Clinical practice guidelines for hypothyroidism in adults: cosponsored by the American Association of Clinical Endocrinologists and the American Thyroid Association

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

Introduction

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.

Materials and methods

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%.

Results

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.

Conclusion

Even though the relative bias exceeded allowable criteria for the QC samples, this was not manifested on the patients' samples.

Refractory hypothyroidism in children: an overview

Refractory hypothyroidism (RF) defined as raised serum levels of thyroid stimulating hormone (TSH) above upper limit of the reference range with or without the persistence of hypothyroid symptoms following a 6-week interval after the dosage was last increased to upper limits of dose per age. The most common cause of RH is inadequate compliance. In addition, diet, concomitant medication interactions, and gastrointestinal diseases can all result in l-thyroxine (LT4) malabsorption, which can cause RH. Moreover, weight gain, switching brands of LT4, poor storage of LT4, chronic liver disorders, cystic fibrosis, nephrotic syndrome, consumptive hypothyroidism, Addison's disease are significant contributors to RF in children. RH in children is frequently asymptomatic, when symptoms do occur, they are typically minor and resemble those of hypothyroidism. It is essential to identify RH early and treat its underlying cause in order to avoid overusing LT4, which can lead to cardiac and bone problems. Endocrinologists should handle children who they suspect of having RH methodically after making sure there is enough compliance. Searching for undiagnosed illnesses and/or other factors that can affect LT4 absorption could be part of this. We present this review after an extensive literature search and long-standing clinical experience. This review's objective is to shed light on the causes, clinical manifestations, investigations, and treatment of RH in children.

Efficacy of Thyroid Hormone Replacement Therapy in Nasopharyngeal Carcinoma Patients with Radiation-Induced Subclinical Hypothyroidism

AIMS

Hypothyroidism is a common side effect of radiotherapy for nasopharyngeal carcinoma. However, the impact of thyroid hormone replacement therapy on patients with radiation-induced subclinical hypothyroidism has not been extensively explored. This study aimed to analyze the efficacy of thyroid hormone replacement therapy in nasopharyngeal carcinoma patients with subclinical hypothyroidism.

METHODS

Patients diagnosed with nasopharyngeal carcinoma who developed subclinical hypothyroidism after definitive radiotherapy between September 2019 and December 2020 were selected for inclusion in this study. Prior to thyroid hormone replacement therapy and after maintaining euthyroidism for 6-12 months through thyroid hormone replacement therapy, assessments using the SF36 Brief Health Status Scale and the Hypothyroidism-related Symptom Questionnaire were conducted via trained questionnaires. Lipid profiles were assessed at baseline and after 6-12 months of thyroid hormone replacement therapy. Statistical analyses were performed using matched samples T-test or Mann-Whitney U test.

RESULTS

The median follow-up period was 14.5 months. The median score of hypothyroid symptoms was 5.5 out of 19 points, with the most common symptoms being chills (65.0%), fatigue (50.0%), weight gain (45.0%), and limb numbness (40.0%). Thyroid hormone replacement therapy did not significantly improve the quality of life, hypothyroidism-related symptoms, or blood lipid profile in patients. However, there was an observed downward trend in serum cholesterol levels following treatment (P=0.052).

CONCLUSION

Thyroid hormone replacement therapy did not have a significant impact on alleviating hypothyroid symptoms, improving quality of life, or enhancing lipid profiles in patients with radiation-induced subclinical hypothyroidism. Nevertheless, a potential decrease in serum cholesterol levels was noted after thyroid hormone replacement therapy.

Influence of a Novel Morphology-Driven Classification on Limb Salvage after Isolated Tibial Intervention for Chronic Limb Threatening Ischemia

BACKGROUND

Infra-popliteal interventions for chronic limb-threatening ischemia (CLTI) can be impacted by the morphology of the tibial vessels. The aim of this study was to examine the impact of a novel morphology-driven classification on the outcomes of isolated tibial intervention for CLTI.

METHODS

A database of patients undergoing isolated tibial interventions for CLTI at a single center between 2010 and 2020 was retrospectively queried. Patients with isolated infra-popliteal disease were identified, and their anatomy was scored as present or absent for lesion calcification (1 point), target vessel diameter<3.0 mm (1 point), lesion length>300 mm (1 point), and poor pedal runoff score (1 point). Patients were then divided into 3 groups: low risk (0 or 1 points), moderate risk (2 points), and high risk (3 or 4 points). Intention to treat analysis by the patient was performed. Limb-based patency (the absence of reintervention, occlusion, critical stenosis [>70%], or hemodynamic compromise with ongoing symptoms of CLTI as it related to the patency of the preoperatively determined target artery pathway) was assessed. Patient-oriented outcomes of amputation-free survival (AFS; survival without major amputation) and freedom from major adverse limb events (MALE; above ankle amputation of the index limb or major reintervention: new bypass graft, jump/interposition graft revision) were evaluated.

RESULTS

1,607 patients (55% male, average age 60 years, 3,846 vessels) underwent tibial intervention for CLTI. The majority of the patients were diabetic and of Hispanic origin. Morphologically, 27%, 31%, and 42% of the vessels were categorized as low risk, moderate risk, and high risk, respectively. There was a significant worsening of the infra-popliteal Global Limb Anatomic Staging System (GLASS) grading as the morphological risk increased. The 30-day major adverse cardiac events (MACE) were equivalent across the groups and were under the stated objective performance goal (OPG) of ≤10%. In contrast, both the 30-day MALE and the 30-day major amputations were significantly different across the groups, with the low-risk group remaining under the OPG of ≤9% and ≤4%, respectively, while the moderate risk and high risk exceeded the goal threshold. For the OPG, freedom from MALE was 60 ± 5%, 46 ± 5%, and 22 ± 9% at 5 years for low-, moderate-, and high-risk groups, respectively (mean ± standard error of the mean; P = 0.008). Overall AFS was 55 ± 5%, 37 ± 6%, and 18 ± 7% at 5 years for low-, moderate-, and high-risk groups, respectively (mean ± standard error of the mean; P = 0.003).

CONCLUSIONS

Tibial anatomic morphology impacts isolated tibial endovascular intervention with adverse morphology associated with poorer short- and long-term outcomes. Risk stratification based on anatomic predictors should be an additional consideration as one intervenes on infra-popliteal vessels for CLTI.

Evaluation of the etiology of subclinical hypothyroidism in children

OBJECTIVES

Subclinical hypothyroidism (SH) is defined by normal free triiodothyronine (fT3) and free thyroxine (fT4) levels, elevated thyroid-stimulating hormone levels, and the absence of overt clinical signs of hypothyroidism. The natural course of SH is influenced by the underlying etiology. The purpose of this study was to evaluate the etiologic causes of SH.

METHODS

A total of 135 patients aged 1-18 years, diagnosed with SH by at least two analytical measurements, were included in the study. The anthropometric measurements, demographic characteristics, and laboratory findings of the patients were determined. A comparison was conducted between patients with Hashimoto's thyroiditis and patients with non-autoimmune etiology.

RESULTS

The median age was 9.7 (6.5) years, and 82 of the 135 patients were female. The most prevalent etiology was idiopathic, affecting 39 (28.9 %) patients. This was followed by obesity, which was identified in 21 (15.6 %) patients. Hashimoto's thyroiditis was the third most common cause, accounting for 18 (13.3 %) patients. In patients with Hashimoto's disease, fT4 levels were significantly lower, and the rate of initiation of LT4 treatment was higher than in patients with other etiologies. A heterozygous variation in the TSH receptor (TSHR) gene was detected in six patients.

CONCLUSIONS

In our study, idiopathic cases were the most frequently identified in the etiology of SH. It is important to determine whether there is autoimmune thyroiditis. In cases of idiopathic SH, it is recommended to perform TSHR gene analysis, particularly in the presence of positive family history and newborn screening results. This approach will help elucidate the underlying etiology.

Levothyroxine Treatment of Subclinical Hypothyroidism and the Risk of Adverse Cardiovascular Events

Importance: There is uncertainty as to whether treatment of subclinical hypothyroidism (SCH) is associated with cardiovascular outcomes. Objectives: To determine whether levothyroxine replacement therapy decreases the risk of major adverse cardiovascular events (MACE) among individuals with SCH defined as having a thyrotropin (TSH) level between 5 and 10 mU/L. Design: We conducted a population-based cohort study using a prevalent new-user design. Setting: The study utilized data from the United Kingdom Clinical Practice Research Datalink. Participants: We identified a base cohort of individuals aged ≥18 years with incident SCH defined as having at least two TSH levels between 5 and 10 mU/L within one year between 1998 and 2018. We matched 76,946 levothyroxine treated to 76,946 untreated individuals based on age, sex, calendar time, duration of SCH, and time-conditional propensity score. We compared individuals with SCH treated with levothyroxine with individuals with no treatment. Exposure: Levothyroxine treatment versus no treatment. Main Outcome Measures: The primary outcome, MACE, was defined as a composite of nonfatal myocardial infarction, nonfatal ischemic stroke, and cardiovascular-related mortality. Results: The mean age of the study cohort was 62.8 years, and 76.5% were women. During a median follow-up time of 1.6 years (interquartile range: 0.5-4.2), the incidence rate for MACE among individuals treated with levothyroxine was 12.8 per 1000 person-years; confidence interval (CI): 12.2-13.3 and 13.9 per 1000 person-years; CI: 13.4-14.3 among nontreated individuals. Levothyroxine treatment was associated with a small decreased risk of MACE (hazard ratio: 0.88; CI: 0.83-0.93). Conclusions: Levothyroxine treatment of SCH was associated with a small decreased risk of MACE. However, given the observational nature of the study, residual confounding should be considered in the interpretation of this finding.

