High Thyroid-stimulating Hormone Research Articles

Atrial fibrillation screening to prevent stroke in persons with low-normal thyrotropin

Abstract Background Screening for atrial fibrillation (AF) has been proposed as a method to prevent strokes in high-risk individuals. Recent trials were unable to prove efficacy for stroke prevention but suggested that a more refined approach may be beneficial. Low-normal thyroid-stimulating hormone (TSH) is a marker for AF and stroke risk and may be used to select individuals for AF screening. Purpose To explore TSH as a tool to select individuals for AF screening to prevent stroke. Methods Post hoc analysis of a clinical trial enrolling 6004 participants with stroke risk factors but no known AF randomized 1:3 to implantable loop recorder (ILR) screening for AF and initiation of oral anticoagulation (OAC) upon AF detection versus usual care (control group). The primary outcome was stroke or systemic embolism (SE). Secondary outcomes included the combination of stroke, SE, or cardiovascular (CV) death, all-cause death, AF diagnosis, and OAC initiation. All outcomes were adjudicated. Results Baseline TSH was measured in 6003 participants (99.98%); 1500 randomized to ILR vs 4503 to control. The mean age was 75±4 years, 2836 (47%) were women. The tertiles of TSH were at ≤1.2, 1.2-1.9, and >1.9 mIU/L. Participants in the first tertile had slightly higher levels of the thyroid hormones (T3, T4, and free T4), were slightly younger, had more smoking pack-years, and higher pulse rate compared to other tertiles. The median follow-up duration was 5.4 (4.9-5.8) years, and no participants were lost to follow-up. AF was diagnosed in 476 (31.7%) participants in the ILR group vs 550 (12.2%) in the control group and this difference was similar across tertiles (p-interaction=0.44). Similar patters were observed for OAC initiation. In the first TSH tertile, participants in the ILR group were significantly less likely to experience the primary outcome (hazard ratio 0.52 [0.30–0.90]; p=0.019) or the combination of stroke, SE, or CV death (hazard ratio 0.54 [0.35–0.84]; p=0.006, respectively) compared to control, while there was no effect in participants with higher TSH (p-interaction 0.029 and 0.014, respectively) and there was no effect on all-cause death in any tertile. When TSH was modelled as a continuous variable, the effect of ILR screening gradually increased with decreasing TSH, with the upper bound of the confidence interval reaching HR<1 at TSH<1.2-1.5 mIU/L. Sensitivity analyses excluding participants with baseline TSH outside reference range (0.3-4.0 mIU/L) and/or treated with thyroid hormone replacement or antithyroid agents yielded similar results. Conclusion In persons with stroke risk factors and TSH <1.2-1.5 mIU/L, ILR screening for AF and anticoagulation upon detection led to significantly decreased stroke risk. There was no effect in persons with higher TSH, though the yield of screening was similar across levels. This suggests that low-normal TSH may indicate benefit from AF screening while higher levels may lead to overdiagnosis.TableFigure

The influence of calibration on bias in quality control and patient results for TSH on Vitros XT 7600 analyzer.

Thyroid-stimulating hormone (TSH) is a glycoprotein secreted by the anterior pituitary gland and is regulated by negative feedback from the serum free thyroid hormones. In this study we aimed to quantitate the relative bias caused by calibration drifting as seen in our TSH Levey-Jennings quality control (QC) charts and assess the magnitude of bias on patients' samples. In the period from October 2021 to August 2022 we looked at the QC results of ten 28-days' calibration time intervals and calculated relative bias compared to the mean. For each time interval the mean from three QC points before and after calibration was calculated. The average from 10 pre- and post-calibration means was calculated and the relative bias, pre- and post-calibration, was then calculated. We used 5 patient samples with low, normal and high TSH concentrations and calculated relative bias pre- and post-calibration. The allowed relative bias for TSH is ± 6.7%. At both QC levels, with the respective means of 5.14 mIU/L (coefficient of variation, CV% = 3.1%) and 27.80 mIU/L (CV% = 3.2%) had their respective relative bias - 8.2% and - 7.9%. The patient samples with low (0.586 mIU/L), normal (2.89 mIU/L and 5.19 mIU/L) and high (20.5 mIU/L and 39.8 mIU/L) TSH had - 4.1%, - 4.0%, - 3.5%, - 5.1% and - 4.1%, respectively. Even though the relative bias exceeded allowable criteria for the QC samples, this was not manifested on the patients' samples.

