Comparison of efficacy and adverse effects between methimazole 15 mg+inorganic iodine 38 mg/day and methimazole 30 mg/day as initial therapy for Graves' disease patients with moderate to severe hyperthyroidism

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.

Effect of previous administration of potassium iodine and different durations of low iodine diets for radioiodine therapy on the treatment of Graves' disease in iodine-rich areas

PURPOSE

To examine whether adherence to a low-iodine diet (LID) enhances the therapeutic efficacy of radioiodine therapy (RAI) in Graves' hyperthyroidism (GH) in iodine-rich areas.

METHODS

We retrospectively evaluated 185 patients with GH from Aichi (n = 114) and Hokkaido (n = 71) Prefectures. Patients aged ≥ 18 years with GH who underwent RAI between December 2012 and March 2022 were divided into subgroups based on pretreatment with anti-thyroid drug (ATD) or potassium iodide (KI). Patients were followed up with LID from 18 days (group A) or 7 days (group H) before RAI to 3 days after RAI. The dose of radioactive iodine 131 (131I) was adjusted to deliver > 100 Gy to the thyroid. The associations between urinary iodine concentration on UIC2 vs. 24hRU and UIC2 vs. the 1-year RAI success rate (SR) were investigated.

RESULTS

Compared with UIC1, UIC2 was significantly decreased in all subgroups (P < 0.01). An inverse correlation between UIC2 and 24hRU was observed in the four groups; however, the difference was insignificant. The SR in groups A and H was 85% and 89%, respectively. Univariate analysis revealed no association between UIC2 and SR in each group. Additionally, stratification of the 185 patients into quartiles using UIC2 yielded no significant differences in SR (p = 0.79).

CONCLUSIONS

LID sufficiently reduced UIC in patients undergoing RAI. Although a lower UIC2 may increase 24hRU, it did not increase the success of RAI. The benefit of LID in enhancing the efficacy of RAI in GH treatment remains uncertain.

NADPH Oxidase 3: Beyond the Inner Ear

Reactive oxygen species (ROS) were formerly known as mere byproducts of metabolism with damaging effects on cellular structures. The discovery and description of NADPH oxidases (Nox) as a whole enzyme family that only produce this harmful group of molecules was surprising. After intensive research, seven Nox isoforms were discovered, described and extensively studied. Among them, the NADPH oxidase 3 is the perhaps most underrated Nox isoform, since it was firstly discovered in the inner ear. This stigma of Nox3 as "being only expressed in the inner ear" was also used by me several times. Therefore, the question arose whether this sentence is still valid or even usable. To this end, this review solely focuses on Nox3 and summarizes its discovery, the structural components, the activating and regulating factors, the expression in cells, tissues and organs, as well as the beneficial and detrimental effects of Nox3-mediated ROS production on body functions. Furthermore, the involvement of Nox3-derived ROS in diseases progression and, accordingly, as a potential target for disease treatment, will be discussed.

Different doses of methimazole treatment of children and adolescents with graves' disease: a clinical study based on 161 cases of outpatients

OBJECTIVE

This study aimed to evaluate the association between the initial dose of MMI and the clinical course, as well as adverse effects on young people with GD.

METHODS

One hundred and sixty-one children and adolescents with newly diagnosed GD were enrolled for this study and categorized into four groups based on initial serum-free T3 and T4 levels and daily MMI doses: Group A (mild, 0.3-0.5 mg/kg/day, n = 78), Group B (moderate, 0.6-0.8 mg/kg/day, n = 37), Group C (severe, 0.6-0.8 mg/kg/day, n = 24), and Group D (severe, 0.8-1.0 mg/kg/day, n = 22). The thyroid function, blood cell analysis and liver function were examined before treatment and at 4, 8 and 12 weeks after treatment. Outcome of long-term follow-up were also observed.

RESULTS

After 12 weeks of treatment, 91.0% of the patients in group A and 90.9% of the patients in group D recovered to normalization of FT3, which was slightly higher than the other two groups; 70.8% of the patients in group C recovered to normalization of FT4, which was slightly lower than that in the other three groups. The incidence of minor adverse effects was 12.8% in group A, 13.5% in group B, 16.7% in group C and 40.9% in group D (P < 0.01). Remission was achieved in 38 patients (23.6%).

CONCLUSIONS

Lower doses of MMI (0.3-0.5 mg/kg/day) are suitable for mild GD, and higher doses of MMI (0.6-0.8 mg/kg/day) are advisable for moderate or severe GD. Much higher doses of MMI (0.8-1.0 mg/kg/day) are harmful for initial use in children and adolescents with GD patients.

Possible molecular exploration of herbal pair Haizao-Kunbu in the treatment of Graves' disease by network pharmacology, molecular docking, and molecular dynamic analysis

Objective

To promote the development and therapeutic application of new medications, it is crucial to conduct a thorough investigation into the mechanism by which the traditional Chinese herb pair of Haizao-Kunbu (HK) treats Graves' disease (GD).

Materials and methods

Chemical ingredients of HK, putative target genes, and GD-associated genes were retrieved from online public databases. Using Cytoscape 3.9.1, a compound-gene target network was established to explore the association between prosperous ingredients and targets. STRING, Gene Ontology, and Kyoto Encyclopedia of Genes and Genomes pathway analyses visualized core targets and disease pathways. Additionally, we conducted a refined analysis of the binding interactions between active ingredients and their respective targets. To visualize these findings, we employed precise molecular docking techniques. Furthermore, we carried out molecular dynamics simulations to gain insights into the formation of more tightly bound complexes.

Results

We found that there were nine key active ingredients in HK, which mainly acted on 21 targets. These targets primarily regulated several biological processes such as cell population proliferation, protein phosphorylation, and regulation of kinase activity, and acted on PI3K-AKT and MAPK pathways to treat GD. Analysis of the molecular interaction simulation under computer technology revealed that the key targets exhibited strong binding activity to active ingredients, and Fucosterol-AKT1 and Isofucosterol-AKT1 complexes were highly stable in humans.

Conclusion

This study demonstrates that HK exerts therapeutic effects on GD in a multi-component, multi-target, and multi-pathway manner by regulating cell proliferation, differentiation, inflammation, and immunomodulatory-related targets. This study provides a theoretical foundation for further investigation into GD.