An Evaluation of the Efficacy of Machine Learning in Predicting Thyrotoxicosis and Hypothyroidism: A Comparative Assessment of Biochemical Test Parameters Used in Different Health Checkups

Objective This study assessed the efficacy of machine learning in predicting thyrotoxicosis and hypothyroidism [thyroid-stimulating hormone >10.0 mIU/L] by leveraging age and sex as variables and integrating biochemical test parameters used by the Japan Society of Health Evaluation and Promotion (JHEP) and the Japan Society of Ningen Dock (JND). Methods Our study included 20,653 untreated patients with Graves' disease, 3,435 untreated patients with painless thyroiditis, 4,266 healthy individuals, and 18,937 untreated patients with Hashimoto's thyroiditis. Machine learning was conducted using Prediction One on three distinct datasets: the Ito dataset (age, sex, and 30 blood tests and biochemical test data), the JHEP dataset (age, sex, and total protein,total bilirubin, aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transpeptidase (γGTP), alkaline phosphatase, creatinine (CRE), uric acid (UA), and T-Cho test data), and the JND dataset (age, sex, and AST, ALT, γGTP, CRE, and UA test data). Results The results for distinguishing thyrotoxicosis patients from the healthy control group showed that the JHEP dataset yielded substantial discriminative capacity with an area under the curve (AUC) of 0.966, sensitivity of 92.2%, specificity of 89.1%, and accuracy of 91.7%. The JND dataset displayed similar robustness, with an AUC of 0.948, sensitivity of 92.0%, specificity of 81.3%, and accuracy of 90.4%. Differentiating hypothyroid patients from the healthy control group yielded similarly robust performances, with the JHEP dataset yielding AUC, sensitivity, specificity, and accuracy values of 0.864, 84.2%, 72.1%, and 77.4%, respectively, and the JND dataset yielding values of 0.840, 83.2%, 67.2%, and 74.3%, respectively. Conclusion Machine learning is a potent screening tool for thyrotoxicosis and hypothyroidism.

Common Non-Rheumatic Medical Conditions Mimicking Fibromyalgia: A Simple Framework for Differential Diagnosis

Fibromyalgia (FM) is a chronic non-inflammatory disorder mainly characterized by widespread musculoskeletal pain, fatigue, sleep disturbances, and a constellation of other symptoms. For this reason, delineating a clear distinction between pure FM and FM-like picture attributable to other common diseases can be extremely challenging. Physicians must identify the most significant confounders in individual patients and implement an appropriate diagnostic workflow, carefully choosing a minimal (but sufficient) set of tests to be used for identifying the most plausible diseases in the specific case. This article discusses prevalent non-rheumatological conditions commonly observed in the general population that can manifest with clinical features similar to primary FM. Given their frequent inclusion in the differential diagnosis of FM patients, the focus will be on elucidating the distinctive clinical characteristics of each condition. Additionally, the most cost-effective and efficient diagnostic methodologies for accurately discerning these conditions will be examined.

Hypothyroid-Induced Rhabdomyolysis: A Case Report

Patients frequently present to the emergency department (ED) with non-specific complaints such as body aches and generalized weakness, which can have an extensive differential diagnosis. Hypothyroidism and rhabdomyolysis are known causes of generalized weakness and body aches but are usually considered separate entities.  In this article, we describe a patient who presented to the ED with symptoms including generalized weakness and muscle aches and was diagnosed with rhabdomyolysis. She presented days later with ongoing, worsening symptoms and was diagnosed with hypothyroid-induced rhabdomyolysis and acute kidney injury.  Patients who present with non-specific complaints may have delayed diagnoses that can lead to progression of their disease. Patients with hypothyroidism can develop non-traumatic rhabdomyolysis which can later lead to acute kidney injury. This case illustrates the importance of keeping a wide differential when evaluating patients with generalized complaints and recognizing hypothyroidism as a potential cause of rhabdomyolysis.

Management of depth to achieve timely arteriovenous fistula utilization

OBJECTIVE

Failure to achieve timely arteriovenous fistulae (AVFs) utilization due to excessive depth (>6 mm) remains an ongoing concern for dialysis access. This study evaluates the outcomes of radiocephalic (RCF) and brachiocephalic (BCF) fistula elevation required for access utilization.

METHODS

A retrospective review of all patients undergoing first-time autologous access over 10 years was undertaken. RCF and BCF were analyzed, and cases of initial access failure due to depth alone were selected for study. Primary and staged brachio-basilic AVF were excluded. Outcomes of early thrombosis, line placement, maturation (successful progression to hemodialysis [HD), reintervention, and functional dialysis (continuous HD for 3 consecutive months) were examined.

RESULTS

From January 2012 to December 2022, 1733 patients (67% female; mean age, 61 ± 14 years) underwent autologous AVF placement. Of these, 298 patients (17%) had depth-related AVF access issues (BCF, 71% and RCF, 29%). Nineteen percent of these AVFs underwent a primary balloon-assisted maturation (BAM), and 2% had side branch coil embolization before consideration for elevation. The average time to intervention for depth was 11 ± 4 weeks after primary creation. During elevation, side branch ligation occurred in 38% of cases, and 15% underwent intraoperative BAM, The pre-elevation depth was 8.2 ± 3.1 mm, and the mean post-elevation depth was 4.7 ± 2.9 mm (P = .002). Early thrombosis (<18 days) occurred in 4% of cases. There was no mortality, and the 30-day major adverse cardiac event rate was 2%, with a 30-day morbidity of 5%, which was driven by wound issues. Six percent of the AVFs underwent follow-up BAM within 3 months. Mean maturation of the AVFs was 74% ± 3% vs 72% ± 3% (P = .58) for the elevation vs no-elevation groups at 24 weeks, respectively. However, there was an increase in tunneled central line placement in pre-emptive fistula patients due to the delay in maturation (elevation, 17% vs no-elevation, 8%; P = .008). There was a mean successful access time of 6 ± 3 weeks after elevation (16 ± 4 weeks after access creation). There was a median of 2.4 secondary interventions per year after elevation compared with a median of 2.7 secondary interventions per year without elevation. Mean access functionality was 68% ± 8% vs 75% ± 8% at 3 years for the elevation vs no-elevation groups, respectively (P = .25).

CONCLUSIONS

Elevation of deep BCF and RCF occurs late after placement but can be successfully achieved with low morbidity and satisfactory long-term functionality. It results in an increase in tunneled central line placement in pre-emptive fistula patients. Elevation is a valuable adjunct to AVF maturation and enhances an autologous access policy.

Hypothyroidism after hemithyroidectomy: a systematic review and meta-analysis

BACKGROUND

The incidence of hypothyroidism following hemithyroidectomy and risk factors associated with its occurrence are not completely understood. This systematic review investigated the incidence and risk factors for hypothyroidism, thyroxine supplementation following hemithyroidectomy as well as the course of post-operative hypothyroidism, including the time to hypothyroidism and incidence of transient hypothyroidism.

METHODS

Searches were conducted in MEDLINE, EMBASE, Scopus, and Cochrane library for studies reporting the incidence of hypothyroidism or thyroxine supplementation following hemithyroidectomy.

RESULTS

Sixty-six studies were eligible for inclusion: 36 reported risk factors, and 27 reported post-operative course of hypothyroidism. Median follow-up was 25.2 months. The pooled incidence of hypothyroidism was 29% (95% CI, 25-34%; P<0.001). Transient hypothyroidism occurred in 34% of patients (95% CI, 21-47%; P<0.001). The pooled incidence of thyroxine supplementation was 23% (95% CI, 19-27%; P<0.001), overt hypothyroidism 4% (95% CI, 2-6%, P<0.001). Risk factors for development of hypothyroidism included pre-operative thyroid stimulating hormone (TSH) (WMD, 0.87; 95% CI, 0.75-0.98; P<0.001), TSH ≥ 2 mIU/L (RR, 2.87; 95% CI, 2.43-3.40; P<0.001), female sex (RR, 1.19; 95% CI, 1.08-1.32; P=0.007), age (WMD, 2.29; 95% CI, 1.20-3.38; P<0.001), right sided hemithyroidectomy (RR, 1.35; 95% CI, 1.10-1.65, P=0.003), the presence of autoantibodies anti-TPO (RR, 1.92; 95% CI, 1.49-2.48; P<0.001), anti-Tg (RR, 1.53; 95% CI, 1.40-1.88; P<0.001), and Hashimoto's thyroiditis (RR, 2.05; 95% CI, 1.57-2.68; P=0.001).

CONCLUSION

A significant number of patients will develop hypothyroidism or require thyroxine following hemithyroidectomy. An awareness of patient risk factors and postoperative thyroid function course will assist in counselling patients on their risk profile and guiding management.

Very low serum IGF-1 levels are associated with vertebral fractures in adult males with beta-thalassemia major

PURPOSE

Patients with beta-thalassemia major (BTM) often develop several endocrine disorders due to chronic iron overload. They are also prone to osteoporosis and vertebral fractures. Plasmatic insulin-like growth factor-1 (IGF-1) levels are often low in subjects with BTM, which origin is multifactorial. The aim of this study was to evaluate a possible relationship between serum IGF-1 levels and the presence of osteoporosis and/or vertebral fractures.

METHODS

We retrospectively evaluated the occurrence of vertebral fractures in 30 adult male patients affected by BTM (mean age 43.3 ± 7.9 years) with low serum IGF-1 (median value 52.4 ng/ml, 38.5-83.4). Only 6 of them (20.0%) were diagnosed with GH deficiency (GHD) after GHRH/arginine stimulation test, while 23 (76.7%) had osteoporosis and 12 (40.0%) had known vertebral fractures. All patients except one also showed at least one endocrine disorder.