Understanding Hypothyroidism: Causes, Symptoms, Diagnosis, and Treatment Options for Optimal Thyroid Health

Hypothyroidism is a condition where your thyroid gland doesn’t produce enough thyroid hormone leading to symptoms like fatigue, weight gain, and feeling cold. Globally, the lack of iodine in the environment is the leading cause of hypothyroidism. However, in regions where there is enough iodine, Hashimoto’s thyroiditis, an autoimmune disorder is the most common cause. Risk factors include having a family history of thyroid disease, being over 6o years and being female. Diagnosis done with a simple blood test that measures the levels of serum free thyroxine (FT4) and thyroid-stimulating hormone (TSH). High TSH and FT4 levels usually indicate Hypothyroidism. Even daily medication with synthetic thyroid hormone (levothyroxine), regular follow up with your doctor is important to monitor your TSH level and adjust the dosage of medication as needed.

12611 The Thyroid Adapts Remarkably to Overnutrition to Mitigate Hypothyroidism

Abstract Disclosure: J. Rampy: None. A. Torres Manzo: None. K. Hoffsmith: None. M.A. Loberg: None. H. Wang: None. V.L. Weiss: None. N. Carrasco: None. Obesity affects >40% of the U.S. population and is one of today’s biggest public health concerns. Losing weight is challenging, and maintaining weight loss even more so, owing to the many biochemical and hormonal changes that occur in the pathogenesis of obesity, some of which do not reverse after weight loss. Thyroid hormones (THs) have far-reaching effects on whole-body energy balance. Their synthesis and release by the thyroid are finely regulated by central mechanisms to control serum TH levels. THs are also regulated by nutrient sensing, so that their levels modulate energy expenditure to match energy intake. Given the reciprocal and fine-tuned relationship between THs and energy balance, one would expect strong upregulation of TH levels to counteract diet-induced weight gain, but this is not consistently reported in obesity studies. Thus, we hypothesized that overnutrition impairs thyroid function, preventing a sustained increase in TH levels. We tested this hypothesis in male C57Bl/6J mice fed a high-fat diet and sucrose water. Strikingly, overnutrition decreased T4 levels after just 5 days—and within 3 weeks, we observed mild hypothyroidism, with increased thyroid stimulating hormone (TSH) levels and goiter. After 6 weeks, intrathyroidal T4 levels were significantly decreased, whereas the expression of the TH precursor thyroglobulin (TG) was unchanged, despite high TSH stimulation. Furthermore, we found increased expression of several ER stress-related proteins, including BiP, p-eIF2α, and PDI. These results suggest that TG was not upregulated because overnutrition-induced ER stress impaired protein translation. Remarkably, even though T4 levels were low, the thyroid maintained normal T3 levels, likely due to the pronounced histological and vascular changes we observed, which should promote TH availability. Some changes were consistent with the classical growth effects of TSH stimulation, while others were likely due to upregulation of adrenomedullin 2, a TSH-responsive angiogenic vasodilator. Preliminary studies in female mice showed similar results. Notably, we have observed similar histological changes in human thyroids, which strongly correlate with BMI. Collectively, our results, despite the unchanged T3 levels, are consistent with a struggling thyroid and a mildly hypothyroid state. Existing data suggest that low T4 can itself be problematic, particularly in metabolic tissues that generate T3, the more biologically active form, from T4 to levels beyond those of the T3 available from the bloodstream. Reversibility of this state is being investigated in ongoing experiments. The causal role that overnutrition plays in thyroid impairment and decreased TH availability in the pathogenesis of obesity has scarcely begun to be elucidated. Our work sheds new light on how overnutrition changes thyroid function and highlights the remarkable adaptability of the thyroid. Presentation: 6/1/2024

Prevalence of high neonatal thyroid stimulating hormone levels as an indicator of iodine deficiency in the province of La Pampa: An epidemiological analysis.

