Serum FT4 Levels Research Articles

Higher thyroid function is associated with accelerated hippocampal volume loss in Alzheimer’s disease

BackgroundIn epidemiological studies, higher thyroid hormone (TH) levels have been associated with lower brain volume and increased risk of Alzheimer’s disease (AD) in elderly individuals. However, the relationships between serum THs and hippocampal atrophy rates have previously not been investigated. MethodsA prospective study of patients with AD (n = 55), stable mild cognitive impairment (sMCI; n = 84) and healthy controls (n = 29) recruited at a single memory clinic. We investigated whether serum THs were associated with magnetic resonance imaging (MRI)-estimated hippocampal volumes at baseline and with longitudinal alterations, defined as annualized percent changes. ResultsSerum levels of free triiodothyronine (FT3) and FT3/free thyroxine (FT4) ratio were reduced in AD and sMCI patients compared with the controls (p < 0.05). Hierarchical linear regression analyses showed that higher serum FT3/FT4 ratio was associated with greater baseline hippocampal volume in all study groups. Only in AD patients, higher serum FT4 was associated with lower baseline volume of the left hippocampus. Finally, exclusively in the AD group, higher serum levels of FT3 and FT3/FT4 ratio, and lower serum TSH levels, were associated with greater annual hippocampal volume loss. ConclusionsIn all study groups, FT3/FT4 ratio was related to baseline hippocampal volume. However, only in AD patients, higher levels of THs were associated with greater annual loss of hippocampal volume, suggesting that excessive TH levels exert a deleterious effect on the hippocampus in the presence of existing AD neuropathology.

Abstract 127: Pituitary resistance to thyroid hormone due to a novel mutation in the NCOR2 gene: The first case report

Background: Pituitary resistance to thyroid hormone-β (RTH-β) presents with the symptoms of hyperthyroidism with inappropriate secretion of thyroid stimulating hormone (TSH). Mutation in the coding region of the TR-β gene is not observed in 10% of cases, which are termed as non-TRβ RTH. Till date, the specific contributions of co-repressors and co-activators in pituitary resistance to thyroid hormone remain unknown.Materials and Methods: We present a case of 44-year male with pituitary RTH, showing features suggestive of thyrotoxicosis, atrial fibrillation and goiter. Clinical investigations included estimation of serum FT4, T3, TSH, TRab, TPO antibodies, Tc-thyroid scan, MRI for sella. To understand the genetic cause of the disorder, we undertook the whole genome sequencing (WES) in the proband and family members, which was followed by Sanger's sequencing for confirmation. To validate the possibility of RTH due to the novel gene discovered, we undertook in-vitro functional studies using NCOR2 siRNA.Results: A 44 year old male presented with atrial fibrillation with thyrotoxicosis and elevated serum T4, FT4, and T3, and nonsuppresed TSH levels (serum total T4 24.50 ug/dl, total T3 5.22 nmol/l and TSH 5.50 uIU/ml. On treatment with PTU, he had serum TSH 16.24 uIU/ml, FT4 50 nmol/l, and total T3 6.61 nmol/l. Further clinical workup by 99mTc pertechnetate thyroid scan showed bilateral diffusely increased uptake, negative serum TRAb and TPO antibody. A differential diagnosis of RTH or TSH secreting pituitary adenoma was made. Gadolinium enhanced MRI of sella was normal. We observed loss of inverse correlation of serum T3 and TSH levels, signifying the loss of negative feedback mechanism. WES identified two novel mutations in the NCOR2 gene (p.Ser2304Gly, p.Ala2489Thr) in the proband. Both the mutation (p.Ala2489Thr) were confirmed in the proband and one of his children. Bioinformatics analysis suggested p.Ala2489Thr to be pathogenic. Functional studies in GH3 cell lines using NCOR2 siRNA revealed NCOR2 dependent regulation of TSH levels, further strengthening that NCOR2 mutations could cause RTH.Conclusion: We hereby describe the first case of pituitary RTH due to a novel mutation in the NCOR2 gene in a family with thyrotoxicosis.

Patterns and Determinants of Change in Cortisol Levels and Thyroid Function as a Function of Cardiac Risk in Children Undergoing Cardiac Surgery.

