Serum Thyroid-stimulating Hormone Research Articles

Reference Intervals of Serum Iodine Concentration in Chinese Pregnant Women.

The study aims to establish trimester-specific reference ranges for serum iodine (SI) in Chinese pregnant women and explore its associations with maternal and infantile thyroid function. Apparently healthy pregnant women were enrolled during their first antenatal visit. Fasting venous and spot urine samples were collected for determining serum and urinary iodine (UI) levels by a validated inductively coupled plasma mass spectrometry. Serum free triiodothyronine (FT3), free thyroxine (FT4), thyrotropin (TSH), and neonatal TSH levels were tested by electro-chemiluminescent assay. The reference ranges of SI were established by percentile method and reported as 2.5-97.5%. ROC analysis was applied to compare the discriminative ability of SI, UI, and UI to urinary creatine ratio (UI /UCr) in early pregnancy for various thyroid conditions. The trimester-specific reference ranges of SI for Chinese pregnant women were 60.91-114.53 μg/L for the first trimester (T1, n = 1029), 54.57-103.42 μg/L for the second trimester (T2, n = 379), and 52.03-110.40 μg/L for the third trimester (T3, n = 455). Maternal SI at T1 but not UI and UI/UCr was significantly correlated with FT3 (r = 0.393, P < 0.001), FT4 (r = 0.637, P < 0.001), and TSH (r = -0.299, P<0.001). Maternal SI change% from T1 to T2 (but not SI change% from T1 to T3) had marginal correlation with neonatal TSH (r=-0.106, P=0.046). ROC analysis showed that maternal SI at T1 had better predictability for several thyroid conditions than UIC and UI/UCr.

The Association Between Hypoxic-Ischemic Encephalopathy and Thyroid Hormones.

We aimed to compare serum thyroid-stimulating hormone (TSH) and free thyroxine (fT4) levels in neonates with different hypoxic-ischemic encephalopathy (HIE) stages undergoing therapeutic hypothermia (TH), and to evaluate the TSH and fT4 levels in neonates with HIE/TH in comparison with a control group. This was a retrospective study conducted between January 2020 and December 2022. The neonates with HIE/TH constituted the study group and the neonates with transient tachypnea of the newborn (TTN) constituted the control group. The study group consisted of neonates with stage 2 and stage 3 HIE. Serum TSH and fT4 levels measured at postnatal fifth day were compared between the groups. Of the 202 (47.1%) neonates included in the study group, 144 (71.3%) had stage 2 HIE and 58 (28.7%) had stage 3 HIE. In the control group, there were 227 (52.9%) newborns. Serum TSH and fT4 levels were found to be lower in the newborns with stage 3 HIE compared with those with stage 2 HIE (p = 0.015, 0.002, respectively). Although the serum TSH level was higher in the newborns with HIE compared with the newborns with TTN, serum fT4 levels did not change between the groups (p = < 0.001, 0.14, respectively). When we made the analysis according to the reference intervals, HIE/TH was associated with higher rates of TSH elevation compared with TTN, and the difference was more pronounced in stage 2 HIE/TH (p < 0.001). Although stage 3 HIE/TH was significantly associated with higher rates of low fT4 compared with TTN (p = 0.006), this relationship was not significant between stage 2 HIE/TH and TTN. It would be reasonable to interpret thyroid function tests performed on the fifth day with caution in newborns with HIE/TH, because higher TSH and lower fT4 levels on the fifth day in this patient group may result in unnecessary repetition of tests.

In infertile women with subclinical hypothyroidism, with or without thyroid peroxidase antibodies, serum TSH during pregnancy follows preconception values and thyroid hormones remain stable.

