Selenium in Graves Hyperthyroidism and Orbitopathy

Efficacy of selenium supplementation for patients with Graves' hyperthyroidism during methimazole treatment: protocol for a systematic review and meta-analysis

INTRODUCTION

The most common cause of hyperthyroidism, Graves' disease is a common organ-specific autoimmune disease. Selenium is an essential trace element of the human body that is mainly concentrated in the thyroid gland and is involved in the synthesis and metabolism of thyroid hormones. Most studies have shown that the level of selenium is closely related to the occurrence and development of thyroid diseases, and selenium supplementation can help improve thyroid function. This study aims to evaluate the efficacy of selenium supplementation for patients with Graves' hyperthyroidism during methimazole treatment.

METHODS AND ANALYSIS

We will search the electronic databases including PubMed, Web of Science, Embase, the Cochrane Library, China National Knowledge Infrastructure, Wanfang Data and Chinese Biomedical Literature, and the time was deadline to December 2023. To evaluate the efficacy of methimazole combined with selenium supplementation in the treatment of Graves' hyperthyroidism, randomised controlled trials will be included. The Cochrane Collaboration's risk of bias tool will be used to assess the quality of all included studies, and the baseline data of all the studies are extracted by the authors. A random-effects model or a fixed-effects model is used to analyse the outcomes. The primary outcomes are the levels of selenium, triiodothyronine, free thyroxine and thyroid-stimulating hormone (TSH), whereas the secondary outcomes include TSH receptor antibody, thyroid peroxidase antibody and thyroglobulin antibody.

ETHICS AND DISSEMINATION

Ethics approval is not required since no original data will be collected. The results of this study will be published in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42023410999.

Temporal trends in the clinical presentation of Graves' orbitopathy: a single-center retrospective study

PURPOSE

Graves' ophthalmopathy (GO) is an autoimmune disease that affects orbital soft tissues and represents the most common extrathyroidal manifestation of Graves' disease (GD). The European Group of Graves' Ophthalmopathy (EUGOGO) has attempted to shed light on the European epidemiological picture of GO, suggesting that GO in newly diagnosed patients in recent years has a trend towards a less severe clinical presentation. There are no studies that focus this issue on the population of our area; we aimed to evaluate the trend of GO clinical presentation in our outpatient clinic through an observation period of 10 years.

METHODS

We compared 55 consecutive patients, 11 males (F) and 44 females (M), who came to our observation from January 2005 to December 2006 [Group 1 (G1)], with 56 patients, 15 males, and 41 females, who were referred to us from 2015 to 2016 [Group 2 (G2)]. We studied the following putative predictors of GO presentation and severity: thyroid function, smoking, diabetes, hypercholesterolemia, time from GO diagnosis to referral to our thyroid centre (TGOD), sex and age.

RESULTS

GO severity was significantly reduced in G2 vs. G1 (p = 0.04). TGOD ≥ 3 months was related to clinical characteristics of GO (severity and Clinical Activity Score ≥ 4) and was an independent predictor of GO severity (p = 0.01). The other variables evaluated had no independent effects.

CONCLUSIONS

We found that GO severity at presentation was significantly reduced over a ten-year observation period (2005-2006 vs. 2015-2016) in GO patients referred to our tertiary thyroid centre. TGOD ≥ 3 months was an independent predictor of GO severity.

Thyroid-associated ophthalmopathy: the role of oxidative stress

Thyroid-associated ophthalmopathy (TAO) is an autoimmune condition affecting the eyes, characterized by proptosis, extraocular muscle involvement, and in severe cases, vision impairment including diplopia, optic neuropathy, and potential blindness. The exact etiology of TAO remains elusive; however, increased oxidative stress and decreased antioxidant capacity are pivotal in its pathogenesis. Elevated oxidative stress not only directly damages orbital tissues but also influences thyroid function and autoimmune responses, exacerbating tissue destruction. This review explores the role of oxidative stress in TAO, elucidates its mechanisms, and evaluates the efficacy and limitations of antioxidant therapies in managing TAO. The findings aim to enhance understanding of oxidative stress mechanisms in TAO and propose potential antioxidant strategies for future therapeutic development.

Selenium supplementation in inactive moderate to severe Graves' orbitopathy patients: a randomized controlled trial

PURPOSE

This study was designed to evaluate the effect of selenium supplementation in inactive moderate-severe Graves' orbitopathy (GO) patients.