Background Children undergoing cardiac surgery with cardiopulmonary bypass (CPB) are exposed to the risk of hormonal imbalances resulting from acute stress, which may eventually result in high postoperative mortality and morbidity. Objective We assessed adrenal and thyroid hormonal changes and their determinants following cardiac surgery in children and explored their prognostic value in predicting cardiac outcomes. Study Design and Methods. A prospective cohort study was conducted at King Abdulaziz University Hospital (KAUH), between 2017 and 2018. The study involved 46 children aged 14 years or younger who underwent elective cardiac surgery with cardiopulmonary bypass. Serum levels of cortisol, TSH, fT3, and fT4 were measured preoperatively and 24, 48, and 72 hours after surgery. The cardiac risk was assessed using the risk adjustment for congenital heart surgery (RACHS) scale. A composite cardiovascular outcome was analyzed as a numerical variable and calculated as the number of cardiovascular events. Results Overall, the changes in thyroid function parameters resulted in a U-shaped curve, while cortisol levels yielded a bell-shaped curve. The most significant changes occurred at 24 hours postop, including a decrease in mean TSH by 2.08 μIU/L (p < 0.001), fT3 by 2.39 pmol/L (p < 0.001), and fT4 by 2.45 pmol/L (p < 0.001) and an increase in cortisol levels by 406.48 nmol/L (p < 0.001) with respect to the baseline. Cortisol concentration peaked higher and recovered slower among patients with high cardiac risk than their counterparts. Cardiovascular outcomes were independently predicted by the extent of the decline in fT4 and TSH at 48 and 72 hours postop, with reference to the baseline, and by the cortisol level at 24 h postop, independent of the baseline, besides the RACHS category. Conclusion Cardiac surgery among children yields a high adrenocortical response and a high incidence of nonthyroidal illness syndrome, increasing cardiovascular risk. A preventive management strategy involves improving surgical techniques to minimize trauma-related stress.

Thyroid Function and Low Free Triiodothyronine in Chinese Patients With Autoimmune Encephalitis.

Background and ObjectivesLow free triiodothyronine (FT3) is usually associated with worse functional outcome in critical illness; however, the information on thyroid dysfunction and autoimmune encephalitis (AE) is limited. This study aims to evaluate the clinical prognostic value of thyroid function and low-T3 syndrome in patients with multiple subtypes of AE. MethodsIn this retrospective study, we identified the hospital records of 319 candidate patients with AE admitted between January 2016 and December 2020. We then extracted the clinical features and outcomes. Modified Rankin scale (mRS) scores were used to evaluate the patients’ neurological function. The serum levels of FT3, free thyroxine (FT4), and thyroid-stimulating hormone (TSH) were measured upon admission. Normal thyroid stimulating hormone level with FT3 below the lower limit of the reference interval (2.63 nmol/L) was defined as low-T3 syndrome.ResultsA total of 237 AE cases remained after screening. Among these, 57.81% (137/237) were men and the average age at onset was 41 y (interquartile range, 12–61 y). We found that 83.54% (198/237) of the patients had a good prognosis, and 16.46% (39/237) had a poor prognosis. Abnormal thyroid function was observed in 30.80% of these patients, with a relatively greater prevalence in the group with a poor prognosis (p < 0.001). The serum FT3 levels in the poor-prognosis group were significantly lower than those in the good-prognosis group (p < 0.001). Low-T3 syndrome occurred in 15.19% of AE cases and was more frequent in patients with poor prognosis (p < 0.001).ConclusionsAbnormal thyroid function in AE is frequent, and serum FT3 levels in patients with poor prognosis are significantly lower than in those with good prognosis. Low-T3 syndrome could be a potential candidate for predicting the prognosis of AE following future research.

“ASSESSMENT OF SERUM BIOMARKERS WITH TREATMENT OUTCOME AMONG PATIENTS WITH IDIOPATHIC PARKINSON'S DISEASE IN A TERTIARY CARE HOSPITAL, KOLKATA”

