Hyperthyroidism: A Review

Farming activity and risk of treated thyroid disorders: Insights from the TRACTOR project, a nationwide cohort study

BACKGROUND

Epidemiological data regarding thyroid diseases are lacking, in particular for occupationally exposed populations.

OBJECTIVES

To compare the risk of hypothyroidism and hyperthyroidism between farming activities within the complete population of French farm managers (FMs).

METHODS

Digital health data from retrospective administrative databases, including insurance claims and electronic health/medical records, was employed. This cohort data spanned the entirety of French farm managers (FMs) who had undertaken work at least once from 2002 to 2016. Survival analysis with the time to initial medication reimbursement as timescale was used to examine the association (hazard ratio, HR) between 26 specific farming activities and both treated hypothyroidism and hyperthyroidism. A distinct model was developed for each farming activity, comparing FMs who had never engaged in the specific farming activity between 2002 and 2016 with those who had. All analyses were adjusted for potential confounders (e.g., age), and sensitivity analyses were conducted.

RESULTS

Among 1088561 FMs (mean age 46.6 [SD 14.1]; 31% females), there were 31834 hypothyroidism cases (75% females) and 620 hyperthyroidism cases (67% females), respectively. The highest risks were observed for cattle activities for both hyperthyroidism (HR ranging from 1.75 to 2.42) and hypothyroidism (HR ranging from 1.41 to 1.44). For hypothyroidism, higher risks were also observed for several animal farming activities (pig, poultry, and rabbit), as well as fruit arboriculture (HR = 1.22 [1.14-1.31]). The lowest risks were observed for activities involving horses. Sex differences in the risk of hypothyroidism were observed for eight activities, with the risk being higher for males (HR = 1.09 [1.01-1.20]) than females in viticulture (HR = 0.97 [0.93-1.00]). The risk of hyperthyroidism was two times higher for male dairy farmers than females.

DISCUSSION

Our findings offer a comprehensive overview of thyroid disease risks within the FM community. Thyroid ailments might not stem from a single cause but likely arise from the combined effects of various causal agents and triggering factors (agricultural exposome). Further investigation into distinct farming activities-especially those involving cattle-is essential to pinpoint potential risk factors that could enhance thyroid disease monitoring in agriculture.

High prevalence of erectile dysfunction in men with hyperthyroidism: a meta-analysis

OBJECTIVE

The objective of this study was to evaluate the association between hyperthyroidism and the risk of developing erectile dysfunction (ED).

METHODS

A comprehensive search of multiple databases, including PubMed, Embase, Cochrane, and Web of Science, was conducted to identify relevant studies investigating the relationship between hyperthyroidism and ED in men. The quality of the included studies was assessed using the Newcastle‒Ottawa Quality Rating Scale, and a meta-analysis was performed using Stata 16.0 and RevMan 5.3 software.

RESULTS

A total of four papers encompassing 25,519 study subjects were included in the analysis. Among these, 6,429 individuals had hyperthyroidism, while 19,090 served as controls. The overall prevalence of ED in patients with hyperthyroidism was determined to be 31.1% (95% CI 0.06-0.56). In patients with uncomplicated hyperthyroidism, the incidence of ED was 21.9% (95% CI 0.05-0.38). The combined odds ratio (OR) for the four studies was 1.73 (OR: 1.73; 95% CI [1.46-2.04]; p < .00001).

CONCLUSION

Our findings demonstrate a higher incidence of ED in patients with hyperthyroidism. These results provide valuable information for healthcare professionals and can facilitate discussions surrounding appropriate treatment options for ED in patients with hyperthyroidism.

Prospective study to evaluate radioactive iodine of 20 mCi vs 10-15 mCi in Graves' disease

OBJECTIVES

To assess whether increasing radioactive iodine dose can increase treatment efficacy in Graves' disease.

METHODS

A prospective study was conducted, including 106 patients receiving 20 mCi (740 MBq) radioactive iodine (RAI), compared with a retrospective data, including 113 patients receiving 10-15 mCi (370-555 MBq) RAI. Remission and failure rates were evaluated at 6 months post-RAI. Statistical analysis was performed using logistic regression and Kaplan-Meier curves.

RESULTS

Patients receiving 20 mCi RAI demonstrated a significantly higher remission rate compared to the 10-15 mCi group (82.1% vs 66.4%, p = 0.009). Median time to remission was shorter in the 20 mCI group (3 vs 4 months, p = 0.002). Hypothyroidism at 6 months was more prevalent in the 20 mCi group (67% vs 53%, p = 0.03). Larger thyroid size (> 60 g) was associated with treatment failure (p = 0.02).

CONCLUSIONS

Higher dosage (20 mCi) RAI showed superior efficacy in achieving remission compared to lower dosages (10-15 mCi) in Graves' disease treatment.