Introduction. Iodine plays a key role in human metabolism, growth, and development. During pregnancy and childhood, the demand for this micronutrient increases notably. Increased neonatal thyroid stimulating hormone (nTSH) levels, defined as nTSH ≥ 5 mIU/L, are a marker of iodine deficiency in a population if its prevalence is higher than 3%. Objective. To establish the prevalence of nTSH ≥ 5 in La Pampa in the 2021-2022 period, analyze its correlation with different variables, and compare it with data from a historical cohort. Population and methods. Cross-sectional, descriptive-analytical study in a population of newborn infants born in the 5 health regions of the province of La Pampa in 2021 and 2022. Results. Of the 5778 assessed newborn infants, 9.6% had nTSH levels ≥ 5 mIU/L. It was reported that 70.4% of these measurements were done after the third day of life. No significant differences were observed in the frequency of high nTSH levels by year of birth, birth weight, or days until sample collection. A higher prevalence was observed among male infants (10.6% versus 8.5%; p = 0.007) and term infants (9.8% versus 6.6%; p = 0.02). The prevalence of high TSH levels was superior to that observed in the 2001-2002 cohort. Conclusions. The prevalence of high nTSH levels in La Pampa during 2021 and 2022 was 9.6%, suggesting the presence of mild iodine deficiency in the population of this province, higher that what had been reported 2 decades ago.

Anemia among adult patients with diabetes attending King Abdulaziz University Hospital: A retrospective study.

The prevalence of anemia in adults with diabetes is of growing importance due to its impact on overall health and the management of diabetes-related complications. This study aimed to determine the prevalence of anemia among adult patients with diabetes at King Abdulaziz University Hospital in Jeddah, Saudi Arabia. A retrospective study was done on 1208 patients with diabetes >18 years who attended the study setting from 2010 to 2022. Data about patients' demographics, body mass index, glycated hemoglobin (HbA1c; %), hemoglobin (Hb), serum ferritin, iron, mean corpuscular Hb, mean corpuscular volume, free thyroxine and triiodothyronine (T3), and serum thyroid-stimulating hormone (TSH) were collected. Of patients, 86.6% had anemia with a prevalence of 30.2%, 47.6%, and 22.2% for mild, moderate, and severe anemias, respectively. The prevalence of anemia was significantly higher among females, those with high serum ferritin, normal serum iron or normal serum T3, lower mean HbA1c level (%), lower serum iron or T3, and higher serum ferritin or TSH. A significant positive correlation was found between Hb level and HbA1c level (%), serum iron, free T3, and body mass index. A significant negative correlation was found between Hb level and mean corpuscular volume, serum ferritin, and serum TSH. Being female, having high serum ferritin, lower mean free T3, and a high TSH were risk factors for anemia. The prevalence of severe anemia was significantly higher among patients with uncontrolled diabetes mellitus. A high prevalence of anemia was found among studied diabetics. Anemia screening should be included in the routine assessment of patients with diabetes. A multidisciplinary approach involving endocrinologists, hematologists, and dietitians is recommended to ensure holistic care and address all aspects of the patient's health. In addition, further research should be supported to better understand the mechanisms linking diabetes and anemia and to establish evidence-based guidelines for managing anemia in diabetics.

Frequency of seropositive celiac disease and hypothyroidism among children and adolescents with congenital heart disease: A case-control study

BackgroundThe prevalence of celiac disease (CD) and hypothyroidism exhibit significant variation in different studies among patients with congenital heart disease (CHD). This study evaluated the frequency of laboratory test abnormalities in children and adolescents with CHD in Shiraz, Iran.MethodsThis prospective case-control study was conducted on 223 children and adolescents with CHD and healthy individuals referred to the heart clinic affiliated with Shiraz University of Medical Sciences between February 2019 and December 2021. They were classified into case and control groups. Blood tests were performed for total IgA antibody, anti-tissue transglutaminase IgA antibody (anti-TTG Ab), T4, and thyroid stimulating hormone (TSH) and anti-thyroid peroxidase antibodies in serum, along with transthoracic echocardiography. Likewise, demographic characteristics of patients, including age, sex, weight, height, and body mass index (BMI), were recorded. Also, anti-TTG Ab levels were compared among CHD patients according to cyanosis status, gender, age (above and below five years), and BMI (under and over 18.5).ResultsNinety-eight CHD patients and 100 healthy individuals with an average age of 5.32 ± 4.05 years (1–18 years) were examined. In children with CHD, atrial septal defect (27%), ventricular septal defect (20%), and tetralogy of Fallot (13%) were the most prevalent disorders. Only one CHD patient had an anti-TTG Ab level of 16.6 unit/mL, considered borderline for seropositive CD diagnosis. There was no difference in anti-TTG Ab levels between age (above and below five years), BMI (under and over 18.5), cyanosis status, and gender groups. Seven CHD patients had high TSH levels, three had cyanotic CHD, and one had Down syndrome. The TSH levels and non-autoimmune hypothyroidism were significantly higher in CHD patients than in normal subjects (p < 0.05).ConclusionsAccording to the results of this study, the serum level of TSH and prevalence of non-autoimmune hypothyroidism were higher in patients with CHD than in normal subjects, but the serum level of anti-TTG Ab was not different between the two groups.