Obectives: There is a pressing need for robust diagnostic &amp; prognostic biomarkers in idiopathic Parkinson's disease. So far most of potential biomarkers have been studied in isolation.No study has yet been done taking all the biomarkers into consideration. Our study thus aimed to investigate the diagnostic &amp; prognostic potential of a panel of biomarkers in IPD patients of West Bengal. Methods: 55 untreated patients of clinically diagnosed idiopathic Parkinson's disease within the age group 50 – 80 years visiting in the neurology out-patient department of R. G. Kar Medical College and Hospital, were taken as cases , included in the study, based on a set of xed inclusion &amp; exclusion criteria. Serum TSH, fT3 ,Uric acid, Homocysteine were measured in diagnosed untreated cases and 3&amp; 6 months post treated cases of Idiopathic Parkinson's disease. Also correlation of above-mentioned biomarkers with disease seveirity ( UPDRS 2) were also assayed. Thin layer chromatography was done with aromatic amino acids( Phenylalanine, Tyrosine and Tryptophan) in untreated cases of IPD as well as 3 &amp; 6 months post treated too. Results: The results of statistical analysis showed that levels of serum Uric acid ( P value &lt; 0.0001) and serum homocysteine ( P value= 0.0003) were signicantly raised in patients of IPD compared to their apparently healthy age and sex matched controls .We also found signicantly raised value of serum level of TSH ( P &lt;0.0001) &amp;Uric acid ( P value &lt; 0.0.0001) and signicantly lowered value of serum fT3 ( P &lt; 0.0001) in 3 months and 6 months post treated cases compared to untreated cases of IPD.A Signicant correlation was found between serum levels of fT3(P value= 0.0344, Pearson r= 0.2857) with disease severity(UPDRS 2) of IPD. Interpretation: Serum Uric acid and Homocysteine level is associated with increase risk factor of IPD . Serum TSH ,Uric acid and fT3would be a better upcoming diagnostic and prognostic marker for diagnosis of IPD patients .

Serum level of free thyroxine is an independent risk factor for non-alcoholic fatty liver disease in euthyroid people.

Non-alcoholic fatty liver disease (NAFLD) has become a major public health problem concern in recent decades. The specific mechanism of NAFLD is still not clear. Previous studies had shown the correlation between NAFLD and thyroid dysfunction. The correlation between thyroid hormones within the euthyroid range and NAFLD has not yet been clarified. This study sought to investigate the association between NAFLD and thyroid hormones in euthyroid patients. A retrospective cross-sectional study was conducted at Beijing Tiantan Hospital from January 1, 2019, to October 1, 2021. Eighty-one NAFLD patients with normal thyroid function and 34 healthy individuals were enrolled. Participants' demographic information, biochemical parameters, and thyroid hormone levels were collected. The severity of NAFLD was assessed by abdominal computed tomography (CT). The association between NAFLD and thyroid hormones was analyzed. Patients in the NAFLD group were older and more likely to be female than those in the healthy control group (P<0.05). Compared to the healthy control group, the serum levels of fasting plasma glucose (FPG), alanine transaminase (ALT), plasma aspartate transaminase (AST), triglyceride, gamma-glutamyl transferase (γ-GT), and uric acid (UA) were higher, but the levels of high-density lipoprotein cholesterol (HDL-C), and free thyroxine (FT4) were lower in the NAFLD group (P<0.05). NAFLD is more severe in females than males (P<0.05). ALT, AST, low-density lipoprotein cholesterol (LDL-C), γ-GT, tetraiodothyronine, and free triiodothyronine (FT3) levels increased significantly as the severity of NAFLD increased (P<0.05). The results of the Spearman correlation analysis indicated that the severity of NAFLD was positively correlated with ALT (r=0.376, P=0.001), AST (r=0.275, P=0.015), and LDL (r=0.313, P=0.007). The multiple logistic regression analysis showed that age [odds ratio (OR) =1.071; 95% confidence interval (CI): 1.010-1.136, P=0.021], ALT (OR =1.091; 95% CI: 1.034-1.150, P=0.001), HDL-C (OR =0.085; 95% CI: 0.010-0.690, P=0.021), and FT4 (OR =0.738; 95% CI: 0.545-1.001, P=0.046) were independently related to the risk of NAFLD in patients with normal thyroid function. FT4 within the normal range was lower in the NAFLD group compared to the healthy control group. The serum level of FT4 is an independent risk factor of NAFLD in euthyroid people.

Aging-related Characteristics of Subclinical Hypothyroidism Detected in General Practice.

