Thyroid disease assessment and management: summary of NICE guidance

The need for the GREAT+ score to predict relapse in Graves' disease: a questionnaire among patients and internal medicine specialists

PURPOSE

Graves' disease (GD) is an auto-immune cause of hyperthyroidism. First-line treatment often consists of a 12-18 month course of antithyroid drugs (ATD). After discontinuation of ATD, GD relapses in approximately 50% of patients. The 'Graves recurrent event after therapy+ ' (GREAT+) score may predict individual relapse chances after ATD discontinuation more accurately based on clinical and laboratory parameters at diagnosis. We investigated the need for the GREAT+ score through an online questionnaire among GD patients and physicians treating GD.

METHODS

An anonymous online questionnaire was distributed to patients and physicians between June 2022 and August 2023.

RESULTS

The questionnaire was completed by 532 patients and 44 physicians. Results showed that 94% of patients were interested in knowing their GREAT+ score at the start of treatment. 55% would consider definite treatment (radioiodine/thyroidectomy) as first-line treatment in case of a high relapse chance. 98% of the physicians indicated the GREAT + score would support patient counseling. 84% may change their advice for first-line treatment if a patient has a high relapse chance based on the score.

CONCLUSION

Patients and physicians considered the GREAT+ score as a valuable addition to the current available information which could change treatment decisions. Therefore, external validation of the GREAT+ score is justified to implement this score in clinical practice.

Associations between thyroid function, thyroid diseases, and primary aldosteronism

OBJECTIVE

Previous studies focusing on primary aldosteronism (PA) and thyroid diseases were controversial. Hence, this study aimed to examine associations between thyroid function, thyroid diseases, and PA and its subtypes.

DESIGN AND METHODS

This was a cross-sectional study, which enrolled 1023 patients with PA and 6138 patients with essential hypertension (EH) admitted to Hypertension Center of People's Hospital of Xinjiang Uygur Autonomous Region from August 2011 to June 2022. All patients with PA were accurately classified into aldosterone-producing adenoma (APA) and idiopathic hyperaldosteronism (IHA) by adrenal vein sampling (AVS). Multivariate logistic regression analysis was used to assess the relationship of thyroid function, thyroid nodules, and PA and its subtypes.

RESULTS

A total of 7161 patients (327 APA and 696 IHA, and 6138 EH) were included with a mean age of 48.20 ± 8.83 years. PA patients and PA subtypes showed lower FT4, FT3, TT4, TT3, and prevalence of positive TPOAb, meanwhile higher prevalence of thyroid nodules than EH patients (PA: 56.10%, IHA: 56.90%, APA: 54.80%, and EH: 48.90%, respectively). PA (adjusted OR: 1.290, 95% CI: 1.035-1.607, P = .02) and its subtype (IHA) (adjusted OR: 1.316, 95% CI: 1.005-1.724, P = .04) were significantly associated with thyroid nodules. Compared to patients with lower plasma aldosterone concentration (PAC) levels (<12 ng/dL), patients with PAC levels ≥ 12 ng/dL presented a higher prevalence of thyroid nodules.

CONCLUSIONS

PA patients had lower thyroid function and higher prevalence of thyroid nodules compared to EH patients. Therefore, the screening of thyroid function and thyroid nodules may be indispensable for PA patients.

Canadian Association of Radiologists Head and Neck Imaging Referral Guideline

The Canadian Association of Radiologists (CAR) Head and Neck Expert Panel consists of radiologists, a laryngologist and laryngeal surgeon, a patient advisor, and an epidemiologist/guideline methodologist. After developing a list of 11 clinical/diagnostic scenarios, a systematic rapid scoping review was undertaken to identify systematically produced referral guidelines that provide recommendations for one or more of these clinical/diagnostic scenarios. Recommendations from 17 guidelines and contextualization criteria in the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) for guidelines framework were used to develop 26 recommendation statements across the 11 scenarios. This guideline presents the methods of development and the referral recommendations for sinus disease, tinnitus, thyroid and parathyroid disease, neck mass of unknown origin, acute sialadenitis, chronic salivary conditions, and temporomandibular joint dysfunction.

Enhanced predictive validity of integrative models for refractory hyperthyroidism considering baseline and early therapy characteristics: a prospective cohort study

BACKGROUND

A subset of Graves' disease (GD) patients develops refractory hyperthyroidism, posing challenges in treatment decisions. The predictive value of baseline characteristics and early therapy indicators in identifying high risk individuals is an area worth exploration.

METHODS

A prospective cohort study (2018-2022) involved 597 newly diagnosed adult GD patients undergoing methimazole (MMI) treatment. Baseline characteristics and 3-month therapy parameters were utilized to develop predictive models for refractory GD, considering antithyroid drug (ATD) dosage regimens.

