The relationship between oxidative stress and autoimmunity in Hashimoto's thyroiditis

Petunidin suppresses Hashimoto's thyroiditis by regulating Th1/Th17 homeostasis and oxidative stress

Hashimoto's thyroiditis (HT) is a prevalent autoimmune thyroid disease, necessitating further research to identify effective treatment strategies. Two key pathophysiological factors of HT are inflammation and oxidative stress. Petunidin (PET) is an anthocyanin with anti-inflammatory and antioxidant properties. This study aimed to investigate the effect and mechanism of PET on HT. C57BL/6N mice were injected with thyroglobulin emulsified with adjuvant to establish the HT animal model. Our results showed that PET administration decreased the concentrations of TPOAb, TgAb, T3, T4, IgG, IgA and IgM in HT mice, accompanied by significant alterations in follicle shape and increased lymphocyte infiltrations. Additionally, the apoptosis rate, ROS level, MDA content, CD4+ level, IFN-γ and IL-17A levels, as well as the concentrations of IFN-γ and IL-17, were elevated in HT mice and reduced by PET treatment. Furthermore, HT patients exhibited higher levels of NOX4 and PKM2, which were positively correlated with TPOAb, IFN-γ, and IL-17 concentrations. In HT mice, PET therapy decreased the expression of PKM2 and NOX4 proteins. In summary, PET can improve thyroid dysfunction by suppressing apoptosis, oxidative stress and Th1/Th17 differentiation through regulation of the NOX4/PKM2 axis in HT mice, suggesting its promising potential for HT intervention.

Assessment of thiol-disulfide and glutathione homeostasis after levothyroxine replacement in individuals with autoimmune or nonautoimmune hypothyroidism

Objective

Thyroid hormones are known to affect the biosynthesis and degradation of antioxidant compounds, suggesting a possible link between hypothyroidism and oxidative stress. However, there is no clear consensus in the literature regarding this association. The aim of this study was to evaluate oxidative stress markers (extracellular thiol-disulfide homeostasis and intracellular glutathione homeostasis) in patients with hypothyroidism due to autoimmune (Hashimoto's thyroiditis) or nonautoimmune thyroid disease rendered euthyroid after levothyroxine replacement.

Subjects and methods

The study included 116 patients admitted to the Taksim Training and Research Hospital (Istanbul, Türkiye). Of these, 50 had hypothyroidism due to Hashimoto's thyroiditis (HT group), 30 had nonautoimmune hypothyroidism (NAIH group), and 36 were healthy controls (control group). All participants were women. Extracellular thiol-disulfide homeostasis and intracellular glutathione homeostasis tests were assessed as oxidative stress markers.

Results

Thiol-disulfide homeostasis in both HT and NAIH groups was shifted toward the oxidative spectrum. Compared with the control group, the HT and NAIH groups had lower levels of native (p < 0.001 and p = 0.001, respectively) and total (p = 0.002 and p = 0.012, respectively) thiol, as well as a lower native thiol/total thiol ratio (p < 0.001 for both). The HT group also had higher disulfide levels than the control group (p = 0.027). Reduced glutathione (GSH) and oxidized glutathione (GSSG) values were comparable across all three groups, but the HT and NAIH groups had higher GSSG/GSH (p < 0.001 for both) and GSSG/(GSH+GSSG) ratios (p = 0.003 and p = 0.005, respectively), along with lower GSH/(GSH+GSSG) ratio (p = 0.001 and p = 0.002, respectively) than the control group.

Conclusion

Levothyroxine replacement was ineffective in ameliorating oxidative stress in patients with hypothyroidism due to Hashimoto's thyroiditis or nonautoimmune causes, as extracellular thiol-disulfide homeostasis was notably altered in these patients compared with healthy controls. The findings of this study suggest that oxidative stress remains a prevailing issue in patients with autoimmune or nonautoimmune hypothyroidism even after euthyroidism is restored.

Changes in biomarkers of the redox status in whole blood and red blood cell lysates in canine hypothyroidism

Hypothyroidism is the most commonly diagnosed endocrine disease in dogs. The objective of this study was to evaluate the changes in the redox status in canine hypothyroidism using whole blood (WB) and red blood cell (RBCs) lysates. For this purpose, a panel of five antioxidants and five oxidants biomarkers was measured in WB and RBCs lysates of 30 dogs with hypothyroidism, 26 dogs with non-thyroidal illnesses and 15 healthy dogs. The antioxidants measured were cupric reducing antioxidant capacity (CUPRAC), ferric reducing ability of plasma (FRAP), Trolox equivalent antioxidant capacity (TEAC), thiol and paraoxonase type-1 (PON-1). Oxidants measured include the total oxidant status (TOS), peroxide-activity (POX-Act), reactive oxygen-derived metabolites (d-ROMs), advanced oxidation protein products (AOPP) and thiobarbituric acid reactive substances (TBARS). WB showed a significant decrease of the antioxidants CUPRAC, TEAC and thiol, and also an increase in TBARS and a decrease in AOPP in dogs with hypothyroidism compared to healthy dogs. Meanwhile, RBCs lysates showed a significant increase in FRAP and PON-1 in dogs with hypothyroidism. The changes in the redox biomarkers in this study show that WB in canine hypothyroidism had a higher number of changes in biomarkers of the redox status than RBCs lysates, making it a promising sample type for the evaluation of the redox status in this disease. In addition, WB is easier and simpler to process than RBCs lysates and unlike serum, it does not have any hemolysis interference.

Traditional Chinese Medicine for Hashimoto's Thyroiditis: Focus on Selenium and Antioxidant Phytochemicals

Hashimoto's thyroiditis (HT) is not only the most frequent autoimmune thyroid disease (AITD), but it also has a significant impact on patients' health-related quality of life (HRQoL), and it has been variably associated with differentiated thyroid carcinoma. Even though its pathogenesis is still incompletely understood, oxidative stress is believed to play an important role. Hypothyroidism related to later stages of HT can be treated with levothyroxine substitution therapy; various approaches such as selenium supplementation and iodine-restricted diets have been proposed as disease-modifying treatments for earlier stages, and even thyroidectomy has been suggested for refractory cases of painful HT. Nevertheless, many patients still report suboptimal HRQoL, highlighting an unmet medical need in this area. The concepts and approaches of traditional Chinese medicine (TCM) in treating HT are not broadly known in the West. Here, we provide an overview of TCM for HT, including combinations of TCM with selenium. We encompass evidence from clinical trials and other studies related to complex TCM prescriptions, single herbs used in TCM, and phytochemicals; wherever possible, we delineate the probable underlying molecular mechanisms. The findings show that the main active components of TCM for HT have commonly known or presumed antioxidant and anti-inflammatory activities, which may account for their potential utility in HT. Further exploring the practices of TCM for HT and combining them with evidence- and mechanism-based approaches according to Western standards may help to identify new strategies to alter the clinical course of the disease and/or to treat patients' symptoms better and improve their HRQoL.

Assessment of Vitamin Concentrations in Patients with Hashimoto's Thyroiditis and Their Relationships with Thyroid Function, Biochemical Status, and Anthropometric Parameters-A Preliminary Study

Hashimoto's thyroiditis (HT) is the leading cause of hypothyroidism, affecting mainly the female population. Many patients with HT have metabolic disorders and nutritional deficiencies. The aim of this study was to evaluate vitamin D, A, E, B2, and B6 concentrations, thyroid function, metabolic profile, and anthropometric parameters of patients with Hashimoto's thyroiditis. In 81 female patients with HT (study group), vitamin A and B2 concentrations were significantly lower than in 34 healthy women (control group). No differences were noted in vitamin D, E, and B6 concentrations between groups. Moreover, HT patients had similar anthropometric parameters, lipid profiles, and glucose and insulin concentrations compared to controls. This study showed some relationships between vitamin concentrations and anthropometric or biochemical profiles in HT patients. Among others, in the HT group, the concentration of vitamin D was positively correlated with the level of HDL and negatively correlated with BMI, total fat mass, and insulin level, which influence cardiovascular risk. The results indicate that patients with HT should be routinely tested for vitamin concentrations to prevent nutritional deficiencies. Further studies are also needed on the role of vitamins in the development and progression of HT and the presence of metabolic complications in this population.

Evaluation of Health-Related Quality of Life in Patients with Euthyroid Hashimoto's Thyroiditis under Long-Term Levothyroxine Therapy: A Prospective Case-Control Study

Objectives: To investigate quality of life using the SF-12 scale in euthyroid Hashimoto's thyroiditis patients on levothyroxine therapy for at least three years. Methods: This prospective case-control study included 44 euthyroid Hashimoto's thyroiditis patients and 44 matched controls, conducted at a university hospital's endocrinology clinic from 6 November to 30 December 2023. Participants completed the SF-12 questionnaire; data were analyzed using Shapiro-Wilk, Student's t-test, Mann-Whitney U, Yates chi-squared, and Spearman's tests. Results: The study involved 88 participants (Hashimoto's group: 35 females, 9 males; control group: 31 females, 13 males), with average ages of 49.50 and 47.43 years old, respectively. Significant differences were observed in TSH, T4 levels, and family history (p < 0.05). The Hashimoto's thyroiditis group showed higher thyroid peroxidase antibodies (95.69 IU/mL) and lower scores on both physical and mental sub-dimensions of SF-12, with a significant difference in physical scores (p < 0.05). Significant correlations were found between age and Anti-TG; Anti-TPO and Anti-TG; BMI and T3; TSH and T4; HDL and triglycerides; MCS-12 and PCS-12; Anti-TPO and T3; cholesterol and T3; and LDL and cholesterol (p < 0.05). Other variables showed no significant correlations (p > 0.05). Conclusions: Our study shows that effective control of hypothyroidism is not sufficient to reduce the negative effects of Hashimoto's thyroiditis on patients' health-related quality of life. Beyond the normalization of hormone levels, comprehensive therapeutic strategies targeting the autoimmune aspects of the disease are essential for the management of Hashimoto's thyroiditis. This study provides a foundation for developing effective therapies that can enhance quality of life for patients with Hashimoto's thyroiditis.