Subclinical hypothyroidism (SCH) is diagnosed when serum thyrotropin (TSH) is elevated despite a normal thyroxine level and is known to increase the risk of metabolic disorders. This study was conducted to identify potential laboratory markers suspicious for latent SCH. We retrospectively reviewed 958 outpatients in whom thyroid functions had been examined. Eighty-five (9.1%) of the 939 analyzed subjects had SCH (73% females). In the SCH group, median serum TSH and FT4 levels were 5.04 μU/ml and 1.19 ng/dl, respectively, and auto-thyroid antibodies were detected in 53.8% of patients. SCH group patients were significantly older than patients in the euthyroid group, while there was no intergroup difference in BMI. However, 56.5% of the SCH patients were asymptomatic. In the SCH group, serum aspartate aminotransferase and low-density lipoprotein cholesterol (LDL-C) levels were significantly higher, and the estimated glomerular filtration rate (eGFR) was significantly lower than in the euthyroid group. Among patients less than 65 years of age, SCH patients tended to have lower eGFR and higher LDL-C than euthyroid patients. Age-dependent reductions of red blood cells and serum albumin were more prominent in the SCH than the euthyroid group. Biochemical changes with aging are useful as potential clues for suspecting latent SCH.

Clinical effect of methimazole combined with selenium in the treatment of toxic diffuse goiter in children.

BACKGROUNDThe incidence of toxic diffuse goiter (Graves’ disease) is higher in adolescents and preschool-aged children, with an upward trend. The incidence at 6–13 years of age is approximately 11.0%, and the incidences in men and women are 7.8% and 14.3%, respectively.AIMTo explore the clinical effect of methimazole combined with selenium in the treatment of toxic diffuse goiter (Graves’ disease) in children and its effect on serum anti-thyroglobulin antibody (TRAb) and anti-thyroid peroxidase antibody (TPOAb).METHODSA total of 103 children with Graves’ disease treated in our hospital from January 2018 to June 2021 were divided into a traditional group and a combined group (15-20 mg methimazole orally given to children) and a combined group (50 µg selenium added on the basis of traditional treatment) according to different treatment methods to explore the therapeutic effects of the two methods and to observe the changes in thyroid volume and serum TRAb, TPOAb, free thyroxine (FT4) and inflammatory factor levels before and after treatment. The time taken for FT4 to return to normal was compared between the two groups.RESULTSTreatment was significantly more effective in the combined group than in the traditional group (P < 0.05). The thyroid volumes of the children in the two groups was measured before and after treatment. Thyroid volume decreased significantly after treatment in both groups, and the thyroid volume was significantly lower in the combined group than in the traditional group (P < 0.05). The serum levels of interleukin-6 (IL-6), IL-8, TRAb, TPOAb and FT4 in the two groups were detected before and after treatment. The levels of IL-6, IL-8, TRAb, TPOAb and FT4 were significantly lower in the combined group than in the traditional group (P < 0.05). Follow-up of the children in the two groups showed that compared with the traditional group, it took less time for children in the combined group to return to the normal level (P < 0.05).CONCLUSIONMethimazole combined with selenium can effectively treat Graves’ disease in children, reduce the expression of TRAb, TPOAb, FT4 and inflammatory factors, and improve the curative effect. Thus, the combined treatment warrants further clinical research.

Association between thyroid function and assessment of hepatic fat and iron contents by magnetic resonance imaging

The associations of thyroid function parameters with non-alcoholic fatty liver disease (NAFLD) and hepatic iron overload are not entirely clear. We have cross-sectionally investigated these associations among 2734 participants of two population-based cross-sectional studies of the Study of Health in Pomerania. Serum levels of thyroid-stimulating hormone (TSH), free tri-iodothyronine (fT3), and free thyroxine (fT4) levels were measured. Liver fat content (by proton-density fat fraction) as well as hepatic iron content (by transverse relaxation rate; R2*) were assessed by quantitative MRI. Thyroid function parameters were associated with hepatic fat and iron contents by median and logistic regression models adjusted for confounding. There were no associations between serum TSH levels and liver fat content, NAFLD, or hepatic iron overload. Serum fT4 levels were inversely associated with liver fat content, NAFLD, hepatic iron contents, and hepatic iron overload. Serum fT3 levels as well as the fT3 to fT4 ratio were positively associated with hepatic fat, NAFLD, hepatic iron contents, but not with hepatic iron overload. Associations between fT3 levels and liver fat content were strongest in obese individuals, in which we also observed an inverse association between TSH levels and NAFLD. These findings might be the result of a higher conversion of fT4 to the biologically active form fT3. Our results suggest that a subclinical hyperthyroid state may be associated with NAFLD, particularly in obese individuals. Furthermore, thyroid hormone levels seem to be more strongly associated with increased liver fat content compared to hepatic iron content.