RESULTS

Among 346 patients analyzed, 49.7% developed ATD-refractory GD, marked by recurrence and sustained Thyrotropin Receptor Antibody (TRAb) positivity. Key baseline factors, including younger age, Graves' ophthalmopathy (GO), larger goiter size, and higher initial free triiodothyronine (fT3), free thyroxine (fT4), and TRAb levels, were all significantly associated with an increased risk of refractory GD, forming the baseline predictive model (Model A). Subsequent analysis based on MMI cumulative dosage at 3 months resulted in two subgroups: a high cumulative dosage group (average ≥ 20 mg/day) and a medium-low cumulative dosage group (average < 20 mg/day). Absolute values, percentage changes, and cumulative values of thyroid function and autoantibodies at 3 months were analyzed. Two combined predictive models, Model B (high cumulative dosage) and Model C (medium-low cumulative dosage), were developed based on stepwise regression and multivariate analysis, incorporating additional 3-month parameters beyond the baseline. In both groups, these combined models outperformed the baseline model in terms of discriminative ability (measured by AUC), concordance with actual outcomes (66.2% comprehensive improvement), and risk classification accuracy (especially for Class I and II patients with baseline predictive risk < 71%). The reliability of the above models was confirmed through additional analysis using random forests. This study also explored ATD dosage regimens, revealing differences in refractory outcomes between predicted risk groups. However, adjusting MMI dosage after early risk assessment did not conclusively improve the prognosis of refractory GD.

CONCLUSION

Integrating baseline and early therapy characteristics enhances the predictive capability for refractory GD outcomes. The study provides valuable insights into refining risk assessment and guiding personalized treatment decisions for GD patients.

Designing a combined liothyronine (LT3), L- thyroxine (LT4) trial in symptomatic hypothyroid subjects on LT4 - the importance of patient selection, choice of LT3 and trial design

Approximately 10%-15% of subjects with hypothyroidism on L-thyroxine (LT4) alone have persistent symptoms affecting their quality of life (QoL). Although the cause is unclear, there is evidence that "tissue T3 lack" may be responsible. If so, combining liothyronine (LT3) with LT4 would be helpful. However, randomized controlled trials (RCT), have not established greater efficacy for the LT3 + LT4 combination in these subjects than for LT4 alone. While the trial design may have been responsible, the use of unphysiological, short-acting LT3 preparations and non-thyroid-specific patient-reported outcome measures (PROMs) may have contributed. We recommend attention to the following aspects of trial design for future RCTs of LT3 + LT4 compared to LT4 alone: (a) Subject selection-(i) measurable symptoms (disadvantages should be recognized); (ii) using a validated thyroid specific PROM such as ThyPRO39 or the Composite scale derived from it; (iii) those taking over 1.2 μg/day or 100 μg/day (for pragmatic reasons) of LT4 defining a population likely without intrinsic thyroid activity who depend on exogenous LT4; (iv) recruiting a preponderance of subjects with autoimmune thyroiditis increasing generalisability; and (v) those with a high symptom load with a greater response to combination therapy e.g. those with the deiodinase 2 polymorphism. (b) The use of physiological LT3 preparations producing pharmacokinetic similarities to T3 profiles in unaffected subjects: two long-acting LT3 preparations are currently available and must be tested in phase 2b/3 RCTs. (c) The superiority of a crossover design in limiting numbers and costs while maintaining statistical power and ensuring that all subjects experienced the investigative medication.

Prevalence and Trends of Thyroid Disease Among Adults, 1999-2018

BACKGROUND

Thyroid disease is a prominent endocrine disorder, yet the clinical epidemiology of this condition remains unclear. This study aims to describe the recent trends in the prevalence of thyroid disease in US adults from 1999-2018.

METHODS

This cross-sectional study used nationally representative data collected through the National Health and Nutrition Examination Survey (NHANES) from January 1, 1999 to December 31, 2018. Patients with thyroid disease were defined as patients who reported having a thyroid disease and were on thyroid-related treatment. Age-standardized prevalence of thyroid disease was calculated within 4-year survey periods (1999-2002, 2003-2006, 2007-2010, 2011-2014, and 2015-2018).

RESULTS

During the NHANES 1999-2018, a total of 57 540 participants were examined. The age-standardized prevalence of thyroid disease was 5.05% (95% CI, 4.55%-5.60%) from 2015-2018, signifying a significant increase from the 1999-2002 period (P <.0002). However, prevalent thyroid disease remained steady between 2003 and 2014. The highest prevalence of thyroid disease was observed in non-Hispanic Whites (8.1%; 95% CI, 7.3%-9.0%), individuals aged ≥60 years (15.4%; 95% CI, 13.3%-17.8%), and tended to be higher in women (7.6%; 95% CI, 6.8%-8.5%). Multiple regression analysis revealed that age, women sex, non-Hispanic White and Mexican American, body mass index, higher education and incomes were independently associated with increased risks of thyroid disease.

CONCLUSION

The age-standardized prevalence of thyroid disease among US adults increased from 1999-2003, remained stable between 2003 and 2014, and then saw an increase from 2014-2018, with the highest rate observed among elders, women, and non-Hispanic Whites.

Hyperthyroidism: A Review

Importance

Overt hyperthyroidism, defined as suppressed thyrotropin (previously thyroid-stimulating hormone) and high concentration of triiodothyronine (T3) and/or free thyroxine (FT4), affects approximately 0.2% to 1.4% of people worldwide. Subclinical hyperthyroidism, defined as low concentrations of thyrotropin and normal concentrations of T3 and FT4, affects approximately 0.7% to 1.4% of people worldwide. Untreated hyperthyroidism can cause cardiac arrhythmias, heart failure, osteoporosis, and adverse pregnancy outcomes. It may lead to unintentional weight loss and is associated with increased mortality.

