Combined treatment with Myo-inositol and selenium ensures euthyroidism in subclinical hypothyroidism patients with autoimmune thyroiditis

Investigating the effect of combined use of selenium and Myo-inositol supplements on thyroid function and autoimmune characteristics in thyroid disorders: a systematic review and meta-analysis

BACKGROUND

This study aimed to systematically review the effect of selenium and inositol combination on thyroid function, autoimmune characteristics in thyroid diseases.

RESEARCH DESIGN AND METHODS

To identify eligible studies, a systematic search was conducted in the PubMed/MEDLINE, Science-Direct, CINHAL, EMBASE, SCOPUS, Psychinfo, Cochrane, ProQuest, and Web of Science were searched using the main concepts, and all English-written articles that were published between 2007 and 2022 and had an available full text were examined.

RESULTS

The data analysis of this research revealed that after the simultaneous use of selenium and inositol supplements, the level of Triiodothyronine(T3) increased by 0.105 in patients with thyroid disorders although this increase was not significant (P-value: 0.228). The level of Thyroxine (T4) significantly increased by 0.06 (P-value: 0.04). Anti-Thyroid Peroxidase Antibody (TPOAb) titer decreased by 119.36%, which was not significant (P-value: 0.070). Finally, the level of Thyroid-stimulating hormone (TSH) decreased by 1.45%, which was a significant change (P-value: 0.001).

CONCLUSION

It was observed that simultaneous use of selenium and inositol supplements did not change the T3 and TPOAb titer levels; however, it leads to a decrease in TSH and increase in T4 levels. Further studies are required due to the limited number of studies.

Autoimmunity, New Potential Biomarkers and the Thyroid Gland-The Perspective of Hashimoto's Thyroiditis and Its Treatment

Autoimmune thyroid disease (AITD) is the most common organic specific illness of the thyroid gland. It may manifest as the overproduction or the decline of thyroxine and triiodothyronine. Hyperthyroidism develops due to the overproduction of hormones as an answer to the presence of stimulatory antibodies against the TSH receptor. Hashimoto's thyroiditis (HT) is generally characterized by the presence of thyroid peroxidase and thyroglobulin antibodies, with a concomitant infiltration of lymphocytes in the thyroid. Due to the progressive destruction of cells, AITD can lead to subclinical or overt hypothyroidism. Pathophysiology of AITD is extremely complicated and still not fully understood, with genetic, environmental and epigenetic factors involved in its development. Due to increasing incidence and social awareness of this pathology, there is an urgent need to expand the background concerning AITD. A growing body of evidence suggests possible ways of treatment apart from traditional approaches. Simultaneously, the role of potential new biomarkers in the diagnosis and monitoring of AITD has been highlighted recently, too. Therefore, we decided to review therapeutic trends in the course of AITD based on its pathophysiological mechanisms, mainly focusing on HT. Another aim was to summarize the state of knowledge regarding the role of new biomarkers in this condition.

Sexual Function and Depressive Symptoms in Young Women with Euthyroid Hashimoto's Thyroiditis Receiving Vitamin D, Selenomethionine and Myo-Inositol: A Pilot Study

Thyroid autoimmunity is associated with an increased risk of sexual dysfunction. The aim of this study was to compare sexual functioning and depressive symptoms in women with Hashimoto's thyroiditis receiving different treatments. The study included euthyroid women with autoimmune thyroiditis, untreated or receiving vitamin D, selenomethionine, or myo-inositol. Apart from measuring antibody titers and hormone levels, all participants completed questionnaires evaluating female sexual function (FSFI) and depressive symptoms (BDI-II). In untreated women, the overall FSFI scores and domain scores for desire, arousal, lubrication, and sexual satisfaction were lower than in women receiving vitamin D, selenomethionine, and myo-inositol. In the vitamin D-treated women, the total FSFI scores and scores for desire and arousal were higher than in women receiving the remaining micronutrients. The BDI-II score was lowest in the vitamin D-treated women and highest in the untreated patients with thyroiditis. Vitamin D-treated women were also characterized by lower antibody titers and higher testosterone levels than the women receiving the remaining micronutrients. There were no differences in sexual functioning and depressive symptoms between the selenomethionine- and myo-inositol-treated women. The study results suggest that although all antibody-lowering treatments are associated with better sexual functioning and well-being in young women with euthyroid autoimmune thyroiditis, the greatest benefits are observed in patients receiving vitamin D.