Clinical manifestations and early effectiveness of methimazole in patients with graves' hyperthyroidism-related severe hepatic dysfunction

BACKGROUND

Graves' hyperthyroidism (GH) is often accompanied by mild to moderate liver injury, but severe hepatic dysfunction (SHD) is relatively rare. Whether patients with GH-related SHD can be treated with methimazole (MMI) remains controversial. This study aimed to determine the clinical characteristics and to evaluate the role of low-dose MMI for such patients.

METHODS

33 patients with GH-related SHD were selected for this retrospective study in the Fifth Medical Center of Chinese PLA General Hospital from January 2017 to July 2022. The clinical manifestations, therapeutic responses, and effectiveness of MMI were evaluated.

RESULTS

Systemic jaundice (100.0%), yellow urine (100.0%), fatigue (87.9%), and goiter (66.7%) were the main symptoms. Total bilirubin (TBIL) had no linear correlation with free triiodothyronine (FT3) (r = -0.023, p = .899), free thyroxine (FT4) (r = 0.111, p = .540), T3 (r = -0.144, p = .425), and T4 (r = 0.037, p = .837). On the 14th day after admission, FT3, FT4, T3, T4, TBIL, direct bilirubin (DBIL), alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), γ-glutamyltransferase (GGT), and international normalized ratio (INR) decreased compared with the baseline (p < .05). The decrease rates of FT3, FT4, T3, T4, TBIL, and DBIL in the MMI group were higher than those in the non-MMI group (p < .05). The improvement rate of the MMI group (77.8%) was higher than that of the non-MMI group (9.5%, p = .001). MMI treatment is an independent predictor affecting the early improvement of patients (OR = 0.022, p = .010).

CONCLUSIONS

The main clinical manifestations of patients with GH-related SHD were symptoms related to liver disease. Low-dose MMI was safe and effective for them.

Turning on the Antimicrobial Activity of Gold Nanoclusters Against Multidrug-Resistant Bacteria

In this work, we show that the addition of thiourea (TU) initiated broad-spectrum antimicrobial activity of otherwise inactive D-maltose-capped gold nanoclusters (AuNC-Mal). For example, AuNC-Mal/TU was effective against multidrug-resistant Pseudomonas aeruginosa with a minimum inhibitory concentration (MIC) of 1 μg mL-1 (2.5 μM [Au]) while having 30-60 times lower in vitro cytotoxicity against mammalian cells. The reaction of AuNC-Mal and TU generated the antimicrobial species of [Au(TU)2 ]+ and smaller AuNCs. TU increased the accumulation of Au in bacteria and helped maintain the oxidation state as AuI (vs. AuIII ). The modes of action included the inhibition of thioredoxin reductase, interference with the CuI regulation and depletion of ATP. Moreover, the antimicrobial activity did not change in the presence of colistin or carbonyl cyanide 3-chlorophenylhydrazone, suggesting that AuNC-Mal/TU was indifferent to the outer membrane barrier and to bacterial efflux pumps.

The Mediation Role of Thyrotropin Receptor Antibody in the Relationship Between Age and Severity of Hyperthyroidism in Graves' Disease

Background: The severity of hyperthyroidism in Graves' disease (GD) has been reported to be worse in younger patients and to gradually improve with advancing age, accompanied by declining thyrotropin (TSH) receptor antibody (TRAb) values. This study was conducted to explore the extent to which the declining TRAb production may contribute to a decrease in severe hyperthyroidism with advancing age in patients with GD. Methods: This study was a cross-sectional analysis of retrospectively reviewed data. The medical records of patients newly diagnosed with GD at Ito Hospital, between January 2005 and June 2019, were examined. Patients were divided into age-stratified groups for evaluation. Multivariable logistic regression was performed to estimate the odds ratio (OR) of severe hyperthyroidism by increasing age. Mediation analyses were also conducted to quantify the association between age and declining severity of hyperthyroidism mediated through decreased TRAb productivity. Results: A total of 21,018 patients with newly diagnosed GD (3848 male and 17,170 female) were included. A correlation was observed between TRAb value and thyroid hormone values in each age-stratified group, which became weaker with an increase in age. Patients aged <40 years had a higher risk of severe hyperthyroidism (free thyroxine [fT4] level >7.0 ng/dL [n = 5616], OR [confidence interval, CI] = 1.80 [1.68-1.92]; free triiodothyronine [fT3] level >25 pg/mL [n = 4501], OR [CI] = 2.06 [1.92-2.23]) than those aged ≧40 years. In examining the relationship between age and severe hyperthyroidism, the proportion mediated through TRAb productivity was 8.5% and 8.4% using fT4 and fT3 as an outcome index, respectively. Conclusions: Declining TRAb value mediated only 8.5% of the negative association between age and severity of hyperthyroidism. The presence of other underlying mechanisms, such as the decline in the reactivity of thyrocytes to TSH stimulation, requires further investigation.

Clinical Review and Update on the Management of Thyroid Storm

Thyroid storm is a severe manifestation of thyrotoxicosis. Thyroid storm is diagnosed as a combination of thyroid function studies showing low to undetectable thyroid stimulating hormone (TSH) (<0.01mU/L) with elevated free thyroxine (T4) and/or triiodothyronine (T3), positive thyroid receptor antibody (TRab) (if Graves' disease is the underlying etiology), and with clinical signs and symptoms of end organ damage. Treatment involves bridging to a euthyroid state prior to total thyroidectomy or radioactive iodine ablation to limit surgical complications such as excessive bleeding from highly vascular hyperthyroid tissue or exacerbation of thyrotoxicosis. The purpose of this article is a clinical review of the various treatments and methodologies to achieve a euthyroid state in patients with thyroid storm prior to definitive therapy.

2022 Update on Clinical Management of Graves Disease and Thyroid Eye Disease

The management of hyperthyroidism and extrathyroidal manifestations of Graves disease remains complex. Considerations that include patient preference, age, comorbidity, pregnancy, tobacco smoking, and social determinants of health must all be weaved into a cohesive management plan. A multidisciplinary team is required to manage all aspects of Graves disease, particularly thyroid eye disease, for which new therapeutic options are now available.