RESULTS

Serum IGF-1 was significantly lower in BTM patients with vertebral fractures compared to patients without vertebral fractures (U = 41.0, p = 0.005) while it was not significantly different between patients with low bone mass compared to patients without low bone mass. The diagnosis of GHD was significantly associated with lower serum IGF-1 (p = 0.001) and vertebral fractures (p = 0.002) but not with low bone mass. After ROC analysis, we found that very low IGF-1 (≤ 50.0 ng/dl) was associated with vertebral fractures (sensitivity 83.3%, specificity 75.0%) and was also predictive of GHD (sensitivity 75.0%, specificity 100.0%).

CONCLUSION

Our study shows that, in male patients with BTM, serum IGF-1 ≤ 50.0 ng/dl is a marker of vertebral fractures and it is predictive of a diagnosis of GHD.

Effect of Levothyroxine Therapy on the Lipid Profile of Patients With Hypothyroidism: A Systematic Review

Hypothyroidism, also known as underactive thyroid, is a condition where the thyroid gland does not produce enough thyroid hormone. Deficiency or lack of thyroid hormone causes patients to have a slower metabolism, which may lead to secondary medical issues such as weight gain, fatigue, depression, and increased cardiovascular risk. This systematic review aims to explore the effect of levothyroxine therapy on the lipid profile of hypothyroid patients. Through a comprehensive search, 3096 articles were retrieved using keywords such as Hypothyroidism, Levothyroxine, Lipid, Dyslipidemia, and Cholesterol from PubMed, PubMed Central, Google Scholar, and ScienceDirect databases. The Medical Subject Headings (MeSH) strategy was also leveraged to extensively search the PubMed database. Research articles that were published from the year 2020 until May 2024, including randomized control trials, observational studies, meta-analyses, systematic reviews, literature reviews, and case reports, were included in the research. Research papers published before 2020, written in languages other than English, and animal studies were excluded. The 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria were used in the design of the systematic review. Levothyroxine therapy is the treatment of choice in patients suffering from hypothyroidism, and based on our review, the treatment has a positive impact, leading to a significant decrease in total cholesterol, low-density lipoproteins, and triglyceride values in hypothyroid patients. The research highlights the importance of starting timely levothyroxine therapy in hypothyroid patients to maintain normal lipid levels and reduce the associated cardiovascular risk.

Pituitary Hyperplasia Due to Longstanding Primary Hypothyroidism: A Case Report and Comprehensive Review of the Literature

Hypothyroidism is a frequently diagnosed endocrine disorder. Common signs and symptoms include fatigue, cold intolerance, hoarseness, dry skin, constipation, a slow relaxation phase of deep tendon reflexes, and bradycardia. However, some patients may exhibit atypical signs and symptoms, which can result in diagnostic confusion. Pituitary hyperplasia resulting from longstanding primary hypothyroidism was first described by Niepce in 1851. It is usually asymptomatic, but sometimes, in addition to symptoms of overt hypothyroidism, patients may complain of headaches, hypopituitarism, visual field impairment, and hyperprolactinemia. Furthermore, on imaging, pituitary hyperplasia can be mistaken for a pituitary adenoma. Distinguishing between the two is crucial, as their management differs; the former often responds to thyroid hormone replacement therapy, while the latter might need treatment with surgery and/or radiotherapy. Here we describe a patient who developed pituitary hyperplasia in the setting of longstanding uncompensated primary hypothyroidism due to a lack of compliance with levothyroxine replacement therapy. We also review the clinical, laboratory, and radiologic findings of the case reports available in the literature up to now in order to improve the knowledge and the care of the disease.

Machine Learning Approach with Harmonized Multinational Datasets for Enhanced Prediction of Hypothyroidism in Patients with Type 2 Diabetes

Type 2 diabetes (T2D) is a global health concern with increasing prevalence. Comorbid hypothyroidism (HT) exacerbates kidney, cardiac, neurological and other complications of T2D; these risks can be mitigated pharmacologically upon detecting HT. The current HT standard of care (SOC) screening in T2D is infrequent, delaying HT diagnosis and treatment. We present a first-to-date machine learning algorithm (MLA) clinical decision tool to classify patients as low vs. high risk for developing HT comorbid with T2D; the MLA was developed using readily available patient data from harmonized multinational datasets. The MLA was trained on data from NIH All of US (AoU) and UK Biobank (UKBB) (Combined dataset) and achieved a high negative predictive value (NPV) of 0.989 and an AUROC of 0.762 in the Combined dataset, exceeding AUROCs for the models trained on AoU or UKBB alone (0.666 and 0.622, respectively), indicating that increasing dataset diversity for MLA training improves performance. This high-NPV automated tool can supplement SOC screening and rule out T2D patients with low HT risk, allowing for the prioritization of lab-based testing for at-risk patients. Conversely, an MLA output that designates a patient to be at risk of developing HT allows for tailored clinical management and thereby promotes improved patient outcomes.

Subclinical hypothyroidism in Wales from 2000 to 2021: A descriptive cohort study based on electronic health records

BACKGROUND

Subclinical hypothyroidism (SCH) is a biochemical thyroid disorder characterised by elevated levels of Thyroid Stimulating Hormone (TSH) together with normal levels of thyroid hormones. Evidence on the benefits of treatment is limited, resulting in persistent controversies relating to its clinical management.

AIM

This study describes the demographic and clinical characteristics of patients identified as having subclinical hypothyroidism in Wales between 2000 and 2021, the annual cumulative incidence during this period and the testing and treatment patterns associated with this disorder.

METHODS

We used linked electronic health records from SAIL Databank. Eligible patients were identified using a combination of diagnostic codes and Thyroid Function Test results. Descriptive analyses were then performed.

RESULTS

199,520 individuals (63.8% female) were identified as having SCH, 23.6% (n = 47,104) of whom received levothyroxine for treatment over the study period. The median study follow-up time was 5.75 person-years (IQR 2.65-9.65). Annual cumulative incidence was highest in 2012 at 502 cases per 100,000 people. 92.5% (n = 184,484) of the study population had TSH levels between the upper limit of normal and 10mIU/L on their first test. 61.9% (n = 5,071) of patients identified using Read v2 codes were in the treated group. 41.9% (n = 19,716) of treated patients had a history of a single abnormal test result before their first prescription.

CONCLUSION

In Wales, the number of incident cases of SCH has risen unevenly between 2000 and 2021. Most of the study population had mild SCH on their index test, but more than a third of the identified patients received levothyroxine after a single abnormal test result. Patients with clinically recorded diagnoses were more likely to be treated. Given the expectation of steadily increasing patient numbers, more evidence is required to support the clinical management of subclinical hypothyroidism.

Risks of suboptimal and excessive thyroid hormone replacement across ages

BACKGROUND

Hypothyroidism is prevalent at all ages and represents a non-communicable disease with preventable consequences.

METHOD

Narrative review.

REVIEW

In children and adolescents, the most devastating consequences of undertreatment with levothyroxine (LT4) are poor growth and development. Delayed treatment in congenital hypothyroidism can lead to permanent brain damage. In young to middle-aged adults, symptoms are often overlooked, and treatment delayed by many years. The resulting consequences are also at this age group compromised brain and physical function but less severe and partly reversible with treatment. The under-treated condition often results in a higher risk of, e.g., increased cardiovascular disease burden, obesity, hypertension, poor physical capacity, and poor quality of life. Excessive replacement is at all adult age groups associated with increased risk of cardiac death, osteoporosis, loss of muscle function, psychological instability and poor quality of life. In young fertile women, the consequences of undertreatment with LT4 are subnormal fertility, recurrent pregnancy loss, compromised fetal growth, and neurocognitive development. On the other hand, excessive LT4 treatment has been related to gestational hypertension, preeclampsia and preterm birth. In the elderly, care must be given to avoid confusing a slightly high age-related serum TSH with requirement for LT4 treatment in a truly hypothyroid patient. Excessive LT4 treatment in patients of high age is associated with an increased mortality.

CONCLUSION

Suboptimal and excessive LT4 replacement of the preventable non-communicable disease hypothyroidism requires more focus from the healthcare system and from the global political systems to prevent the personally devastating and socioeconomically challenging consequences.

Subclinical hypothyroidism in the infertile female population: a guideline

There is controversy regarding whether to treat subtle abnormalities of thyroid function in infertile female patients. This guideline document reviews the risks and benefits of treating subclinical hypothyroidism in female patients with a history of infertility and miscarriage, as well as obstetric and neonatal outcomes in this population.

Polyethylene glycol thyroid-stimulating hormone (PEG-TSH) testing in the management of pediatric thyroid dysfunction

PURPOSE

The polyethylene glycol (PEG) methodology is used for investigating incongruities in laboratory assays, such as thyroid-stimulating hormone (TSH) measurements. The aim of the study is to investigate the practical application of PEG-TSH testing in cases of discrepancies between elevated TSH and normal free thyroxine (FT4) levels.

METHODS

A real-life observational study conducted in a tertiary medical center. The hospital's electronic database was queried for TSH tests performed in pediatric patients between 2015 and 2023. Of those, PEG-TSH were identified. Patients' clinical and biochemical characteristics and PEG-TSH-guided management were assessed.

RESULTS

In total, 2949 TSH tests were performed in 891 children and adolescents for various indications. Among them were 61 (2.1%) PEG-TSH results, mean age 7.1 ± 5.3 years, of 38 patients (4.3%), comprised of 16 with congenital hypothyroidism, 16 with subclinical hypothyroidism, and 6 with Hashimoto thyroiditis. Both the TSH and the PEG-TSH levels of patients with congenital hypothyroidism were higher than those of the other two groups (P = 0.021 and P = 0.009, respectively), with no group differences in FT4 levels. Spearman's correlation analysis revealed a strong association between TSH and PEG-TSH levels: r = 0.871, P < 0.001. In nearly one-half of the cases, clinical decisions made by clinicians (decreasing the dose or not initiating L-thyroxine treatment) were affected by the PEG-TSH results.