Investigating the mechanism and efficacy material basis of Xiehuo Xiaoying decoction for treating Graves' disease via thyroid cell apoptosis based on proteomics and molecular docking techniques

ETHNOPHARMACOLOGICAL RELEVANCE

For numerous years, the Xiehuo Xiaoying decoction (XHXY), a traditional Chinese medicine formula, has demonstrated substantial promise in treating Graves' disease (GD) in clinical settings, showcasing significant potential. However, the therapeutic mechanism and efficacy material basis of XHXY remains obscure.

AIM OF THE STUDY

This work aims to investigate the underlying mechanisms and to study the efficacy material basis of XHXY in anti-GD effect using a combination of TMT quantitative proteomics and molecular docking method.

MATERIALS AND METHODS

GD model was initiated by administering Ad-TSH289. Subsequently, the mice underwent a four-week regimen that included oral gavage of XHXY at doses of 17 g/kg·d and 34 g/kg·d, along with intraperitoneal injections of Gentiopicroside (GPS). Utilizing the principles of pharmacological chemistry in traditional Chinese medicine, we employed high-performance liquid chromatography quadrupole time-of-flight mass spectrometry (HPLC-QTOF/MS) to discern prescribed prototype composition of XHXY in serum samples from mouse. TMT proteomics research provided evidence of XHXY's putative targets and important pathways in vivo. The binding activity of probable action targets and prototype composition was detected by molecular docking. Finally, Immunohistochemistry (IHC) and TUNEL staining were used to verify the mechanism of XHXY and GPS in anti-GD.

RESULTS

XHXY and GPS alleviated GD by ameliorating the pathological changes and reducing thyroxine and TRAb levels. In mouse serum, a total of 31 prototypical XHXY ingredients were detected, and the majority of these components were from monarch and minister medicine. Proteomics study results indicated that the XHXY may mainly regulate targets including FAS-associated death domain protein (FADD), Apolipoprotein C-III, etc. and main pathways are Apoptosis, Cholesterol metabolism, TNF signalling pathway, etc. Strong binding activity of the prototypical active ingredient and GPS towards FADD, Caspase 8, and Caspase 3 was demonstrated by molecular docking. XHXY and its primary component, GPS, elevated the expression of FADD, Caspase 8, and Caspase 3, and enhance apoptosis in thyroid cells, as lastly validated by TUNEL and IHC staining.

CONCLUSIONS

XHXY exhibits a favorable therapeutic effect in treating GD by promoting apoptosis in thyroid cells through the upregulation of FADD, Caspase 8, and Caspase 3 expression. And GPS is the main efficacy material basis for its therapeutic effect in anti-GD.

Reappraising the role of thyroid scintigraphy in the era of TIRADS: A clinically-oriented viewpoint

Thyroid nodules (TNs) are a common entity, with the majority being benign. Therefore, employing an accurate rule-out strategy in clinical practice is essential. In the thyroid field, the current era is significantly marked by the worldwide diffusion of ultrasound (US)-based malignancy risk stratification systems of TN, usually reported as Thyroid Imaging Reporting And Data System (TIRADS). With the advent of US (and later TIRADS), the role of thyroid scintigraphy (TS) in clinical practice has gradually diminished. The authors of the present paper believe that the role of TS should be reappraised, also considering its essential role in detecting autonomously functioning thyroid nodules and its limited contribution to detecting thyroid cancers. Thus, this document aims to furnish endocrinologists, radiologists, surgeons, and nuclear medicine physicians with practical information to appropriately use TS.

Evaluation of Neuro-Hormonal Dynamics after the Administration of Probiotic Microbial Strains in a Murine Model of Hyperthyroidism

The microbiota-gut-brain axis has received increasing attention in recent years through its bidirectional communication system, governed by the ability of gut microorganisms to generate and regulate a wide range of neurotransmitters in the host body. In this research, we delve into the intricate area of microbial endocrinology by exploring the dynamic oscillations in neurotransmitter levels within plasma and brain samples. Our experimental model involved inducing hyperthyroidism in mice after a "probiotic load" timeframe using two strains of probiotics (Lactobacillus acidophilus, Saccharomyces boulardii, and their combination). These probiotic interventions continued throughout the experiment and were intended to uncover potential modulatory effects on neurotransmitter levels and discern if certain probiotic strains exhibit any protection from hyperthyroidism. Moreover, we aimed to outline the eventual connections between the gut microbiota and the hypothalamus-pituitary-thyroid axis. As our study reveals, there are significant fluctuations in crucial neurotransmitters within the hyperthyroidism model, related to the specific probiotic strain or combination. These findings could support future therapeutic approaches, help healthcare professionals choose between different probiotic therapies, and also allow us proceed with caution when administering such treatments, depending on the health status of hyperthyroid patients.

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.

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.

Changing the structure of PFOA and PFOS: a chemical industry strategy or a solution to avoid thyroid-disrupting effects?