Clinical Outcomes of MOK Pharmacopuncture in an Elderly Male Patient with Hypothyroidism-A Case Report and Literature Review

Hypothyroidism is more common in women and individuals between 30 and 50 years old. This case report depicts the clinical outcomes of MOK pharmacopuncture, a type of Korean medicine treatment, for an elderly male patient with hypothyroidism who was on long-term L-thyroxine (LT4) therapy but still felt chronically lethargic and tired and was generally in poor health. A 72-year-old Korean man has been on LT4 since being diagnosed with hypothyroidism 16 years ago and has tried to discontinue hormone supplements in the past. The patient was treated with MOK pharmacopuncture, mainly at the ST10 acupoint, twice a week for four months. Following the treatment, the T3, free-T4, and TPO Ab levels and thyroiditis status on ultrasound showed improvement. Additionally, there were a normalization of ESR levels, an enhancement in the quality of life, a reduction in depression scores, an improvement in the antioxidant status, and an alleviation of major symptoms when compared to pre-treatment conditions. This case report demonstrates the potential of MOK pharmacopuncture as a complementary treatment for an elderly man with hypothyroidism who had a poor quality of life due to fatigue and lethargy despite LT4 treatment.

The effect of low-level laser therapy on the oxidative stress level and quality of life in patients with Hashimoto's thyroiditis

This study aimed to examine the effects of low-level laser therapy (LLLT) combined with levothyroxine replacement therapy on thyroid function, oxidative stress (OS), and quality of life in patients with Hashimoto's thyroiditis (HT). Forty-six patients diagnosed with HT were randomized to receive active LLLT (n = 23) and sham LLLT (n = 23) twice a week for three weeks. Clinical and laboratory evaluations of the participants were performed before treatment and three months after treatment. Biochemical parameters were taken from the patient file requested by the physician as a routine examination. Malondialdehyde and nitricoxide indicating oxidant stress and superoxide dismutase, catalase, and glutathione, which indicate antioxidant capacity, were used in OS evaluation. The Oxidative Stress Index was calculated by measuring the Total Antioxidant Status and the Total Oxidant Status. At the end of our study, a significant improvement in oxidant and antioxidant biomarker levels showing OS and quality of life was observed in the treatment groups (p < 0.05). There was no change in thyroid function and autoimmunity at the end of the treatment between the two groups (p > 0.05). Improvements in glutathione levels and quality of life were significantly higher in the active treatment group than in the sham-controlled group. LLLT was found to be more effective on OS and quality of life in patients with HT than in patients in the sham-controlled group. It was concluded that LLLT is a safe and effective method that can be used in the treatment of patients with HT.

Interactions between Polygenetic Variants and Lifestyle Factors in Hypothyroidism: A Hospital-Based Cohort Study

Hypothyroidism is a prevalent endocrine disorder and is associated with a variety of metabolic disturbances. This study aimed to investigate the polygenic variants associated with hypothyroidism risk and the interaction of polygenic risk scores (PRS) with dietary patterns in influencing disease risk in 56,664 participants aged >40 in a hospital-based cohort. The participants were classified as having hypothyroidism (n = 870) diagnosed by a physician and no hypothyroidism (n = 55,794). Genetic variants associated with hypothyroidism were identified using a genome-wide association study (GWAS). Genetic variants interacting with each other were selected using a generalized multifactor dimensionality reduction analysis, and the PRS generated was evaluated for interaction with lifestyle parameters. Coffee, alcohol, meat intake, and a Korean balanced diet were inversely associated with hypothyroidism risk, as were selenium, copper, and manganese intakes. White blood cell (WBC) counts and serum alkaline phosphatase and triglyceride concentrations were positively associated with hypothyroidism risk, as were osteoporosis and thyroid cancer. The GMDR analysis generated a three-single nucleotide polymorphism (SNP) model comprising dual oxidase-1 (DUOX1)_rs1648314; thyroid-stimulating hormone receptor (TSHR)_rs75664963; and major histocompatibility complex, class-II, DQ Alpha-1 (HLA-DQA1)_rs17426593. The PRS derived from the three- and seven-SNP models were associated with a 2.11- and 2.32-fold increase in hypothyroidism risk, respectively. Furthermore, the PRS from the three-SNP model showed interactions with WBC counts, wherein the positive association with hypothyroidism risk was more pronounced in participants with low WBC counts than those with high WBC counts (≥4 × 109 /L). Dietary patterns, such as the plant-based diet (PBD) and the Western-style diet (WSD), along with smoking status, exhibited interactions with the PRS, influencing hypothyroidism risk. In participants with a high PRS, those in the high-PBD, low-WSD, and smoker groups had a higher proportion of hypothyroidism than those in the low-PBD, high-WSD, and non-smoker groups. In conclusion, genetic variants related to immunity and thyroid hormone secretion were linked to hypothyroidism risk, and their PRS interacted with PBD and WSD intake and smoking status. These results contribute to a better understanding of hypothyroidism and its prevention strategies for precision medicine intervention.

Exposure of Akwesasne Mohawk women to polychlorinated biphenyls and hexachlorobenzene is associated with increased serum levels of thyroid peroxidase autoantibodies

Persistent organic pollutants (POPs) including polychlorinated biphenyls (PCBs), hexachlorobenzene (HCB), and dichlorodiphenyltrichloroethane (p,p'-DDT) were reported to influence immunological activity. As endocrine-disrupting chemicals (EDC), these pollutants may disrupt normal thyroid function and act as catalysts for development of autoimmune thyroid disease by directly and indirectly affecting levels of thyroid peroxidase antibodies (TPOAbs). Native American communities are disproportionately exposed to harmful toxicants and are at an increased risk of developing an autoimmune disease. The aim of this study was to determine the association between POPs and TPOAbs in serum obtained from Native American women. This assessment was used to measure whether increased risk of autoimmune thyroid disease occurred as a result of exposure to POPs. Data were collected from 183 Akwesasne Mohawk women, 21-38 years of age, between 2009 and 2013. Multivariate analyses were conducted to determine the association between toxicant exposure and levels of TPOAbs. In multiple logistic regression analyses, exposure to PCB congener 33 was related to elevated risk of individuals possessing above normal levels of TPOAbs. Further, HCB was associated with more than 2-fold higher risk of possessing above normal levels of TPOAbs compared to women with normal levels of TPOAbs. p,p'-DDE was not associated with TPOAb levels within this study. Exposure to PCB congener 33 and HCB was correlated with above normal levels of TPOAbs, a marker of autoimmune thyroid disease. Additional investigations are needed to establish the causes and factors surrounding autoimmune thyroid disease which are multiple and complex.

Comprehensive analysis of hub biomarkers associated with immune and oxidative stress in Hashimoto's thyroiditis

Hashimoto's thyroiditis (HT) is a type of autoimmune disorder with a complex interplay between immune disorder and oxidative stress (OS). This research aimed to discover biomarkers and potential treatment targets associated with immune and OS dysregulation in HT through integrated bioinformatics analysis and clinical validations. Differential gene expression analysis of GSE138198 dataset from the GEO database identified 1490 differentially expressed genes (DEGs) in HT, including 883 upregulated and 607 downregulated genes. Weighted gene co-expression network analysis explored module genes associated with HT. Overlapping the differentially expressed module genes with immune-related and OS-related genes identified eight differentially expressed module genes associated with immune and OS (DEIOGs) in HT. Protein-protein interaction network analysis identified five hub genes (TNFAIP3, FOS, PTK2B, STAT1, and MMP9). We confirmed four hub genes (TNFAIP3, PTK2B, STAT1 and MMP9) in GSE29315 dataset and clinical thyroid samples, which showed high diagnostic accuracy (AUC >0.7) for HT. The expression of these four genes was positively correlated with serum thyroid peroxidase antibody, thyroglobulin antibody levels, and inflammatory infiltration scores in clinical thyroid samples. Immune profiling revealed distinct profiles in HT, such as B cells memory, monocytes and macrophages. Additionally, all hub genes were inversely associated with monocytes. Further, miRNA-mRNA network analysis was conducted, and a regulatory network comprising four hub genes, 238 miRNAs and 32 TFs was established. These findings suggest that immune cells play a crucial role in the development of HT, and the hub genes TNFAIP3, PTK2B, STAT1, and MMP9 may be key players in HT through immune- and OS-related signaling pathways. Our results may provide valuable insights into the pathogenesis and therapeutic monitoring of HT.

The Influence of Food Regimes on Oxidative Stress: A Permutation-Based Approach Using the NPC Test

(1) Background: This paper aims to assess the existence of significant differences between two dietary regimes (omnivorous vs. semi-vegetarian) with reference to some oxidative stress markers (SOD, GPx, TRxR, GR, AGEs, and AOPPs) using non-parametric combination methodology based on a permutation test. (2) Methods: At the endocrinology unit of Messina University Hospital, two hundred subjects were asked to fill out a questionnaire about their dietary habits. None were under any pharmacological treatment. Using the NPC test, all comparisons were performed stratifying patients according to gender, age (≤40 or >40 years), BMI (normal weight vs. overweight), physical activity (sedentary vs. active lifestyle), TSH, FT4 levels in quartiles, and diagnosis of Hashimoto's thyroiditis. We evaluated differences in oxidative stress parameters in relation to two examined dietary regimes (omnivorous vs. semi-vegetarian). (3) Results: The antioxidant parameters GPx and TRxR were significantly lower in subjects with an omnivorous diet than in semi-vegetarians, particularly in females, both age groups, subjects with normal weight, those not affected by Hashimoto's thyroiditis, and both the sedentary and active lifestyle groups. Finally, the AGE and AOPP markers were significantly lower in semi-vegetarians. (4) Conclusion: Thanks to the NPC methodology, we can state that dietary patterns exert a significant influence on some oxidative stress parameters.