Observations

The most common cause of hyperthyroidism is Graves disease, with a global prevalence of 2% in women and 0.5% in men. Other causes of hyperthyroidism and thyrotoxicosis include toxic nodules and the thyrotoxic phase of thyroiditis. Common symptoms of thyrotoxicosis include anxiety, insomnia, palpitations, unintentional weight loss, diarrhea, and heat intolerance. Patients with Graves disease may have a diffusely enlarged thyroid gland, stare, or exophthalmos on examination. Patients with toxic nodules (ie, in which thyroid nodules develop autonomous function) may have symptoms from local compression of structures in the neck by the thyroid gland, such as dysphagia, orthopnea, or voice changes. Etiology can typically be established based on clinical presentation, thyroid function tests, and thyrotropin-receptor antibody status. Thyroid scintigraphy is recommended if thyroid nodules are present or the etiology is unclear. Thyrotoxicosis from thyroiditis may be observed if symptomatic or treated with supportive care. Treatment options for overt hyperthyroidism from autonomous thyroid nodules or Graves disease include antithyroid drugs, radioactive iodine ablation, and surgery. Treatment for subclinical hyperthyroidism is recommended for patients at highest risk of osteoporosis and cardiovascular disease, such as those older than 65 years or with persistent serum thyrotropin level less than 0.1 mIU/L.

Conclusions and Relevance

Hyperthyroidism affects 2.5% of adults worldwide and is associated with osteoporosis, heart disease, and increased mortality. First-line treatments are antithyroid drugs, thyroid surgery, and radioactive iodine treatment. Treatment choices should be individualized and patient centered.

Thyroid function test variability and cardiovascular morbidity in hyperthyroidism

OBJECTIVE

The variability of thyroid function tests (TFTs) during antithyroid drug (ATD) therapy and its association with adverse health outcomes have not been previously studied. The aim of this study was to evaluate the association of TFT variability and cardiovascular morbidity during ATD therapy.

DESIGN

Retrospective cohort study.

PATIENTS AND MEASUREMENTS

Hyperthyroid patients (n = 394) treated with ATD therapy at Tampere University Hospital between March 2016 and December 2018 were followed up for a median time of 1.5 years (interquartile range 0.8-2.0). The coefficients of variation (CVs) of the follow-up thyroid-stimulating hormone (TSH), free thyroxine (fT4) and free triiodothyronine (fT3) measurements were determined. The associations of TFT variability and baseline clinical factors with cardiovascular disease (CVD) -associated hospital visits were assessed with logistic regression analyses.

RESULTS

In the multivariable analyses, age (odds ratio [OR]: 1.06, 95% confidence interval [CI]: 1.03-1.09), male gender (OR: 2.33, 95% CI: 1.03-5.28) and fT4-CV (OR: 1.02, 95% CI: 1.01-1.04) were independent risk factors for cardiovascular morbidity, whereas baseline positive thyrotropin receptor antibodies (TRAbs) were associated with lower cardiovascular morbidity (OR: 0.29, 95% CI: 0.14-0.61). When the patients with baseline TRAb positivity were studied separately, fT4-CV was associated with cardiovascular morbidity (OR: 1.03, 95% CI: 1.00-1.05).

CONCLUSIONS

During ATD therapy, fT4 variability is associated with an increased cardiovascular morbidity. Although positive TRAbs are associated with a lower cardiovascular morbidity compared with hyperthyroidism with negative autoantibodies, the variability of fT4 is associated with cardiovascular morbidity also in patients with positive TRAbs.

Refining personalized diagnosis, treatment and exploitation of hypothyroidism related to solid nonthyroid cancer

Hypothyroidism in the setting of cancer is a puzzling entity due to the dual role of the thyroid hormones (TH) in cancer – promoting versus inhibitory – and the complexity of the hypothyroidism itself. The present review provides a comprehensive overview of the personalized approach to hypothyroidism in patients with solid nonthyroid cancer, focusing on current challenges, unmet needs and future perspectives. Major electronic databases were searched from January 2011 until March 2022. The milestones of the refinement of such a personalized approach are prompt diagnosis, proper TH replacement and development of interventions and/or pharmaceutical agents to exploit hypothyroidism or, on the contrary, TH replacement as an anticancer strategy. Further elucidation of the dual role of TH in cancer – especially of the interference of TH signaling with the hallmarks of cancer – is anticipated to inform decision-making and optimize patient selection.

SFE-AFCE-SFMN 2022 Consensus on the management of thyroid nodules: Initial work-up for thyroid nodules

The SFE-AFCE-SFMN 2022 consensus deals with the management of thyroid nodules, a condition that is a frequent reason for consultation in endocrinology. In more than 90% of cases, patients are euthyroid, with benign non-progressive nodules that do not warrant specific treatment. The clinician's objective is to detect malignant thyroid nodules at risk of recurrence and death, toxic nodules responsible for hyperthyroidism or compressive nodules warranting treatment. The diagnosis and treatment of thyroid nodules requires close collaboration between endocrinologists, nuclear medicine physicians and surgeons, but also involves other specialists. Therefore, this consensus statement was established jointly by 3 societies: the French Society of Endocrinology (SFE), French Association of Endocrine Surgery (AFCE) and French Society of Nuclear Medicine (SFMN); the various working groups included experts from other specialties (pathologists, radiologists, pediatricians, biologists, etc.). This section deals with the initial work-up for thyroid nodules in adult patients, including clinical and biological evaluation, standardized ultrasound characterization and EU-TIRADS-based nodule selection for fine-needle aspiration biopsy. Indications for thyroid core-biopsies or open surgical biopsies and for cross-sectional imaging of the neck and upper chest are also mentioned.