The Relationship Between Primary Thyroid Lymphoma and Various Types of Thyroid Autoimmunity: A Retrospective Cohort Study of 498 Cases, Including 9 Cases with Graves' Disease

Background: Primary thyroid lymphoma (PTL) is known to develop mostly in patients with Hashimoto's thyroiditis (HT), and it is rare for it to develop in patients with Graves' disease (GD). The objective of this study was to investigate the clinical features, pathological findings, and long-term outcomes of PTL patients, grouped according to the presence of GD, HT, or no autoimmune thyroid disease (AITDs). The GD group was of major interest due to limited knowledge of the relationship with PTL. Methods: In this single-center retrospective cohort study, we reviewed the medical records of all patients diagnosed with PTL between August 1979 and October 2021, and we characterized the patients according to the presence of HT, GD, or no AITDs. Pathological specimens were classified according to the World Health Organization classification. Staging was performed in accordance with the Ann Arbor classification. Results: During the 42-year period, 498 participants were diagnosed with PTL. The median age was 68 (interquartile range 61-76) years, and 221 patients were stage IE, whereas the remaining 277 patients were stage IIE. Of the PTL patients, 431 (86.6%) were diagnosed with HT, 9 (1.8%) were diagnosed with GD, and 58 (11.6%) did not have AITDs. All nine patients with GD were positive for anti-thyroglobulin antibody and/or anti-thyroid peroxidase antibody. All patients with GD were treated with anti-thyroid medication. There were no significant differences in the proportions of each subtype of PTL between the PTL patients with GD and all subjects with PTL (p = 0.51), PTL patients with HT (p = 0.51), or PTL patients without AITDs (p = 0.48). The median follow-up time was 6.2 (interquartile range 3.0-10.7) years after the diagnosis of PTL. The Kaplan-Meier curve analyses showed no significant differences in overall survival and event-free survival between PTL patients with GD and those with HT (p = 0.37), or between PTL patients with GD and those without AITDs (p = 0.43). Conclusions: The PTL was observed with HT in a majority of cases, and rarely with GD (1.8%). The proportions of each pathological subtype of PTL and the prognosis of PTL were not different between the patients with GD and those with HT or those without AITDs.

Survey of the actual administration of thiamazole for hyperthyroidism in Japan by the Japan Thyroid Association

To clarify the actual administration of thiamazole (MMI), the first choice of antithyroid drugs, the actual therapy provided by the Japan Thyroid Association (JTA) members for the following conditions was surveyed. The subjects included adult patients, pregnant women, and pediatric patients with Graves' disease who visited each medical institution from September 2019 to February 2020. Initial doses, frequency of administration, maintenance doses, maximum doses, consultation intervals for pregnant women, and dosages administrated to breastfeeding mothers were surveyed. The total number of cases collected was 11,663. Administration of 15 mg once a day was the most common initial therapy, constituted 74.4% (2,526/3,397 cases) of adults, 33.8% (44/130) of pregnant women, and 50.8% (61/120) of children. The maintenance dose before discontinuation was equivalent to 2.5 mg/day in 52.3% (3,147/6,015). The most common maximum dose for adults and children was 30 mg/day, administrated to 57.5% of adults (223/388) and 59.6% (28/47) of children; for pregnant women, it was 15 mg/day, administrated to 71.1% (27/38). The most common consultation interval for pregnant women was every four weeks (32.1%, 341/1,063). In lactating mothers, the dose was 10 mg/day or less in 366 of 465 cases (78.7%). Breastfeeding was also allowed 4-6 hours after the administration of 15-20 mg/day in 69 patients (14.8%). Breastfeeding was prohibited in 26 patients (5.6%). In conclusion, initial MMI therapy was started with 15 mg once a day in most patients, and MMI was also administrated to lactating mothers following the Graves' disease treatment guidelines by the JTA.

Methimazole plus levothyroxine for treating hyperthyroidism in children: a systematic review and meta-analysis

BACKGROUND

Hyperthyroidism is a disease of excessive synthesis and secretion of thyroid hormones, and there is a lack of studies that have systematically evaluated the efficacy of the combination in treating hyperthyroidism. This study aimed to systematically evaluate the effectiveness and safety of methimazole combined with levothyroxine for treating hyperthyroidism in children.

METHODS

We searched PubMed, CNKI, Wanfang Database, EMBASE, Web of Science, and other online electronic databases to find correlation studies of methimazole combined with levothyroxine in treating hyperthyroidism in children from 2010 to 2021. Meta-analysis was performed using Stata 16 software.

RESULTS

Finally, 15 relevant articles were included comprising 1,718 pediatric patients. Meta-analysis results indicated that compared with methimazole alone (control group), the experimental group administered methimazole + levothyroxine had no evident difference in the level of thyroid-stimulating hormone [standardized mean difference (SMD) =-0.34, 95% confidence interval (CI): -1.02, 0.35, P=0.33], but notably improved the efficacy of clinical treatment of hyperthyroidism in children [odds ratio (OR) =5.77, 95% CI: 2.62, 12.74, P<0.001]. Meanwhile, the experimental group had lower adverse reaction rates (OR =0.28, 95%CI: 0.19, 0.40, P<0.001), free triiodothyronine (FT3) level (SMD =-0.85, 95% CI: -1.57, 0.13, P=0.02), free tetraiodothyronine (FT4) level (SMD =-0.94, 95% CI: -1.59, -0.30, P=0.004) and reduced thyroid volume (SMD =-1.3, 95% CI: -1.67, 0.93, P<0.001).

DISCUSSION

Using methimazole + levothyroxine to treat hyperthyroidism in children can raise the levels of FT3 and FT4, reduce the thyroid volume, improve clinical efficacy, and lower the adverse reaction rate of patients.

Cardiac Troponin Is Elevated in Patients with Thyrotoxicosis and Decreases as Thyroid Function Improves and Brain Natriuretic Peptide Levels Decrease

INTRODUCTION

High-sensitive cardiac troponin reflects micro-myocardial injury in the absence of overt myocardial infarction.

OBJECTIVE

This study aimed to clarify how thyrotoxicosis affects cardiac troponin.

METHODS

This was a prospective observational study in Japan. Untreated patients with thyrotoxicosis who visited Ito Hospital were enrolled, and medical treatment was initiated for hyperthyroidism. Thyroid function, high-sensitive troponin I (hsTnI), and brain natriuretic peptide (BNP) were measured at baseline and then every 3 months for 1 year.