CONCLUSION

Our findings support PEG-TSH testing for determining appropriate TSH levels and avoid unnecessary thyroid hormone treatment among children and adolescents. We propose the suitability of managing their clinical condition based upon age-appropriate clinical parameters and FT4 levels when their PEG-TSH levels are within the normal range.

Consequences of undertreatment of hypothyroidism

PURPOSE

To provide an overview of consequences of undertreatment with levothyroxine (LT4) in the common non-communicable disease, hypothyroidism.

METHODS

Narrative review of the literature.

RESULTS

Hypothyroidism is globally very prevalent at all age groups and represents a non-communicable disease in which the risks and consequences are preventable. In children and adolescents, the most devastating consequences of undertreatment are poor growth and development. Lack of early treatment in congenital hypothyroidism can lead to permanent damage of brain function. In young to middle-aged adults, consequences are often overlooked, and treatment delayed by many years. The resulting consequences are also at this age group compromised brain and physical functioning but less severe and partly reversible with treatment. The undertreated condition often results in a higher risk of several secondary devastating diseases such as increased cardiovascular disease burden, obesity, hypertension, poor physical capacity, poor quality of life. In young women of fertile age the consequences of undertreatment with LT4 are subnormal fertility, recurrent pregnancy loss, preeclampsia, compromised fetal growth and neurocognitive development. There is a further risk of 30-50% of developing postpartum thyroiditis. In the elderly population care must be given to avoid confusing a slightly high serum TSH as result of physiological age adaptation with a requirement for LT4 treatment in a truly hypothyroid patient.

CONCLUSION

Undertreatment of the preventable non-communicable disease hypothyroidism requires more focus both from caretakers in the healthcare system, but also from the global political systems in order to prevent the personally devastating and socioeconomically challenging consequences.

What could be the reasons for not losing weight even after following a weight loss program?

INTRODUCTION

Approximately four million people worldwide die annually because of obesity. Weight loss is commonly recommended as a first-line therapy in overweight and obese patients. Although many individuals attempt to lose weight, not everyone achieves optimal success. Few studies point out that weight loss eventually slows down, stagnates or reverses in 85% of the cases.

RESEARCH QUESTION

What could be the reasons for not losing weight even after following a weight loss program?

METHODS

A scoping review of the literature was performed using weight loss-related search terms such as 'Obesity,' 'Overweight,' 'Lifestyle,' 'weight loss,' 'Basal Metabolism,' 'physical activity,' 'adherence,' 'energy balance,' 'Sleep' and 'adaptations. The search involved reference tracking and database and web searches (PUBMED, Science Direct, Elsevier, Web of Science and Google Scholar). Original articles and review papers on weight loss involving human participants and adults aged > 18 years were selected. Approximately 231 articles were reviewed, and 185 were included based on the inclusion criteria.

DESIGN

Scoping review.

RESULTS

In this review, the factors associated with not losing weight have broadly been divided into five categories. Studies highlighting each subfactor were critically reviewed and discussed. A wide degree of interindividual variability in weight loss is common in studies even after controlling for variables such as adherence, sex, physical activity and baseline weight. In addition to these variables, variations in factors such as previous weight loss attempts, sleep habits, meal timings and medications can play a crucial role in upregulating or downregulating the association between energy deficit and weight loss results.

CONCLUSION

This review identifies and clarifies the role of several factors that may hinder weight loss after the exploration of existing evidence. Judging the effectiveness of respective lifestyle interventions by simply observing the 'general behavior of the groups' is not always applicable in clinical practice. Each individual must be monitored and advised as per their requirements and challenges.

Acupuncture treatment for Hashimoto's thyroiditis: An exploratory randomized controlled trial

Background

Hashimoto's thyroiditis (HT) has a high incidence rate and unresolved clinical symptoms. Although Hand Yangming Meridian Penetrating Acupuncture has been used to treat thyroid diseases in China, there is no randomized controlled trial (RCT) on HT.

Methods

This exploratory RCT aims to preliminarily evaluate the efficacy, safety, and feasibility of Hand Yangming Meridian Penetrating Acupuncture in the treatment of HT. Included subjects were randomly assigned to the acupuncture group and the waiting treatment group at a ratio of 1:1. Subjects in the acupuncture group received 16 weeks of acupuncture treatment, followed by a 16-week follow-up observation phase. Subjects in the waiting group received thyroxine supplementation for 16 weeks, followed by 16 weeks of compensation treatment. Serum thyroid peroxidase antibody (TPOab) and thyroglobulin antibody (TGab) levels were the main indicators, and Thyroid-Related Patient-Reported Outcome short form (ThyPRO-39), MOS Item Short Form Health Survey (SF-36), and Hospital Anxiety and Depression Scale (HADS) scores were also recorded.

Results

In total, 58 subjects were included. After 16 weeks of treatment, there was no statistical difference in the changes in TPOab levels between the two groups, but the TGab level in the acupuncture group was significantly lower than in the waiting group (difference: -141.97 [95 % CI: -222.4 to -61.5], P = 0.011). Moreover, the total ThyPRO-39 and SF-36 scores were statistically different between the two groups (PThyPRO-39 < 0.001, PSF-36 = 0.005). There was no statistical difference in HADS between the two groups.

Conclusions

Hand Yangming Meridian Penetrating Acupuncture may be safe and feasible for HT hypothyroidism to improve symptoms and reduce TGab levels.

Trial registration number

This trial was registered at Acupuncture-Moxibustion Clinical Trial Registry: AMCTR-IOR-19000308 (ChiCTR1900026830, https://www.chictr.org.cn/searchprojEN.html).

Thyroid hormones mediate the impact of early-life stress on ventral tegmental area gene expression and behavior

Proper thyroid function is essential to the developing brain, including dopamine neuron differentiation, growth, and maintenance. Stress across the lifespan impacts thyroid hormone signaling and anxiety disorders and depression have been associated with thyroid dysfunction (both hypo- and hyper-active). However, less is known about how stress during postnatal development impacts thyroid function and related brain development. Our previous work in mice demonstrated that early-life stress (ELS) transiently impinged on expression of a transcription factor in dopamine neurons, Otx2, shown to be regulated by thyroid hormones. We hypothesized that thyroid hormone signaling may link experience of ELS with transcriptional dysregulation within the dopaminergic midbrain, and ultimately behavior. Here, we find that ELS transiently increases thyroid-stimulating hormone levels (inversely related to thyroid signaling) in both male and female mice at P21, an effect which recovers by adolescence. We next tested whether transient treatment of ELS mice with synthetic thyroid hormone (levothyroxine, LT4) could ameliorate the impact of ELS on sensitivity to future stress, and on expression of genes related to dopamine neuron development and maintenance, thyroid signaling, and plasticity within the ventral tegmental area. Among male mice, but not females, juvenile LT4 treatment prevented hypersensitivity to adult stress. We also found that rescuing developmental deficits in thyroid hormone signaling after ELS restored levels of some genes altered directly by ELS, and prevented alterations in expression of other genes sensitive to the second hit of adult stress. These findings suggest that thyroid signaling mediates the deleterious impact of ELS on VTA development, and that temporary treatment of hypothyroidism after ELS may be sufficient to prevent future stress hypersensitivity.

Outcomes of one-stage and two-stage aneurysm repair in arteriovenous fistulae

OBJECTIVE

Maintenance of long-term arteriovenous access is important in long-term care for patients with end-stage renal disease. Arteriovenous access is associated in the long term with the development of fistula aneurysms (FAs). This study aims to evaluate the outcomes of staged FA treatment in dialysis access arteriovenous fistulae (AVF).

METHODS

A retrospective review of all patients over a 12-year period with primary autogenous AVF was undertaken at a single center. Patients undergoing elective open aneurysm repair were identified and were categorized into three groups: single FA repair (single, control group) and staged and unstaged repair of two FAs (staged and unstaged). A staged repair was a procedure in which the initial intent was to treat both aneurysms in the AVF and in which the most symptomatic aneurysm was treated first. When the incision from the first surgery had healed, the second symptomatic aneurysm in the AVF was treated. An unstaged repair was a procedure in which the initial intent was to repair both symptomatic aneurysms simultaneously. All patients had a fistulogram before the FA repair. Thirty-day outcomes, cannulation failure, line placement, reintervention, and functional dialysis (continuous hemodialysis for 3 consecutive months) were examined.

RESULTS

Five hundred twenty-seven patients presented with FA that met requirements for open intervention; 44% underwent single FA repair, whereas the remaining 34% and 22% underwent staged and unstaged repair of two FAs, respectively. The majority of patients were diabetic and Hispanic. Ninety-one percent of the patients required percutaneous interventions of the outflow tract (37%) and the central veins (54%). Thirty-day major adverse cardiovascular events were equivalent across all modalities. Thirty-day morbidity and early thrombosis (<18 days) were significantly higher in the unstaged group (4.3%) compared with the two other groups (1.3% and 2.1%, single and staged, respectively), which led to an increased need for a short-term tunneled catheter (8.9%) compared with the two other groups (3.4% and 4.4%, single and staged, respectively), Unstaged repair resulted in an increased incidence of secondary procedures (5.0%) compared with the two other groups (2.6% and 3.1%, single and staged, respectively). Functional dialysis at 5 years was equivalent in the single and staged groups but was significantly decreased in the unstaged group.

CONCLUSIONS

Open interventions are successful therapeutic modalities for FAs, but unstaged rather than staged repair of two concurrent FAs results in a higher early thrombosis, an increased secondary intervention rate, and a need for a short-term tunneled central line. Staged and single FA repairs have equivalent results. In the setting of two symptomatic FAs, staged repair is recommended.