Interplay between cardiovascular and thyroid dysfunctions: A review of clinical implications and management strategies

Cardiovascular diseases (CVD) and thyroid dysfunction are two of the most prevailing disorders in the world that are closely interlinked. Actions of thyroid hormones are mediated via thyroid receptors present in the myocardium and the vascular tissue. Primary mechanism that links thyroid dysfunction with CVD is the modification of cardiovascular risk factors (dyslipidemia, blood pressure, coagulation parameters, etc.) resulting in endothelial and left ventricular systolic and diastolic dysfunction.

Both overt and subclinical hyperthyroidism and hypothyroidism may cause adverse alterations in cardiac function. Hyperthyroidism gives rise to palpitation, atrial fibrillation, systolic hypertension, and heart failure, whereas hypothyroidism increases diastolic hypertension, pericardial effusion, and the risk of ischemic heart disease via altering lipid and coagulation parameters. Early recognition and treatment of thyroid dysfunction may prevent adverse cardiovascular events in patients with or without pre-existing CVD.

Certain cardiac conditions and medications can cause alterations in thyroid function that may predispose an individual to higher morbidity and mortality. In certain situations, thyroid dysfunction treatment may have cardiovascular benefits. This study deals with the interplay between cardiovascular and thyroid dysfunctions associated with clinical implications and management strategies.

Laboratory policies and practices for thyroid function tests in Croatia: survey on behalf of Working Group for Laboratory Endocrinology of the Croatian Society of Medical Biochemistry and Laboratory Medicine

Introduction

Laboratory plays important part in screening, diagnosis, and management of thyroid disorders. The aim of this study was to estimate current laboratory preanalytical, analytical and postanalytical practices and policies in Croatia.

Materials and methods

Working Group for Laboratory Endocrinology of the Croatian Society of Medical Biochemistry and Laboratory Medicine designed a questionnaire with 27 questions and statements regarding practices and protocols in measuring thyroid function tests. The survey was sent to 111 medical biochemistry laboratories participating in external quality assurance scheme for thyroid hormones organized by Croatian Centre for Quality Assessment in Laboratory Medicine. Data is presented as absolute numbers and proportions.

Results

Fifty-three participants returned the questionnaire. Response rate varied depending on question, yielding a total survey response rate of 46-48%. All respondents perform thyroid stimulating hormone (TSH). From all other thyroid tests, most performed is free thyroxine (37/53) and least TSH-stimulating immunoglobulin (1/53). Laboratories are using nine different immunoassay methods. One tenth of laboratories is verifying manufacturer’s declared limit of quantification for TSH and one third is verifying implemented reference intervals for all performed tests. Most of laboratories (91%) adopt the manufacturer’s reference interval for adult population. Reference intervals for TSH are reported with different percentiles (90, 95 or 99 percentiles).

Conclusion

This survey showed current practices and policies in Croatian laboratories regarding thyroid testing. The results identified some critical spots and will serve as a foundation in creating national guidelines in order to harmonize laboratory procedures in thyroid testing in Croatia.

How to approach clinically discordant FT4 results when changing testing platforms: real-world evidence

PURPOSE

Measurement of thyroid-stimulating hormone (TSH) and free thyroxine (FT4) is important for assessing thyroid dysfunction. After changing assay manufacturer, high FT4 versus TSH levels were reported at Ente Ospedaliero Cantonale (EOC; Bellinzona, Switzerland).

METHODS

Exploratory analysis used existing TSH and FT4 measurements taken at EOC during routine clinical practice (February 2018-April 2020) using Elecsys® TSH and Elecsys FT4 III immunoassays on cobas® 6000 and cobas 8000 analyzers (Roche Diagnostics). Reference intervals (RIs) were estimated using both direct and indirect (refineR algorithm) methods.

RESULTS

In samples with normal TSH levels, 90.9% of FT4 measurements were within the normal range provided by Roche (12-22 pmol/L). For FT4 measurements, confidence intervals (CIs) for the lower end of the RI obtained using direct and indirect methods were lower than estimated values in the method sheet; the estimated value of the upper end of the RI (UEoRI) in the method sheet was within the CI for the UEoRI using the direct method but not the indirect method. CIs for the direct and indirect methods overlapped at both ends of the RI. The most common cause of increased FT4 with normal TSH was identified in a subset of patients as use of thyroxine therapy (72.6%).

CONCLUSIONS

It is important to verify RIs for FT4 in the laboratory population when changing testing platforms; indirect methods may constitute a convenient tool for this. Applying specific RIs for selected subpopulations should be considered to avoid misinterpretations and inappropriate clinical actions.