R243W Mutation in Thyroid Hormone Resistance Syndrome Beta

A three-year-old female with a history of recurrent tonsillitis was investigated for failure to thrive and global developmental delay. Clinically, she had a triangular face with low-set ears and intermittent tachycardia. She had growth failure with her weight under the third centile while her height was within normal limits. Other systemic examinations were unremarkable. The presence of an elevated free T4 (FT4) with an inappropriately high thyroid stimulating hormone (TSH) in this patient raised the clinical suspicion of Thyroid Hormone Resistance Syndrome. DNA sequencing confirmed the diagnosis, which showed R243W gene mutation in Thyroid Hormone Receptor-Beta1 (THRB1).

Prevalence and clinical correlates of abnormal lipid metabolism in older Chinese patients with first-episode drug-naïve major depressive disorder

BackgroundOlder major depressive disorder (MDD) patients have more complex clinical symptoms and higher abnormal lipid metabolism (ALM) rates. This study aimed to compare clinical differences between those with and without ALM in a sample of older first-episode drug naïve (FEDN) patients.MethodsWe recruited 266 older MDD patients. Socio-demographic variables, clinical data, and lipid parameters were obtained. The Hamilton Depression Rating Scale (HAMD), Hamilton Anxiety Rating Scale (HAMA), and the positive subscale of the Positive and Negative Syndrome Scale (PANSS-P) were conducted to evaluate patients’ depression, anxiety and psychotic symptoms, respectively.ResultsIn this study, we found that the prevalence of comorbid ALM was 86.1% in older MDD patients. Compared with the non-abnormal lipid metabolism (NALM) group, the ALM group had a higher duration of illness, higher clinical global impression of severity scale (CGI-S) and HAMD scores, higher thyroid stimulating hormone (TSH) and glucose levels. Logistic regression analysis indicated that duration of illness (OR = 1.11, P = 0.023, 95%CI = 1.015–1.216) and CGI-S score (OR = 2.28, P = 0.014, 95%CI = 1.18–4.39) were associated with ALM in older MDD patients.ConclusionThe importance of regular lipid assessment in older MDD patients needs to be taken into account.

Post-gastric sleeve gastrectomy mixed Wernicke's and Hashimoto's encephalopathies with brain atrophy: A case-report from Qatar

We present a case of a 21-year-old male patient who presented with progressive dizziness, gait instability, and ataxia of 1-week duration. Three months prior to presentation, the patient underwent Laparoscopic Sleeve Gastrectomy (LSG). His workup showed a very low level of thiamine, high thyroid-stimulating hormone (TSH) level, and very low free thyroxine (T4). The patient was diagnosed with Wernicke Encephalopathy (WE) post LSG, exacerbated by Hashimoto Encephalopathy (HE), given the history of an underlying uncontrolled Hashimoto's thyroiditis (HT).

Relation between Thyroid Function Tests and Body Mass Index among Thyroid Dysfunction Patients

Background: Obesity has the potential to impact thyroid function through various pathways, even in individuals considered euthyroid. The relationship between thyroid function and body mass index (BMI) remains a subject of ongoing debate. Therefore, the primary objective of this study was to ascertain the correlation existing among thyroid stimulating hormone (TSH), thyroid hormones, and BMI in patients experiencing thyroid dysfunction within the context of the Smart Health Tower. Methods: This cross-sectional study was conducted in Smart Health Tower in Sulaimani city from November 9, 2021, to March 1, 2022. One hundred and sixty-six patients with thyroid dysfunction (128 individuals had hypothyroidism, eight individuals had hyperthyroidism, and 30 individuals were the other type of thyroid dysfunction) were enrolled in this study. Their mean age was 43.62 ± 11.17 and 50.6% of the participation were male. Patients were divided into four groups based on BMI value: Underweight (BMI &lt;18.5 kg/m2), normal (BMI: 18.5–24.9 kg/m2), overweight (BMI: 25–29.9 kg/m2), and obese (BMI ≥30 kg/m2). Results: The highest rate of age group was between (30 and 40) years old (84%) of them were male. The participants with higher BMI had higher TSH and this trend continued from underweight to Obese. The mean TSH of the underweight group was 0.47 ± 0.61 mIU/L, the normal weight group 1.5 ± 1.91 mIU/L, the overweight group 2.8± 3.87 mIU/L and the obese group 2.7 ± 2.37 mIU/L. Conclusion: A significant relationship between serum TSH and BMI and mean TSH increased as BMI increased. Further large-scale data from the population are required to confirm these findings.