RESULTS

Data from a total of 143 patients (median age, 42 years; 32 men and 111 women) were investigated. At baseline, median hsTnI was 1.9 pg/mL and ranged from 0 to 69.6 pg/mL. Five patients (3.5%) had a high hsTnI value that exceeded 26.2 pg/mL, which is used as the cutoff for diagnosis of myocardial infarction, and 22 patients (15.4%) had an intermediate value between 5.0 and 26.2 pg/mL. Multivariable regression analysis showed that significant predictors of the hsTnI value were age (β = 0.20, p = 0.01) and BNP (β = 0.43, p < 0.0001) (R² = 0.27, F = 26.0, p < 0.0001), and significant predictors of the BNP value were age (β = 0.23, p = 0.001), hemoglobin (β = -0.43, p < 0.0001), free T₄ (FT₄) (β = 0.23, p = 0.001), and hsTnI (β = 0.27, p < 0.0001) (R² = 0.49, F = 33.8, p < 0.0001). Correlations were found between a decrease in hsTnI and BNP in the first 3 months (ρ = 0.49, p < 0.0001). A decrease in FT₄ in the first 3 months was weakly correlated with decreases in hsTnI (ρ = 0.32, p = 0.0004) and BNP (ρ = 0.32; p = 0.0003). Of the 27 patients with elevated hsTnI (≥5.0 pg/mL), the hsTnI level was normalized in 20 patients within a year.

CONCLUSIONS

In thyrotoxicosis, the myocardial biomarker hsTnI is elevated in about 20% of patients; hsTnI levels decrease as thyroid function improves and BNP decreases.

Prevalence and Treatment Outcomes of Marine-Lenhart Syndrome in Japan

INTRODUCTION

Marine-Lenhart syndrome (MLS) is now understood to be a combination of Graves' disease and autonomously functioning thyroid nodule(s) (AFTNs). The prevalence of the syndrome and suitable treatments for those living in iodine-sufficient areas are uncertain.

OBJECTIVES

We aimed to investigate the prevalence, treatment, and prognosis of MLS in Japan, an iodine-sufficient area.

METHODS

This study involved patients who visited our hospital between February 2005 and August 2019. Among patients with both thyrotoxicosis and thyroid nodule(s) larger than 10 mm, MLS and isolated AFTNs were diagnosed based on serum thyroid-stimulating hormone receptor antibody levels and scintigraphy using radioiodine or technetium-99m and thyroid uptake.

RESULTS

Twenty-two patients were found to have MLS, compared to 372 with isolated AFTNs and 8,343 with Graves' disease, during the period. Therefore, the rate of MLS cases was 0.26% among all patients with Graves' disease (22/8,343). Treatments and outcomes were assessed for cases of MLS (n = 18) and isolated AFTNs (n = 269). Antithyroid drugs (ATDs) were withdrawn in 27.8% of cases in the MLS group and 10.3% in the isolated AFTN group. There was no significant difference in the clinical outcome after ATD withdrawal between the 2 groups. However, the rate of hypothyroidism after radioactive iodine (RAI) administration was significantly higher in the MLS group than in the isolated AFTN group (42.9 vs. 9.0%, p = 0.005) despite similar doses of RAI.

CONCLUSIONS

The prevalence of MLS among patients with Graves' disease was 0.26% in Japan. RAI therapy induces hypothyroidism more frequently than in those with AFTNs probably because RAI is taken up in the surrounding Graves' tissues.

Does Age or Sex Relate to Severity or Treatment Prognosis in Graves' Disease?

Background: The prognosis of Graves' disease (GD) is reportedly related to sex, age, and genetic factors, although there is no consensus. The objective of this study was to investigate the relationship between severity and prognosis of GD and sex or age. Methods: Subjects were patients newly diagnosed with GD between January 2005 and June 2019, and medical records were retrospectively reviewed. Patients diagnosed between January 2009 and December 2010 and followed up for at least 12 months were enrolled. Patients were divided into nine age-stratified groups. Remission was defined as maintenance of a euthyroid state for more than one year after withdrawal of antithyroid drugs (ATDs). Results: Participants comprised 21,633 patients (3954 males, 17,679 females). Initial free triiodothyronine (fT3) and free thyroxine (fT4) levels significantly decreased with increasing age, including after sex stratification. fT4 was significantly higher in males than females aged 20-39 years. In 2191 patients treated with ATDs alone, median durations until remission were 37.7 and 30.6 months in males and females, respectively. Remission and recurrence were observed in 1391 patients (204 males, 1187 females) and 262 patients (37 males, 225 females), respectively. By Kaplan-Meier analyses, males required a significantly longer time to achieve remission than females (p < 0.0001), although there were no significant age-related differences (p = 0.08). Cox proportional hazard modeling showed a 41% higher hazard ratio (HR) for remission in females than males (adjusted HRs [aHR] confidence interval [CI] = 1.41 [1.21-1.64]), and each additional 10 years of age had a 14% lower rate of recurrence (age [per 10-year increase], aHR [CI] = 0.86 [0.78-0.94]); no significant relationship between recurrence rate and sex was identified. Conclusions: Severity of hyperthyroidism in GD was significantly higher in males in their 20s and 30s, declining with advancing age in both sexes. Females were more likely to achieve remission than males, and younger patients had a higher risk of recurrence, although recurrence was unrelated to sex.

Clinical Course of Euthyroid Subjects With Positive TSH Receptor Antibody: How Often Does Graves' Disease Develop?

Background

Thyroid stimulating hormone receptor antibody (TRAb) is detected in the serum of patients with Graves’ disease (GD). This study aims to investigate the prevalence of euthyroid individuals showing positive results for TRAb and to clarify the clinical course of thyroid function and TRAb levels in these subjects.

Objective

Subjects were female patients who newly visited our hospital for a screening test prior to fertility treatment and showed normal thyroid function and volume without nodules between 2014 and 2017. After excluding subjects with a history of thyroid disease, 5,622 subjects were analyzed.

Results

Forty-seven of the 5,622 subjects showed positive results for TRAb (reference range, <2.0 IU/L) at the initial visit. Median initial TRAb was 2.9 IU/L (range, 2.0-14.7 IU/L) and median follow-up was 18.3 months (range, 0-66.5 months). Six of the 47 subjects (12.8%) developed GD and median duration until development was 6.6 months (range, 1.2-13.2 months). Median TRAb values initially and at diagnosis of GD for those 6 patients were 3.7 IU/L (range, 2.7-5.1 IU/L) and 7.2 IU/L (range 3.6-21.4 IU/L), respectively. TRAb results turned negative for 20 of the 47 subjects but remained positive despite normal thyroid function in 13 of the 47 subjects.

Conclusion

GD developed over time in 12.8% of euthyroid young female patients showing positive TRAb within a median of 6.6 months. A positive result for TRAb itself did not mean development of GD, so other factors must be essential for the pathogenesis of GD.