Quantitative Detection of Thyroid-Stimulating Hormone in Patient Samples with a Nanomechanical Single-Antibody Spectro-Immunoassay

Functional disorders of the thyroid remain a global challenge and have profound impacts on human health. Serving as the barometer for thyroid function, thyroid-stimulating hormone (TSH) is considered the single most useful test of thyroid function. However, the prevailing TSH immunoassays rely on two types of antibodies in a sandwich format. The requirement of repeated incubation and washing further complicates the issue, making it unable to meet the requirements of the shifting public health landscape that demands rapid, sensitive, and low-cost TSH tests. Herein, a systematic study is performed to investigate the clinical translational potential of a single antibody-based biosensing platform for the TSH test. The biosensing platform leverages Raman spectral variations induced by the interaction between a TSH antigen and a Raman molecule-conjugated TSH antibody. In conjunction with machine learning, it allows TSH concentrations in various patient samples to be predicted with high accuracy and precision, which is robust against substrate-to-substrate, intra-substrate, and day-to-day variations. It is envisioned that the simplicity and generalizability of this single-antibody immunoassay coupled with the demonstrated performance in patient samples pave the way for it to be widely applied in clinical settings for low-cost detection of hormones, other molecular biomarkers, DNA, RNA, and pathogens.

Screening factors affecting proper levothyroxine therapy among patients with primary hypothyroidism: a cross-sectional study

Primary hypothyroidism, the most common form of hypothyroidism, requires effective patient understanding and management for successful long-term treatment. This study aimed to investigate the influence of patient knowledge, attitude, practice (KAP), depression, and medication adherence on treatment response in primary hypothyroidism. A cross-sectional observational study was conducted at Al Hassan Metabolism, Endocrine, and Diabetes Center (HMEDC) in Iraq between September 2022 and March 2023. We enrolled 111 patients with signs and symptoms of primary hypothyroidism over 6 months. A validated questionnaire assessed patient knowledge, attitude, practice (KAP), depression, and medication adherence. Thyroid-stimulating hormone (TSH) levels were measured to assess treatment response. Data were analyzed using SPSS v26, with categorical variables presented as percentages. The student's t-test was used to assess statistical significance, with P - valuess below 0.05 considered significant and P - values below 0.01 considered highly significant. The mean age of patients was 45 ± 11.9 years. Approximately 34% of patients had insufficient knowledge, and 30% indicated a positive attitude towards their treatment. A total of 35% of patients had excellent practice. There was no statistically significant association between KAP and age or gender. There was a significant positive correlation between higher levels of education and improved KAP scores. A total of 44.1% of participants reported moderate depression, and 58% demonstrated adherence to levothyroxine (LT4) treatment. Despite good adherence, the combination of fair knowledge and moderate-to-severe depression resulted in suboptimal outcomes for replacement treatment.

Emerging Therapies in Hypothyroidism

Levothyroxine (LT4) is effective for most patients with hypothyroidism. However, a minority of the patients remain symptomatic despite the normalization of serum thyrotropin levels. Randomized clinical trials including all types of patients with hypothyroidism revealed that combination levothyroxine and liothyronine (LT4+LT3) therapy is safe and is the preferred choice of patients versus LT4 alone. Many patients who do not fully benefit from LT4 experience improved quality of life and cognition after switching to LT4+LT3. For these patients, new slow-release LT3 formulations that provide stable serum T3 levels are being tested. In addition, progress in regenerative technology has led to the development of human thyroid organoids that restore euthyroidism after being transplanted into hypothyroid mice. Finally, there is a new understanding that, under certain conditions, T3 signaling may be compromised in a tissue-specific fashion while systemic thyroid function is preserved. This is seen, for example, in patients with metabolic (dysfunction)-associated fatty liver disease, for whom liver-selective T3-like molecules have been utilized successfully in clinical trials.

Randomized double-blind placebo-controlled trial on levothyroxine and liothyronine combination therapy in totally thyroidectomized subjects: the LEVOLIO study

OBJECTIVE

Despite having normal thyroid-stimulating hormone levels, many hypothyroid patients are dissatisfied with the treatment. The primary aim of this study was to evaluate the effect of twice-daily, combination therapy with levothyroxine (LT4) and liothyronine (LT3), at doses adapted according to TSH-level, on peripheral tissues as reflected by sex hormone binding globulin (SHBG) levels in totally thyroidectomized patients. Changes in other tissue markers and quality of life considering DIO2-rs225014 and MCT10-rs17606253 genetic variants were also assessed.

DESIGN

Double-blind, randomized, placebo-controlled.

METHODS

One hundred and forty-one subjects were randomized to LT4 + LT3 group (LT4 + LT3 in the morning and LT3 in the evening; n = 70) or placebo group (LT4 in the morning and placebo in the evening; n = 71). Pituitary-thyroid axis compensation was assessed after 6, 12, and 24 weeks. Clinical parameters, quality of life, and tissue markers (sex hormone binding globulin, serum lipids, bone markers) were evaluated at 12 and 24 weeks. DIO2 and MCT10 single nucleotide polymorphisms were genotyped.

RESULTS

The LT4 + LT3 group was treated with mean daily LT3 doses of 5.00 µg, with a mean daily LT4 reduction of 15 µg. After 6 months of treatment, neither SHBG and other tissue markers nor quality of life differed significantly between groups. Combination treatment required greater dose adjustments than placebo (25% vs 54%, P < .001), due to thyroid-stimulating hormone reduction, without hyperthyroidism signs or symptoms. At the end of treatment, the LT4 + placebo group had significantly lower fT3/fT4 compared to the LT4 + LT3 group (0.26 ± 0.05 vs 0.32 ± 0.08, P < .001). No preference for combination therapy was found. Genetic variants did not influence any outcomes.

CONCLUSIONS

Six months of combination therapy with twice-daily LT3 dose adapted according to TSH-level do not significantly change peripheral tissue response or quality of life, despite an increase in the fT3/fT4 ratio.

Is Kidney Stone Associated with Thyroid Disease? The United States National Health and Nutrition Examination Survey 2007-2018

BACKGROUND

Kidney stones and thyroid disease are two common diseases in the general population, with multiple common risk factors. The associations between kidney stones and thyroid disease are unclear.

AIM

This study aims to assess the association between 'once had a thyroid disease' and the odds of kidney stones.

METHODS

Adult participants from the National Health and Nutrition Examination Survey (NHANES) 2007-2018 with reliable kidney stone and thyroid disease data were included. Adjusting for age, gender, race, education level, and marital status, diabetes, hypertension, gout, angina pectoris, stroke, and asthma, logistic regression was used to examine the relationship between kidney stones and thyroid illness.

RESULTS

Using stratified analysis, the association between thyroid illness and kidney stones was investigated further. Among the participants, 4.9% had kidney stones, and 10.1% had thyroid disease. Kidney stone was associated with thyroid disease (OR=1.441, (95% CI:1.294-1.604), p <0.01), which remained significant (OR=1.166, (95% CI:1.041-1.305), p <0.01) after adjustments with age, gender, race, education level and marital status, diabetes, hypertension, gout, angina pectoris, stroke, and asthma. Stratified by blood lead, blood cadmium, and blood urea nitrogen levels in the human body, the odds of kidney stones still increased with once having a previous thyroid disease.

CONCLUSIONS

In this large nationally representative survey over 10 years, kidney stone was strongly associated with thyroid disease. In this cross-sectional study, we explored the association between thyroid disease and kidney stones, which may help clinicians intervene in them early.

Evaluation of Bone Mineral Changes in Panoramic Radiographs of Hypothyroid and Hyperthyroid Patients Using Fractal Dimension Analysis

Objective Hyperthyroidism and hypothyroidism are endocrinopathies that cause a decrease in bone mineral density. The aim of this study is to investigate possible bone changes in the mandible caused by hyperthyroidism and hypothyroidism using fractal analysis (FA) on panoramic radiographs. Material and Methods Panoramic radiographs of a total of 180 patients, including 120 patient groups (60 hyperthyroid, 60 hypothyroid) and 60 healthy control groups, were used. Five regions of interests (ROI) were determined from panoramic radiographs and FA was performed. ROI1: geometric midpoint of mandibular notch and mandibular foramen, ROI2: geometric midpoint of mandibular angle, ROI3: anterior of mental foramen, ROI4: basal cortical area from distal mental foramen to distal root of first molar, ROI5: geometric center of mandibular foramen and mandibular ramus. Results While a significant difference was observed between the patient and control groups regarding ROI1 and ROI2 (p < 0.05); there was no significant difference between the groups in relation to ROI3, ROI4, and ROI5. All FA values were lower in the hyperthyroid group than in the hypothyroid group. Conclusion Fractal analysis proves to be an effective method for early detection of bone mass changes. In the present study, it was concluded that while the mandibular cortical bone was intact, trabecular rich regions were affected by osteoporosis caused by thyroid hormones. Necessary precautions should be taken against the risk of osteoporosis in patients with thyroid hormone disorders.

Potency and Powder X-ray Diffraction (PXRD) Evaluation of Levothyroxine Sodium Tablets under Ambient, Accelerated, and Stressed Conditions

Levothyroxine tablets, although highly prescribed in the United States, have been one of the most frequently recalled products. Because of the importance of the medication, several efforts have been put in place by the United States Food and Drug Administration (US FDA) to control the quality of levothyroxine tablets available to patients using the drug. The choice of excipients used in the formulation has been shown to impact the hygroscopicity and microenvironment, and ultimately the stability of the levothyroxine tablets formulations. Based on information generated from the US FDA Enforcement Report database, one of the main reasons for recalls is the low potency of different batches of the product. The yearly product recall trends for levothyroxine formulations were determined using the FDA Enforcement Report database. Three brands of levothyroxine tablets were selected with excipient lists similar to those products that have been historically recalled. The samples were placed at ambient (~23 °C), accelerated stability (40 °C/75% RH), and stress (50 °C/75% RH) conditions for up to 6 months. Sample potencies were determined at 0, 1.5, 3, and 6 months using the methods for assay and impurities in the United States Pharmacopeia (USP) monograph for levothyroxine tablets. Additional sample monitoring was conducted by overlaying the initial powder X-ray diffractograms (PXRD) of the samples from 0 months with the patterns generated thereafter. There has been a decline in the number of levothyroxine tablets recalled over the years. The highest numbers of recalls were recorded in the years 2013 [33] and 2020 [23]; no recalls occurred in the years 2019 and 2022. All of the brands evaluated met the USP 95.0-105.0% assay requirements at 1.5 months under accelerated conditions; only one of the brands complied at 3 months. Under ambient conditions, two brands were stable at 6 months, with borderline assay results. For stability, levothyroxine was found in microgram quantities in the formulations and PXRD could not detect changes at these low levels. However, we found some distinguishing data for samples under stress conditions.