How does subclinical hypothyroidism, defined in infertile women during preconception by thyroid-stimulating hormone (TSH) >2.5 or >4.5 mIU/l, with or without thyroid peroxidase antibodies (anti-TPO) >100 IU/ml, impact thyroid hormone levels during pregnancy and after birth? During pregnancy, TSH levels remain similar to those in preconception, even with supplementary thyroxine, whereas the serum levels of anti-TPO progressively decline. Overt hypothyroidism impacts both pregnancy and offspring but randomized clinical trials and cohort studies failed to detect the benefit of treatment with thyroxine in cases with low-threshold TSH or with anti-TPO during pregnancy. First, the prevalence and reproducibility of two candidate cut-off levels of subclinical hypothyroidism in a cohort of 177 infertile women was compared with 171 women not aiming for pregnancy. Second, the impact of distinct setpoints of TSH in preconception (with or without anti-TPO) was monitored during pregnancy in 87 previously infertile women by high-frequency monitoring of thyroid function. Both studies were carried out from 2007 to 2019. Reproducibility and prevalence of subclinical hypothyroidism were examined in infertile women presenting in the fertility care unit of an academic institution. Women not aiming for pregnancy participated as controls. In both groups, TSH and anti-TPO were measured two times on different occasions. In addition, a group of previously infertile women with known preconception setpoints of TSH (with or without anti-TPO) were followed up prospectively throughout pregnancy and after birth. During pregnancy, serum was sampled weekly until Week 12, then monthly until delivery, and once after birth. Only cases with preconception TSH >4.5 mIU/l were supplemented with thyroxine. After collection of all samples, the serum levels of anti-TPO and the major thyroid hormones were measured. Prolactin with known fluctuations during pregnancy was used as reference. Measures of both TSH and anti-TPO at two different time points were accurate and reproducible. The odds of subclinical hypothyroidism in infertile women and controls were similar. During pregnancy, TSH closely followed preconception TSH levels, whereas serum levels of the thyroid hormones predominantly remained within or above (not below) the reference. Treatment of infertile women with preconception TSH >4.5 mIU/l with thyroxine resulted in higher free thyroxine (fT4) serum levels. The serum levels of anti-TPO declined as pregnancies evolved. The numbers of participants both in the prevalence study and in pregnancy did not reach the a priori estimated numbers. For ethical reasons, the patients with preconception TSH >4.5 mIU/l were treated with thyroxine. The findings apply to infertile women only. We propose to use >4.5 mIU/l as the serum TSH threshold for supplementing women with thyroxine before pregnancy. During pregnancy, fT4 may be the better marker to monitor thyroid function. The consistent decrease of anti-TPO antibody levels during ongoing pregnancies must be considered a protective element. The prevalence part of this study was supported by Merck-Serono, Geneva (TH006/EMR200007-603). The hormone measurements of the serum samples collected during the follow-up pregnancies were made possible by financial support of Roche Diagnostica (November 1721, 2017, Rotkreuz, Switzerland). I.D.G. was supported by a grant of the Repronatal Foundation, Basel, Switzerland. All authors declare no conflict of interest. Research Database of UniBasel, project no. 576691 (2007).

Thyroid profile prognostic value on disease severity and mortality in COVID-19

Background: Precise accurate triage of Coronavirus disease 2019 (COVID-19) patients during hospitalization for early identification of individuals at risk of developing severe disease is essential as Intensive Care Units (ICUs) are overwhelmed by the pandemic burden. The aim of this study was to evaluate thyroid function in patients with COVID-19. Methods: 60 healthy controls and 180 patients were admitted to a cardiothoracic hospital, Minia University, Egypt, between March 2020 and September 2021 without a history of thyroid disease. Patients divided as 60 non-COVID pneumonia patients with a similar degree of severity were included as another control group to find any unique effects of COVID-19 on thyroid function, 120 positive COVID-19 divided according to clinical classifications into moderate (n = 58), severe (n = 21), and critical (n = 41), Critical group were admitted to ICU and classified to survivors (n = 33) and non-survivors (n = 8). COVID patients also were divided into tertiles according to their FT3 levels. Lowes tertile (n = 45), middle tertile (n = 37) and highest tertile (n = 38). All participants underwent routine physical checkups, acute physiology, and chronic health evaluation (APACHE-II) scores. The outcome measure was death during hospitalization; intensive care admission, mechanical ventilation, and length of hospitalization. We analyzed the ability of each parameter to predict mortality in participants. Further, we also evaluated whether the combination of free triiodothyronine (FT3) level with APACHE-II score could improve the mortality prediction. Results: Thyroid Stimulating Hormone (TSH) was lower than normal range in 56.7% (68/120) of patients with COVID-19. TSH and serum-free triiodothyronine (FT3) were significantly lower in COVID-19 patients than healthy control and non-COVID-19 pneumonia patients. TSH and FT3 were lower in severe COVID-19 with statistical significance (p &lt; 0.001) and both positively correlated with the severity. The free thyroxine (FT4) in COVID-19 patients was not significantly different from the control group. Patients in the lowest FT3 tertile had significantly higher rates of mortality (18/40), mechanical ventilation (24/53.3), and intensive care unit admission (20/44.4). In univariate analyses, FT3 remained the most significant independent predictor of death. Conclusion: The changes in serum TSH and FT3 levels may be important manifestations of COVID-19 courses.FT3 levels can serve as a prognostic tool for disease severity in early presentation of COVID-19.

Hormonal changes in the first 24 postoperative hours after cardiac surgical procedures.