Thyroid functions as a parameter in monitoring of antiepileptic drugs

ABSTRACT Introduction Epilepsy is a chronic neurological disorder that is treated with multiple medications that can have significant side effects. This study investigated the potential effects of antiepileptic drugs on thyroid function. Methods The participants in this study were epileptic adults who had been consistently monitored in follow-up care. The effects of antiepileptic drugs on the serum levels of the thyroid stimulating hormone (TSH), free T3 (fT3), and free T4 (fT4) of these patients were investigated retrospectively by comparing laboratory recordings in three defined periods: prior to antiepileptic drug treatment, between 6 months and 1 year of treatment (early stage), and after 1 year of treatment (late stage). Results A total of 300 epileptic patients (F/M: 175/125) were included in the study. Significant differences in TSH and fT4 serum levels in the late stage compared to the pre-treatment stage (p = 0.006 and p = 0.0005, respectively) were found. TSH values in the late stage of treatment were abnormally high in one case and low in five cases; all six of these cases had normal pre-treatment and early-stage TSH values. Patients who received monotherapy with valproic acid, levetiracetam or carbamazepine were evaluated separately and there was no statistically significant difference in TSH and fT3 levels, while fT4 levels were significantly increased during treatment in each treatment group. Conclusions A significant increase in TSH levels was found in epileptic patients on polytherapy. Our results give us the opportunity to highlight the potential unique or cumulative effect of antiepileptic drugs on thyroid hormone levels.

Triiodothyronine (T3), inflammation and mortality risk in patients with acute myocardial infarction.

ObjectivesTo study the relationship between serum-free T3 (FT3), C-reactive protein (CRP) and all-cause mortality in patients with acute myocardial infarction (AMI).DesignProspective multicentre longitudinal cohort study.MethodsBetween December 2014 and December 2016, thyroid function and CRP were analysed in AMI (both ST-elevation (STEMI) and non-ST-elevation) patients from the Thyroxine in Acute Myocardial Infarction study. The relationship of FT3 and CRP at baseline with all-cause mortality up to June 2020 was assessed. Mediation analysis was performed to evaluate if CRP mediated the relationship between FT3 and mortality.ResultsIn 1919 AMI patients (29.2% women, mean (s.d.) age: 64.2 (12.1) years and 48.7% STEMI) followed over a median (interquartile range) period of 51 (46–58) months, there were 277 (14.4%) deaths. Overall, lower serum FT3 and higher CRP levels were associated with higher risk of mortality. When divided the patients into tertiles based on the levels of FT3 and CRP; the group with the lowest FT3 and highest CRP levels had a 2.5-fold increase in mortality risk (adjusted hazard ratio (95% CI) of 2.48 (1.82–3.16)) compared to the group with the highest FT3 and lowest CRP values. CRP mediated 9.8% (95% CI: 6.1–15.0%) of the relationship between FT3 and mortality.ConclusionsIn AMI patients, lower serum FT3 levels on admission are associated with a higher mortality risk, which is partly mediated by inflammation. Adequately designed trials to explore the potential benefits of T3 in AMI patients are required.

The Association Between COVID-19 and Thyroxine Levels: A Meta-Analysis.

ObjectivesRecently, a number of reports have described the potential relationship between COVID-19 and thyroid hormones, but the results were conflicting. We performed a meta-analysis to evaluate the effect of the severity of COVID-19 on thyroid-related hormones and the effect of thyroid-related hormones on the outcome of COVID-19 in order to try to confirm the association between the serum levels of free triiodothyronine (FT3), free thyroxine (FT4) and thyroid stimulating hormone (TSH) and the severity or mortality of coronavirus-19 patients.MethodsThe methodology was already registered in the International Prospective Register of Systematic Reviews (PROSPERO) database, and the protocol number is CRD42021269246. Systematic searches were carried out on the Cochrane Library, Embase, PubMed and Web of Science databases on November 15, 2021. We set up the literature search strategy based on the following keywords: [(T3 OR FT3 OR triiodothyronine) or (T4 OR FT4 OR thyroxine) or (TSH or thyrotropin)] and (COVID-19 OR SARS-CoV-2), without time restrictions.ResultsTwenty studies satisfied the inclusion/exclusion criteria and were included in the meta-analysis. A total of 3609 patients were enrolled in the study. From the analysis of the included studies, the incidence of thyroid-related hormone abnormalities was higher in patients with severe COVID-19, and the serum levels of FT3 and TSH were lower than those of patients with nonsevere COVID-19. However, the difference in the FT4 levels was not significant. Similar characteristics were shown between survivors and nonsurvivors. In addition, the outcomes of the meta-analysis showed that patients with abnormal thyroid-related hormones had greater mortality.ConclusionsLow FT3 serum levels, low FT4 serum levels and low TSH serum levels may increase the mortality of COVID-19 patients during admission. On the other hand, the higher the severity level of COVID-19, the higher the probability of decreases in the FT3, FT4, TSH levels.