The continuum of care of anticancer treatment-induced hypothyroidism in patients with solid non thyroid tumors: time for an intimate collaboration between oncologists and endocrinologists

INTRODUCTION

Hypothyroidism is a common adverse event of various anticancer treatment modalities, constituting a notable paradigm of the integration of the endocrine perspective into precision oncology.

AREAS COVERED

The present narrative review provides a comprehensive and updated overview of anticancer treatment-induced hypothyroidism in patients with solid non-thyroid tumors. A study search was conducted on the following electronic databases: PubMed, Google Scholar, Scopus.com, ClinicalTrials.gov, and European Union Clinical Trials Register from 2011 until August 2021.

EXPERT OPINION

In patients with solid non-thyroid tumors, hypothyroidism is a common adverse event of radiotherapy, high dose interleukin 2 (HD IL-2), interferon alpha (IFN-α), bexarotene, immune checkpoint inhibitors (ICPi), and tyrosine kinase inhibitors (TKIs), while chemotherapy may induce hypothyroidism more often than initially considered. The path forward for the management of anticancer treatment-induced hypothyroidism in patients with solid non-thyroid tumors is an integrated approach grounded on 5 pillars: prevention, vigilance, diagnosis, treatment and monitoring. Current challenges concerning anticancer treatment-induced hypothyroidism await counteraction, namely awareness of the growing list of related anticancer treatments, identification of predictive factors, counteraction of diagnostic pitfalls, tuning of thyroid hormone replacement, and elucidation of its prognostic significance. Close collaboration of oncologists with endocrinologists will provide optimal patient care.

The Clinical Relevance of Hypothyroidism in Patients with Solid Non-Thyroid Cancer: A Tantalizing Conundrum

Hypothyroidism in patients with solid non-thyroid cancer is a tantalizing entity, integrating an intriguing thyroid hormones (THs)-cancer association with the complexity of hypothyroidism itself. The present narrative review provides a comprehensive overview of the clinical relevance of hypothyroidism in solid non-thyroid cancer. Hypothyroidism in patients with solid non-thyroid cancer is reminiscent of hypothyroidism in the general population, yet also poses distinct challenges due to the dual role of THs in cancer: promoting versus inhibitory. Close collaboration between oncologists and endocrinologists will enable the prompt and personalized diagnosis and treatment of hypothyroidism in patients with solid non-thyroid cancer. Clinical data indicate that hypothyroidism is a predictor of a decreased or increased risk of solid non-thyroid cancer and is a prognostic factor of favorable or unfavorable prognosis in solid non-thyroid cancer. However, the impact of hypothyroidism with respect to the risk and/or prognosis of solid non-thyroid cancer is not a consistent finding. To harness hypothyroidism, or THs replacement, as a personalized anticancer strategy for solid non-thyroid cancer, four prerequisites need to be fulfilled, namely: (i) deciphering the dual THs actions in cancer; (ii) identifying interventions in THs status and developing agents that block tumor-promoting THs actions and/or mimic anticancer THs actions; (iii) appropriate patient selection; and (iv) counteracting current methodological limitations.

The impact of the management strategies for patients with subclinical hypothyroidism on long-term clinical outcomes: An umbrella review

AIM

This umbrella review summarises and compares synthesised evidence on the impact of subclinical hypothyroidism and its management on long-term clinical outcomes.

METHODS

We conducted comprehensive searches on MEDLINE, EMBASE, Scopus, Web of Science, Cochrane Database of Systematic Reviews, JBI Evidence Synthesis, the PROSPERO register, Epistemonikos Database and PDQ Evidence from inception to February and July 2021 using keywords on subclinical hypothyroidism, treatment with levothyroxine, monitoring and primary outcomes (all-cause mortality, cardiovascular events, stroke, frailty fractures and quality of life). Only systematic reviews and meta-analyses on adult patient populations were considered. Study selection, data extraction and quality appraisal using AMSTAR-2 were done independently by two reviewers and discrepancies were resolved through discussion. Overlap across the selected reviews was also assessed, followed by a narrative synthesis of findings.

RESULTS

A total of 763 studies were identified from literature searches; 20 reviews met inclusion criteria. Methodological quality ratings were high (n = 8), moderate (n = 7), and low (n = 5), but no reviews were excluded on this basis. Though there was slight overlap across all reviews, some pairwise comparisons had high corrected covered area scores. Compared to euthyroidism, untreated subclinical hypothyroidism was associated with a higher risk of cardiovascular events or death if Thyroid Stimulating Hormone was above 10mIU/L at baseline. Treatment was associated with a lower risk of death from all causes for patients younger than 70 years and possibly better cognitive and quality of life scores than untreated individuals. Evidence on the risk of strokes and fractures was inconclusive.

CONCLUSION

In the long term, treatment of subclinical hypothyroidism may be beneficial for some patient groups. However, the findings of this review are negatively impacted by the relative sparseness and poor quality of available evidence. Additional large and adequately powered studies are needed to investigate this topic further.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO (CRD42021235172).

Does Radioactive Iodine Therapy for Hyperthyroidism Cause Cancer?