Hormone level changes after heart surgeries are a widely observed phenomenon due to neurohormonal feedback mechanisms that may affect postoperative morbidity and mortality. The current study aimed to analyze the changes in thyroid and sex hormones in the first 24 postoperative hours after heart surgery. This prospective, observational study (registered on ClinicalTrials.gov: NCT03736499; 09/11/2018) included 49 patients who underwent elective cardiac surgical procedures at a tertiary heart center between March 2019 and December 2019. Thyroid hormones, including thyroid-stimulating hormone (TSH), triiodothyronine (T3), and thyroxine (T4), and sex hormones, including prolactin (PRL) and total testosterone, were measured preoperatively and at 24 h postoperatively. Significant decreases in serum TSH (P < 0.001), T3 (P < 0.001) and total testosterone (P < 0.001) levels were noted, whereas T4 (P = 0.554) and PRL (P = 0.616) did not significantly change. Intensive care unit (ICU) hours (P < 0.001), mechanical ventilation (P < 0.001) and Vasoactive-Inotropic Score (VIS) (P = 0.006) were associated with postoperative T3 level. ICU hours were associated with postoperative T4 level (P=0.028). Postoperative and delta testosterone levels were in connection with lengths of stay in ICU (P=0.032, P = 0.010 respectively). Model for End-Stage Liver Disease (MELD) scores were associated with thyroid hormone levels and serum testosterone. T3 may represent a marker of nonthyroidal illness syndrome and testosterone may reflect hepatic dysfunction. In addition, PRL may act as astress hormone in female patients.

Urine concentrating ability in cats with hyperthyroidism: Influence of radioiodine treatment, masked azotemia, and iatrogenic hypothyroidism.

Hyperthyroid cats often have urine specific gravity (USG) values <1.035. It remains unclear how USG changes after treatment, if USG can be used to predict azotemia after treatment, or how iatrogenic hypothyroidism influences USG values. To determine the proportion of hyperthyroid cats with USG <1.035 vs ≥1.035; if USG changes after treatment; and whether USG <1.035 correlated with unmasking of azotemia or hypothyroidism. Six hundred fifty-five hyperthyroid cats treated with radioiodine; 190 clinically normal cats. Prospective, before-and-after study. Hyperthyroid cats had serum thyroxine, thyroid-stimulating hormone, and creatinine concentrations, and USG measured before and 6 months after successful treatment with radioiodine. Of untreated hyperthyroid cats, USG was ≥1.035 in 346 (52.8%) and <1.035 in 309 (47.2%). After treatment, 279/346 (80.6%) maintained USG ≥1.035, whereas 67/346 (19.4%) became <1.035; 272/309 (88%) maintained USG <1.035, whereas 37/309 (12%) became ≥1.035. Only 22/346 (6.4%) with USG ≥1.035 developed azotemia after treatment, compared with 136/309 (44%) with <1.035 (P < .001). Of cats remaining nonazotemic, 38% had USG <1.035, compared with 20% of normal cats (P < .001). The 137 cats with iatrogenic hypothyroidism had lower USG after treatment than did 508 euthyroid cats (1.024 vs 1.035), but USGs did not change after levothyroxine supplementation. USG <1.035 had high sensitivity (86.1%) but moderate specificity (65.2%) in predicting azotemia after treatment. Hyperthyroidism appears not to affect USG in cats. However, cats with evidence of sub-optimal concentrating ability before radioiodine treatment (USG < 1.035) are more likely to develop azotemia and unmask previously occult chronic kidney disease. Iatrogenic hypothyroidism itself did not appear to affect USG values.

High Thyroid-Stimulating Hormone and Low Free Triiodothyronine Levels Are Associated with Chronic Kidney Disease in Three Population-Based Studies from Germany.

High serum thyroid-stimulating hormone (TSH) levels have previously been associated with a low estimated glomerular filtration rate (eGFR), but studies associating thyroid hormone levels with albuminuria revealed inconsistent results. We used cross-sectional data from 7933 individuals aged 20 to 93 years of the Berlin Aging Study II and the Study of Health in Pomerania to associate serum TSH, fT3, and fT4 levels with eGFR and albuminuria. In multivariable analyses adjusted for confounding, we found inverse non-linear associations of serum TSH levels with eGFR, while serum fT3 levels showed a positive association with eGFR. High as well as low serum fT4 levels were associated with a lower eGFR. Age but not sex modified the association between thyroid hormone levels and eGFR. The inverse associations between serum TSH levels and eGFR were strongest in the youngest age groups, while the positive associations between serum fT3 levels and eGFR were strongest in older individuals. No significant associations between thyroid hormone levels and albuminuria were found. Our results indicate that hypothyroidism might be associated with a reduced kidney function. Thyroid function might be more tightly related to the eGFR than to albuminuria in the general population.

A comparative study on outcomes of fasting vs postprandial thyroid function tests among pregnant mothers in a tertiary care setting in Sri Lanka.