Peripartum Torpor: A Chilling Case Report and Review of the Literature

Purpose: To report a rare case of peripartum maternal hypothermia and bradycardia. Methods: Case report. Results: Torpor is a transient state of hibernation with hypothermia and bradycardia. Hypothermia is defined as an abnormally low core body temperature less than 36°C.1 Sinus bradycardia is defined as less than 60 beats/min. While occasionally hypothermia or bradycardia is seen in obstetric patients undergoing vaginal delivery, when combined together, it can be a rare, life-threatening state that requires prompt intervention to prevent adverse maternal and fetal outcomes. A 23 year-old G2P0102 at 33+3 weeks of gestation was admitted to the high risk obstetric service for preterm labor complicated by fetal growth restriction. She had a history of preeclampsia in a previous pregnancy, but otherwise denied any chronic medical problems. Upon arrival, her vital signs showed a temperature of 37°C, a pulse of 53 bpm, and blood pressure of 126/62 mmHg. Her white blood cell count was 12.4 x 109/L and hemoglobin was 11.3 g/dL. She received betamethasone for fetal lung maturity and penicillin for Group B streptococcus prophylaxis. As her cervix continued to dilate, she received an epidural for pain management. Once she was in active labor, she became bradycardic with a pulse in the 30s-40s bpm, as confirmed by EKG. She was completely asymptomatic at this time, and fetal heart tones were reassuring with a baseline between 110’s-130’s bpm. She delivered vaginally with 150 mL of estimated blood loss, and her bradycardia continued postpartum even after the epidural was discontinued. When she complained of feeling cold, multiple attempts with different oral and axillary thermometers could not obtain a reading. She was warmed with forced-air warming blankets, warmed blankets, and hot packs in her groin and axilla. During this time, discussion with the NICU staff revealed that her baby was also hypothermic at 33.3°C and hypoglycemic at 28 mg/dL at birth. Other than feeling cold, the patient continued to be asymptomatic despite hypotension and bradycardia. She appeared somnolent but was responsive to questions. Her uterus was firm with minimal vaginal bleeding and no purulent or foul-smelling vaginal discharge. Repeat laboratory testing revealed a white blood count of 19 x 109/L and lactate was 3.3 mmol/L. Her comprehensive metabolic panel was unremarkable. A chest x-ray was clear. A C-reactive protein was &lt; 0.3 mg/dL and sedimentation rate was 14 mm/h. A rectal continuous thermometer was placed, which eventually recorded a temperature at 33.3°C and upon recheck was 31.7°C. A multidisciplinary team, including Anesthesia, Internal Medicine, and Neurology, evaluated the patient due to concern for a central nervous system insult. She received fluid resuscitation and broad-spectrum antibiotics for sepsis protocol. Due to the concern for potential septic shock, the decision was made to transport her to the Medical ICU for further management. As she was leaving Labor &amp; Delivery, her temperature had increased to 36.9°C and her pulse to 61. Thyroid studies the next day revealed a normal Free T4 of 1.00 ng/dL and a high thyroid stimulating hormone level of 9.55 uIU/mL. However, despite an extensive workup, no clear etiology of her hypothermia and bradycardia was identified. Intervention with fluids and application of forced-air warming system resolved the hypothermia in less than 6 hours without relapse. Antibiotics were discontinued after one day due to low suspicion for systemic infection. She remained vitally stable and was discharged on postpartum day 2 without further complications. Conclusions: Maternal hypothermia is relatively common during cesarean delivery; however, very few cases report maternal hypothermia during vaginal delivery. An English language literature search for maternal hypothermia during vaginal delivery yielded less than 10 case reports – few of which identified a cause of the hypothermia – and none of which reported simultaneous maternal bradycardia. While our case is a very rare presentation and the etiology is still unknown, it highlights the importance of prompt recognition of vital sign derangements in peripartum patients as well as multidisciplinary attention.