The interplay of oxidative stress and immune dysfunction in Hashimoto's thyroiditis and polycystic ovary syndrome: a comprehensive review

In recent years, there has been a significant increase in the concomitant incidence of Hashimoto's thyroiditis (HT) and polycystic ovary syndrome (PCOS), both in terms of incidence, etiology, and clinical consequences. PCOS patients suffering from autoimmune thyroid diseases show insulin resistance, impaired glucose tolerance, weight gain, and metabolic and reproductive complications. Studies have shown that chronic stress and its consequence, i.e. oxidative stress, play an important role in the pathomechanism of both disorders. It has also been shown that long-term exposure to stress triggers biological mechanisms, in particular related to the regulation of the inflammatory cascade, which plays a key role in autoimmune diseases. The paper is a review of the literature on the role of chronic stress, oxidative stress, and immune processes in the pathogenesis of HT and PCOS. In addition, the review is a source of knowledge about the treatment of these diseases, and in particular the use of antioxidants in therapeutic management.

Associations between empirically derived dietary patterns and oxidative stress and inflammation in adults with primary hypothyroidism: a case-control study

BACKGROUND

Primary hypothyroidism is a common endocrine disorder caused by impaired production of thyroid hormones. Recent studies have shown that dietary habits, oxidative stress, and inflammation may play roles in thyroid hypofunction. Thus, the present article aimed to determine the relationship between major dietary patterns and oxidative stress and inflammation in primary hypothyroid patients and healthy people in Iranian adults.

METHODS

This matched case-control study was conducted on 200 participants (100 cases and 100 controls). The presence of primary hypothyroidism was determined by endocrinologists based on American Thyroid Association (ATA) criteria. Dietary intake was assessed using a validated 168-item, semi-quantitative food frequency questionnaire (FFQ). The principal component analysis (PCA) method was used to derive major dietary patterns. Statistical analysis was performed using logistic regression analysis, and the findings were reported using odds ratios (ORs) with 95% CIs.

RESULTS

We identified 2 major dietary patterns (i.e., healthy and Western dietary patterns). After adjusting for confounding variables, participants in the highest tertile of the healthy eating pattern had lower odds of primary hypothyroidism. Also, there was a significant relationship between total antioxidant capacity (TAC) levels and thyroid hypofunction; however, no significant correlation was seen between the Western dietary pattern and malondialdehyde (MDA) and C-reactive protein (CRP) with hypothyroidism.

CONCLUSIONS

There were statistically direct associations between healthy dietary patterns (loaded with vegetables, nuts and seeds, fruits, dried fruits, olives, garlic, black pepper, starchy vegetables, low-fat dairy, and legumes) and increased TAC levels with a decreased risk of thyroid hypofunction. However, Western dietary patterns and MDA and CRP levels did not associate with an underactive thyroid.

Clinical significance of thyroglobulin antibodies and thyroid peroxidase antibodies in Graves' disease: a cross-sectional study

PURPOSE

The significance of thyroglobulin antibodies (TgAbs) and thyroid peroxidase antibodies (TPOAbs) in Graves' disease (GD) remains unclear. Therefore, this study aimed to clarify the clinical significance of TgAbs and TPOAbs in GD.

METHODS

A total of 442 patients with GD were recruited and divided into four groups based on TgAb and TPOAb positivity. Their clinical parameters and the characteristics of the groups were compared. Cox proportional hazard regression analysis was performed to assess risk factors for GD remission.

RESULTS

The free triiodothyronine (FT3) level was significantly higher in groups positive for TgAbs and TPOAbs than in the other groups. The FT3 to free thyroxine (FT4) (FT3/FT4) ratio was significantly higher and thyrotropin-stimulating hormone (TSH) receptor antibodies (TRAbs) were significantly lower in the TgAb+/TPOAb- group. Time to FT4 recovery was significantly shorter for groups negative for TPOAbs, whereas time to TSH recovery was significantly longer for groups positive for TPOAbs. Cox proportional hazard regression analysis revealed that TgAb positivity, prolonged treatment duration with antithyroid drugs, and Graves' ophthalmopathy treated with methylprednisolone were significantly associated with GD remission and that a smoking history, elevated FT3/FT4 ratio, and treatment with propylthiouracil hindered GD remission.

CONCLUSION

The contributions of TgAbs and TPOAbs to GD pathogenesis differ. Patients positive for TgAbs develop GD with lower TRAb titers and undergo earlier remission than those negative for TgAbs. Patients positive for TPOAbs develop GD with high TRAb titers and need a long time to achieve remission.

Changes in biomarkers of redox status in serum and saliva of dogs with hypothyroidism

BACKGROUND

Hypothyroidism is the most common endocrine disorder diagnosed in dogs, leading to deleterious effects on a dog's life quality. This study aims to evaluate changes in the redox status in canine hypothyroidism. For this purpose, a comprehensive panel of antioxidants and oxidants biomarkers were measured in serum and saliva of 23 dogs with hypothyroidism, 21 dogs with non-thyroidal illness, and 16 healthy dogs. Among the antioxidants, cupric reducing antioxidant capacity (CUPRAC), ferric reducing ability of plasma (FRAP), Trolox equivalent antioxidant capacity (TEAC), thiol, paraoxonase type 1 (PON-1) and glutathione peroxidase (GPx) were determined in serum and CUPRAC, ferric reducing ability of saliva (FRAS) and TEAC in saliva. The oxidant biomarkers included were total oxidant status (TOS), peroxide-activity (POX-Act), reactive oxygen-derived compounds (d-ROMs), advanced oxidation protein products (AOPP), and thiobarbituric acid reactive substances (TBARS) in serum and AOPP and TBARS in saliva.

RESULTS

Results showed a significantly higher TEAC, PON-1, GPx, TOS, POX-Act, and d-ROMs, and a significantly lower AOPP in serum of dogs with hypothyroidism. Meanwhile, significantly lower FRAS and AOPP were observed in saliva of dogs with hypothyroidism. Once salivary concentrations were corrected based on their total protein concentrations, the only analyte showing significant changes was TBARS which was significantly higher in dogs with hypothyroidism.

CONCLUSIONS

Our results show that dogs with hypothyroidism present alterations in the redox status in both serum and saliva. This study should be considered a preliminary study and further research addressing these changes should be made using larger populations.

Oxidative stress in Hashimoto's thyroiditis: possible adjuvant therapies to attenuate deleterious effects

A number of studies have shown that oxidative stress is related to the pathogenesis of several immunological diseases, such as Hashimoto's thyroiditis (HT), although there is no plausible mechanism to explain it. Thus, we aimed at hypothesizing and providing some possible mechanisms linking oxidative stress to autoimmunity aspects and its implications for HT, as well as adjuvant therapeutic proposals to mitigate the deleterious effects. Our hypothesis is that deficient eating habits, autoimmune regulator gene predisposing gene, dysbiosis and molecular mimicry, unfolded proteins and stress in the endoplasmic reticulum, and thymus involution appear to be the main potential factors leading to HT oxidative stress. Likewise, we show that the use of minerals selenium and zinc, vitamins D and C, as well as probiotics, can be interesting adjuvant therapies for the control of oxidative damage and poor prognosis of HT. Further clinical trials are needed to understand the real beneficial and side effects of these supplements.

Metabolic Characteristics of Hashimoto's Thyroiditis Patients and the Role of Microelements and Diet in the Disease Management-An Overview

Hashimoto’s thyroiditis (HT) is the most common autoimmune disease and the leading cause of hypothyroidism, in which damage to the thyroid gland occurs due to the infiltration of lymphocytes. It is characterized by increased levels of antibodies against thyroid peroxidase and thyroglobulin. In this review, we present the metabolic profile, the effectiveness of micronutrient supplementation and the impact of dietary management in patients with HT. For this current literature review, the databases PubMed, Cochrane, Medline and Embase were reviewed from the last ten years until March 2022. This article provides a comprehensive overview of recent randomized controlled trials, meta-analyses, and clinical trials. Many patients with HT, even in the euthyroid state, have excess body weight, metabolic disorders, and reduced quality of life. Due to frequent concomitant nutritional deficiencies, the role of vitamin D, iodine, selenium, magnesium, iron and vitamin B12 is currently debated. Several studies have underlined the benefits of vitamin D and selenium supplementation. There is still no specific diet recommended for patients with HT, but a protective effect of an anti-inflammatory diet rich in vitamins and minerals and low in animal foods has been suggested. There is insufficient evidence to support a gluten-free diet for all HT patients. Pharmacotherapy, along with appropriate nutrition and supplementation, are important elements of medical care for patients with HT. The abovementioned factors may decrease autoantibody levels, improve thyroid function, slow down the inflammatory process, maintain proper body weight, relieve symptoms, and prevent nutritional deficiencies and the development of metabolic disorders in patients with HT.

Receptor of advanced glycation end product (RAGE) polymorphism and oxidative status in Hashimoto’s thyroiditis in Egyptian female patients: case control study

Background

Hashimoto's thyroiditis is the most widespread autoimmune illness targeting a specific organ. "Redox homeostasis" is achieved when the production of Reactive Oxygen Species and their elimination are in balance. Advanced glycation end products (AGEs) are formed when glucose and/or α-oxaloaldehydes react non-enzymatically with the amino groups of lipids, proteins, and DNA. Nowadays, many studies are concerned with AGEs, the polymorphisms of their receptors, and their association with increased risk of HT. However, few studies investigated the role of receptors of advanced glycation end product (RAGE) SNP in Egyptian females.