Accurate estimation of serum thyrotropin (TSH) is crucial in the diagnosis of subclinical hypothyroidism (SCH) in pregnancy. We aimed to investigate whether there are significant differences between fasting and nonfasting thyroid function tests (TFTs) among pregnant mothers. We studied 100 pregnant mothers with previously unknown thyroid dysfunction. An equal number of participants were included in each trimester. All pregnant mothers underwent fasting and 2-hour postprandial TFTs (TSH, free T4). Postprandial TSH (mean 1.01 mIU/L, SD 0.80) was significantly lower than the fasting TSH (mean 1.47 mIU/L, SD 1.18) in pregnancy (P < .01). Postprandial free T4 (mean 10.30 pmol/L, SD 2.01) was also lowered compared with fasting free T4 (mean 10.70 pmol/L, SD 1.99) in pregnancy (P < .01). The prevalence of SCH in pregnancy estimated using fasting TSH was 9.4% (SD 3%). In contrast, the prevalence was only 3.5% (SD 2%) when postprandial TSH was used. Compared with the fasting state, postprandial TSH demonstrates a statistically significant reduction that greatly influences the diagnosis of SCH in pregnant mothers. Therefore, we conclude that the timing of sampling for TFTs should be standardized, especially in the pregnant population.

Thyroid dysfunction in pediatric Fontan patients is associated with unfavorable hemodynamic status and severity of protein-losing enteropathy: A report from the Fontan care network

BackgroundThyroid dysfunction may have adverse effects on Fontan hemodynamics. Data on thyroid function in pediatric Fontan patients with or without protein-losing enteropathy (PLE) are limited. MethodsThis retrospective multicenter study included 67 Fontan patients (median age 10.9 years; 35.8% female; 28.4% PLE) in whom thyroid function testing was performed. ResultsSubclinical hypothyroidism (SHT) was present in 16 (23.9%) patients. Subjects with SHT had significantly lower systolic blood pressure (p = 0.014) and body weight z-score (p = 0.006), were in a worse New York Heart Association (NYHA) functional class (p = 0.004), were more often pacing dependent (p = 0.007), and were more likely to have PLE (p = 0.033, 8/19 (42.1%) patients). Serum thyroid stimulating hormone (TSH) levels were significantly higher in patients with NYHA class ≥ II (p = 0.005), significant atrioventricular valve regurgitation (p = 0.023), elevated serum natriuretic peptides (p = 0.031), and in those with PLE (p = 0.002). Patients with active PLE had significantly higher TSH levels than those in remission (p = 0.003). A strong inverse relationship was found between lower free triiodothyronine (fT3) levels and natriuretic peptides (r: −0.599, p = 0.040). Using binary logistic regression analysis we found that worse NYHA class was an independent predictor of SHT (OR 4.2; 95% CI 1.1–16.1, p = 0.036). ConclusionsSubclinical thyroid dysfunction is common in Fontan, particularly in patients with hemodynamic derangements and PLE. Future studies are needed to address the prognostic implications of thyroid dysfunction in the Fontan population.

Association of metabolic syndrome with hypothyroidism and hyperuricemia: A cross-sectional study in a tertiary care hospital, Kolkata, West Bengal

Background: Metabolic Syndrome (MetS) (Syndrome X, insulin resistance syndrome, MetS) consists of a constellation of metabolic abnormalities which include central obesity, hyperglycemia, insulin resistance, high triglycerides, low high-density lipoprotein (HDL) cholesterol, and hypertension. Obesity is a critical component of MetS. It causes alteration in the thyroid hormones and hyperuricemia. Furthermore, insulin resistance seen in MetS causes decreased uric acid excretion. Aims and Objectives: To study the association of MetS with hypothyroidism and hyperuricemia. Materials and Methods: A cross-sectional study was conducted among patients from the outpatient department of General Medicine, IPGME and R, Kolkata from January 2012 to June 2013. A total of 112 patients, consisting of 53 patients with MetS and 59 patients without MetS were selected. Patients’ history, clinical and laboratory findings were recorded and data were analyzed. Results: Majority (66%) of the patients with MetS were female and the rest were male. The mean Body mass index of patients with MetS was 33.31±4.36 (Mean±SD) kg/m2 and without MetS was 25.21±2.62 (Mean±SD) kg/m2. A significant association was observed between weight, height, waist circumference, fasting blood sugar, HDL value, and MetS (P&lt;0.05). About 39.6% of the patients with MetS had hyperuricemia. The association between MetS and hyperuricemia was found to be significant. Similarly, 45.3% of the patients with MetS had hypothyroidism. This association was also found to be significant. Serum thyroid-stimulating hormone had a minimal correlation with serum uric acid in patients with MetS (correlation coefficient r=0.344), while no correlation was observed between fT3, fT4 with serum uric acid. Conclusion: Increased prevalence of hyperuricemia and hypothyroidism was seen among patients with MetS. More extensive population-based research is needed to support this finding.