Management of Graves Thyroidal and Extrathyroidal Disease: An Update

CONTEXT

Invited update on the management of systemic autoimmune Graves disease (GD) and associated Graves orbitopathy (GO).

EVIDENCE ACQUISITION

Guidelines, pertinent original articles, systemic reviews, and meta-analyses.

EVIDENCE SYNTHESIS

Thyrotropin receptor antibodies (TSH-R-Abs), foremost the stimulatory TSH-R-Abs, are a specific biomarker for GD. Their measurement assists in the differential diagnosis of hyperthyroidism and offers accurate and rapid diagnosis of GD. Thyroid ultrasound is a sensitive imaging tool for GD. Worldwide, thionamides are the favored treatment (12-18 months) of newly diagnosed GD, with methimazole (MMI) as the preferred drug. Patients with persistently high TSH-R-Abs and/or persistent hyperthyroidism at 18 months, or with a relapse after completing a course of MMI, can opt for a definitive therapy with radioactive iodine (RAI) or total thyroidectomy (TX). Continued long-term, low-dose MMI administration is a valuable and safe alternative. Patient choice, both at initial presentation of GD and at recurrence, should be emphasized. Propylthiouracil is preferred to MMI during the first trimester of pregnancy. TX is best performed by a high-volume thyroid surgeon. RAI should be avoided in GD patients with active GO, especially in smokers. Recently, a promising therapy with an anti-insulin-like growth factor-1 monoclonal antibody for patients with active/severe GO was approved by the Food and Drug Administration. COVID-19 infection is a risk factor for poorly controlled hyperthyroidism, which contributes to the infection-related mortality risk. If GO is not severe, systemic steroid treatment should be postponed during COVID-19 while local treatment and preventive measures are offered.

CONCLUSIONS

A clear trend towards serological diagnosis and medical treatment of GD has emerged.

Therapeutic efficacy and limitations of potassium iodide for patients newly diagnosed with Graves' disease

The efficacy of potassium iodide (KI) for Graves' disease (GD) has been reported, although few clinical reports have examined the long-term efficacy of treatment. The objective of this study was to investigate the efficacy and limitations of KI treatment for GD. This study enrolled patients newly diagnosed with mild GD, defined as free thyroxine (FT4) <5.0 ng/dL, between July 2014 and June 2016. KI was started at a dose of 50 mg/day, and if FT4 values did not decrease after initiation of treatment, doses were increased to 100 mg/day. Patients for whom thyroid hormone levels could not be controlled with KI at 100 mg/day were regarded as non-responders. Of the 122 patients (13 males, 109 females) included in this study, 71 (58.2%) responded to KI therapy. The remaining 51 patients (41.8%) were non-responders. The median duration required to judge non-responsiveness was 5.9 months. Multiple logistic regression analysis performed on parameters measured at the initial visit indicated FT4 (odds ratio (OR) 2.19, 95% confidence interval (CI) 1.28-3.75; p = 0.0007) and male sex (OR 3.58, 95%CI 1.04-12.3; p = 0.04) were significantly associated with KI responsiveness. Receiver operating characteristic (ROC) curve analysis of the relationship between FT4 and KI responsiveness indicated an FT4 cut-off of 2.76 ng/dL was optimal for differentiating between responders and non-responders. KI therapy was effective and safe for about 60% of patients with mild GD.

Characteristics of Patients with Graves' Disease Whose Thyroid Hormone Levels Increase After Substituting Potassium Iodide for Methimazole in the First Trimester of Pregnancy

Background: The clinical course of Graves' disease (GD) in women who switched from methimazole (MMI) to potassium iodide (KI) during the first trimester of pregnancy has never been reported in detail. Objective: To investigate the characteristics of GD patients whose thyroid hormone levels increase after substituting KI for MMI. Patients: Two hundred forty women with GD who had been treated with MMI and switched from MMI to inorganic iodide to control hyperthyroidism during the first trimester between January 1, 2005, and March 31, 2018. Results: In 133 (55.4%) of the GD patients, medication was completely tapered during pregnancy, and the other 107 (44.6%) GD patients were taking medication at delivery: 57 were taking KI alone and 50 were taking an antithyroid drug with or without KI. It was difficult to control the maternal thyrotoxicosis of 22 of the 107 patients with KI alone, and a higher dose of MMI compared with the dose at the time of conception was required (worsened group). Multivariate analysis revealed that the TRAb value at the time of switch from MMI to KI was the only factor that predicted continuation of the thyroid suppression medication, but none of the parameters was a predictor of the worsened group. Conclusions: It must be kept in mind that a certain proportion of GD patients escape from the antithyroid effect of iodide and that careful follow-up is necessary after switching a pregnant patient's medication to KI.

Safety of long-term antithyroid drug treatment? A systematic review

Continued low-dose MMI treatment for longer than 12-18 months may be considered in patients not in remission. However, ATDs are not free from adverse effects. We undertook a systematic review to clarify safety of long-term ATD treatment. Medline and the Cochrane Library for trials published between 1950 and Nov 2018 were systematically searched. We included original studies containing data for long-term (> 18 months) ATD treatment. Two reviewers independently extracted data from included trials and any disagreement was adjudicated by consensus. Of 615 related articles found, 12 fulfilled the criteria. Six articles had data for adults, five for non-adults and one article had data for both groups. The sample sizes ranged between 20 and 249 individuals, and the mean duration of ATD treatment ranged between 2.1 and 14.2 years. Considering all data from 1660 patients treated with ATD for a mean duration of 5.8 years (around 10,000 patient-years), major complications occurred only in 14 patients: 7 severe agranulocytosis, 5 severe liver damage, one ANCA-associated glomerulonephritis and one vasculitis with small cutaneous ulcerations. Minor complications rates were between 2 and 36%, while more complications were in higher doses and in the children. The most reported AE was cutaneous reaction; the other adverse events were elevated liver enzymes, leukocytopenia, arthritis, arthralgia, myalgia, thrombocytopenia, fever, nausea and oral aphthous. Long-term ATD treatment is safe, especially in low dose and in adults, indicating that it should be considered as an earnest alternative treatment for GD.

A New Highly Thyrotropin Receptor-Selective Small-Molecule Antagonist with Potential for the Treatment of Graves' Orbitopathy

BACKGROUND

The thyrotropin receptor (TSHR) is the target for autoimmune thyroid stimulating antibodies (TSAb) triggering hyperthyroidism. Whereas elevated thyroid hormone synthesis by the thyroid in Graves' disease can be treated by antithyroid agents, for the pathogenic activation of TSHR in retro-orbital fibroblasts of the eye, leading to Graves' orbitopathy (GO), no causal TSHR directed therapy is available.