BACKGROUND

The family of perfluoroalkyl and polyfluoroalkyl substances (PFAS) raised concern for their proven bioaccumulation and persistence in the environment and animals as well as for their hazardous health effects. As a result, new congeners of PFAS have rapidly replaced the so-called "old long-chain PFAS" (mainly PFOA and PFOS), currently out-of-law and banned by most countries. These compounds derive from the original structure of "old long-chain PFAS", by cutting or making little conformational changes to their structure, thus obtaining new molecules with similar industrial applications. The new congeners were designed to obtain "safer" compounds. Indeed, old-long-chain PFAS were reported to exert thyroid disruptive effects in vitro, and in vivo in animals and humans. However, shreds of evidence accumulated so far indicate that the "restyling" of the old PFAS leads to the production of compounds, not only functionally similar to the previous ones but also potentially not free of adverse health effects and bioaccumulation. Studies aimed at characterizing the effects of new-PFAS congeners on thyroid function indicate that some of these new-PFAS congeners showed similar effects.

PURPOSE

The present review is aimed at providing an overview of recent data regarding the effects of novel PFAS alternatives on thyroid function.

RESULTS AND CONCLUSIONS

An extensive review of current legislation and of the shreds of evidence obtained from in vitro and in vivo studies evaluating the effects of the exposure to novel PFOA and PFOS alternatives, as well as of PFAS mixture on thyroid function will be provided.

Causality of blood metabolites and metabolic pathways on Graves' disease and Graves' ophthalmopathy: a two-sample Mendelian randomization study

OBJECTIVES

There is ample that metabolic dysregulation is involved in Graves' disease (GD) and Graves' ophthalmopathy (GO). Recent studies have identified numerous metabolites associated with GD and GO. However, the causal impact of metabolites on GD and GO remains to be investigated.

METHODS

This two-sample Mendelian randomization (MR) analysis investigated the causal relationships between 486 blood metabolites and GD and GO. Sensitivity analysis was also performed to examine heterogeneity and pleiotropy.

RESULTS

MR analysis showed that 9 and 13 metabolites were associated with GD and GO, respectively, each meeting the nominal significance criteria (inverse variance weighted, p < 0.05). Additionally, four metabolic pathways were identified for each condition using network-based MetaboAnalyst 5.0.

CONCLUSIONS

The metabolites and pathways discovered in this study could serve as circulating metabolic biomarkers for clinical screening and prevention of GD and GO. They can be also used for further studies on the mechanisms and drug targets in GD and GO.

Associations of hyperthyroidism with epilepsy: a Mendelian randomization study

Prior studies have revealed an increased susceptibility to epilepsy in hyperthyroid individuals, but the genetic basis of the hyperthyroidism-epilepsy relationship is not fully comprehended, prompting this study to explore this potential association. We conducted a two-sample Mendelian randomization (TSMR) study to explore the relationship between hyperthyroidism and epilepsy by utilizing aggregated statistics from Genome-Wide Association Studies (GWAS). Data for hyperthyroidism were derived from a GWAS encompassing 462,933 participants, while epilepsy data were sourced from the International League Against Epilepsy (ILAE) consortium. Five distinct methods were employed for TSMR analysis, which included the inverse variance weighting method, MR Egger method, weighted median method, simple model, and weighted model. In our sensitivity analysis, we employed the MR Egger and MR PRESSO methods to assess pleiotropy, and inverse variance weighting and MR Egger in Cochran's Q statistics to assess heterogeneity. In the IEU database, utilizing the MR-Egger method, we obtained an odds ratio (OR) of 2.631 (95% CI 0.608, 9.796) with a p-value of 0.122. Meanwhile, employing the Weighted Median method yielded an OR of 1.813 (95% CI 0.786, 4.181) with a p-value of 0.163. The IVW method exhibited an OR of 1.986 (95% CI 1.127, 3.502) with a p-value of 0.018. In the assessment of heterogeneity, the MR-Egger method produced a Q statistic of 65.205, accompanied by a p-value of 0.087, while the IVW method recorded a Q statistic of 66.668 with a p-value of 0.083. The multifactorial analysis results showed an intercept term with a standard error (SE) value of 0.009 and a p-value of 0.291. In the FinnGen database, employing the MR-Egger method for all epilepsy data, we observed an OR of 0.952 (95% CI 0.831, 1.093) with a p-value of 0.539. Simultaneously, the Weighted Median method produced an OR of 0.986 (95% CI 0.953, 1.021) with a p-value of 0.423. The IVW method indicated an OR of 0.992 (95% CI 0.965, 1.019) with a p-value of 0.541. The MR-Egger method's assessment of heterogeneity resulted in a Q statistic of 2.671, associated with a p-value of 0.445, while the IVW method generated a Q statistic of 3.011 with a p-value of 0.556. The multifactorial analysis results displayed an intercept term with a SE-value of 0.019 and a p-value of 0.601. Sensitivity analysis found no evidence of horizontal pleiotropy or heterogeneity. Hyperthyroidism was found to be causally related to all epilepsy but had no effect on other types of epilepsy.