Development of a predictive score for post-hemithyroidectomy hypothyroidism using skeletal muscle index, remnant thyroid index, and thyroid-stimulating hormone levels: a retrospective cohort study.

Hypothyroidism is a major complication of hemithyroidectomy. Low remnant thyroid volume and high serum thyroid-stimulating hormone (TSH) levels are suggested as risk factors for post-hemithyroidectomy hypothyroidism. Reduced skeletal muscle mass is associated with a variety of postoperative complications. However, its impact on post-hemithyroidectomy hypothyroidism has not yet been studied. This study aimed to evaluate the association between skeletal muscle mass and the onset of post-hemithyroidectomy hypothyroidism and develop a predictive score using skeletal muscle mass in combination with previously reported risk factors. This study retrospectively analyzed 226 consecutive patients who underwent hemithyroidectomy at Shinshu University Hospital between January 2011 and December 2020. The skeletal muscle area at the fourth thoracic vertebral level and maximal remnant thyroid area were quantified using preoperative computed tomography and standardized by dividing them by the square of the patient's height, designated as the skeletal muscle index (SMI) and remnant thyroid volume index (RTI). Subclinical hypothyroidism was defined as a postoperative elevated serum TSH level (>5 µU/mL) with a normal free thyroxine (FT4) level (≥0.9 ng/dL), overt hypothyroidism as a postoperative increase in serum TSH level (>5 µU/mL) and a decrease in serum FT4 level (<0.9 ng/dL), and symptomatic hypothyroidism as an elevated serum TSH level (>5 µU/mL) with hypothyroidism-related symptoms. Logistic regression analysis was used to determine the factors associated with the onset of hypothyroidism. Patients with euthyroid status had significantly higher SMI and RTI than those who developed post-hemithyroidectomy hypothyroidism (SMI, euthyroid: 12.0±2.4 vs. subclinical hypothyroid: 10.2±1.7, P<0.001, euthyroid vs. overt or symptomatic hypothyroid: 10.1±1.7, P<0.001, RTI, euthyroid: 1.19±0.41 vs. subclinical hypothyroid: 0.92±0.35, P<0.001, euthyroid vs. overt or symptomatic hypothyroid: 0.84±0.30, P<0.001). Multivariable analysis demonstrated that low SMI, low RTI [hazard ratio (HR): 3.35, P<0.001], and preoperative high serum TSH levels (HR: 2.54, P=0.003) were independent predictive factors for hypothyroidism. Patients who had low SMI, low RTI, and preoperative high serum TSH levels were more likely to develop hypothyroidism (68.8%) than those with either one (25.3%), two (47.8%), or none (15.2%) of these three factors. Preoperative evaluation of the SMI, RTI, and serum TSH levels may be useful in predicting the development of post-hemithyroidectomy hypothyroidism.

Clinical study to evaluate the efficacy of Commiphora muku (Muqil) on thyroid function in hypothyroidism

Background: Hypothyroidism is a common endocrine disorder in which there is deficient production of thyroid hormone. Even though hormone replacement therapy is the mainstay treatment of hypothyroidism, but due to adverse effects on long term use, safe and effective Unani herbal drugs need to be researched. A decrease in serum concentrations of thyroid hormone causes an increased secretion of thyroid stimulating hormone (TSH), thus resulting in elevated serum TSH concentration. Methods: The methods used to determine thyroid dysfunction are still serum thyroid stimulating hormone and the main circulating thyroid hormones thyroxine and triiodothyronine either as total or estimated free concentrations, and it is indeed the improved assay sensitivities and specificities that have made it possible to diagnose these milder forms. TSH, T3 and T4 with safety parameters tests were done before treatment and after completion of treatment in both the groups in order to make the proper diagnosis, to exclude other systemic ailments and to assess the efficacy/safety of the proposed herbal drug. Results: The effects of test drug on lowering the raised serum TSH are attributed to the thyroid activities of the test drug which shoes highly significance p&lt;0.01 before and after intervention. In respect of thyroxin there were no significant results between the test and control group. Conclusions: The study concluded that the efficacy of Commiphora mukul (Muqil) on thyroid function was designed to explore the role of Unani herbal drugs in the management of hypothyroidism on Unani principles is effective, safe and cost effective.

Gender differences in the association between anxiety symptoms and thyroid hormones in young patients with first-episode and drug naïve major depressive disorder.