Maternal thyroid function and offspring birth anthropometrics in women with polycystic ovary syndrome.

Polycystic ovary syndrome (PCOS) and thyroid disorders have both been linked to adverse pregnancy and neonatal outcomes. Even small variations in thyroid function within the normal range may influence fetal growth. Our aim was to investigate whether maternal thyroid function is associated with newborn anthropometrics in PCOS and explore the potential modifying effect of metformin. Post-hoc analyses of two RCTs in which pregnant women with PCOS were randomized to metformin or placebo, from first trimester to delivery. Maternal serum levels of thyroid stimulating hormone (TSH) and free thyroxine (fT4) were measured at gestational weeks (gw) 5-12, 19, 32 and 36 in 309 singleton pregnancies. The mean z-scores of birthweight, birth length, and head circumference were estimated in the offspring. Associations of maternal thyroid parameters with offspring anthropometrics and the outcomes large for gestational age (LGA) and small for gestational age (SGA) were studied using linear and logistic regression models, with adjustment for body mass index (BMI) when relevant. Maternal fT4 at baseline was negatively associated with birth length (b= -0.09, p=0.048). Furthermore, ΔfT4 during pregnancy correlated positively to z-score of both birth weight and length (b=0.10, p=0.017 and b=0.10, p=0.047 respectively), independently of treatment group. TSH at baseline and gw19 was inversely associated with LGA (OR 0.47, p=0.012 and OR 0.58, p=0.042), while ΔTSH was positively associated with LGA (OR 1.99, p=0.023). There were inverse associations between TSH at baseline and SGA (OR 0.32, p=0.005) and between ΔfT4 and SGA (OR 0.59, p=0.005) in the metformin group only. There were no associations between maternal thyroid function and head circumference of the newborns. In women with PCOS, a higher maternal fT4 in early pregnancy and a greater decrease in fT4 during pregnancy was associated with a lower offspring birthweight and shorter birth length. Higher TSH by mid-gestation and smaller increase in TSH during pregnancy was associated with less risk of LGA. Subclinical variations in maternal thyroid function might play a role for birth anthropometrics of PCOS offspring.

#742 High TSH and low FT3 levels are associated with chronic kidney disease in three population-based studies from Germany

Abstract Background and Aims 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. The aim of our study was to investigate associations of serum levels of TSH, fT3 and fT4 with eGFR and albuminuria in population-based cohorts. Method We used cross-sectional data from 7,933 individuals aged 20 to 93 years of the Berlin Aging Study II (BASE II) and the Study of Health in Pomerania (SHIP-START; SHIP-TREND) to associate serum TSH, fT3, and fT4 levels with eGFR and albuminuria. To calculate eGFR, CKD-EPI and FAS equations were used. Albuminuria was defined as an urinary albumin-to-creatinine ratio (UACR) ≥ 30 mg/g. Results 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 with 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. Conclusion In conclusion, we showed that high TSH, low fT3 as well as low and high fT4 levels were independently associated with a reduced kidney function in a non-linear fashion. Our results indicate that high TSH / 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.

Associations between short-term exposure to air pollution and thyroid function in a representative sample of the Korean population

BackgroundDisruption of thyroid function can profoundly affect various organ systems. However, studies on the association between air pollution and thyroid function are relatively scarce and most studies have focused on the long-term effects of air pollution among pregnant women. ObjectivesThis study aimed to explore the associations between short-term exposure to air pollution and thyroid function in the general population. MethodsData from the Korea National Health and Nutrition Examination Survey (2013–2015) were analyzed (n = 5,626). Air pollution concentrations in residential addresses were estimated using Community Multiscale Air Quality models. The moving averages of air pollution over 7 days were set as exposure variables through exploratory analyses. Linear regression and quantile g-computation models were constructed to assess the effects of individual air pollutants and air pollution mixture, respectively. ResultsA 10-ppb increase in NO2 (18.8-μg/m3 increase) and CO (11.5-μg/m3 increase) was associated with 2.43% [95% confidence interval (CI): 0.42, 4.48] and 0.19% (95% CI: 0.01, 0.36) higher thyroid-stimulating hormone (TSH) levels, respectively. A 10-μg/m3 increase in PM2.5 and a 10-ppb increase in O3 (19.6-μg/m3 increment) were associated with 0.87% (95% CI: 1.47, −0.27) and 0.59% (95% CI: 1.18, −0.001) lower free thyroxine (fT4) levels, respectively. A simultaneous quartile increase in PM2.5, NO2, O3, and CO levels was associated with lower fT4 but not TSH levels. ConclusionsAs the subtle changes in thyroid function can affect various organ systems, the present results may have substantial public health implications despite the relatively modest effect sizes. Because this was a cross-sectional study, it is necessary to conduct further experimental or repeated-measures studies to consolidate the current results.