Radioactive iodine has been considered a safe and effective therapeutic option for hyperthyroidism secondary to Graves disease and autonomously functioning thyroid nodules since the mid-20th century. The question of whether I-131 at the doses used for hyperthyroidism might increase the risk of cancer has been investigated in a number of observational cohort studies over the years, with the preponderance of evidence being reassuring as to its safety. In particular, the 1998 Cooperative Thyrotoxicosis Therapy Follow-up Study (CTTFUS) has been widely cited as compelling evidence that I-131 is safe in hyperthyroidism therapy with respect to carcinogenesis. However, in 2019, a study by Kitahara and colleagues re-analyzed the CTTFUS cohort, extending the follow-up time and applying a novel dosimetric model for estimating tissue absorbed doses of radiation. This new analysis concluded that radioactive iodine was associated with an increased risk for mortality from overall cancer, breast cancer, and non-breast solid cancers. Reaction to this study was vociferous and particularly negative in the nuclear medicine literature. This mini-review was inspired by the 2019 CTTFUS controversy, and it is intended to provide the necessary context for clinicians to provide nuanced advice to their patients on the subject. To that end, the pre-2019 literature is surveyed, the 2019 CTTFUS study and a 2020 follow-up are discussed, and lessons from the literature and critical commentaries are considered.

OUP accepted manuscript

Background

The relationship between good early control of thyroid hormone levels after thyroidectomy for Graves’ disease (GD) and subsequent risks of mortality and morbidities is not well known. The aim of this study was to examine the association between thyroid hormone levels within a short interval after surgery and long-term mortality and morbidity risks from a population-based database.

Methods

Patients with GD who underwent complete/total thyroidectomy between 2006 and 2018 were selected from the Hong Kong Hospital Authority clinical management system. All patients were classified into three groups (euthyroidism, hypothyroidism, and hyperthyroidism) according to their thyroid hormone levels at 6, 12, and 24 months after surgery. Cox proportional hazards models were performed to compare the risks of all-cause mortality, cardiovascular disease (CVD), Graves’ ophthalmopathy, and cancer.

Results

Over a median follow-up of 68 months with 5709 person-years, 949 patients were included for analysis (euthyroidism, n = 540; hypothyroidism, n = 282; and hyperthyroidism, n = 127). The hypothyroidism group had an increased risk of CVD (HR = 4.20, 95 per cent c.i. 2.37 to 7.44, P < 0.001) and the hyperthyroidism group had an increased risk of cancer (HR = 2.14, 95 per cent c.i. 1.55 to 2.97, P < 0.001) compared with the euthyroidism group. Compared with patients obtaining euthyroidism both at 6 months and 12 months, the risk of cancer increased in patients who achieved euthyroidism at 6 months but had an abnormal thyroid status at 12 months (HR = 2.33, 95 per cent c.i. 1.51 to 3.61, P < 0.001) and in those who had abnormal thyroid status at 6 months but achieved euthyroidism at 12 months (HR = 2.52, 95 per cent c.i. 1.60 to 3.97, P < 0.001).

Conclusions

This study showed a higher risk of CVD in postsurgical hypothyroidism and a higher risk of cancer in hyperthyroidism compared with achieving euthyroidism early after thyroidectomy. Patients who were euthyroid at 6 months and 12 months had better outcomes than those achieving euthyroidism only at 6 months or 12 months. Attaining biochemical euthyroidism early after thyroidectomy should become a priority.

Have We Got Thy3 Wrong in the UK? A Four-Year Single-Site Analysis of Malignancy Rates in Thy3 Nodules

Introduction

Thyroid nodules routinely undergo ultrasound-guided fine-needle aspiration (FNA), as recommended by the National Institute for Health and Care Excellence (NICE) and the British Thyroid Association (BTA). The cytology results are classified using the “Thy” system from Thy1 to Thy5. Intermediate Thy3 FNA results are challenging, as this suggests malignancy is possible, but the relatively low rates of malignancy can make decision-making difficult. Thy3 is further subdivided into Thy3a and Thy3f.

BTA recommends further ultrasound with or without FNA cytology for Thy3a nodules and hemithyroidectomy for Th3yf nodules based on a published positive predictive value (PPV) for malignancy of 17% for Thy3a and up to 40% for Thy3f results.

We aim to compare the actual malignancy rates of Thy3 nodules in our unit to these figures.

Methods

A retrospective study was performed looking at the histologically confirmed malignancy rates in Thy3a and Thy3f cytology over four years between January 2016 and December 2019.

Results

There were 162 separate Thy3 nodules in 156 patients included in this study, of which 60 were classified as Thy3a and 102 as Thy3f. 10% of patients with Thy3a nodules underwent repeat cytology. The histologically confirmed malignancy rate was 33% in Thy3a and 11% in Thy3f lesions.

Discussion

We found the rates of histologically confirmed malignancy are reversed compared to the published PPVs with a higher rate in Thy3a nodules and a lower rate in Thy3f. This suggests that the surgical decision-making and patient counselling may be based on flawed data in our unit and possibly throughout the UK, making a wider study involving multiple centers desirable.

Real-life practice of thyroid hormone use in hypothyroid and euthyroid patients: a detailed view from the THESIS* questionnaire survey in France

AIM

To describe practices of French physicians regarding thyroid hormone therapy, focusing on available LT4 formulations.