Gender differences are prevalent in major depressive disorder (MDD), but the gender differences in the relationship between comorbid anxiety and thyroid hormones in young first-episode and drug-naive (FEND) MDD patients are unknown. A total of 1,289 young outpatients with FEDN MDD were recruited. Demographic and clinical data were collected for each patient. The patient's blood glucose, blood pressure, thyroid hormone, and thyroid antibody levels were measured. The Hamilton depression scale (HAMD), Hamilton anxiety scale (HAMA), and Positive and Negative Syndrome Scale (PANSS) were used to assess patients' depression, anxiety, and positive symptoms, respectively. The prevalence of comorbid anxiety disorders was 80.4 and 79.4% in male and female MDD patients, respectively. Patients with anxiety had higher HAMD and PANSS scores, higher serum thyroid stimulating hormone (TSH), anti-thyroglobulin antibody (A-TG), and thyroid peroxidase antibody (A-TPO) levels, higher blood glucose and blood pressure levels, and more patients with psychotic symptoms and suicide attempts. Male patients were younger and had a younger age of onset. Logistic regression analysis showed that HAMD score and comorbid suicide attempts were significant predictors of anxiety symptoms in both males and females, whereas A-TG predicted anxiety symptoms in female patients only. Limitations: No causal relationship could be drawn due to the cross-sectional design. This study showed gender differences in factors associated with anxiety symptoms in patients with MDD. Some factors were associated with anxiety symptoms in both male and female patients, while A-TG was only associated with anxiety symptoms in female patients.

Effect of levothyroxine administration on oxidative stress and cytokine levels in rats with experimental hypothyroidism

In this study, it was aimed to determine the effects of levothyroxine (L-T4) administration on serum free triiodothyronine (fT3), free thyroxine (fT4), thyroid stimulating hormone (TSH) and serum total antioxidant capacity (TAC), serum total oxidant capacity (TOC), oxidative stress index (OSI) and superoxide dismutase (SOD) activity, liver malondialdehyde (MDA) and the effects of cytokines on tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) levels in rats with experimental hypothyroidism. In the study, 48, 39-day-old, male Wistar albino rats were randomly divided into 3 groups containing 16 rats in each as control, hypothyroid and levothyroxine (L-T4) treated hypothyroid group. The rats in the control group were injected with 1 mL of saline and the rats in the hypothyroid group were injected via intraperitoneal (i.p.) route with 6-n-propyl thiouracil (PTU) at a dose of 10 mg/kg/day for 28 days. In the levothyroxine treated group, after induction of hypothyroidism 5 µg of levothyroxine diluted in 1 mL of sodium chloride (NaCl) administered via i.p. route for 15 days. At the end of the study, serum and liver samples were taken from the rats. In hypothyroidism group, serum fT3, fT4 and TAK levels as well as SOD (P&lt;0.001) activity decreased statistically compared to the control group while serum TSH, TOC, OSI (P&lt;0.001), liver MDA (P&lt;0.01), TNF-α and IL-6 (P&lt;0.001) levels increased significantly. The decreased serum fT3, fT4, TAC levels and SOD (P&lt;0.001) activity in the hypothyroidism group increased with levothyroxine administration whereas the increased serum TSH, TOC, OSI and tissue MDA (P&lt;0.01), TNF-α and IL-6 (P&lt;0.001) levels were found to be decreased and approached to control levels. In conclusion, it has been shown that levothyroxine administration is effective against PTU-induced hypothyroidism in rats, inhibits lipid peroxidation and increases antioxidant status, minimizes the levels of inflammatory markers and protects against PTU-induced liver damage in rats. Because, the potential therapeutic use of levothyroxine in the treatment of hypothyroidism is thought to be appropriate.

Thyroid function test abnormalities-isolated TPOAb+, SCH and hypothyroxinemiaand preschool children's neurodevelopment.

Thyroid function test abnormalities are frequent and associated with the offspring's adverse neurodevelopment. This study aimed to examine the relationship between maternal thyroid function test abnormalities before 20 gestational weeks and children's cognitive, emotional and behavioural development at 3-6 years of age. A total of 2243 mother-child pairs were included in the final analysis. Maternal thyroid function was evaluated retrospectively during the children's preschool period. The serum thyrotrophin, free thyroxine and thyroid peroxidase antibodies(TPOAb) were detected by chemiluminescence immunoassay during the follow-up period. The neurodevelopmental status of preschoolers aged 3-6 years was evaluated by parental versions of The Behavior Rating Inventory of Executive Function-Preschool and The Strengths and Difficulties Questionnaires. The associations between maternal thyroid function test abnormalities and preschoolers'neurodevelopment were examined using Poisson regression models. After adjusting for potential confounders in Poisson regression analyses, it showed that maternal isolated TPOAb positivity before 20 gestational weeks may be associated with the increased risk of abnormalities in peer problems (odds ratio [OR] = 1.90, 95% confidence interval[CI]: 1.26, 287). Maternal isolated SCH before 20 gestational weeks was observed to be related with increased risk of abnormalities in inhibition (OR = 2.73, 95%CI: 1.37, 5.41), working memory (OR = 1.67, 95%CI: 1.04, 2.70), conduct problems (OR = 1.80, 95%CI: 1.05, 3.09), hyperactivity (OR = 1.94, 95% CI:1.08, 3.49)and total difficulties (OR = 1.94, 95%CI: 1.13, 3.34). Maternal isolated hypothyroxinemia before 20 gestational was observed to be related with increased risk of abnormalities in peer problems (OR = 2.71, 95%CI: 1.17, 6.27). Thyroid function test abnormalities before 20 gestational weeks may be associated with children's neurodevelopment at 3-6 years of age.