Pituitary Hyperplasia and Overt Hypothyroidism Induced by Methimazole in an Adolescent Girl with Resistance to Thyroid Hormone Accompanying Hashimoto’s Thyroiditis: A Case Report

We describe a 13-year-old girl who presented at her local hospital with a diffuse goiter and had discrepant thyroid function test (TFT) of elevated free T4 (FT4), free T3 (FT3) levels with mildly elevated thyroid-stimulating hormone (TSH) and a pituitary magnetic resonance imaging (MRI) report of a pituitary hyperplasia. She was referred to our hospital where a repeat TFT found low FT4 and high TSH levels, and high levels of antithyroid peroxidase (anti-TPO) and anti-thyroglobulin (anti-TG) antibodies, leading to the diagnosis of Hashimoto’s thyroiditis (HT) with overt primary hypothyroidism. The girl had a good response after daily 100 µg levothyroxine treatment for 8 months with decreased goiter size along with disappearance of the pituitary mass. However, her FT4 and FT3 levels were elevated while the TSH was in the high normal range, although at this time there were no signs of hyperthyroidism. A genetic study confirmed our provisional diagnosis that the patient had a p.Pro453Thr monoallelic loss-of-function mutation of the thyroid hormone receptor beta (THRB) gene, suggesting the diagnosis of coexisting resistance to thyroid hormone-β (RTHβ) and HT in this patient.

Thyroid paradox in older age

BACKGROUND: The thyroid gland plays an important role in our body, influencing almost all metabolic processes in the body throughout life. However, literature data on the effect of decreased thyroid function on mortality in older people is contradictory.&#x0D; AIM: To evaluate the impact of thyroid-stimulating hormone levels on 5-year survival in older adults.&#x0D; MATERIALS AND METHODS: This work was carried out on the basis of the second screening of the Crystal study of community-dwelling individuals 65+ (n = 383). Main study parameters: thyroid-stimulating hormone level, blood test, lipid profile, albumin, total protein, comprehensive geriatric assessment, 5 years of follow-up.&#x0D; RESULTS: A thyroid-stimulating hormone level of 3.3–10.0 mIU/L was associated with a 44.6% reduced risk of all-cause mortality (hazard ratio 0.554; 95% confidence interval 0.307–0.999) at 5 years of follow-up, regardless of the presence of non-communicable diseases and geriatric status. A thyroid-stimulating hormone level more 10.0 mIU/L is not associated with an increased risk of mortality. The lower risk of mortality in patients with high thyroid-stimulating hormone levels may be due to a larger thigh muscle circumference. After adjustment for all covariates used and thyroid-stimulating hormone level, a 1 cm increase in thigh muscle circumference was associated with a 4.5% reduction in the risk of all-cause mortality (hazard ratio 0.955; 95% confidence interval 0.932–0.979).&#x0D; CONCLUSIONS: The lowest risk of all cause-mortality mortality in persons aged 65 years and older is observed with a thyroid-stimulating hormone level of 3.3–10.0 mIU/L. Thyroid-stimulating hormone level more 10.0 mIU/L is not associated with an increased risk of all cause-mortality.

Relationship between autoimmune thyroid antibodies and anti-nuclear antibodies in general patients.