The relationship between subclinical hypothyroidism and invasive papillary thyroid cancer

Background

Subclinical hypothyroidism is the most common thyroid dysfunction. Approximately 10% of patients with thyroid cancer have subclinical hypothyroidism. There is a paucity of real-world studies examining the relationship between subclinical hypothyroidism and known correlates of invasiveness of papillary thyroid carcinoma (PTC).

Materials and methods

A retrospective cohort study of 13,717 patients with PTC was conducted. Odds ratios were calculated to assess the relationship between subclinical hypothyroidism and extrathyroidal extension (ETE) after adjusting for BMI and genders. The Cancer Genome Atlas (TCGA) data were utilized for the analysis of TSHR-associated pathways, while qRT-PCR was employed to validate the expression levels of pivotal genes in the relevant signaling pathways.

Results

In total, 13,717 PTC patients (10,769 women and 2,948 men; mean [SD] age, 42.90 [9.43] years) were included in the retrospective study. Subclinical hypothyroidism was an independent risk factor for ETE (OR adjusted, 1.168 [95% CI, 1.028-1.327]; P=0.017). In normal-weight patients, subclinical hypothyroidism was an independent risk factor for ETE (OR adjusted, 1.287 [95% CI, 1.089-1.520]; P=0.003). However, this risk was not observed in under-weight, overweight, and obese patients. Compared to females, subclinical hypothyroidism was a higher risk factor for ETE in male patients with normal body weight (OR male=2.363 vs. OR female=1.228). Subclinical hypothyroidism was found to be a significant risk factor for ETE in the subgroup of patients younger than 38 years old (OR1 adjusted, 1.382 [95% CI, 1.032-1.852], P=0.030). The findings from Gene Set Enrichment Analysis (GSEA) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis revealed the involvement of the autophagy signaling pathway in TSHR/ETE/EMT regulation. Moreover, the gene expression levels demonstrated a concentration-dependent relationship between TSH intervention levels and the expression of key genes in the autophagy pathway of thyroid cancer cells.

Conclusion

Subclinical hypothyroidism was an independent risk factor for ETE in patients with PTC. This association was particularly significant in normal-weight and younger patients. The risk of ETE associated with subclinical hypothyroidism was higher in males compared to females. Our study indicates a potential involvement of the autophagy pathway in regulating the ETE phenotype in thyroid cancer, specifically in the context of subclinical hypothyroidism.

Estimation of left ventricular functions in patients with subclinical hypothyroidism: a meta-analysis

Objective

To evaluate left ventricular (LV) function in patients with subclinical hypothyroidism (ScH) compared to healthy individuals and to provide clinical hints for practitioners.

Methods

PubMed, Embase, Cochrane Library, and Web of Science were systematically searched in this meta-analysis. Studies evaluating LV function in ScH patients were included. Standardized mean difference (SMD) and the 95% confidence intervals (CIs) were calculated as effect size. Heterogeneity and risks of bias of included studies were assessed.

Results

A total of 9 studies were identified as eligible. The SMD for fractional shortening (FS, %) was -0.21 (95% CI: -0.60, 0.17; z = -1.08, p = 0.2788). The pooled SMD for systemic vascular resistance (SVR, dynes/sec·cm-5) was -0.41 (95% CI: -1.31, 0.49; z = -0.89, p = 0.3744). The pooled SMD for early diastolic mitral flow velocity/late diastolic mitral flow velocity (E/A) ratio was -0.74 (95% CI: -1.09, -0.39; z = -4.13, p < 0.001). The pooled SMD for ejection fraction (EF, %) was -0.35 (95% CI: -0.59, -0.12; z = -2.95, p = 0.0032).

Conclusion

ScH patients had significantly worse LV function parameters than healthy controls. These changes in LV function may be involved in the management of ScH.

Prevalence of thyroid dysfunction among Iranian older adults: a cross-sectional study

There is limited data on the prevalence of thyroid dysfunction in the older population. This study aimed to determine the prevalence of thyroid dysfunction among a sample of Iranian older adults. A cross-sectional analysis of older adults who aged 60 years and over was conducted. A total of 363 subjects were randomly selected from Birjand longitudinal aging study (BLAS) cohort study. Serum thyroid-stimulating hormone (TSH) level, total thyroxine (T4) and total triiodothyronine (T3) were measured by the enzyme-linked immunosorbent assay (ELISA). Based on thyroid function tests and history of taking medicines used to treat thyroid disorders, participants were classified into the following groups: euthyroid, overt/subclinical hypothyroidism, and overt/subclinical hyperthyroidism. Subsequently, the crude and World Health Organization (WHO) age-standardized prevalence were estimated for different thyroid function categories. A total of 171 men and 192 women, aged 60-94 years, were randomly selected. The crude prevalence of total hypothyroidism was 22.31% (subclinical [18.46%], overt [3.86%]), and that of hyperthyroidism was 1.66% (subclinical [1.38%], overt [0.28%]). The crude prevalence of total thyroid dysfunction was, therefore, 23.97%. A female preponderance was noticed in both total (P-value = 0.035) and overt (P-value = 0.035) hypothyroidism. An increasing trend with age was noticed in the prevalence of total hypothyroidism (P-value = 0.049). Age-standardized prevalence of total hypothyroidism and hyperthyroidism was 26.63% (95% confidence interval [CI] 20.58-33.69%) and 1.11% (95% CI 0.49-2.51%), respectively. A considerable proportion of our study population demonstrated evidence of thyroid dysfunction, particularly subclinical hypothyroidism. Our findings highlight the importance of further investigation of thyroid disorders among older Iranian adults.

Demographic, Healthcare Access, and Dietary Factors Associated With Thyroid Hormone Treatments for Hypothyroidism

CONTEXT

Clinical guidelines have recommended a trial of liothyronine (LT3) with levothyroxine (LT4) in select patients with hypothyroidism. However, little is known about the real-world use of LT3 and desiccated thyroid extract (DTE) and the characteristics of patients treated with LT3 and DTE.

OBJECTIVES

(1) Determine national trends of new LT4, LT3, and DTE prescriptions in the United States; (2) determine whether sociodemographic, healthcare access, and dietary factors are associated with different thyroid hormone (TH) therapies.

METHODS

Parallel cross-sectional studies were conducted using 2 datasets: (1) a national patient claims dataset (2010-2020) and (2) the National Health and Nutrition Examination Study (NHANES) dataset (1999-2016). Included participants had a diagnosis of primary or subclinical hypothyroidism. Study outcomes included the impact of demographics and healthcare access on differences in the proportion of TH therapies consisting of LT4, LT3, and DTE (patient claims) and differences in dietary behaviors between DTE-treated participants and LT4-treated matched controls (NHANES).

RESULTS

On an average annual basis, 47 711 adults received at least 1 new TH prescription, with 88.3% receiving LT4 monotherapy, 2.0% receiving LT3 therapy, and 9.4% receiving DTE therapy. The proportion receiving DTE therapy increased from 5.4% in 2010 to 10.2% in 2020. In the analysis between states, high primary care and endocrinology physician densities were associated with increased use of LT4 monotherapy (odds ratio 2.51, P < .001 and odds ratio 2.71, P < .001). DTE-treated NHANES participants (n = 73) consumed more dietary supplements compared to LT4-treated participants (n = 146) (4.7 vs 2.1, P < .001).

CONCLUSIONS

The proportion of new TH therapies containing DTE for hypothyroidism doubled since 2010 while LT3 therapies remained stable. DTE treatment was associated with decreased physician density and increased dietary supplement use.

Impact of Variation between Assays and Reference Intervals in the Diagnosis of Endocrine Disorders

Method-related variations in the measurement of hormones and the reference intervals used in the clinical laboratory can have a significant, but often under-appreciated, impact on the diagnosis and management of endocrine disorders. This variation in laboratory practice has the potential to lead to an errant approach to patient care and thus could cause harm. It may also be the source of confusion or result in excessive or inadequate investigation. It is important that laboratory professionals and clinicians know about these impacts, their sources, and how to detect and mitigate them when they do arise. In this review article, we describe the historical and scientific context from which inconsistency in the clinical laboratory arises. Examples from the published literature of the impact of the method, reference interval, and clinical decision threshold-related discordances on the assessment and monitoring of various endocrine disorders are discussed to illustrate the sources, causes, and effects of this variability. Its potential impact on the evaluation of growth hormone deficiency and excess, thyroid and parathyroid disorders, hyperandrogenism, hypogonadism, glucocorticoid excess and deficiency, and diabetes mellitus is elaborated. Strategies for assessment and mitigation of the discordance are discussed. The clinical laboratory has a responsibility to recognise and address these issues, and although a lot has been accomplished in this area already, there remains more to be done.

Effect of extra-low dose levothyroxine supplementation on pregnancy outcomes in women with subclinical hypothyroidism undergoing in vitro fertilization and embryo transfer

OBJECTIVE

This study was undertaken to test the therapeutic effect of extra-low dose of levothyroxine (LT4; 25 mcg/day) to preconception and pregnant women with subclinical hypothyroidism (SCH).