METHODS

This study was a single-center, placebo-controlled, double-masked, randomized trial. Inactive moderate-severe GO participants were randomized to receive six months of 200 micrograms/day of selenium supplementation or placebo. Thorough eye exams, clinical activity score (CAS), Graves' Ophthalmopathy quality of life questionnaire (GO-QOL), and serum selenium level were evaluated at baseline and 6 months after the interventions. The chi-squared or Fisher's exact test was used to compare categorical variables. The t-test and the paired t-test were used to compare continuous variables between two independent samples and two dependent samples, respectively.

RESULTS

A total of 25 participants were enrolled, 13 in the selenium group and 12 in the placebo group. Both groups had adequate baseline serum selenium levels at 98.96 ± 15.63 mcg/L and 102.55 ± 17.71 mcg/L, respectively. After 6 months of intervention, the selenium group showed a greater improvement in palpebral aperture (mean difference: -1.4 ± 1.7 mm, p = .04) compared to the placebo group (-0.3 ± 2.7 mm). Notably, 5(41.67%) people in the placebo group developed larger palpebral apertures. Proptosis, ocular motility, and soft tissue signs did not change significantly. GO-QOL and CAS score improvement showed no statistically significant difference between both groups. Minor adverse effects were observed.

CONCLUSIONS

Selenium supplementation has a positive effect on eyelid aperture even in inactive moderate-to-severe GO patients with a sufficient baseline selenium level.

Thyroid hormones and minerals in immunocorrection of disorders in autoimmune thyroid diseases

Thyroid hormones and essential elements iodine (I), selenium (Se), iron (Fe), copper (Cu), zinc (Zn), calcium (Ca), magnesium (Mg), etc. play an important role in the work of many organs and systems of the body, including the immune system and the thyroid gland, and a violation of their supply can be the cause of pathological changes in them. In pathology, the interaction between thyroid hormones (TG), minerals and the immune system is disturbed. The review of the literature examines the immunomodulatory role of TG, minerals, their properties, and their participation in the pathogenesis of autoimmune thyroid diseases (AITD). The study of the relationship between the excess or deficiency of minerals and AITD is described. The basis of the development of AITD - Hashimoto's thyroiditis (HT), Graves' disease (GD), Graves' ophthalmopathy (GO) is the loss of immune tolerance to thyroid antigens - thyroid peroxidase (TPO), thyroglobulin (Tg) and thyroid-stimulating hormone receptor (TSH-R). Immune-mediated mechanisms - production of autoantibodies to thyroid antigens and lymphocytic thyroid infiltration - are involved in the pathogenesis of AITD. Insufficiency of regulatory T cells (Treg) and regulatory B cells (Breg), imbalance between Th17-lymphocytes and Treg-lymphocytes, abnormal production of pro-inflammatory cytokines has a significant influence on the progression of AITD. With AITD, the balance between oxidants and antioxidants is disturbed and oxidative stress (OS) occurs. The lack of modern effective pharmacological therapy of AITD prompted us to consider the mechanisms of influence, possibilities of immunocorrection of pathogenetic factors using TG, micro/macronutrients. In order to develop a more effective treatment strategy, as well as approaches to prevention, a critical analysis of the ways of immunotherapeutic use of dietary supplements of I, Se, Zn, Mg and other minerals in AITD was carried out.

Management of patients with dysthyroid optic neuropathy treated with intravenous corticosteroids and/or orbital decompression surgery

Purpose

To assess the characteristics and long-term outcomes of adult patients with dysthyroid optic neuropathy (DON) who underwent orbital decompression surgery and/or received intravenous (IV) methylprednisolone.

Methods

Retrospective chart review of 98 eyes of 49 patients who were diagnosed and treated with bilateral DON between 2007 and 2018 at the Department of Ophthalmology and Optometry and Oral and Maxillofacial Surgery of the Medical University of Vienna.

Results

The mean follow-up period was 4.1 ± 2.7 years. The most common presenting symptoms were eyelid and periorbital swelling (45%) representing active inflammation. Upgaze restriction was the most common clinical finding (73%). At time of diagnosis, the mean clinical activity score was 4 ± 1/4 ± 1 (right/left eye, respectively). Sixty-three percent (31/49) of the patients were treated both with IV methylprednisolone and underwent orbital decompression surgery, 22% (11/49) were treated with IV methylprednisolone alone and 14% (7/49) underwent surgical decompression only. Seventy-one percent (30/42) of the patients underwent 3-wall decompression. The mean reduction of proptosis in patients treated with both IV methylprednisolone and orbital decompression surgery was 4/5 mm. Mean of reduction in proptosis in patients receiving IV methylprednisolone only was 1/0 mm and in patients with surgical decompression only was 5/5 mm. Mean VA was 0.1 ± 0.5/0.1 ± 0.5 logMAR at baseline and 0.05 ± 0.7/0.05 ± 0.7 at final follow-up. In 92% (45/49), VA was preserved or improved at final follow-up.