There is no doubt that both Hashimoto thyroiditis and Graves' disease are autoimmune thyroid diseases (AITDs), but the relationship between anti-nuclear antibody (ANA) and AITDs is poorly studied. The association between thyroid autoantibody levels and ANA positivity was evaluated to assess the role of ANA in AITDs. We conducted an analysis using data from 1,149,893 patients registered at our hospital and 53,021 patients registered in the National Health and Nutrition Examination Survey databases. We focused on patients with data for thyroid peroxidase antibody (TPOAb)/ANA, TPOAb/immunoglobulin G (IgG), thyroid-stimulating hormone (TSH) receptor antibody (TRAb)/ANA, TRAb/IgG, TSH/ANA, or TSH/IgG. ANA positivity rates were 12.88% and 21.22% in TPOAb/ANA and TSH/ANA patients, respectively. In TPOAb/IgG and TSH/IgG data, high IgG levels (≥15 g/L) were detected in 2.23% and 4.06% of patients, respectively. There were significant differences in ANA positivity rates and high IgG proportions among patients with different TPOAb and TSH levels. TPOAb level was correlated with ANA positivity rate and high IgG proportion, and TSH level was correlated with ANA positivity rate. Regression analysis showed positive correlations between TPOAb levels and ANA positivity risk or high IgG risk, TSH levels and high IgG risk, and elevated TSH and ANA positivity risk. Of patients with TRAb/ANA data, 35.99% were ANA-positive, and 13.93% had TRAb levels ≥1.75IU/L; 18.96% of patients with TRAb/IgG data had high IgG levels, and 16.51% had TRAb levels ≥1.75IU/L. ANA positivity rate and high IgG proportion were not significantly different among different TRAb levels. TRAb levels, ANA positivity risk and high IgG risk were not correlated. ANA positivity and high IgG are related to Hashimoto thyroiditis but not Graves' disease, which implies distinct pathophysiological mechanisms underlying the AITDs.

Factors affecting need for hormone replacement after thyroid lobectomy

Aims: The aim of this study is to determine the incidence and risk factors of postoperative hormone replacement in patients who underwent thyroid lobectomy.&#x0D; Methods: Patients who underwent thyroid lobectomy in our clinic between January 2015 and January 2021 were retrospectively scanned. Age, gender, preoperative hemogram and thyroid function tests (TFT) were screened. During postoperative follow-up, current TFT, height, weight, thyroid hormone replacement status and hypothyroidism symptoms were questioned. Pathology reports were examined.&#x0D; Results: The pathology (patological examination results of specimen of the patients) were nodular hyperplasia in 81.1% (n=30) and Papillary thyroid carcinoma (PTC) in 18.9% (n=7). While the need for hormone replacement developed in 37.8% (n=14) of the patients in the postoperative follow-up, it did not develop in 62.2% (n=23). It was determined that high preoperative thyroid stimulating hormone (TSH) significantly increased the need for postoperative hormone replacement (p

The Association Between Thyroid Hormones and Renal Function in Euthyroid Chinese Individuals: A Population-Based Cross-Sectional Study.

Objective This population-based cross-sectional study aimed to investigate the association between thyroid hormones and renal function in euthyroid Chinese individuals, as the relationship between thyroid hormones and renal function in this population remains unclear. Methods A total of 661 participants were included in the study after excluding individuals with thyroid diseases, incomplete clinical measurements, or those taking medications affecting thyroid function. Participants were categorized into three groups based on serum thyroid hormone and antibody levels. The study adjusted for covariates and assessed the glomerular filtration rate (GFR) and urine albumin-to-creatinine ratio (ACR) in relation to thyroid hormone levels. Results After adjusting for covariates, the study found a significant increase in GFR in the middle and highest tertiles of free triiodothyronine (FT3) and the highest tertile of total triiodothyronine (TT3). Serum FT3 and TT3 levels were significantly associated with GFR. Additionally, the study observed a significantly lower GFR in the highest tertile of thyroid-stimulating hormone (TSH) compared to the lowest tertile. However, thyroid hormone and antibody levels were not associated with the ACR. Furthermore, the highest tertiles of TT3 and total thyroxine (TT4) were associated with a decreased risk of chronic kidney disease (CKD). Conclusion In our study among euthyroid Chinese individuals, we observed a significant association between thyroid functionand GFR. Specifically, lower FT3, TT3, and higher TSH were associated with reduced GFR, indicating a potential role for thyroid hormones in maintaining renal function. Furthermore, lower levels of TT3and TT4were associated with an increased risk of CKD. These findings suggest a direct link between thyroid and renal function, even in euthyroid individuals, emphasizing the need for further investigation to elucidate the underlying mechanisms and potential therapeutic implications.