Objective

The goals of this investigation were to ascertain whether oxidative stress plasma malondialdehyde (MDA) and total antioxidant capacity (TAC) were associated with HT, in addition, to assess the association of RAGE polymorphisms (− 374 T > A and the − 429 T > C and Gly82Ser) with HT.

Subject and methods.

Our case–control study has 80 patients enrolled who have newly been diagnosed with HT and 80 age and sex-matched healthy female controls. Each participant underwent a thorough medical history, physical examination, and laboratory investigations, which included Genotyping of RAGE Gly82Ser, − 374 T > A and − 429 T > C using polymerase chain reaction-restriction fragment length polymorphisms (PCR–RFLP).

Results

Chi-square revealed a significant association regarding the distribution of RAGE (− 374 T < C) genotypes TT and CC between patients and control (P = 0.04). Non-significant associations regarding the distribution of Gly82Ser genotypes Gly/Gly, Gly/Ser, Ser/Ser were found between patients and control (P = 0.5), and non-significant associations related to − 429 T > C gene polymorphism were revealed. In addition, patients with HT had higher MDA and lower TCA compared with controls.

Conclusion

The elevated MDA and decreased TAC as an antioxidant may be one of several risk factors associated with the prevalence of HT in individuals with the − 429 T > C RAGE mutation polymorphism that is associated with an increased risk of HT in Egyptian females.

Thyroid receptor β might be responsible for breast cancer associated with Hashimoto's thyroiditis: a new insight into pathogenesis

Breast cancer is the most common cancer affecting females worldwide. Often it is observed that women suffering from Hashimoto's thyroiditis exhibit a greater propensity towards development of breast cancer. The exact mechanism for the same is unknown. However, multiple experimental evidences suggest a significant role of thyroid receptor β (TR-β) in regulating cell growth and proliferation and thus play a potent role as a tumor suppressor in several cancers, including breast cancer. Thyroid receptor β shows anti-proliferative action through mediators like β-catenin, RUNX2, PI3K/AKT, and cyclin regulation. The present review explores the link between these pathways and how they may be dysregulated due to Hashimoto's thyroiditis. Further, we propose a new mechanism for cancer prognosis associated with Hashimoto's thyroiditis, which may lead to the development of TR-β targeting as a novel therapeutic approach.

Serum Levels of Soluble Receptor for Advanced Glycation End Products Are Reduced in Euthyroid Children with Newly Diagnosed Hashimoto's Thyroiditis: A Pilot Study

OBJECTIVE

No data are available on advanced glycation end products (AGEs) and their soluble receptor (sRAGE) in pediatric patients with Hashimoto's thyroiditis (HT). The present study was aimed to simultaneously evaluate serum levels of sRAGE, AGEs, and advanced oxidation protein products (AOPPs) and investigate the relationships between these oxidative stress markers and clinical and biochemical parameters of thyroid function in euthyroid children with HT.

DESIGN

This is a case-control study carried out in a single university hospital center.

METHODS

We enrolled 19 newly diagnosed euthyroid HT pediatric patients (3 M, 16 F; median age 12.44 years, range 6.54-15.81 years) and 16 age-, sex-, and BMI-matched healthy controls (5 M, 11 F; median age 12.83 years, range 5.68-15.07 years). None was on levothyroxine treatment. The exclusion criteria were autoimmune, inflammatory, and infection comorbidities. Patients did not differ significantly from controls with regard to lipid or for anthropometric parameters.

RESULTS

sRAGE levels were significantly lower in HT patients (median 414.30 pg/mL, range 307.30-850.30 pg/mL) than in controls (561.30, 273.20-1121.60 pg/mL; p = 0.034). No differences emerged between patients and controls with regard to serum AGEs (124.25 AU/g prot, 71.98-186.72 vs. 133.90, 94.06-200.78 AU/g prot, p = 0.707) and AOPPs (1.13 nmol/mL, 0.62-1.83 vs. 1.17, 0.76-1.42 nmol/mL, p = 0.545).

CONCLUSIONS

sRAGE levels were decreased in euthyroid children/adolescents at the onset of HT, suggesting that autoimmunity per se seems to play an important role in such a reduction of sRAGE, irrespective of any functional alteration. Children and adolescents suffering from HT may exhibit increased susceptibility to oxidative damage, even when in euthyroid status.

SERUM LEVELS OF OXIDATIVE STRESS MARKERS IN SUBCLINICAL AND OVERT HYPOTHYROIDISM VERSUS CONTROL GROUP IN POPULATION OF KUTAHYA CITY, TURKEY

Background: Overproduction of oxygen-related free radicals and inadequate antioxidant defense are critical in hypothyroidism, as they might lead to future life-threatening diseases. The objectives of this study were to compare serum levels of oxidative stress markers; total oxidant status (TOS), total antioxidant status (TAS), oxidative stress index (OSI), paraoxonase-1 (PON-1), and arylesterase (ARYL) in patients with subclinical hypothyroidism (SH) and overt hypothyroidism (OH) versus healthy controls in population of Kutahya city, Turkey.Materials Methods: This cross-sectional study was conducted at Department of Biochemistry, Faculty of Medicine, Kutahya University of Health Sciences, Kutahya, Turkey, from July to December, 2016. Three study groups of 45 each were formed as healthy controls, patients with SH and OH. Serum levels of TOS, TAS, OSI, PON-1, and ARYL were five research variables with ratio scale, but skewed, so described by median and IQR with 95% Cl. Kruskal-Wallis and multiple comparison tests were used for hypotheses testing.Results: Serum levels of TOS and OSI were higher in SH group (p-values 0.032; .0001; respectively) and OH group (p-values .0001; .0001, respectively) than healthy controls, while serum levels of TAS, PON-1 and ARYL were lower in SH group (p-values .0001; .0001; .0001, respectively) and OH group (p-values .0001; .0001; .0001, respectively) than control group.Conclusion: Our study showed that serum levels of TOS and OSI were higher in subclinical and overt hypothyroidism than in healthy controls; while serum levels of TAS, PON-1, and ARYL were lower in subclinical and overt hypothyroidism than in healthy controls.

The Influence of Oxidative Stress on Thyroid Diseases

Thyroid diseases, including neoplasms, autoimmune diseases and thyroid dysfunctions, are becoming a serious social problem with rapidly increasing prevalence. The latter is increasingly linked to oxidative stress. There are many methods for determining the biomarkers of oxidative stress, making it possible to evaluate the oxidative profile in patients with thyroid diseases compared to the healthy population. This opens up a new perspective for investigating the role of elevated parameters of oxidative stress and damage in people with thyroid diseases, especially of neoplastic nature. An imbalance between oxidants and antioxidants is observed at different stages and in different types of thyroid diseases. The organ, which is part of the endocrine system, uses free radicals (reactive oxygen species, ROS) to produce hormones. Thyroid cells release enzymes that catalyse ROS generation; therefore, a key role is played by the internal defence system and non-enzymatic antioxidants that counteract excess ROS not utilised to produce thyroid hormones, acting as a buffer to neutralise free radicals and ensure whole-body homeostasis. An excess of free radicals causes structural cell damage, undermining genomic stability. Looking at the negative effects of ROS accumulation, oxidative stress appears to be implicated in both the initiation and progression of carcinogenesis. The aim of this review is to investigate the oxidation background of thyroid diseases and to summarise the links between redox imbalance and thyroid dysfunction and disease.

Positive effects of selenium supplementation in women with newly diagnosed Hashimoto's thyroiditis in an area with low selenium status

OBJECTIVE

Autoimmune thyroid diseases, including Hashimoto's thyroiditis, are the most common ones among autoimmune diseases. The reported effects of selenium supplementation on the course of Hashimoto's thyroiditis are not consistent. It is therefore important to continue this line of research.

DESIGN

The participants received selenium in the form of sodium selenite(IV) at a dose of 100 µg/day for 6 months.

PATIENTS

Newly diagnosed and previously untreated Hashimoto's thyroiditis with euthyroidism or subclinical hypothyroidism. A total of 36 patients (aged 20 to 52 years) qualified for this study, of whom 29 women were successfully enrolled and completed the intervention.

MEASUREMENTS

Both before and after supplementation the following parameters in serum were tested: anti-thyroid peroxidase antibodies, thyroid function indicators, selenium as well as antioxidant status parameters and other biochemical parameters (lipid profile, glucose). Iodine supply and subjective assessment of physical and psychological health were also monitored.

RESULTS

Selenium supplementation decreased significantly level of anti-thyroid peroxidase antibodies what might have had a stabilizing effect on thyroid function, as values of thyroid parameters were within normal range before and at the end of the study. Mean level of selenium among patients was not different to healthy people in Poland. Median of ioduria was within normal range.

CONCLUSIONS

The study shows a potential way of protective effect of selenium in limiting development of overt hypothyroidism. The increase in the concentrations of Se and SELENOP in the serum of patients verifies successful supplementation and good compliance, but did not affect the antioxidant status parameters measured.

Characteristics of Patients with Type 1 Diabetes and Additional Autoimmune Disease in the DPV Registry

CONTEXT

Autoimmune diseases affect ~8% of the population. Type 1 diabetes mellitus (T1DM) is linked to other autoimmune diseases (AIDs), such as autoimmune thyroid disease or Addison's disease (AD), that may impact diabetes therapy and outcome.