Conclusions

The majority of patients with DON were treated both with IV corticosteroids and 3-wall decompression surgery. Vision could be successfully preserved in most cases and reduction of proptosis was achieved, especially after orbital decompression surgery.

A Comprehensive Review on Selenium and Its Effects on Human Health and Distribution in Middle Eastern Countries

Selenium (Se) is an important microelement with numerous positive effects on human health and diseases. It is important to specify that the status and consumption of Se are for a specific community as the levels of Se are extremely unpredictable between different populations and regions. Our existing paper was based on the impacts of Se on human health and disease along with data on the Se levels in Middle Eastern countries. Overall, the findings of this comprehensive review show that the consumption and levels of Se are inadequate in Middle Eastern nations. Such findings, together with the growing awareness of the importance of Se to general health, require further work primarily on creating an acceptable range of blood Se concentration or other measures to determine optimal Se consumption and, consequently, to guarantee adequate Se supplementation in populations at high risk of low Se intake.

Oral selenium improved the disease activity in patients with mild Graves' orbitopathy

BACKGROUND

Graves' orbitopathy (GO) is the most common extrathyroidal manifestation of Graves' disease (GD), an autoimmune disorder arising from the activity of T lymphocytes against antigens that infiltrate thyroid tissue, orbital tissue and extraocular muscles. An increase in oxidative stress has been discovered in autoimmune thyroid disease, encouraging investigation into new forms of treatment. Selenium has been described as a treatment option given its antioxidant properties. The present study evaluates the decrease of progression and inflammatory signs in patients with mild GO with oral selenium supplementation.

METHODS

Controlled, randomized, single center trial at an ophthalmology referral center in Mexico City. Patients at least 18years of age with mild GO according to the CAS classification were included; exclusion criteria in addition to corticosteroid treatment included smokers or selenium allergy. Each patient was randomized into one of two groups. Group A took placebo tablets which consisted of 100μg of starch twice a day for 6months, and group B took a 100μg selenium tablet twice a day for 6months. The patients from both groups were examined and evaluated using a CAS score before and after the first, third and sixth month of treatment.

RESULTS

Thirty eyes of 30 patients were studied. The pretreatment values showed no statistically significant differences between groups (P>0.05). Intergroup analysis showed statistically significant differences in palpebral fissure and CAS score between the pretreatment values and six months after treatment in the selenium group (P<0.05). No differences were found in any variables in the placebo group during the study period (P>0.05). No adverse events were reported.

CONCLUSIONS

This is the first study in a Mexican population demonstrating that oral selenium decreases clinical activity and stops progression in patients with mild GO.

Orbital diseases mimicking graves' orbitopathy: a long-standing challenge in differential diagnosis

Graves' orbitopathy (GO) is the most common cause of orbital tissue inflammation, accounting for ~ 60% of all orbital inflammatory conditions in the population aged 21-60 years, and for ~ 40% in the population aged > 60 year. GO is observed in 25-30% of patients with Graves' hyperthyroidism and more rarely in association with hypothyroid autoimmune thyroiditis. In addition, a small proportion of GO patients (1-2%) do not have a clinically overt thyroid dysfunction. Clinically, GO is characterized by proptosis, inflammation involving the eyelids and the conjunctiva, extraocular muscle hypertrophy, with consequent reduction of ocular motility and diplopia, and in the most severe cases, compression of the optic nerves at the orbital apex, with reduction of visual acuity. At CT scan or MRI, a muscle increase involving the superior, medial and inferior rectus is quite typical. In the most severe forms, compression of the optic nerves at the orbital apex can be observed. Euthyroid GO is usually an early sign of a full-blown Graves' disease; however, in some cases, the orbital disease can remain isolated. Moreover, euthyroid GO can rarely be unilateral, which makes the picture even more confusing. Under those circumstances, the diagnostic process becomes obviously quite difficult, having other conditions mimicking GO been excluded. A number of inflammatory conditions affecting orbital tissue can mimic GO, thereby requiring an accurate evaluation for a proper differential diagnosis. The majority of these conditions are immune mediated. Most of them are benign, but they can be rather aggressive and some can cause visual loss. The most common inflammatory condition affecting orbital tissues and mimicking GO is idiopathic orbital inflammation. Other, more rare, orbital diseases that should be considered in the differential diagnosis are infections, orbital manifestations of systemic diseases, primitive and secondary orbital neoplasms, and orbital vascular alterations. In most instances, when an orbitopathy occurs in the absence of hyperthyroidism, the diagnosis of the disease underlying the ocular symptoms and signs is based on exclusion of the other conditions. Here we review the conditions that can mimic GO and how to distinguish them from this obnoxious eye disease.