Analysis of thyroid function in Japanese patients with coronavirus disease 2019.

Thyroid dysfunction that is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is becoming increasingly recognized. However, only a few reports in Japan have addressed this issue to date. In this study, we sought to clarify whether infection with SARS-CoV-2 affected thyroid hormone levels and whether these hormones could be better predictors of prognosis in patients with coronavirus disease 2019 (COVID-19). Accordingly, we retrospectively examined 147 cases wherein thyroid hormones were measured at the time of admission among 848 Japanese patients with COVID-19 admitted to the Hyogo Prefectural Kakogawa Medical Center. All patients underwent thyroid function testing upon hospital admission. More than half (59.1%) of the patients were euthyroid. Twenty-four percent of patients had serum thyroid-stimulating hormone (TSH) levels lower than the reference range with normal serum free thyroxine (fT4) levels, and 3.4% of the patients had low TSH with high fT4 levels. Over 70% of the patients with moderate and severe COVID-19 had low serum free triiodothyronine (fT3) levels. Serum TSH and fT3 levels were inversely correlated with disease severity. The mortality rate in patients with low serum fT3 levels was significantly higher than that in those with normal serum fT3 levels.

Relationship between Vitamin D Level and Subclinical Hypothyroidism in Patients with Gestational Diabetes Mellitus.

The aim was to investigate the relationship between the vitamin D (VitD) level and the incidence rate of subclinical hypothyroidism in patients with gestational diabetes mellitus (GDM) in early pregnancy. Ninety eligible patients who underwent physical examination from March 2015 to September 2017 were selected. The levels of serum 25-hydroxyvitamin D (25-OH-VD), free thyroxine (FT4), free triiodothyronine (FT3), thyroid stimulating hormone (TSH), and thyroid peroxidase antibody (TPOAb) were measured. The correlations of VitD level with those of thyroid function-related indices were analyzed. The serum 25-OH-VD level was (17.82 ± 3.45) ng/mL in the 90 GDM patients in early pregnancy, including 64.44% patients in VitD deficiency group, 22.22% patients in VitD insufficiency group, and 13.33% in VitD sufficiency group. No significant differences in the levels of serum FT4, FT3, and TSH were found among different VitD groups (p > 0.05), but the level of TPOAb gradually decreased (p < 0.05). There was no significant difference in the incidence rate of subclinical hypothyroidism among different VitD groups (p > 0.05). VitD level was not correlated with those of FT4, FT3, and TSH (p > 0.05), but negatively correlated with that of TPOAb (p < 0.05). An increase of TPOAb level raised the risk of VitD deficiency in pregnant women (p < 0.05). Patients suffered from significant 25-OH-VD deficiency in spring and winter (p < 0.05). GDM patients in early pregnancy display VitD deficiency, and their serum 25-OH-VD level is affected by seasons and not significantly related to subclinical hypothyroidism. However, the increased level of TPOAb may raise the risk of VitD deficiency in pregnant women.

Iodide-sensitive Graves' hyperthyroidism and the strategy for resistant or escaped patients during potassium iodide treatment.

The effectiveness of potassium iodide (KI) (100 mg/day) was evaluated in 504 untreated patients with Graves' hyperthyroidism (GD). Initial response to KI within 180 days, the effect of additional methylmercaptoimidazole (MMI) or radioactive iodine (RI) in resistant or escaped patients, and long-term prognosis were evaluated. Serum fT4 levels became low or normal in 422 patients (83.7%, KI-sensitive group) without serious side effects. Among these patients, serum TSH levels became high (n = 92, hypothyroid) or normal (n = 78) in 170 patients (33.7%) (KI-sensitive with a recovered TSH response, Group A), but remained suppressed in 252 patients (50.0%) (KI-sensitive with TSH suppression, Group B). Serum fT4 levels decreased but remained high in 82 patients (16.3%) (KI-resistant, Group C). Older patients, or those with small goiter and mild GD were more KI-sensitive with a recovered TSH response than others. Escape from KI effect occurred in 0%, 36% and 82% in Group A, B and C, respectively. Patients in Group B and C were successfully treated with additional low-dosage MMI or RI. After 2-23 years' treatment (n = 429), remission (including possible remission) and spontaneous hypothyroidism were significantly more frequent in Group A (74.3% and 11.1%, respectively,) than in Groups B (46.3% and 2.8%, respectively) or C (53.6% and 1.5%, respectively) (p < 0.0001). In conclusion, a high KI sensitivity with a recovered TSH response was observed in about a third of the patients in GD associated with a better prognosis. Additional MMI or RI therapy was effective in escaped or KI-resistant patients with suppressed TSH level.