OBJECTIVE

To analyze demographic and clinical characteristics of other AIDs in T1DM from a large standardized registry, the Prospective Diabetes Follow-up Registry (DPV).

METHODS

We searched the registry for T1DM with the additional diagnosis of Hashimoto's thyroiditis (HT), Graves' disease (GD), and/or AD. T1DM with other AIDs (n = 6166, 5.4%) were compared with isolated T1DM (n = 107 457). For group comparisons, we used multivariable regression models with age, sex, diabetes duration, migration background, and type of insulin regimen as basic adjustments (microvascular endpoints: additionally adjusted for glycated hemoglobin).

RESULTS

Patients with additional AIDs were more often female (54.7 vs 32.0%, P < .001) and had a longer diabetes duration (7.9 [4.2-12.5] vs 6.7 [2.7-12.9] years, P < .001). After adjustment, daily insulin dosage was higher in AD and HT than in isolated T1DM (0.858 ± 0.032 and 0.813 ± 0.005 vs 0.793 ± 0.001 IU/kg per day). Retinopathy was less common in HT (1.5%), whereas it was more frequent in GD (3.1%) than in isolated T1DM (1.8%). In both GD and HT, microalbuminuria occurred less often (10.6% and 14.3% vs 15.5%) and neuropathy (2.1% and 1.8% vs 0.8%) was more common than in isolated T1DM. All P < .05.

CONCLUSION

T1DM with additional AIDs show heterogeneous differences compared with isolated T1DM. T1DM plus AD or HT requires more insulin. Further, the rate of neuropathy is higher in HT or GD, whereas the rate of microalbuminuria is lower.

Serum lipids are novel predictors for thyroid autoimmunity in the general population with normal TSH levels from a cross-sectional study

OBJECTIVE

Serum lipids have been shown to regulate inflammatory and immune processes, but little is known about their association with thyroid autoimmunity. This study aimed to investigate the association of serum lipids with thyroid autoantibody positivity in the general population with normal thyroid-stimulating hormone (TSH) levels.

METHODS

Data regarding the 7688 subjects' baseline characteristics were retrospectively collected. All subjects were categorized into four groups according to thyroid autoantibodies against thyroglobulin (TgAb) and thyroid peroxidase (TPOAb) positivity and serum lipid levels were compared. Binary logistic regression models were used to evaluate the risk of TgAb or TPOAb positivity with increasing serum lipid levels.

RESULTS

In 6456 included subjects, after adjusting for confounders, the risk of TgAb positivity was positively associated with increasing low-density lipoprotein cholesterol (LDL-C) levels (OR 1.14, 95% CI 1.03-1.27, P = 0.011) and negatively correlated with the increasing high-density lipoprotein cholesterol (HDL-C) levels (OR 0.77, 95% CI 0.61-0.98, P = 0.035). In female subjects, the association between increasing LDL-C (OR 1.16, 95% CI 1.04-1.28, P = 0.007) or HDL-C levels (OR 0.77, 95% CI 0.61-0.99, P = 0.037) and TgAb positivity become more pronounced.

CONCLUSION

We have shown the associations of HDL-C and LDL-C with TgAb positivity in the general population with normal TSH levels in a gender-dependent manner. This study highlights that serum lipids may be new predictors of thyroid autoimmunity even when TSH is within the reference range.

The Level of Zinc, Copper and Antioxidant Status in the Blood Serum of Women with Hashimoto's Thyroiditis

The aim of this study was to analyze selected indicators of oxidative stress. The study subjects consisted of 42 women with Hashimoto’s disease and a control group of 30 healthy women. The concentration of zinc (Zn) and copper (Cu) in the serum was determined by Atomic Absorption Spectrometry (AAS) and the total antioxidative potential by the Ferric Reducing Ability of Plasma (FRAP) method. In addition, an assessment of concentrations of thiobarbituric acid reactive substances (TBARS) and total phenolics was carried out. Our research showed a significant difference in TBARS concentration (p < 0.0001 (ES: 0.92)) without significant differences in Zn, Cu, FRAP and total phenolics concentrations. Analysis of the correlation of the obtained results of biochemical tests for both groups showed a highly significant dependence of FRAP and total phenolics concentration in the blood of the examined women (r = 0.5283, p = 0.0003). The obtained results indicate no differences in Cu, Zn, and FRAP concentrations in the blood between two analyzed groups and a significantly higher concentration of TBARS in Hashimoto’s thyroiditis women. The concentration of total phenolics significantly influences the value of the FRAP.

Cytokine/Chemokine/Growth Factor Profiles Contribute to Understanding the Pathogenesis of the Salivary Gland Dysfunction in Euthyroid Hashimoto's Thyroiditis Patients

Hashimoto's thyroiditis (HT) is one of the most common autoimmune diseases. It is suggested that, in addition to thyroid gland dysfunction, HT is responsible for impaired secretion from the salivary glands. The aim of this study was to evaluate the extent of symptoms of salivary gland dysfunction. We also assessed the relationship between the levels of selected cytokines, chemokines, and growth factors in unstimulated whole saliva (UWS) and the rate of UWS secretion and symptoms of xerostomia in HT patients. The study group consisted of 25 female patients diagnosed with Hashimoto's disease in its spontaneous euthyroid state who had never received hormonal treatment. In more than half of the examined patients, we observed the level of UWS secretion below 0.2 mL/min, indicating impaired secretory function of the salivary glands. Moreover, we demonstrated that the clinical symptoms of salivary gland dysfunction worsen with disease duration. Nevertheless, the inflammatory changes occurring in these glands are independent of general inflammation in the course of HT. Our results clearly indicate an abnormal profile of cytokines, chemokines, and growth factors in the UWS of HT euthyroid women as well as the fact that concentrations of IL-6 and IL-1 as well as INF-γ, TNF-α, and IL-12 may be potential biomarkers for salivary gland dysfunction in the course of HT. Furthermore, salivary IL-12 (p40) may be helpful in assessing the progression of autoimmunity-related inflammation in the course of HT. In conclusion, secretory dysfunction of the salivary glands is closely related to autoimmunity-related inflammation in the course of HT, which leads to objective and subjective symptoms of dry mouth.

Oxidative Stress-Induced Sirtuin1 Downregulation Correlates to HIF-1α, GLUT-1, and VEGF-A Upregulation in Th1 Autoimmune Hashimoto's Thyroiditis

In Hashimoto’s thyroiditis (HT), oxidative stress (OS) is driven by Th1 cytokines’ response interfering with the normal function of thyrocytes. OS results from an imbalance between an excessive production of reactive oxygen species (ROS) and a lowering of antioxidant production. Moreover, OS has been shown to inhibit Sirtuin 1 (SIRT1), which is able to prevent hypoxia-inducible factor (HIF)-1α stabilization. The aims of this study were to determine the involvement of NADPH-oxidases (NOX), SIRT1, and HIF-1α in HT pathophysiology as well as the status of antioxidant proteins such as peroxiredoxin 1 (PRDX1), catalase, and superoxide dismutase 1 (SOD1). The protein expressions of NOX2, NOX4, antioxidant enzymes, SIRT1, and HIF-1α, as well as glucose transporter-1 (GLUT-1) and vascular endothelial growth factor A (VEGF-A), were analyzed by Western blot in primary cultures of human thyrocytes that were or were not incubated with Th1 cytokines. The same proteins were also analyzed by immunohistochemistry in thyroid samples from control and HT patients. In human thyrocytes incubated with Th1 cytokines, NOX4 expression was increased whereas antioxidants, such as PRDX1, catalase, and SOD1, were reduced. Th1 cytokines also induced a significant decrease of SIRT1 protein expression associated with an upregulation of HIF-1α, GLUT-1, and VEGF-A proteins. With the exception of PRDX1 and SOD1, similar results were obtained in HT thyroids. OS due to an increase of ROS produced by NOX4 and a loss of antioxidant defenses (PRDX1, catalase, SOD1) correlates to a reduction of SIRT1 and an upregulation of HIF 1α, GLUT-1, and VEGF-A. Our study placed SIRT1 as a key regulator of OS and we, therefore, believe it could be considered as a potential therapeutic target in HT.

The Relationship between Hepatic Myeloid-Derived Suppressor Cells and Clinicopathological Parameters in Patients with Chronic Liver Disease

Myeloid-derived suppressor cells (MDSCs) have attracted attention due to their important role in inflammation. Several studies have investigated the involvement of MDSCs in chronic liver disease. However, due to the difference of MDSC phenotypes, patient types, and sample sources among the studies, the results are inconsistent and controversial. We took advantage of a large well-defined cohort of 98 (24 patients with CHB, 18 with NAFLD, 13 with HCC, 16 with PBC, and 27 with AIH) patients with liver inflammation and 12 healthy controls to investigate the expression of MDSCs, and the relationships between the expression of hepatic MDSCs and the clinical characteristics were analyzed. We found that the expression of CD11b+CD33+ MDSCs is closely related to chronic liver disease and positively correlated with clinical parameters such as ALT, AST, and globulin. Ultimately, the present study suggests that hepatic CD11b+CD33+ MDSCs are increased in HCC and AIH and positively correlate with the liver stages of hepatitis activity and liver fibrosis stage.