MATERIALS AND METHODS

This is a retrospective study, SCH women who succeeded in their first in vitro fertilization (IVF) cycle between January 1, 2018, to December 31, 2020 were included. SCH is defined as normal serum free thyroxine (T4) level and an elevated serum thyroid stimulating hormone (TSH) level >4 mIU/L. Extra-low dose of levothyroxine (LT4; 25 mcg/day) was prescribed to the SCH women from the establish of diagnosis of SCH to the end of pregnancy. The pregnancy outcomes (miscarriage, live birth, preterm birth, and small for gestational age baby) were compared to the euthyroid pregnant women.

RESULTS

Totally, 589 women were screened, and 317 cases received their first time IVF treatment. 167 women were clinically pregnant after IVF treatment, 155 of them were euthyroid and 12 of these women were diagnosed to have SCH. The average age of the participants was 35 years old. There were no significant differences in age, body mass index (BMI), anti-müllerian hormone (AMH), types of embryo transfer, number of embryos to transfer, or embryo stage during transfer between two groups. The live birth rate, miscarriage rate, and preterm birth rate in women with SCH supplemented with extra-low dose of LT4 were non-inferior to euthyroid patients (miscarriage rate: P = 0.7112; live birth rate: P = 0.7028; preterm delivery: P = 0.2419; small for gestational age: P = 0.2419).

CONCLUSION

Our result demonstrated that supplementation with extra-low dose of levothyroxine at 25 mcg/day to SCH women can produce the comparable obstetrical and neonatal outcome as that in euthyroid pregnant women. Accordingly, we suggest extra-low-dose of levothyroxine may be considered as a safe and effective alternative for those SCH pregnant women who were not tolerated to the standard dose of levothyroxine.

Development and Validation of a Prediction Model for Incident Hypothyroidism in a National Chronic Kidney Disease Cohort

CONTEXT

Hypothyroidism is a common yet under-recognized condition in patients with chronic kidney disease (CKD), which may lead to end-organ complications if left untreated.

OBJECTIVE

We developed a prediction tool to identify CKD patients at risk for incident hypothyroidism.

METHODS

Among 15 642 patients with stages 4 to 5 CKD without evidence of pre-existing thyroid disease, we developed and validated a risk prediction tool for the development of incident hypothyroidism (defined as thyrotropin [TSH] > 5.0 mIU/L) using the Optum Labs Data Warehouse, which contains de-identified administrative claims, including medical and pharmacy claims and enrollment records for commercial and Medicare Advantage enrollees as well as electronic health record data. Patients were divided into a two-thirds development set and a one-third validation set. Prediction models were developed using Cox models to estimate probability of incident hypothyroidism.

RESULTS

There were 1650 (11%) cases of incident hypothyroidism during a median follow-up of 3.4 years. Characteristics associated with hypothyroidism included older age, White race, higher body mass index, low serum albumin, higher baseline TSH, hypertension, congestive heart failure, exposure to iodinated contrast via angiogram or computed tomography scan, and amiodarone use. Model discrimination was good with similar C-statistics in the development and validation datasets: 0.77 (95% CI 0.75-0.78) and 0.76 (95% CI 0.74-0.78), respectively. Model goodness-of-fit tests showed adequate fit in the overall cohort (P = .47) as well as in a subcohort of patients with stage 5 CKD (P = .33).

CONCLUSION

In a national cohort of CKD patients, we developed a clinical prediction tool identifying those at risk for incident hypothyroidism to inform prioritized screening, monitoring, and treatment in this population.

Hypothyroidism in Adult Women: The Utility of Targeted vs Universal Thyroid Screening

Hypothyroidism is a common disease that is more prevalent in female populations. The purpose of this paper is to discuss the evidence, risks, and benefits of screening asymptomatic women for hypothyroidism. There is lack of evidence to support clinical management of asymptomatic individuals with an elevated TSH and normal serum thyroxine levels. Patients with subclinical hypothyroidism, especially the elderly, are at risk of overtreatment. Given these considerations, the majority of US and UK professional organizations do not support universal screening. Many do offer caveats for special groups, including pregnant people, who may need screening if there are clinical symptoms or family history of autoimmune disease. In conclusion, targeted screening may be best recommended based on risk factors, symptoms, and clinical suspicion, rather than at a universal level.

The effect of low dose thyroid replacement therapy in patients with episodic migraine and subclinical hypothyroidism: A randomised placebo-controlled trial

INTRODUCTION

Migraine is a common headache syndrome associated with various other comorbidities. Thyroid replacement in migraine patients with hypothyroidism improves headaches; however, thyroid hormone replacement in subclinical hypothyroidism is debatable, and its efficacy is not known.

OBJECTIVE AND METHODOLOGY

This prospective, single-centre, quasi-randomised interventional study was conducted on patients visiting the General Medicine and Neurology outpatient department at a tertiary centre to look at the efficacy of thyroxine in subclinical hypothyroidism.

RESULTS

We assessed 87 patients for analysis; no patients were lost to follow-up. There was a decrease in all parameters evaluated (headache frequency, severity, duration, MIDAS score, MIDAS grade) at three months of follow-up in the treatment group compared to placebo group. There was a significant decrease in headache frequency and severity in the levothyroxine group compared to the placebo group at three months of follow-up. Also, the follow-up MIDAS score (mean ± SD: 6.30 ± 2.455 scores vs. 8.45 ± 5.757 scores) was significantly decreased by treatment at three months follow-up.

CONCLUSION

Treatment of subclinical hypothyroidism effectively reduces migraine headaches, and it is logical to check thyroid function status in patients presenting with migraine headaches. However, a larger randomised controlled trial is required to prove the efficacy of levothyroxine in migraine with subclinical hypothyroidism.

The optimal healthy ranges of thyroid function defined by the risk of cardiovascular disease and mortality: systematic review and individual participant data meta-analysis

BACKGROUND

Reference intervals of thyroid-stimulating hormone (TSH) and free thyroxine (FT4) are statistically defined by the 2·5-97·5th percentiles, without accounting for potential risk of clinical outcomes. We aimed to define the optimal healthy ranges of TSH and FT4 based on the risk of cardiovascular disease and mortality.

METHODS

This systematic review and individual participant data (IPD) meta-analysis identified eligible prospective cohorts through the Thyroid Studies Collaboration, supplemented with a systematic search via Embase, MEDLINE (Ovid), Web of science, the Cochrane Central Register of Controlled Trials, and Google Scholar from Jan 1, 2011, to Feb 12, 2017 with an updated search to Oct 13, 2022 (cohorts found in the second search were not included in the IPD). We included cohorts that collected TSH or FT4, and cardiovascular outcomes or mortality for adults (aged ≥18 years). We excluded cohorts that included solely pregnant women, individuals with overt thyroid diseases, and individuals with cardiovascular disease. We contacted the study investigators of eligible cohorts to provide IPD on demographics, TSH, FT4, thyroid peroxidase antibodies, history of cardiovascular disease and risk factors, medication use, cardiovascular disease events, cardiovascular disease mortality, and all-cause mortality. The primary outcome was a composite outcome including cardiovascular disease events (coronary heart disease, stroke, and heart failure) and all-cause mortality. Secondary outcomes were the separate assessment of cardiovascular disease events, all-cause mortality, and cardiovascular disease mortality. We performed one-step (cohort-stratified Cox models) and two-step (random-effects models) meta-analyses adjusting for age, sex, smoking, systolic blood pressure, diabetes, and total cholesterol. The study was registered with PROSPERO, CRD42017057576.

FINDINGS

We identified 3935 studies, of which 53 cohorts fulfilled the inclusion criteria and 26 cohorts agreed to participate. We included IPD on 134 346 participants with a median age of 59 years (range 18-106) at baseline. There was a J-shaped association of FT4 with the composite outcome and secondary outcomes, with the 20th (median 13·5 pmol/L [IQR 11·2-13·9]) to 40th percentiles (median 14·8 pmol/L [12·3-15·0]) conveying the lowest risk. Compared with the 20-40th percentiles, the age-adjusted and sex-adjusted hazard ratio (HR) for FT4 in the 80-100th percentiles was 1·20 (95% CI 1·11-1·31) for the composite outcome, 1·34 (1·20-1·49) for all-cause mortality, 1·57 (1·31-1·89) for cardiovascular disease mortality, and 1·22 (1·11-1·33) for cardiovascular disease events. In individuals aged 70 years and older, the 10-year absolute risk of composite outcome increased over 5% for women with FT4 greater than the 85th percentile (median 17·6 pmol/L [IQR 15·0-18·3]), and men with FT4 greater than the 75th percentile (16·7 pmol/L [14·0-17·4]). Non-linear associations were identified for TSH, with the 60th (median 1·90 mIU/L [IQR 1·68-2·25]) to 80th percentiles (2·90 mIU/L [2·41-3·32]) associated with the lowest risk of cardiovascular disease and mortality. Compared with the 60-80th percentiles, the age-adjusted and sex-adjusted HR of TSH in the 0-20th percentiles was 1·07 (95% CI 1·02-1·12) for the composite outcome, 1·09 (1·05-1·14) for all-cause mortality, and 1·07 (0·99-1·16) for cardiovascular disease mortality.

INTERPRETATION

There was a J-shaped association of FT4 with cardiovascular disease and mortality. Low concentrations of TSH were associated with a higher risk of all-cause mortality and cardiovascular disease mortality. The 20-40th percentiles of FT4 and the 60-80th percentiles of TSH could represent the optimal healthy ranges of thyroid function based on the risk of cardiovascular disease and mortality, with more than 5% increase of 10-year composite risk identified for FT4 greater than the 85th percentile in women and men older than 70 years. We propose a feasible approach to establish the optimal healthy ranges of thyroid function, allowing for better identification of individuals with a higher risk of thyroid-related outcomes.

FUNDING

None.

Periorbital Oedema Associated with Hypothyroidism - A Case Report

INTRODUCTION

Pituitary microadenomas are said to be common, with an incidence of 27%. Hypothyroidism causing periorbital oedema (PO) remains rare in the literature, but it is still within the etiological factors.