METHODS

Due to the therapeutic gap for severe GO, TSHR inhibitors were identified by high-throughput screening in Chinese hamster ovary cells expressing the TSHR. Stereo-selective synthesis of the screening hits led to the molecule S37, which contains seven chiral centers. Enantiomeric separation of the molecule S37 resulted in the enantiopure molecule S37a-a micro-molar antagonist of thyrotropin-induced cyclic adenosine monophosphate accumulation in HEK 293 cells expressing the TSHR.

RESULTS

The unique rigid bent shape of molecule S37a may mediate the observed high TSHR selectivity. Most importantly, the closely related follitropin and lutropin receptors were not affected by this compound. S37a not only inhibits the TSHR activation by thyrotropin itself but also activation by monoclonal TSAb M22 (human), KSAb1 (murine), and the allosteric small-molecule agonist C2. Disease-related ex vivo studies in HEK 293 cells expressing the TSHR showed that S37a also inhibits cyclic adenosine monophosphate formation by oligoclonal TSAb, which are highly enriched in GO patients' sera. Initial in vivo pharmacokinetic studies revealed no toxicity of S37a and a remarkable 53% oral bioavailability in mice.

CONCLUSION

In summary, a novel highly selective inhibitor for the TSHR is presented, which has promising potential for further development for the treatment of GO.

ANNIVERSARY REVIEW: Antithyroid drug therapy: 70 years later

The thionamide antithyroid drugs were discovered in large part following serendipitous observations by a number of investigators in the 1940s who found that sulfhydryl-containing compounds were goitrogenic in animals. This prompted Prof. Edwin B Astwood to pioneer the use of these compounds to treat hyperthyroidism in the early 1940s and to develop the more potent and less toxic drugs that are used today. Despite their simple molecular structure and ease of use, many uncertainties remain, including their mechanism(s) of action, clinical role, optimal use in pregnancy and the prediction and prevention of rare but potentially life-threatening adverse reactions. In this review, we summarize the history of the development of these drugs and outline their current role in the clinical management of patients with hyperthyroidism.

Treatment of adult Graves' disease

Treatment strategy in Graves' disease firstly requires recovery of euthyroid status by antithyroid therapy. Treatment modalities, precautions, advantages and side-effects are to be discussed with the patient. No particular treatment modality has demonstrated superiority. Pregnancy or pregnancy project affects choice of treatment and monitoring. Graves' orbitopathy is liable to be aggravated by iodine-131 treatment and requires pre-treatment assessment. Iodine-131 treatment aims at achieving hypothyroidism. Thyroid surgery for Graves' disease should preferably be performed by an expert team. In case of recurrence of hyperthyroidism, the various treatment options should be discussed with the patient. Empiric treatment of thyroid dermopathy uses local corticosteroids in occlusive dressing.

Iodine-Rich Herbs and Potassium Iodate Have Different Effects on the Oxidative Stress and Differentiation of TH17 Cells in Iodine-Deficient NOD.H-2h4 Mice

Iodine-rich herbs such as seaweed, kelp, and sea tangle were widely used to treat various types of goiter with good effect and without any adverse side effects in China. When compared with potassium iodate (PI), iodine-rich herbs had a positive effect on the recovery of goiter resulting from iodine deficiency without any obvious harmful effects. In NOD.H-2^h4 mice, an autoimmune thyroiditis-prone model, iodine excess can increase infiltration of lymphocytes and structural damage of the thyroid follicles, hence resulting in thyroiditis. Until now, there has been little research on the comparative effects of PI and iodine-rich herbs on thyroid in an autoimmune thyroiditis-prone model. This study was designed to compare the different effects of iodine-rich herbs and PI on the thyroid gland in iodine-deficient NOD.H-2^h4 mice. Excessive intake of PI cause oxidative injury in the thyroid gland and increase the risk of autoimmune thyroiditis, while iodine-rich herbs cause less oxidative injury, significantly enhancing antioxidant capacity, and inhibit the high differentiation of Th17 cells in the thyroid glands of NOD.H-2^h4 mice.

Clinical course of thyroid function and thyroid associated-ophthalmopathy in patients with euthyroid Graves' disease

Background

Euthyroid Graves’ disease (EGD) is a rare condition defined as the presence of thyroid-associated ophthalmopathy (TAO) in patients with normal thyroid function. Due to the rarity of this disease, only a limited number of studies and case reports are available for further evaluation of the characteristics of the disease. The aim of this study was to examine the changes in the thyroid function, thyrotropin receptor antibodies (TRAb) and eye symptoms, and then determine whether TRAb is related to TAO in EGD patients. TRAb in this study was defined as including both thyrotropin-binding inhibitory immunoglobulin (TBII) and thyroid-stimulating immunoglobulin (TSAb).

Patients and methods

Medical records of patients diagnosed with EGD were reviewed. Ophthalmologists specializing in TAO examined the eyes of all subjects.

Results

Of the 58 patients diagnosed with EGD, 24.1% developed hyperthyroidism, while 3.4% developed hypothyroidism. A total of 72.4% of the 58 patients remained euthyroid throughout the entire follow-up period. At the initial presentation, TBII and TSAb were positive in 74.5% and 70.5%, respectively. Ophthalmic treatments were administered to 30 (51.7%) out of the 58 patients. A significant spontaneous improvement of the eye symptoms was found in 28 of the EGD patients who did not require eye treatments. EGD patients exhibited positive rates for both TBII and TSAb, with the number of the TRAb-positive patients gradually decreasing while the eye symptoms spontaneously improved over time. There were no correlations found between TRAb at initial presentation and the eye symptoms.

Conclusion

TBII and TSAb were positive in about 70% of EGD patients at their initial visit. Thyroid functions of EGD patients who have been euthyroid for more than 6.7 years may continue to remain euthyroid in the future.