Influence of Dietary Habits on Oxidative Stress Markers in Hashimoto's Thyroiditis

Background: There is a growing awareness that nutritional habits may influence risk of several inflammatory and immune-mediated disorders, including autoimmune diseases, through various mechanisms. The aim of the present study was to investigate dietary habits and their relationship with redox homeostasis in the setting of thyroid autoimmunity. Materials and Methods: Two hundred subjects (173 females and 27 males; median age, 37 years) were enrolled. None were under any pharmacological treatment. Exclusion criteria were any infectious/inflammatory/autoimmune comorbidity, kidney failure, diabetes, and cancer. In each subject, serum thyrotropin (TSH), free thyroxine, antithyroid antibodies, and circulating oxidative stress markers were measured. A questionnaire on dietary habits, evaluating the intake frequencies of food groups and adherence to the Mediterranean diet, was submitted to each participant. Results: Among the 200 recruited subjects, 81 (71 females and 10 males) were diagnosed with euthyroid Hashimoto's thyroiditis (HT); the remaining 119 (102 females and 17 males) served as controls. In questionnaires, HT subjects reported higher intake frequencies of animal foods (meat, p = 0.0001; fish, p = 0.0001; dairy products, p = 0.004) compared with controls, who reported higher intake frequencies of plant foods (legumes, p = 0.001; fruits and vegetables, p = 0.030; nuts, p = 0.0005). The number of subjects who preferentially consumed poultry instead of red/processed meat was lower in HT subjects than in controls (p = 0.0141). In logistic regression analysis, meat consumption was associated with increased odds ratio of developing thyroid autoimmunity, while the Mediterranean diet traits were protective. In HT subjects, serum advanced glycation end products (markers of oxidative stress) were significantly higher (p = 0.0001) than in controls, while the activity of glutathione peroxidase and thioredoxin reductase, as well as total plasma antioxidant activity, were lower (p = 0.020, p = 0.023, and p = 0.002, respectively), indicating a condition of oxidative stress. Stepwise regression models demonstrated a significant dependence of oxidative stress parameters on consumption of animal foods, mainly meat. Conclusions: The present study suggests a protective effect of low intake of animal foods toward thyroid autoimmunity and a positive influence of such nutritional patterns on redox balance and potentially on oxidative stress-related disorders.

Role of selenium and myo-inositol supplementation on autoimmune thyroiditis progression

Previous reports indicate that selenium supplementation may be useful to reduce cell oxidative stress. In particular, selenium may decrease the level of thyroid autoantibodies in patients with Hashimoto's thyroiditis (HT). Recent studies also indicate that myo-inositol may have beneficial effects on thyroid function in patients with HT. Hence, the aim of the present study is to evaluate whether myo-inositol may enhance the protective effect of selenium on HT progression to hypothyroidism. The study was designed as observational and retrospective. Thyroid hormones were evaluated in patients with HT who were either euthyroid or subclinically hypothyroid. These patients were subdivided into three groups: untreated, treated with selenomethionine alone (Se-meth: 83 μg/day) and treated with Se-meth plus myo-inositol (Se-meth + Myo-I: 83 μg/day + 600 mg/day). Outcome evaluation was performed at baseline and after 6 and 12 months of treatment. High-resolution ultrasound of the thyroid gland was performed to evaluate changes in thyroid echoic pattern during the study. Compared to baseline, levels of thyroid-stimulating hormone (TSH) increased significantly in untreated patients but decreased by 31% and 38%, respectively, in those treated with Se-meth and Se-meth + Myo-I. Moreover, in the latter group the TSH reduction was observed earlier than in the Se-meth-treated group. Densitometric analysis of thyroid ultrasonography showed an echoic pattern improvement in both treated groups compared to untreated patients, although this difference was not statistically significant. Thus, Se-meth treatment is effective in patients with HT and its effect may be improved in combination with Myo-I through earlier achievement of TSH levels closer to physiological concentrations.

Minerals: An Untapped Remedy for Autoimmune Hypothyroidism?

For decades, the focus of managing autoimmune hypothyroidism has been on thyroxine replacement. Correcting lab parameters such as thyroid stimulating hormone (TSH) has been a primary goal. The increasing prevalence of Hashimoto’s thyroiditis (HT) continues to impact the quality of life in patients. We believe a holistic approach to this disease entity, considering its underlying complex etiopathogenesis, would benefit patients. Nutraceuticals are combinations of essential nutrients and are becoming a part of novel medical treatments despite the lack of regulation. This review aims to present a concise summary of recent developments regarding minerals such as zinc, selenium, magnesium, iron, and their potential clinical benefit as nutraceuticals in patients with HT. We have explored the potential benefits and associations of these minerals in HT and thyroid function. We reviewed relevant articles, metanalyses, and clinical trials in literature platforms such as PubMed, PubMed Central, and Google Scholar. Significant data found in the literature suggesting a potential health benefit of these minerals in HT though there were many studies to the contrary. Many trials demonstrated the restoration of residual symptoms, reversal of HT-associated thyroid morphological changes, and improvement in thyroid functions. Many of these trials lack statistical power due to the small sample sizes, and their external validity may be questionable due to unaccounted confounding factors. In our opinion, to support an evidence-based holistic clinical approach, further scientific evidence is needed. The association of these elements in thyroid function necessitates more large scale pragmatic trials to elucidate the benefits of nutraceuticals in HT.

Oxidative stress as a key feature of autoimmune thyroiditis: an update

INTRODUCTION

Oxidative stress has been proposed as one of the factors concurring in the pathophysiology of autoimmune thyroid diseases. Reactive oxygen species are the main expression of oxidative stress in biological systems, and their production can overcome antioxidant defenses ultimately leading to cell damage, apoptosis, and death. The present review was aimed at describing the state of the art of the relationships between oxidative stress and autoimmune thyroiditis. The most used biomarkers of oxidative stress and their correlation with thyroid function are reported.

EVIDENCE ACQUISITION

We conducted a search of the literature in the English language starting from 2000, using the following search terms: "Hashimoto thyroiditis," "autoimmune thyroiditis," "hypothyroidism," "hyperthyroidism," "oxidative stress," "oxidants," "antioxidant," "advanced glycation end products." Both clinical studies and animal models were evaluated.

EVIDENCE SYNTHESIS

Data form clinical studies clearly indicate that the balance between oxidants and antioxidants is shifted towards the oxidative side in patients with autoimmune thyroiditis, suggesting that oxidative stress may be a key event in the pathophysiology of the disease, irrespective of thyroid function. Studies in animal models, such as the NOD.H2h4 mouse, confirm that thyroidal accumulation of ROS plays a role in the initiation and progression of autoimmune thyroiditis.

CONCLUSIONS

Oxidant/antioxidant imbalance represent a key feature of thyroid autoimmunity. Oxidative stress parameters could be used as biochemical markers of chronic inflammation, to better predict the disease evolution along its natural history. Dietary habits and antioxidant supplements may provide protection from autoimmunity, opening new perspectives in the development of more tailored therapies.

Serum levels of advanced glycation end products (AGEs) are increased and their soluble receptor (sRAGE) reduced in Hashimoto's thyroiditis

PURPOSE

Advanced glycation end products (AGEs) are increased in conditions of oxidative stress and promote inflammation by interacting with their receptor RAGE on cell membrane. By contrast, the soluble receptor sRAGE exerts protective effects by competing with RAGE for ligand binding. AGEs/sRAGEs interaction is involved in the pathogenesis of several diseases related to oxidative stress. In the present study, we evaluated the AGEs/sRAGEs oxidative balance in Hashimoto' thyroiditis (HT).

METHODS

We measured the levels of sRAGE, by ELISA, and AGEs, by spectrophotometric method, in the serum of 50 HT patients (5 M, 45 F; mean age 38.5 ± 12 years) and 50 age-, sex- and BMI-matched healthy controls. All subjects were euthyroid at recruitment and none was on LT-4 therapy.

RESULTS

Serum sRAGEs were significantly lower (median 424 vs 738 pg/ml; p = 0.001) and AGEs higher (205 vs 114 AU/g prot; p = 0.001) in HT patients compared to controls, and the two parameters were inversely correlated (p = 0.016). Accordingly, the AGEs/sRAGEs ratio was threefold higher in HT patients than controls (0.48 vs 0.15; p = 0.0001). In regression analysis models, serum TPO-Ab were the main predictors for AGEs and sRAGEs levels and AGEs/sRAGEs ratio (p < 0.0001), irrespective of TSH and/or FT4 values.

CONCLUSION

sRAGEs were decreased and AGEs increased, suggesting a dysregulation of AGE/sRAGEs-related oxidative homeostasis in HT patients, even when in euthyroid status. Autoimmunity per se seems to play an important role in AGEs/sRAGE imbalance, irrespective of thyroid function alterations.

Enhanced Salivary and General Oxidative Stress in Hashimoto's Thyroiditis Women in Euthyreosis

Hashimoto’s thyroiditis (HT) is one of the most common autoimmune diseases. Although HT is inextricably linked to oxidative stress, there have been no studies assessing salivary redox homeostasis or salivary gland function in patients with HT. This study is the first to compare antioxidant defense and oxidative stress biomarkers in non-stimulated (NWS) and stimulated (SWS) whole saliva and plasma/erythrocytes of HT patients compared to controls. The study included 45 women with HT in the euthyreosis period as well as an age- and gender-matched control group. We showed that NWS secretion was significantly lower in HT patients compared to healthy controls, similar to salivary amylase activity in NWS and SWS. Catalase and peroxidase activities were considerably higher in NWS and SWS of HT patients, while the concentrations of reduced glutathione and uric acid were significantly lower in comparison with healthy subjects. Total antioxidant potential was significantly lower, while total oxidant status and the level of oxidation products of proteins (advanced glycation end products, advanced oxidation protein products) and lipids (malondialdehyde, lipid hydroperoxides) were significantly higher in NWS, SWS and plasma of HT patients. In conclusion, in both salivary glands of women with HT in euthyreosis, the ability to maintain redox homeostasis was hindered. In HT patients we observed oxidative damage to salivary proteins and lipids; thus, some biomarkers of oxidative stress may present a potential diagnostic value.

Does autoimmune hypothyroidism increase the risk of neurovascular complications in type 1 diabetes?

