although there is some evidence that mild thyroid alterations predispose to cases of depression, the specific abnormalities involving the thyroid and depressive conditions remain poorly understood. However, there is a causal link.