Nonthionamide Drugs for the Treatment of Hyperthyroidism: From Present to Future

Hyperthyroidism is a common endocrine disease. Although thionamide antithyroid drugs are the cornerstone of hyperthyroidism treatment, some patients cannot tolerate this drug class because of its serious side effects including agranulocytosis, hepatotoxicity, and vasculitis. Therefore, nonthionamide antithyroid drugs (NTADs) still have an important role in controlling hyperthyroidism in clinical practice. Furthermore, some situations such as thyroid storm or preoperative preparation require a rapid decrease in thyroid hormone by combination treatment with multiple classes of antithyroid drugs. NTADs include iodine-containing compounds, lithium carbonate, perchlorate, glucocorticoid, and cholestyramine. In this narrative review, we summarize the mechanisms of action, indications, dosages, and side effects of currently used NTADs for the treatment of hyperthyroidism. In addition, we also describe the state-of-the-art in future drugs under development including rituximab, small-molecule ligands (SMLs), and monoclonal antibodies with a thyroid-stimulating hormone receptor (TSHR) antagonist effect.

Thyroid Storm: A Japanese Perspective

BACKGROUND

Thyroid storm (TS) is life threatening. In the mid-2000s, its incidence was poorly defined, peer-reviewed diagnostic criteria were not available, and management and treatment did not seem to be verified based upon evidence and latest advances in medicine.

METHODS

First, diagnostic criteria were developed based on 99 patients in the literature and seven patients in this study. Then, initial and follow-up surveys were conducted from 2004 through 2008, targeting all hospitals in Japan to obtain and verify information on patients who met diagnostic criteria for TS. Based on these data, the diagnostic criteria were revised, and management and treatment guidelines were created.

RESULTS

The incidence of TS in hospitalized patients in Japan was estimated to be 0.20 per 100,000 per year and 0.22% of all thyrotoxic patients. The mortality rate was 10.7%. Multiple organ failure was the most common cause of death, followed by congestive heart failure, respiratory failure, and arrhythmia. In the final diagnostic criteria for TS, the definition of jaundice as serum bilirubin concentration >3 mg/dL was added. Based upon nationwide surveys and the latest information, guidelines for the management and treatment for TS were extensively revised and algorithms were developed.

CONCLUSIONS

TS remains a life-threatening disorder, with >10% mortality in Japan. New peer-reviewed diagnostic criteria for TS are presented and its clinical features, prognosis, and incidence are clarified based on nationwide surveys. Furthermore, this information helped to establish detailed guidelines for the management and treatment of TS. A prospective prognostic study to validate the guidelines is eagerly anticipated.

Lugol's solution and other iodide preparations: perspectives and research directions in Graves' disease

Lugol's solution and other preparations containing iodide have for almost a century been used as an adjuvant treatment in patients with Graves' disease planned for thyroidectomy. Iodide has been shown to decrease thyroid hormone levels and reduce blood flow within the thyroid gland. An escape phenomenon has been feared as the iodide effect has been claimed to only be temporary. Lugol's solution has many additional effects and is used in other settings beside the thyroid. Still, there are questions of its mode of action, which doses should be deployed, if it should be used preoperative in all thyroidectomies or only in a few selected ones if at all, what is its use in other forms of thyrotoxicosis besides Graves' disease, and what is the mechanism acting on the vasculature and if these effects are confined only to arterial vessels supporting the thyroid or not. This review aims to collate current available data about Lugol's solution and other iodide preparations in the management of Graves' disease and give some suggestions where more research is needed.

Rare NOX3 Variants Confer Susceptibility to Agranulocytosis During Thyrostatic Treatment of Graves' Disease

Agranulocytosis is a rare and serious adverse effect of antithyroid drugs, with unknown etiology. The present study aimed to uncover genetic susceptibility and underlying mechanisms of antithyroid drug-induced agranulocytosis (ATDAC). We studied two independent families with familial Graves' disease, of which several members developed ATDAC. In addition, six sporadic ATDAC patients with Graves' disease were investigated. Whole exome sequencing analysis of affected and unaffected family members was performed to identify genetic susceptibility variants for ATDAC, followed by functional characterization of primary granulocytes from patients and unrelated healthy controls. Whole exome sequencing, cosegregation analysis, and stringent selection criteria of candidate gene variants identified NOX3 as a genetic factor related to ATDAC. Functional studies revealed increased apoptosis of methimazole-treated granulocytes from patients carrying NOX3 variants. In conclusion, genetic variants in NOX3 may confer susceptibility to antithyroid drug-induced apoptosis of granulocytes. These findings contribute to the understanding of the mechanisms underlying ATDAC.

Guidelines for the treatment of childhood-onset Graves' disease in Japan, 2016

Purpose behind developing these guidelines: Over one decade ago, the “Guidelines for the Treatment of Graves’ Disease with Antithyroid Drug, 2006” (Japan Thyroid Association (JTA)) were published as the standard drug therapy protocol for Graves’ disease. The “Guidelines for the Treatment of Childhood-Onset Graves’ Disease with Antithyroid Drug in Japan, 2008” were published to provide guidance on the treatment of pediatric patients. Based on new evidence, a revised version of the “Guidelines for the Treatment of Graves’ Disease with Antithyroid Drug, 2006” (JTA) was published in 2011, combined with the “Handbook of Radioiodine Therapy for Graves’ Disease 2007” (JTA). Subsequently, newer findings on pediatric Graves’ disease have been reported. Propylthiouracil (PTU)-induced serious hepatopathy is an important problem in pediatric patients. The American Thyroid Association’s guidelines suggest that, in principle, physicians must not administer PTU to children. On the other hand, the “Guidelines for the Treatment of Graves’ Disease with Antithyroid Drug, 2011” (JTA) state that radioiodine therapy is no longer considered a “fundamental contraindication” in children. Therefore, the “Guidelines for the Treatment of Childhood-Onset Graves’ Disease with Antithyroid Drug in Japan, 2008” required revision.

Relationship between dose of antithyroid drugs and adverse events in pediatric patients with Graves' disease

Graves’ disease (GD) accounts for a large proportion of pediatric hyperthyroidism, and the first-line treatment is antithyroid drug (ATD) therapy. Methimazole (MMI) is effective in most patients but is associated with significant adverse events (AEs). We reviewed the medical records of GD patients (n = 56) with onset age of <15 yr and investigated the relationship between MMI dose and AEs. The study population comprised 11 male and 45 female patients and the median age at diagnosis was 11 yr. All patients were initially treated with ATDs. Among the 52 patients initially treated with MMI, 20 received a low dose, and 32 received a high dose of MMI (< 0.7 vs ≥ 0.7 mg/kg/day, respectively). AEs occurred in 20% of the patients in the low-dose MMI group, and in 50% patients in the high-dose MMI group (p = 0.031). A greater variety of AEs was observed in the high-dose group. Neutropenia and rash were observed in both groups. With treatment transition to low-dose MMI according to the Japanese Society for Pediatric Endocrinology guidelines, we expect a decrease in the incidence of AEs in future. However, we should be careful as neutropenia and rash can occur independently of the MMI dose.