Thyroid parameters variations in healthcare workers and students exposed to low-dose ionizing radiations

Background. Ionizing Radiations (IR) are an important occupational risk factor for the potential damage that can cause to workers' health and for their presence in numerous professional settings. Health care workers (HCW) can be exposed to IR from various sources, in particular from x-rays using radiological equipment, and represent the largest group of workers occupationally at risk, despite increased regulation and protection which caused exposure to low dose radiations. The thyroid gland is one of the most sensitive organs to damage and an important target of IR, leading to functional and organic diseases. The aim of this study is to assess the variations in thyroid hormones, in a population of HCW exposed to low-dose IR. Methods. 121 individuals of the Teaching Hospital Policlinico Umberto I in Rome exposed to low-dose of IR (78 HCW, 17 Residents and 26 Radiology Technicians Students) were observed assessing serum levels of different thyroid function parameters as free triiodothyronine, free thyroxine and thyroid stimulating hormone at T1, T2 and DeltaT. Age, gender, history of thyroid diseases, BMI and smoke were analyzed as possible influencing factors using linear and multiple logistic regression analysis. Results. Analyzing TSH, fT3 and fT4 serum levels, in two different measurement (T1 and T2) and considering Delta between them, adjusting for different confounding factors, data showed no variation of TSH levels related to occupational exposure, a decrease of fT3 hormone values in HCW and residents, and an increase of fT4 in HCW. Discussion. The analysis of our results revealed that hospital occupation has an impact on thyroid hormones variations, with an increase of fT4 and a decrease of fT3 and no variations of TSH. These results are in conflict with previous studies evidences, in which both free hormones decreased with a concomitant increase of TSH. Conclusion. Exposure to low dose IR influences levels of free thyroid hormones, with no variation in TSH, which could result in a functional or organic disease. For this reason it is recommended continuous surveillance through a periodic check of all the thyroid hormones for an overall view of each HCW. However, further studies are necessary to confirm hormones trend and assess any related thyroid diseases.

Iodine nutrition level and thyroid function in pregnant women in the Yongchuan district of Chongqing

This study aims to investigate thyroid function-associated parameters and the incidence of thyroid disorders in pregnant women, with the overarching aim to ensure that pregnant women do not develop said disorders due to aberrant iodine levels during the course of pregnancy. A total of 300 pregnant women who underwent routine check-ups at the Yongchuan Hospital Affiliated to Chongqing Medical University from January to December 2021 were enrolled. Venous blood and morning urine were collected. Serum thyroid-stimulating hormone (TSH), free thyroxine (FT4), and free triiodothyronine (FT3) were determined by chemiluminescence immunoassay. Urinary iodine concentration (UIC) was detected by arsenic cerium catalytic spectrophotometry. Thyroid disorders were extrapolated from the measured parameters. The overall median UIC was 203 μg/L, which was within normal range. Subgroup analysis revealed that the median UIC in the first trimester was 187.5 μg/L, 211.8 μg/L in the second trimester, and 239.9 μg/L in the third trimester. However, based on the WHO criteria, 32%, 30%, and 18% of pregnant women were iodine deficient during their first, second, and third trimester, respectively. The proportion of women with iodine deficiency in the first and second trimesters was higher compared to the third trimester (P < 0.05). Serum FT3 and FT4 concentrations were higher in subjects in their first and second trimester versus the third trimester, while serum TSH levels were lower in subjects in their first and second trimester versus the third trimester (P < 0.05). The TSH concentration in subjects with inadequate iodine intake (UIC < 150 μg/L) was lower compared to subjects with adequate iodine intake (UIC 150 - 249 μg/L), but higher than in subjects with more than adequate intake (UIC 250 - 499 μg/L) and excess iodine intake (UIC ≥ 500 μg/L) (P < 0.05). TSH concentration and UIC were positively correlated (r = 0.1945, P = 0.0007), while no relationship was observed between UIC and FT3 and FT4 serum levels (r1 = -0.0593, P1 = 0.3053; r2 = -0.0149, P2 = 0.7968). There was no significant difference in FT3 and FT4 concentration between different UIC strata (P > 0.05). The incidence of thyroid disease during pregnancy in iodine-deficient women was greater compared to pregnant women with adequate iodine intake (P < 0.05) and higher in subjects in the more than adequate as well as excessive iodine intake cohorts (P < 0.05). The iodine nutritional intake by pregnant women in Yongchuan District, Chongqing, was generally sufficient to meet developmental and metabolic needs. However, about a third of women in their first and second trimester exhibited iodine deficiency. Iodine deficiency was associated with an increased incidence of thyroid diseases. In clinical practice, the UIC of pregnant women should be measured during key stages in the pregnancy to prevent the manifestation of thyroid diseases.