Immunological Drivers in Graves' Disease: NK Cells as a Master Switcher

Graves' disease (GD) is a common autoimmune cause of hyperthyroidism, which is eventually related to the generation of IgG antibodies stimulating the thyrotropin receptor. Clinical manifestations of the disease reflect hyperstimulation of the gland, causing thyrocyte hyperplasia (goiter) and excessive thyroid hormone synthesis (hyperthyroidism). The above clinical manifestations are preceded by still partially unraveled pathogenic actions governed by the induction of aberrant phenotype/functions of immune cells. In this review article we investigated the potential contribution of natural killer (NK) cells, based on literature analysis, to discuss the bidirectional interplay with thyroid hormones (TH) in GD progression. We analyzed cellular and molecular NK-cell associated mechanisms potentially impacting on GD, in a view of identification of the main NK-cell subset with highest immunoregulatory role.

Current Understanding of the Progression and Management of Thyroid Associated Orbitopathy: A Systematic Review

Thyroid associated orbitopathy (TAO) is a common diagnosis encountered by ophthalmologists and oculoplastic surgeons. TAO has a varying clinical presentation that can include upper eyelid retraction, restrictive strabismus, proptosis, exposure keratopathy, and optic neuropathy. In this review, we discuss the most recent literature on and the current understanding of the pathophysiology of TAO. We also review available and potential future treatment options for the management of TAO.

Dihydrotestosterone regulates oxidative stress and immunosuppressive cytokines in a female BALB/c mouse model of Graves' disease

Background: Graves' disease (GD) is an autoimmune disease that affects more women than men. In our previous study, a potent bioactive androgen, 5α-dihydrotestosterone (DHT) showed a protective effect against GD in female BALB/c mice. Evidence indicates that abnormal oxidative stress and immunosuppressive cytokines (TGF-β, IL-35) play critical roles in the pathogenesis and development of GD. The purpose of this research is to measure these cytokines and oxidative stress markers to explore potential protective mechanisms of DHT in a BALB/c mouse model of GD. Methods: GD was induced in female BALB/c mice by intramuscular injection of an adenovirus expressing the A-subunit of the TSH receptor (Ad-TSHR289). DHT or a matching placebo was injected every 3 days. Mice were sacrificed four weeks after the third virus immunization to obtain blood, thyroid and spleen for further analysis. Results: Thyroid hormones were significantly reduced in DHT treated GD mice. In addition, DHT attenuated thyroid oxidative injuries in GD mice, as shown by decreased total antioxidation capability (TAOC), superoxide dismutase (SOD) and the level of malondialdehyde (MDA). The levels of immunosuppressive cytokines (TGF-β, IL-35) in DHT group were significant higher compared with the GD group. Conclusions: The results demonstrated that DHT could reduce the severity of GD in female BALB/c mice by regulating oxidative stress. The upregulation of immunosuppressive cytokines might be another important protective mechanism.

Role of Selenium Intake for Risk and Development of Hyperthyroidism

PURPOSE

To investigate the importance of dietary selenium (Se) for hyperthyroidism.

METHODS

We performed a more in-depth analysis of a large cross-sectional study of 6152 participants from two counties within the Shaanxi Province, China. These counties are characterized by different habitual Se intake. We investigated the effects of a different dietary Se supply (0.02, 0.18, 0.6, or 2.0 ppm Se) on disease development in a mouse model of Graves disease (GD).

RESULTS

The cross-sectional study revealed a comparable prevalence of hyperthyroidism, irrespective of Se intake, in both counties. However, an unexpected sex-specific difference was noted, and Se deficiency might constitute a risk factor for hyperthyroidism, especially in males. In a mouse model, pathological thyroid morphology was affected, and greater Se intake exerted some protecting effects on the pathological distortion. Circulating thyroid hormone levels, malondialdehyde concentrations, total antioxidant capacity, and the titer of GD-causing TSH receptor autoantibodies were not affected by Se. Expression analysis of the transcripts in the spleen indicated regulatory effects on genes implicated in the immune response, erythropoiesis, and oxygen status. However, the humoral immune response, including the CD4/CD8 or T-helper 1/T-helper 2 cell ratio and the concentration of regulatory T cells, was similar between the experimental groups, despite the difference in Se intake.

CONCLUSIONS

Our data have highlighted a sexual dimorphism for the interaction of Se and thyroid disease risk in humans, with indications of a local protective effects of Se on thyroid gland integrity, which appears not to be reflected in the circulating biomarkers tested.