2016 Guidelines for the management of thyroid storm from The Japan Thyroid Association and Japan Endocrine Society (First edition)

Thyroid storm is an endocrine emergency which is characterized by multiple organ failure due to severe thyrotoxicosis, often associated with triggering illnesses. Early suspicion, prompt diagnosis and intensive treatment will improve survival in thyroid storm patients. Because of its rarity and high mortality, prospective intervention studies for the treatment of thyroid storm are difficult to carry out. We, the Japan Thyroid Association and Japan Endocrine Society taskforce committee, previously developed new diagnostic criteria and conducted nationwide surveys for thyroid storm in Japan. Detailed analyses of clinical data from 356 patients revealed that the mortality in Japan was still high (∼11%) and that multiple organ failure and acute heart failure were common causes of death. In addition, multimodal treatment with antithyroid drugs, inorganic iodide, corticosteroids and beta-adrenergic antagonists has been suggested to improve mortality of these patients. Based on the evidence obtained by nationwide surveys and additional literature searches, we herein established clinical guidelines for the management of thyroid storm. The present guideline includes 15 recommendations for the treatment of thyrotoxicosis and organ failure in the central nervous system, cardiovascular system, and hepato-gastrointestinal tract, admission criteria for the intensive care unit, and prognostic evaluation. We also proposed preventive approaches to thyroid storm, roles of definitive therapy, and future prospective trial plans for the treatment of thyroid storm. We hope that this guideline will be useful for many physicians all over the world as well as in Japan in the management of thyroid storm and the improvement of its outcome.

2016 American Thyroid Association Guidelines for Diagnosis and Management of Hyperthyroidism and Other Causes of Thyrotoxicosis

BACKGROUND

Thyrotoxicosis has multiple etiologies, manifestations, and potential therapies. Appropriate treatment requires an accurate diagnosis and is influenced by coexisting medical conditions and patient preference. This document describes evidence-based clinical guidelines for the management of thyrotoxicosis that would be useful to generalist and subspecialty physicians and others providing care for patients with this condition.

METHODS

The American Thyroid Association (ATA) previously cosponsored guidelines for the management of thyrotoxicosis that were published in 2011. Considerable new literature has been published since then, and the ATA felt updated evidence-based guidelines were needed. The association assembled a task force of expert clinicians who authored this report. They examined relevant literature using a systematic PubMed search supplemented with additional published materials. An evidence-based medicine approach that incorporated the knowledge and experience of the panel was used to update the 2011 text and recommendations. The strength of the recommendations and the quality of evidence supporting them were rated according to the approach recommended by the Grading of Recommendations, Assessment, Development, and Evaluation Group.

RESULTS

Clinical topics addressed include the initial evaluation and management of thyrotoxicosis; management of Graves' hyperthyroidism using radioactive iodine, antithyroid drugs, or surgery; management of toxic multinodular goiter or toxic adenoma using radioactive iodine or surgery; Graves' disease in children, adolescents, or pregnant patients; subclinical hyperthyroidism; hyperthyroidism in patients with Graves' orbitopathy; and management of other miscellaneous causes of thyrotoxicosis. New paradigms since publication of the 2011 guidelines are presented for the evaluation of the etiology of thyrotoxicosis, the management of Graves' hyperthyroidism with antithyroid drugs, the management of pregnant hyperthyroid patients, and the preparation of patients for thyroid surgery. The sections on less common causes of thyrotoxicosis have been expanded.

CONCLUSIONS

One hundred twenty-four evidence-based recommendations were developed to aid in the care of patients with thyrotoxicosis and to share what the task force believes is current, rational, and optimal medical practice.

Hyperthyroidism

Hyperthyroidism is characterised by increased thyroid hormone synthesis and secretion from the thyroid gland, whereas thyrotoxicosis refers to the clinical syndrome of excess circulating thyroid hormones, irrespective of the source. The most common cause of hyperthyroidism is Graves' disease, followed by toxic nodular goitre. Other important causes of thyrotoxicosis include thyroiditis, iodine-induced and drug-induced thyroid dysfunction, and factitious ingestion of excess thyroid hormones. Treatment options for Graves' disease include antithyroid drugs, radioactive iodine therapy, and surgery, whereas antithyroid drugs are not generally used long term in toxic nodular goitre, because of the high relapse rate of thyrotoxicosis after discontinuation. β blockers are used in symptomatic thyrotoxicosis, and might be the only treatment needed for thyrotoxicosis not caused by excessive production and release of the thyroid hormones. Thyroid storm and hyperthyroidism in pregnancy and during the post-partum period are special circumstances that need careful assessment and treatment.

Substituting Potassium Iodide for Methimazole as the Treatment for Graves' Disease During the First Trimester May Reduce the Incidence of Congenital Anomalies: A Retrospective Study at a Single Medical Institution in Japan

BACKGROUND

To control hyperthyroidism due to Graves' disease, antithyroid drugs should be administered. Several studies have shown that exposure to methimazole (MMI) during the first trimester of pregnancy increases the incidence of specific congenital anomalies that are collectively referred to as MMI embryopathy. Congenital anomalies associated with exposure to propylthiouracil (PTU) have also recently been reported.

METHODS

This study investigated whether substituting potassium iodide (KI) for MMI in the first trimester would result in a lower incidence of major congenital anomalies than continuing treatment with MMI alone. The cases of 283 women with Graves' disease (GD) were reviewed whose treatment was switched from MMI to KI in the first trimester (iodine group), as well as the cases of 1333 patients treated with MMI alone (MMI group) for comparison. Another major outcome of interest was the incidence of neonatal thyroid dysfunction. The subjects of the analysis of major congenital anomalies and neonatal thyroid dysfunction were live-born infants.

RESULTS

The incidence of major anomalies was 4/260 (1.53%) in the iodine group, which was significantly lower than the incidence of 47/1134 (4.14%) in the MMI group. Two neonates in the iodine group had anomalies consistent with MMI embryopathy (0.8%), as opposed to 18 neonates in the MMI group (1.6%). None of the neonates exposed to KI had thyroid dysfunction or goiter.

CONCLUSIONS

Substituting KI for MMI as a means of controlling hyperthyroidism in GD patients during the first trimester may reduce the incidence of congenital anomalies, at least in iodine-sufficient regions.