BACKGROUND

Type 1 diabetes (T1DM) often coexists with other autoimmune diseases, most commonly with hypothyroidism. To date, the influence of coexisting autoimmune hypothyroidism (AHT) on the course of chronic neurovascular complications of autoimmune diabetes has not been established. The aim of the study was to assess the relationship between AHT and the occurrence of chronic T1DM complications.

METHODS

The study group comprised 332 European Caucasian participants with T1DM [165 (49.7%) men]. AHT was recognized in subclinical and overt hypothyroidism and confirmed by the presence of anti-thyroid autoantibodies: anti-peroxidase (ATPO) and/or anti-thyroglobulin (ATg) and ultrasonography (hypoechogenicity, parenchymal heterogeneity, lymph nodes assessment).

RESULTS

In the analyzed group, 48.5% of patients were diagnosed with at least one neurovascular complication. At the time of enrollment, 16.3% of participants were diagnosed with AHT. Patients with AHT, compared to those without AHT, were characterized by a higher prevalence of neurovascular complications (64.8 vs. 45.3%; P = 0.009) and retinopathy (55.6 vs. 38.9%; P = 0.02). There were significant differences between groups with and without neurovascular complications, with regard to classic risk factors for chronic diabetes complications: age, T1DM duration, SBP, DBP, HbA_1c, TG, eGFR and hypertension prevalence. In the multivariate logistic regression analysis, AHT was an independent predictor of neurovascular complications after adjusting for age, DBP, HbA_1c and TG (odds ratio, 2.40; 95% confidence interval, 1.17-4.92; P = 0.02).

CONCLUSIONS

AHT coexisting with T1DM was associated with a higher incidence of neurovascular complications.

Selenium exerts protective effects against oxidative stress and cell damage in human thyrocytes and fibroblasts

PURPOSE

Selenium, incorporated into specific seleno-enzymes, is essential to proper thyroid function and protect cells from oxidative damage induced by H₂O₂ during thyroid hormone synthesis. Several studies indicated that low selenium levels are associated with thyroid autoimmunity and related disorders, but real effectiveness of selenium supplementation in such diseases is still controversial. We evaluated the effect of selenium on oxidative damage in human thyrocytes and thyroid fibroblasts in vitro.

METHODS

To induce oxidative stress, primary cultures were exposed to H₂O₂, in the presence or the absence of selenium, as either selenomethionine or selenite. We performed the following assays: cell viability, caspase-3 activity, BCL-2/BAX gene expression, DNA fragmentation, malondialdehyde levels, and glutathione peroxidase (GPx) activity measurements.

RESULTS

Thyrocytes and thyroid fibroblasts exposed to H₂O₂ and preincubated with both selenocompounds displayed a significant dose-dependent increase in cell viability compared to cells incubated with H₂O₂ alone. Pretreatment with selenomethionine and selenite significantly reduced caspase-3 activity and BAX mRNA levels and increased BCL-2 mRNA levels in a dose-dependent manner. Accordingly, H₂O₂ induced a diffuse pattern of DNA degradation and an increase in malondialdehyde levels, which was prevented by the pretreatment with both selenomethionine and selenite. Both selenocompounds induced an increase in GPx activity, suggesting that these protective effects may be, almost in part, mediated by these selenoproteins.

CONCLUSION

In human thyrocytes and fibroblasts in vitro, selenium exerts protective effects against H₂O₂ in a dose-dependent manner, being selenite effective at lower doses than selenomethionine.

The effects of powdered black cumin seeds on markers of oxidative stress, intracellular adhesion molecule (ICAM)-1 and vascular cell adhesion molecule (VCAM)-1 in patients with Hashimoto's thyroiditis

OBJECTIVE

Oxidative stress plays an important role in the pathogenesis of Hashimoto's thyroiditis. Because of the major anti-oxidant properties of black cumin, the current study aimed to evaluate the effect of powdered Nigella sativa seeds on markers of oxidative stress, endothelial dysfunction and serum lipids in patients with Hashimoto's thyroiditis.

METHODS

Forty patients with Hashimoto's thyroiditis, aged between 22 and 50 years old, participated in the trial and were randomly allocated into two groups of intervention and control receiving powdered N. sativa or placebo daily for 8 weeks. Changes in markers of oxidative stress, including total anti-oxidant capacity (TAC), malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GPX), and biomarkers of endothelial dysfunction including Intracellular Adhesion Molecule (ICAM)-1, Vascular Cell Adhesion Molecule (VCAM)-1 and serum lipids were also evaluated.

RESULTS

Treatment with N. sativa, significantly increased serum TAC, SOD and reduced MDA concentrations with no significant change in GPX (P < 0.05). A significant reduction in VCAM-1 (P = 0.0012), body mass index (P = 0.002), serum concentrations of low density lipoprotein cholesterol (P = 0.002) and triglyceride (P = 0.02) were also reported in N. sativa-treated group after 8 weeks; while serum high density lipoprotein cholesterol (HDL) also significantly increased (P < 0.05). No change in other parameters were reported.

CONCLUSIONS

Giving attention to the potent beneficial effects of powdered black cumin seeds in improving oxidative stress, endothelial dysfunction, serum lipids and anthropometric features in patients with Hashimoto's thyroiditis, this medicinal plant can be considered as a therapeutic agent in management of Hashimoto-related metabolic abnormalities.

TRIAL REGISTRATION NUMBER

Iranian registry of clinical trials (registration number IRCT2015021719082N4).

Selenium involvement in mitochondrial function in thyroid disorders

Selenium (Se), an important oligoelement, is a component of the antioxidant system. Over the last decade, it has been ever more frequently discussed in the context of thyroid disorders. Graves' disease and Hashimoto's thyroiditis, differentiated thyroid cancer, and even endemic goiter may have common triggers that are activated by excess reactive oxygen species (ROS), which are involved in various stages of the pathogenesis of thyroid disorders. Most oxidative events occur in mitochondria, organelles that contain enzymes with Se as a cofactor. Mitochondria are responsible for the production of ATP in the cell and are also a major site of ROS production. Thyroid hormone status (the thyroid being the organ with the highest concentration of Se in the body) has a profound impact on mitochondria biogenesis. In this review, we focus on the role of Se in mitochondrial function in thyroid disorders with impaired oxidative stress, since both thyroid hormone synthesis and thyroid dysfunction involve ROS. The role of Se deficiency or its excess in relation to mitochondrial dysfunction in the context of thyroid disorders is therefore of interest.

Thiol/disulfide homeostasis and ischemia modified albumin levels in autoimmune gastritis and their relations with gastric emptying

Background/aim

Autoimmune gastritis is an autoimmune and inflammatory disorder. The aim of this study is to examine dynamic thiol/disulfide homeostasis and ischemia modified albumin levels, and to analyze the association between thiol/disulfide homeostasis and gastric emptying time in autoimmune gastritis.

Materials and methods

Thiol/disulfide homeostasis tests and ischemia modified albumin levels were determined in 50 autoimmune gastritis patients and 53 healthy subjects. Patients with delayed and normal gastric emptying were compared by thiol/disulfide homeostasis tests.

Results

The results showed that native thiol (μmol/L), total thiol (μmol/L), and native thiol/total thiol ratio (%) of the patients with autoimmune gastritis decreased compared to the control group (177.7 ± 34.18 vs. 245.25 ± 33.83, P = 0.001, 227.25 ± 36.78 vs. 284.20 ± 27.19, P = 0.03, and 8.84 ± 1.1 vs. 7.74% ± 1.3%, P = 0.001). In addition, native thiol (μmol/L), total thiol (μmol/L), and native thiol/ total thiol ratio (%) were found to be lower in patients with delayed gastric emptying (198.65 ± 24.27 vs. 167.12 ± 20.51, 241.81 ± 27.14 vs. 213.92 ± 26.35, 8.34 ± 1.29 vs. 7.20 ± 1.83, P = 0.001). Disulfide level, disulfide/native thiol, disulfide/total thiol (P = 0.001) ratios, and ischemia modified albumin levels (ABSU, 0.71 ± 0.08 vs. 0.83 ± 0.07) were found to be higher in autoimmune gastritis patients with delayed gastric emptying (P = 0.001).

Conclusion

The results showed that thiol/disulfide homeostasis in patients with autoimmune gastritis caused an increase in ischemia modified albumin and disulfide whereas a decrease in thiols. An altered thiol/disulfide balance was also observed in patients with delayed gastric emptying. These results suggest that the oxidative process is involved in patients with autoimmune gastritis.

gp91phox, a Novel Biomarker Evaluating Oxidative Stress, Is Elevated in Subclinical Hypothyroidism

BACKGROUND

gp91^phox, the catalytic core of NADPH oxidase (NOX) and biomarker of NOX activation, has been recently recognized as a parameter of systemic oxidative stress in several studies. Subclinical hypothyroidism (SH) is characteristic of elevated level of serum thyroid stimulating hormone (TSH) and is frequently accompanied with cholesterolemia. In this study, the levels of serum soluble gp91^phox were measured to assess the oxidative stress in patients with SH. And the relationship among gp91^phox, low-density lipoprotein-C (LDL-C), and TSH was also investigated.

METHODS

A total of 51 subjects were enrolled and categorized into four groups: the healthy controls subjects (n = 13), controls with high level of LDL-C alone (n = 12), SH with normal level of LDL-C (n = 11), and SH with high level of LDL-C (n = 15). The related clinical and laboratory data were collected for statistical analysis. All the patients were newly diagnosed and did not take any medication. The information of lipid profile and thyroid function was extracted, and the concentrations of gp91phox were obtained with ELISA.