MATERIAL AND METHODS

Members of the French Endocrine Society (FES) and affiliated societies (the Endocrine Tumor Group, French College of Teachers of Endocrinology, Diabetes and Metabolic Diseases and the Union of Endocrinology, Diabetology, Metabolic Diseases and Nutrition Specialists) were invited to participate in an online survey.

RESULTS

534 of the 2,094 persons contacted (25.5%) completed the survey and were included in the analysis. The vast majority (99.4%) reported that levothyroxine (LT4) is the treatment of choice for hypothyroidism. 7.1% and 14.2% of respondents respectively considered liothyronine (LT3) or a combination of LT4 and LT3 for the treatment of hypothyroidism, mainly when symptoms persisted despite achieving normal TSH concentrations with LT4 therapy. For 44% of respondents, thyroid hormone treatment is never indicated in euthyroid patients, while the remainder would consider treating euthyroid patients with a goiter growing over time (40.2%) and/or euthyroid women with positive anti-TPO antibodies and infertility (31.7%). LT4 tablets were the preferred LT4 formulation. A significant proportion of FES members expected no major clinical differences upon changing to formulations such as soft-gel capsules or liquid solutions, even in specific scenarios such as poor biochemical control or suspicion of malabsorption.

CONCLUSION

The treatment of choice for hypothyroidism in France is LT4. LT3-based therapy is considered by some physicians in case of persistent symptoms of hypothyroidism despite normal TSH level. A significant proportion of respondents (66.0%) would consider treating euthyroid patients, contrary to the present state of knowledge. These outdated practices should be addressed by professional bodies such as the FES.

Management strategies for patients with subclinical hypothyroidism: a protocol for an umbrella review

BACKGROUND

Subclinical hypothyroidism is a thyroid disorder diagnosed from the laboratory blood test results of otherwise asymptomatic patients. It has been associated with poor cardiovascular outcomes, mortality and progression to overt thyroid hormone deficiency. Current guidelines on the management of subclinical hypothyroidism differ because of conflicting evidence on long-term treatment benefits. Even though there are several existing systematic reviews on its clinical outcomes, no definitive conclusion has been reached yet. As such, a new synthesis could help provide more insight and consensus on this topic. To this purpose, this umbrella review will evaluate and synthesise current evidence on the long-term clinical outcomes of the different management strategies for subclinical hypothyroidism.

METHODS

This is a protocol for an umbrella review on the management strategies for subclinical hypothyroidism. We will conduct literature searches in multiple electronic databases (from inception onwards), namely MEDLINE, EMBASE, Scopus, Web of Science, Cochrane Database of Systematic Reviews, JBI Evidence Synthesis, Epistemonikos database, PDQ Evidence and the PROSPERO register. There will be no restriction on the date or language of publication. Additional material will be identified through grey literature searches and citation chaining. Review inclusion criteria will be patients with subclinical hypothyroidism, receiving treatment or monitoring, no restrictions on the comparators used and with cardiovascular events, frailty fractures, quality of life and all-cause mortality as primary outcomes of interest. Two reviewers will independently screen all citations, full-text articles and abstract data on a pre-piloted form in duplicate. Methodological quality (or bias) of included studies will be appraised using AMSTAR-2. Any conflicts that arise will be resolved through discussion or involving a third reviewer. A narrative synthesis will be provided with information presented in the main text and tables to summarise and explain the characteristics and findings of the included reviews. Even so, it is not expected that a meta-analysis will be performed due to review variability. Study limitations and methodological quality assessments will also be reported to provide context for the overall summary of evidence.

DISCUSSION

This review will provide a comprehensive summary of the effects of the pharmacological and non-pharmacological management of subclinical hypothyroidism on specific long-term clinical outcomes. It is anticipated that the findings of this umbrella review will aid in the development of consensus-based clinical recommendations for subclinical hypothyroidism, as well as highlight areas for future research. Review findings will be disseminated primarily through peer-reviewed publications.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42021235172.

Phenotype and genotype of 197 British patients with McArdle disease: An observational single-centre study

McArdle disease is caused by recessive mutations in PYGM gene. The condition is considered to cause a "pure" muscle phenotype with symptoms including exercise intolerance, inability to perform isometric activities, contracture, and acute rhabdomyolysis leading to acute renal failure. This is a retrospective observational study aiming to describe phenotypic and genotypic features of a large cohort of patients with McArdle disease between 2011 and 2019. Data relating to genotype and phenotype, including frequency of rhabdomyolysis, fixed muscle weakness, gout and comorbidities, inclusive of retinal disease (pattern retinal dystrophy) and thyroid disease, were collected. Data from 197 patients are presented. Seven previously unpublished PYGM mutations are described. Exercise intolerance (100%) and episodic rhabdomyolysis (75.6%) were the most common symptoms. Fixed muscle weakness was present in 82 (41.6%) subjects. Unexpectedly, ptosis was observed in 28 patients (14.2%). Hyperuricaemia was a common finding present in 88 subjects (44.7%), complicated by gout in 25% of cases. Thyroid dysfunction was described in 30 subjects (15.2%), and in 3 cases, papillary thyroid cancer was observed. Pattern retinal dystrophy was detected in 15 out of the 41 subjects that underwent an ophthalmic assessment (36.6%). In addition to fixed muscle weakness, ptosis was a relatively common finding. Surprisingly, dysfunction of thyroid and retinal abnormalities were relatively frequent comorbidities. Further studies are needed to better clarify this association, although our finding may have important implication for patient management.