Stunting and wasting in neurological Wilson disease: Role of copper, zinc, and insulin-like growth factor-I.

Copper (Cu) and zinc (Zn) are important trace elements for the growth and development of children. In Wilson disease (WD), impaired Cu metabolism may affect growth. This study was conducted to evaluate the height and weight of children with neurological WD and correlate these with serum Cu, Zn, and insulin-like growth factor-I (IGF-I). This prospective cohort study was conducted in a tertiary care teaching institute. Children with neurologic WD were included. The height, weight, and body-mass index of each child were measured and categorized according to the revised national growth chart. Serum Cu, Zn, calcium, alkaline phosphatase, albumin, thyroid-stimulating hormone, and urinary-Cu were measured. Serum IGF-1 was measured by enzyme-linked immunosorbent assay. The relationship between height and weight with trace elements and IGF was analyzed using parametric or non-parametric tests. There were 52 children (5-18 years) with neurologic WD. Thirty-six (69.2%) children had normal height, 12 (23.1%) were tall, and 4 (7.7%) were stunted. Forty-six (88.5%) children had normal weight and six (11.5%) children were underweight. IGF-1 correlated with height, weight, duration of treatment, and serum Zn level. About 15.4% of children had stunting and/or wasting, which was associated with low levels of serum IGF-I, Zn, and calcium. Stunting and/or wasting occurs in 15.4% of children with neurologic WD and is associated with reduced serum IGF-I, Zn, and calcium concentration. Adjunctive Zn and calcium treatment may help in achieving normal growth.

Management of Subclinical Hypothyroidism: A Focus on Proven Health Effects in the 2023 Korean Thyroid Association Guidelines.

Subclinical hypothyroidism (SCH) is characterized by elevated thyroid-stimulating hormone (TSH) and normal free thyroxine levels. The Korean Thyroid Association recently issued a guideline for managing SCH, which emphasizes Korean-specific TSH diagnostic criteria and highlights the health benefits of levothyroxine (LT4) treatment. A serum TSH level of 6.8 mIU/L is presented as the reference value for diagnosing SCH. SCH can be classified as mild (TSH 6.8 to 10.0 mIU/L) or severe (TSH >10.0 mIU/L), and patients can be categorized as adults (age <70 years) or elderly (age ≥70 years), depending on the health effects of LT4 treatment. An initial increase in serum TSH levels should be reassessed with a subsequent measurement, including a thyroid peroxidase antibody test, preferably 2 to 3 months after the initial assessment. While LT4 treatment is not generally recommended for mild SCH in adults, it is necessary for severe SCH in patients with underlying coronary artery disease or heart failure and it may be considered for those with concurrent dyslipidemia. Conversely, LT4 treatment is generally not recommended for elderly patients, regardless of SCH severity. For those SCH patients who are prescribed LT4 treatment, the dosage should be personalized, and serum TSH levels should be regularly monitored to maintain the optimal LT4 regimen.

CORRELATION BETWEEN THYROID FUNCTION AND OBESITY IN TYPE 2 DIABETES INDIVIDUALS

Objectives: In the present study, it is aimed to investigate the prevalence of thyroid dysfunction and blood glucose parameters and their correlation in Type 2 diabetes mellitus (T2DM) obese patients. Methods: The present study was a cross-sectional and observational study conducted for a period of 1 year January 2020–January 2022. The patient demographic data, age, and gender were collected from the medical records. After an overnight fast, venous blood samples were collected in the morning for laboratory tests. Electrochemiluminescence immunoassays were used to assess serum free T3 (FT3), FT4, and thyroid stimulating hormone (TSH). Fasting blood glucose, postprandial blood glucose, and random sugar levels were measured using enzymatic method. Body mass index (BMI) was calculated as weight (kg) divided by squared height (m). Results: In the present study, the mean values of thyroid harmones T3, T4 between the obese and non-obese individuals showed that no much significant variations might be due to low sample size. However, the mean values of TSH values were significantly higher 8.7ng/dl for obese individuals than non-obese individuals. There was a significant positive correlation that was identified for thyroid parameters TSH between obese and non-obese T2DM patients. On the other hand, there was a significant influence of postprandial blood sugar, random blood sugar, hemoglobin A1C, and BMI in obese and non-obese T2DM patients and insignificant influence for thyroid parameters T3 and T4. However, the results also showed that there was a highly significant influence of THS levels in obese T2DM patients. Conclusion: The findings of the present investigation showed a high correlation between thyroid function, mainly TSH levels, and Type 2 diabetes, particularly in obese persons.