RESULTS

The levels of serum soluble gp91phox evidently increased in the patients with SH with a high level of LDL-C (81.52 ± 37.00 ug/mL) as compared to the healthy controls (54.98 ± 1.83ug/mL, p < 0.001), controls with high level of LDL-C (61.21 ± 4.48 ug/mL, p=0.038) and SH with a normal level of LDL-C (62.82 ± 11.67ug/mL, p=0.027). Additionally, the levels of gp91^phox showed a significant positive correlation with both the levels of LDL-C (r = 0.595, p < 0.001) and TSH (r = 0.346, p=0.013) by the Spearman correlation analyses. The correlation remained significant even when the effect of another factor was controlled (TSH: when the effect of LDL-C was controlled, r = 0.453, p=0.001; LDL-C: when the effect of TSH was controlled, r = 0.291, p=0.040). The main effect analysis showed an independent main effect of either LDL-C (p = 0.041) or TSH (p=0.022) on gp91^phox without interaction (p=0.299).

CONCLUSIONS

Our work demonstrated that the levels of gp91^phox, a novel biomarker for measuring the oxidative stress, were significantly elevated in the patients with SH. And LDL-C and TSH were both independent predictors of gp91^phox. Abbreviations. BMI : Body mass index; TC : Total cholesterol; LDL-C : Low-density lipoprotein cholesterol; HDL-C : High-density lipoprotein cholesterol; TG : Triglyceride; FBG : Fasting blood glucose; FT3 : Free triiodothyronine; FT4 : Free thyroxine; TSH: Thyroid stimulating hormone; SBP : Systolic blood pressure; DBP : Diastolic blood pressure; SD : Standard deviation; LSD: Least significant difference.

Selenium Supplementation May Decrease Thyroid Peroxidase Antibody Titer via Reducing Oxidative Stress in Euthyroid Patients with Autoimmune Thyroiditis

OBJECTIVE

Selenium, as an antioxidant, has been implicated in the development of autoimmune thyroiditis (AIT). Many studies showed selenium supplementation could decrease thyroid autoantibodies in patients with AIT. However, the underlying mechanisms have not been well determined. Therefore, we performed a clinical study to investigate the possible mechanism of beneficial effects of selenium treatment on AIT patients.

METHODS

Forty euthyroid patients with AIT were randomized into two groups. Group I was treated with 200 μg/day selenium supplementation, and group II received a placebo over a 3-month period. Thyroid stimulating hormone (TSH), thyroid peroxidase antibody (TPOAb), antithyroglobulin antibody (TgAb), malondialdehyde (MDA), total antioxidant capacity (TAC), and superoxide dismutase (SOD) were measured before and 3 months after treatments. Additionally, twenty healthy volunteers also served as a control group for the evaluation of such parameters in basic condition.

RESULTS

Totally, 32 patients (group I, n = 18; group II, n = 14) completed the clinical study and were incorporated into the statistics. MDA level was higher and SOD activity and TAC were lower in patients compared to healthy individuals. After 3 months, TPOAb titer significantly decreased within group I (P < 0.001) but did not change within group II (P=0.001). There were also no statistically significant changes in TSH and TgAb titers within the two groups (all P > 0.05). Additionally, decreased MDA level (from 6.8 ± 1.3 nmol/ml to 4.9 ± 0.7 nmol/ml; P < 0.001) and increased TAC (from 10.0 ± 1.9 mmol/l to 12.9 ± 3.1 mmol/l; P=0.003) and SOD activity (from 72.3 ± 10.3 U/ml to 84.3 ± 13.2 U/ml; P=0.007) were simultaneously observed after 3 months' selenium treatment. Moreover, there was a negative correlation between TAC and TgAb/TPOAb and a positive correlation between MDA and TgAb/TPOAb in AIT patients.

CONCLUSIONS

Our findings support the hypothesis that selenium treatment could decrease TPOAb titer via enforcing the defense against oxidative stress in euthyroid patients with AIT, which may be a potential underlying mechanism.

Interaction of Genetic Variations in NFE2L2 and SELENOS Modulates the Risk of Hashimoto's Thyroiditis

Background: Several single-nucleotide polymorphisms (SNPs) are known to increase the risk of Hashimoto's thyroiditis (HT); such SNPs reside in thyroid-specific genes or in genes related to autoimmunity, inflammation, and/or cellular defense to stress. The transcription factor Nrf2, encoded by NFE2L2, is a master regulator of the cellular antioxidant response. This study aimed to evaluate the impact of genetic variation in NFE2L2 on the risk of developing HT. Methods: In a case-control candidate gene association study, functional SNPs in the NFE2L2 promoter (rs35652124, rs6706649, and rs6721961) were examined either as independent risk factors or in combination with a previously characterized HT risk allele (rs28665122) in the gene SELENOS, encoding selenoprotein S (SelS). A total of 997 individuals from the north of Portugal (Porto) were enrolled, comprising 481 HT patients and 516 unrelated healthy controls. SELENOS and NFE2L2 SNPs were genotyped using TaqMan^® assays and Sanger sequencing, respectively. Odds ratios (ORs) were calculated using logistic regression, with adjustment for sex and age. Expression of SelS was analyzed by immunohistochemistry in thyroid tissue from HT patients and control subjects. Molecular interactions between the Nrf2 and SelS pathways were investigated in thyroid tissues from mice and in rat PCCL3 thyroid follicular cells. Results: When all three NFE2L2 SNPs were considered together, the presence of one or more minor alleles was associated with a near-significant increased risk (OR = 1.43, p = 0.072). Among subjects harboring only major NFE2L2 alleles, there was no increased HT risk associated with heterozygosity or homozygosity for the SELENOS minor allele. Conversely, in subjects heterozygous or homozygous for the SELENOS risk allele, the presence of an NFE2L2 minor allele significantly increased HT risk by 2.8-fold (p = 0.003). Immunohistochemistry showed reduced expression of SelS in thyroid follicular cells of HT patients. In Nrf2 knockout mice, there was reduced expression of SelS in thyroid follicular cells; conversely, in PCCL3 cells, reducing SelS expression caused reduced activity of Nrf2 signaling. Conclusions: The NFE2L2 promoter genotype interacts with the SELENOS promoter genotype to modulate the risk of HT in a Portuguese population. This interaction may be due to a bidirectional positive feedback between the Nrf2 and SelS pathways.

Oxidative stress markers, trace elements, and endocrine disrupting chemicals in children with Hashimoto's thyroiditis

In this study, we aimed to investigate whether bisphenol A (BPA) and di-(2-ethylhexyl) phthalate (DEHP) exposure have any association with Hashimoto's thyroiditis (HT) and its biomarkers and to determine whether oxidative stress biomarkers and trace element levels showed any alterations in children with HT. We found that superoxide dismutase and glutathione peroxidase activities are lower in HT group from control (24% and 46%, respectively, p < 0.05). Zinc levels were significantly lower in HT group vs. control. In addition, the levels of mono-(2-ethylhexyl) phthalate (MEHP) which is the primary metabolite for DEHP, were markedly higher in HT group compared to control (p < 0.05). A negative correlation was observed between urinary BPA levels and fT4. In children with HT, oxidant/antioxidant balance is changed and these differences may be related by EDC exposure, the importance of which should be elucidated with further studies.

Impaired dynamic thiol/disulfide homeostasis in pubertal gynecomastia

BACKGROUND

The aim of the study was to evaluate the dynamic thiol/disulfide homeostasis (TDH) with a new method in patients with pubertal gynecomastia and also to investigate the relationship between sex hormones.

METHODS

Thiol/disulfide homeostasis, involving native thiol (SH), disulfide (SS) and total thiol (SS + SH), was evaluated between 20 adolescent boys with gynecomastia in mid-puberty and 50 healthy adolescents, who were matched for age, body mass index (BMI) and pubertal stage. The correlations of total serum testosterone (TT) and estradiol (E2) levels with the oxidative parameters were also determined.

RESULTS

No significant difference was found between the total thiol, native thiol, disulfide/native thiol and disulfide/total thiol ratios of the patient and control groups. The mean disulfide concentrations, disulfide/native thiol and the disulfide/total thiol ratios were statistically significantly higher in the patient group than in the controls. A positive correlation was found between the E2 and native thiol levels, also there was a negative correlation between the E2 and disulfide levels. TT was negatively correlated with both native thiol and disulfide levels. All these did not statistically differ between the patients with unilateral and bilateral gynecomastia.

CONCLUSIONS

There was an impaired thiol/disulfide homeostasis in patients with pubertal gynecomastia. According to this result, we can postulate that oxidative stress may be an etiologic factor that contributes to initiation and/or progression of gynecomastia.

The effect of oxidative stress on the progression of Hashimoto's thyroiditis

OBJECTIVE

We aimed to investigate the effects of oxidative stress in the pathogenesis and progression of Hashimoto's thyroiditis (HT).

METHODS

Forty euthyroid and 40 subclinical hypothyroid patients older than 18 years and not yet had received treatment were enrolled in the study.

RESULTS

In the 9 months follow-up, 14 of the HT patients developed overt hypothyroidism. The mean total oxidant status (TOS) and oxidative stress index (OSI) were higher in patients who developed overt hypothyroidism than those who did not (p < .001). And no significant difference was found between the two groups in terms of paraoxanase-1 and arylesterase (p > .05). Multivariable Cox regression model showed thyroid stimulating hormone level (HR = 1.348, p < .001), free-thyroxine level (HR = 0.481, p = .017) and OSI ratio (HR = 2.349, p < .001) to be independent predictors of development of overt hypothyroidism. OSI level, being over 2.96 with 92.9% sensitivity and 62.5% specificity, predicts the risk of hypothyroidism.

CONCLUSION

Oxidative stress may be an effective risk factor in the development of overt hypothyroidism in HT.