Thyroid dysfunction in patients older than 75 years: an analysis of inadequacy of treatment and therapeutic control

PURPOSE

Suboptimal control of thyroid dysfunction may carry harmful health consequences, especially in older population. We aimed to estimate the inadequacy of thyroid dysfunction treatment and control in people aged 75 years and over.

METHODS

A cross-sectional analysis of all serum thyrotropin (TSH) determinations carried out by the Biochemistry laboratory of the Hospital Universitario Puerta de Hierro Majadahonda during 2019 was performed. All samples from outpatients over age 75 years were selected. In patients with serum TSH out of the range of reference (0.35-5.0 mU/l), we calculated the proportions of patients with inadequate control and inadequate treatment.

RESULTS

Of a total of 15,255 patients (mean (SD) age, 82.9 ± 6.1 years; 62.1% females), 13,796 had normal serum TSH (82.8 ± 6.1 years; 61.1% females), 398 low TSH (83.3 ± 6.7 years; 75.6% females), and 1061 high TSH (83.0 ± 4.0 years; 69.5% females). Inadequate control of thyroid function was found in 45.2% (95% CI 40.0-51.0) of patients with low TSH and in 6.93% (95% CI 5.40-8.85) of patients with high TSH. Furthermore, 39.7% (95% CI 34.1-45.6) of patients with low TSH and 27.5% (95% CI 24.5-30.6) of patients with high TSH were not adequately treated. Inadequacy of control was higher in women and patients over 82 years with elevated TSH. Inadequacy of therapy was higher in women.

CONCLUSIONS

Inadequacy in both treatment and control of thyroid dysfunction is found in a significant number of aged patients. Clinicians should strive to improve thyroid medication prescription and closely monitor older patients with thyroid dysfunction.

Graves' hyperthyroidism-related pancytopenia: a case report with literature review

INTRODUCTION

Occurrence of pancytopenia in patients with untreated hyperthyroidism is extremely rare. To the best of our knowledge, only 30 cases have been reported in the English literature. Accurate diagnosis and appropriate tailored therapy are challenging due to the variegated causes of pancytopenia and the potential hematological toxicity of antithyroid drugs (ATDs).

CASE REPORT

We present a 51-year-old Caucasian man with newly diagnosed Graves' disease showing pancytopenia and liver dysfunction. Although in this context the use of ATDs is still under debate, low-dose methimazole therapy was able to induce resolution of both pancytopenia and liver dysfunction, along with euthyroidism restoration.

CONCLUSION

Searching in the English literature for previous studies, we identified only 30 cases worldwide to form our database. A demographic as well as clinical, laboratory, and histopathological analysis was performed. In most cases, the recovery of biochemical euthyroidism through the use of ATDs induced the resolution of pancytopenia (at laboratory and histological levels). Our review provides clinical, laboratory, and histopathological features of Graves's hyperthyroidism-related pancytopenia with a view to improving the knowledge of this rare hematological complication and assisting in the decision-making process regarding therapeutic options.

Neutropenia in patients with hyperthyroidism: Systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

Neutropenia, a low absolute neutrophil count (ANC), may be a sign of new-onset hyperthyroidism. The aim of this systematic review and meta-analysis was to provide the most reliable estimates of prevalence, degree and response to treatments of neutropenia in the pure hyperthyroidism setting.

METHODS

A comprehensive literature search was performed in PubMed and Scopus databases for retrieving articles in English and non-English languages reporting ANC values/neutropenic cases at presentation and after therapy in patients with hyperthyroidism. A proportion meta-analysis was performed with DerSimonian and Laird method (random-effects model). Pooled data were presented with 95% confidence intervals (95% CI) and displayed in a forest plot. I² statistic index was used to quantify the heterogeneity among the studies. Sensitivity analyses for the prevalence of neutropenia and the mean of ANC in hyperthyroid patients were performed by excluding the studies without full details. Trim and fill analysis and Egger's linear regression test were carried out to evaluate the publication bias. A two-sided P-value of <.05 was regarded as significant for all analyses. The National Heart, Lung and Blood Institute Quality Assessment Tool was used to evaluate the quality of studies included.

RESULTS

The literature search yielded 1880 studies of which 13 studies were included for systematic review and meta-analysis. Results of the meta-analysis demonstrated that the prevalence of neutropenia in newly diagnosed and untreated patients with Graves' hyperthyroidism was 10% (CI 5%-19%, I² 88.6%) and summary mean ANC value in neutropenic was 1.4 ± 0.3 × 10⁹ /L. In all neutropenic patients under ATD therapy neutropenia resolved, thus without the worsening of the baseline ANC values or the development of agranulocytosis. The sensitivity analyses showed similar results as those of the main analyses. For all outcomes, the publication bias was not statistically significant or not calculable.

CONCLUSIONS

Graves' disease per se is associated with neutropenia in about 10% of cases. Neutropenia usually appears as a mild to moderate laboratory abnormality with no detectable consequences. Subnormal/mild neutropenia should not be regarded as a contraindication to use ATDs, and clinicians should know that treating hyperthyroidism they have a significant chance to normalize ANC too.