Pulmonary Arterial Hypertension in Hyperthyroidism: Age, Ethnic, and Gender Disparities

Objective: Pulmonary arterial hypertension (PAH) affects 2.6% of adults and 36% of people with chronic obstructive pulmonary disease (COPD). Several case reports and small case series suggested a hyperthyroidism-PAH association.&#x0D; Design: Retrospective chart review.&#x0D; Methods: We undertook a retrospective chart review (1982–2018) to assess PAH prevalence in a multi-ethnic convenience sample of hyperthyroid adults with multiple etiologies. We calculated associations of pulmonary artery maximum systolic pressure (PSAPmax) with subject age, and maximum serum triiodothyronine (T3) and thyroxine (T4), free T3, and T4, minimum serum thyroid-stimulating hormone (TSH), and thyroid antibody titers, comparing PAH prevalence and the odds of being undiagnosed as to hyperthyroidism etiology by gender and ethnicity/race.&#x0D; Results: We found a high prevalence of PAH in hyperthyroid people, like that reported for people with COPD. We found no significant association between PSAPmax and any thyroid function test or thyroid antibody titer. As reported more recently in the general population, PSAPmax significantly correlated with age in hyperthyroid people. There was no significant disparity in the prevalence of PAH among White, non-Hispanic Black, and Latinx hyperthyroid people or between genders. The percentage of patients whose hyperthyroidism etiology was undiagnosed was high with significant disparity only between non-Hispanic Black and White people and between men and women. PAH was common in hyperthyroid subjects with any hyperthyroidism etiology.&#x0D; Conclusions: 2D-echocardiography should be performed in all hyperthyroid people because PAH is common, especially in older people because of their co-morbidities and poorer prognoses. Further research is needed regarding demographic disparities in being undiagnosed as to hyperthyroidism etiology.&#x0D; Principal Verdicts/Significance Statement: We reconfirmed the high PAH incidence in hyperthyroidism, previously reported, but profoundly under-recognized by physicians, to patients’ detriment. Further, we found that the shift in the general PAH population from younger to older individuals is mirrored in hyperthyroid people with PAH. This is concerning because older people have more co-morbidities and worse prognoses, necessitating early, effective intervention. PAH was present with diverse hyperthyroidism etiologies, suggesting that it is multicausal, resulting from autoimmunity, thyroid hormone excess, and goitrous upper airway obstruction and should be considered, regardless of etiology. Our observations that many subjects had no established hyperthyroidism etiology and that males and Blacks were likelier to be undiagnosed are concerning, warranting further study.

Biological variation of serum thyrotropin and thyroid hormones concentrations determined at 8-week intervals for 1 year in clinically healthy cats.

Cats commonly develop thyroid disease but little is known about the long-term biological variability of serum thyroid hormone and thyrotropin (thyroid-stimulating hormone; TSH) concentrations. We aimed to determine the long-term biological variation of thyroid hormones and TSH in clinically healthy cats. A prospective, observational study was carried out. Serum samples for analysis of total thyroxine (T4, by radioimmunoassay [RIA] and homogenous enzyme immunoassay [EIA]), triiodothyronine (T3 ), free T4 (by dialysis), and TSH were obtained every 8 weeks for 1 year from 15 healthy cats, then frozen until single-batch analysis. Coefficients of variation (CV) within individual cats ( ) and among individual cats ( ), as well as the variation between duplicates (ie, analytical variation [ ]) were determined with restricted maximum likelihood estimation. The indices of individuality (IoI) and reference change values (RCVs) for each hormone were calculated. Some thyroid hormones showed similar (total T4 by EIA) or greater (TSH) interindividual relative to intraindividual variation resulting in intermediate to high IoI, consistent with previous studies evaluating the biological variation of these hormones weekly for 5-6 weeks. By contrast, total T4 (by RIA) and free T4 had a low IoI. Total T3 had a high ratio of to ; therefore, interindividual variation could not be distinguished from analytical variation. No seasonal variability in the hormones could be demonstrated. Clinicians might improve the diagnosis of feline thyroid disease by establishing baseline concentrations for analytes with intermediate-high IoI (total T4, TSH) for individual cats and applying RCVs to subsequent measurements.