PATIENT CONCERNS

This study presents a 53-year-old patient who presented with PO and visited the dental clinic to exclude dental infection.

DIAGNOSIS

Based on the evaluation of proper haematological and radiological investigations, pituitary microadenoma was identified with an abrupt increase in the thyroid stimulating hormone (TSH) level.

FOLLOWUP

The patient was followed with further studies to identify the primary cause of PO. It was concluded that the disruption in the drug regimen caused an increase in the TSH and led to PO rather than microadenoma.

The Effects of Patient Characteristics on the Management of Subclinical Hypothyroidism: A Survey of Faculty and Trainees

OBJECTIVE

There is no universal approach to the management of subclinical hypothyroidism (SCH). This study was designed to determine the impact of patient characteristics on management decisions in SCH amongst physician faculty members and trainees.

METHODS

An online survey was distributed to faculty members and medical trainees (ie, interns, residents, and fellows) at multiple academic medical centers. The survey included 9 clinical scenarios describing women with SCH with 5 management options sequenced from most "conservative" (no further treatment or monitoring) to most "aggressive" (treatment with levothyroxine).

RESULTS

Of the 194 survey respondents, 95 (49.0%) were faculty members and 99 (51.0%) were trainees. Faculty members were more likely to report being "confident" or "very confident" in making the diagnosis of SCH compared to trainees (95.8% vs 46.5%, P < .001). Faculty members were also more likely to consider patient preference for treatment (60.0% vs 32.3%, P < .001). Among all respondents, the clinical factors that resulted in the highest predicted probability of treatment were hypothyroid symptoms (predicted probability [PP] 68.8%, 95% CI [65.7%-71.9%]), thyroid stimulating hormone >10 mIU/L in a 31-year-old (PP 63.9%, 95% CI [60.3%-67.3%]), and the desire for fertility (PP 52.2%, 95% CI [48.6%-56.0%]). In general, faculty members favored more aggressive treatment across all clinical scenarios.

CONCLUSION

The presence of symptoms, thyroid stimulating hormone >10 mIU/L, and desire for fertility were most predictive of the decision to treat in SCH. In several clinical scenarios, both trainee and faculty decision-making demonstrated discordance with general SCH management principles.

Protocol for a double-blinded randomised controlled trial to assess the effect of faecal microbiota transplantations on thyroid reserve in patients with subclinical autoimmune hypothyroidism in the Netherlands: the IMITHOT trial

BACKGROUND

Hashimoto's thyroiditis (HT) is a common endocrine autoimmune disease affecting roughly 5% of the general population and involves life-long treatment with levothyroxine, as no curative treatment yet exists. Over the past decade, the crosstalk between gut microbiota and the host immune system has been well-recognised, identifying the gut microbiome as an important factor in host health and disease, including susceptibility to autoimmune diseases. Previous observational studies yielded a link between disruption of the gut microbiome composition and HT. This is the first study that investigates the potential of restoring a disrupted gut microbiome with faecal microbiota transplantations (FMTs) to halt disease progression and dampen autoimmunity.

METHODS AND ANALYSIS

The IMITHOT trial is a randomised, double-blinded, placebo-controlled study evaluating either autologous or allogenic FMTs in medication-naïve patients with subclinical autoimmune hypothyroidism. In total, 34 patients will be enrolled to receive either three allogenic or autologous FMTs. FMT will be made of fresh stool and directly administered into the duodenum. Patients will be evaluated at baseline before the first FMT is administered and at 6, 12 and 24 months post-intervention to assess efficacy and adverse events. The primary outcome measure will be the net incremental increase (incremental area under the curve) on thyrotropin-stimulated free thyroxine and free triiodothyronine release at 6 and 12 months compared with baseline. Results will be disseminated via peer-reviewed journals and international conferences. The recruitment of the first patient and donor occurred on 18 December 2019.

ETHICS AND DISSEMINATION

Ethics approval was obtained from the hospital Ethics Committee (Medical Ethics Committee) at Amsterdam University Medical Center. The trial's outcomes offer high-quality evidence that aids in unveiling distinct patterns within the gut microbiota potentially associated with improved thyroid function. Consequently, this may open avenues for the future clinical applications of microbial-targeted therapy in individuals at risk of developing overt HT.

TRIAL REGISTRATION NUMBER

NL7931.

A Feedback Loop Involving Exosomal miR-146a and NG2 to Propel the Development and Progression of Hypothyroidism

Background: Thyrotropin receptor (TSHR) plays a central role in maintaining thyroid function and TSHR impairment causes hypothyroidism, which is often associated with metabolic disarrangement. The most common type of hypothyroidism is autoimmune disease-related and the mechanism, particularly with respect to the role of microRNAs (miRNAs), has not been delineated. Methods: Serum from 30 patients with subclinical hypothyroidism (SCH) and 30 healthy individuals were collected and exosomal miR-146a (exo-miR-146a) was examined, followed by extensive mechanistic investigation using various molecular and cellular experimental approaches and genetic-knockout mouse models. Results: Our clinical investigation showed that exo-miR-146a was systemically elevated in the serum of patients with SCH (p = 0.04) compared with healthy individuals, prompting us to investigate the biological effects of miR-146a in cells. We found that miR-146a could target and down-regulate neuron-glial antigen 2 (Ng2), with consequent down-regulation of TSHR. We next generated a thyroid-specific Ng2 knockout (Thy-Ng2-/-) mouse model and found a significant down-regulation of TSHR in Thy-Ng2-/- mice, accompanied by the development of hypothyroidism and metabolic disorders. We further found that a decrease in NG2 resulted in decreased receptor tyrosine kinase-linked downstream signaling and down-regulation of c-Myc, consequently resulting in up-regulation of miR-142 and miR-146a in thyroid cells. Up-regulated miR-142 targeted the 3'-untranslated region (UTR) of TSHR messenger RNA (mRNA) and post-transcriptionally down-regulated TSHR, explaining the development of hypothyroidism above. Local up-regulation of miR-146a in thyroid cells augments the earlier cited processes initiated by systemically elevated miR-146a, thereby forming a feedback loop to propel the development and progression of hypothyroidism. Conclusions: This study has uncovered a self-augmenting molecular loop initiated by elevated exo-miR-146a to suppress TSHR through targeting and down-regulating NG2, thereby initiating and propelling the development and progression of hypothyroidism.

Thyroid hormones mediate the impact of early-life stress on ventral tegmental area gene expression and behavior

Proper thyroid function is essential to the developing brain, including dopamine neuron differentiation, growth, and maintenance. Stress across the lifespan impacts thyroid hormone signaling and anxiety disorders and depression have been associated with thyroid dysfunction (both hypo- and hyper-active). However, less is known about how stress during postnatal development impacts thyroid function and related brain development. Our previous work in mice demonstrated that early-life stress (ELS) transiently impinged on expression of a transcription factor in dopamine neurons shown to be regulated by thyroid hormones. We hypothesized that thyroid hormone signaling may link experience of ELS with transcriptional dysregulation within the dopaminergic midbrain, and ultimately behavior. Here, we find that ELS transiently increases thyroid-stimulating hormone levels (inversely related to thyroid signaling) in both male and female mice at P21, an effect which recovers by adolescence. We next tested whether transient treatment of ELS mice with synthetic thyroid hormone (levothyroxine, LT4) could ameliorate the impact of ELS on sensitivity to future stress, and on expression of genes related to dopamine neuron development and maintenance, thyroid signaling, and plasticity within the ventral tegmental area. Among male mice, but not females, juvenile LT4 treatment prevented hypersensitivity to adult stress. We also found that rescuing developmental deficits in thyroid hormone signaling after ELS restored levels of some genes altered directly by ELS, and prevented alterations in expression of other genes sensitive to the second hit of adult stress. These findings suggest that thyroid signaling mediates the deleterious impact of ELS on VTA development, and that temporary treatment of hypothyroidism after ELS may be sufficient to prevent future stress hypersensitivity.

SNP rs11185644 in RXRA gene and SNP rs2235544 in DIO1 gene predict dosage requirements in a cross-sectional sample of hypothyroid patients

BACKGROUND AND PURPOSE

Primary hypothyroidism due to abnormality in the thyroid gland is the most common endocrine disease The recommended starting dose of levothyroxine replacement therapy is 1.6 µg/kg. This dose however is not optimal for every patient and dose adjustments are frequently done. Genetic polymorphisms in the absorption and metabolism pathway of levothyroxine are likely to influence its dose requirements. This study aimed to study the influence of genetic polymorphisms on levothyroxine replacement requirements.

METHODS

This was a cross-sectional study. Participants were recruited through a private nutrition clinic and through announcements distributed in the University of Petra in Amman, Jordan between September 2020 and February 2021. Hypothyroid patients had already been on stable doses of levothyroxine for the previous 3 months. A questionnaire was distributed to collect demographic and clinical information and a blood sample was taken for DNA extraction and clinical biochemistry analysis. rs11249460, rs2235544, rs225014, rs225015, rs3806596, rs11185644, rs4588, rs602662 were analyzed using Applied Biosystems TaqMan™ SNP Genotyping Assays on Rotor-Gene® Q and rs3064744 by direct sequencing. SPSS and Excel were used to perform analysis.

RESULTS

76 patients were studied. The equation we calculated to find predicted daily dose of levothyroxine (mcg/kg) is 3.22+ (0.348 for CT genotype of rs11185644, 0 for other genotypes) + 0.027*disease duration (years) - 0.014*age (years) - 0.434*T3 (pmol/L) levels+ (0.296 for CC genotype of rs2235544, 0 for other genotypes).

CONCLUSION

SNP rs11185644 in RXRA gene and SNP rs2235544 in DIO1 affect dose requirement in hypothyroid patients and if confirmed in larger trials they can be used to individualize thyroxine starting doses.