Effect of Di-(2-ethylhexyl) phthalate on the hypothalamus-pituitary-thyroid axis in adolescent rat.

Di-(2-ethylhexyl) phthalate (DEHP) is extensively used in many personal care and consumer products, which results in widespread human exposure. Limited studies have suggested that exposure to DEHP may affect thyroid function, but little is known about the effect and mechanisms of DEHP exposure on the hypothalamic-pituitary-thyroid axis (HPTA). The present study was conducted to elucidate the potential mechanisms underlying DEHP disrupting the function of the HPTA. DEHP was administered to Wistar rats by gavage at 0, 5, 50, and 500 mg/kg/day for consecutive 28 days and then the rats were sacrificed within 24 h following the last dose. The hormone levels of HPTA were quantified with radioimmunoassay and enzyme-linked immunosorbent assay, the protein levels of thyrotropin-releasing hormone receptor (TRHR) and thyroid-stimulating hormone receptor (TSHR) were analyzed by Western blot and immunohistochemistry, and the expression levels of TRHR and TSHR mRNA were measured by quantitative real-time PCR. The low dose of DEHP increased the body weights of rats. Serum levels of T3, T4, FT3 and FT4 as well as protein and mRNA levels of TSHR decreased in rats treated with 50 mg/kg or 500 mg/kg DEHP compared with those of controls. Although the protein levels of TRH in the hypothalamus or protein and mRNA levels of TRHR in pituitary were up-regulated, serum levels of TSH did not change statistically in rats treated with DEHP. Therefore, DEHP can produce thyroid toxicity and may interfere with the secretion of pituitary TSH. In conclusion, DEHP could interfere with the balance of HPTA of adolescent rats, and disturb the homeostasis of thyroid related hormones and the expression levels of receptors.

Reductions in serum TSH and FT4 levels due to roxadustat in hemodialysis patients：A single-center retrospective study

Reductions in serum TSH and FT4 levels due to roxadustat in hemodialysis patients：A single-center retrospective study

Hormonal trends in patients suffering from long COVID symptoms.

Symptoms of long COVID are complex and long-lasting, and endocrine dysfunction might be involved in the underlying mechanisms. In this study, to clarify the hormonal characteristics of long COVID patients, laboratory data for patients who visited the outpatient clinic for long COVID were evaluated. A retrospective analysis was performed for patients who visited Okayama University Hospital during the period from Feb 2021 to Dec 2021 with focus on the interrelationships between major symptoms and endocrine data. Information and laboratory data were obtained from medical records for 186 patients. The patients had various symptoms, and the most frequent symptoms were general malaise, dysosmia/dysgeusia, hair loss, headache, dyspnea, and sleeplessness. Patients who were suffering from fatigue and dysosmia/dysgeusia were younger, while hair loss was more frequent in older and female patients. As for the characteristics of patients suffering from general fatigue, the scores of depression and fatigue were positively correlated with serum levels of cortisol and free thyroxin (FT4), respectively. Also, patients suffering from general fatigue had lower levels of serum growth hormone and higher levels of serum FT4, while patients with dysosmia/dysgeusia had a significantly lower level of serum cortisol. Serum thyrotropin (TSH) levels were higher and the ratios of FT4/TSH were lower in the initially severe cases, suggesting occult hypothyroidism. In addition, the ratios of plasma adrenocorticotropin to serum cortisol were decreased in patients with relatively high titers of serum SARS-CoV-2 antibody. Thus, hormonal changes seem to be, at least in part, involved in the persistent symptoms of long COVID.