Chemokines in thyroid autoimmunity

The chemokine receptor CXCR3 and its chemokines CXCL9, CXCL10, and CXCL11 are involved in the pathogenesis of autoimmune diseases. Th1 lymphocytes are recruited by Th1 chemokines, secreted by damaged cells. In inflamed tissues, the attracted Th1 lymphocytes induce the IFN-gamma and TNF-alpha release, that stimulates the secretion of Th1 chemokines, initiating and reiterating an amplification feedback loop. Autoimmune thyroid disorders (AITD) are the most recurrent autoimmune diseases, including Graves' disease (GD) and autoimmune thyroiditis, clinically defined by thyrotoxicosis and hypothyroidism, respectively. Graves' ophthalmopathy is one of GD extrathyroidal manifestations, occurring in ~30-50% of GD patients. In the early phase of AITD, the Th1 immune response is prevalent, and a following switch to a Th2 immune response has been shown in the late, inactive, phase. The reviewed data underline the importance of chemokines in thyroid autoimmunity and suggest CXCR3-receptor and its chemokines as potential targets of novel drugs for these disorders.

Antenatal dietary supplementation with myo-inositol for preventing gestational diabetes

BACKGROUND

Gestational diabetes with onset or first recognition during pregnancy is an increasing problem worldwide. Myo-inositol, an isomer of inositol, is a naturally occurring sugar commonly found in cereals, corn, legumes and meat. Myo-inositol is one of the intracellular mediators of the insulin signal and correlates with insulin sensitivity in type 2 diabetes. The potential beneficial effect of improving insulin sensitivity suggests that myo-inositol may be useful for women in preventing gestational diabetes. This is an update of a review first published in 2015.

OBJECTIVES

To assess if antenatal dietary supplementation with myo-inositol is safe and effective, for the mother and fetus, in preventing gestational diabetes.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, WHO ICTRP (17 March 2022) and the reference lists of retrieved studies.

SELECTION CRITERIA

We included published and unpublished randomised controlled trials (RCTs) including cluster-RCTs and conference abstracts, assessing the effects of myo-inositol for the prevention of gestational diabetes in pregnant women. We included studies that compared any dose of myo-inositol, alone or in a combination preparation, with no treatment, placebo or another intervention. Quasi-randomised and cross-over trials were not eligible. We excluded women with pre-existing type 1 or type 2 diabetes.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion, assessed risk of bias and extracted the data. We checked the data for accuracy. We assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS

We included seven RCTs (one conducted in Ireland, six conducted in Italy) reporting on 1319 women who were 10 weeks to 24 weeks pregnant at the start of the studies. The studies had relatively small sample sizes and the overall risk of bias was low. For the primary maternal outcomes, meta-analysis showed that myo-inositol may reduce the incidence of gestational diabetes (risk ratio (RR) 0.53, 95% confidence interval (CI) 0.31 to 0.90; 6 studies, 1140 women) and hypertensive disorders of pregnancy (RR 0.34, 95% CI 0.19 to 0.61; 5 studies, 1052 women). However, the certainty of the evidence was low to very low. For the primary neonatal outcomes, only one study measured the risk of a large-for-gestational-age infant and found myo-inositol was associated with both appreciable benefit and harm (RR 1.40, 95% CI 0.65 to 3.02; 1 study, 234 infants; low-certainty evidence). None of the included studies reported on the other primary neonatal outcomes (perinatal mortality, mortality or morbidity composite). For the secondary maternal outcomes, we are unclear about the effect of myo-inositol on weight gain during pregnancy (mean difference (MD) -0.25 kilogram (kg), 95% CI -1.26 to 0.75 kg; 4 studies, 831 women) and perineal trauma (RR 4.0, 95% CI 0.45 to 35.25; 1 study, 234 women) because the evidence was assessed as being very low-certainty. Further, myo-inositol may result in little to no difference in caesarean section (RR 0.91, 95% CI 0.77 to 1.07; 4 studies, 829 women; low-certainty evidence). None of the included studies reported on the other secondary maternal outcomes (postnatal depression and the development of subsequent type 2 diabetes mellitus). For the secondary neonatal outcomes, meta-analysis showed no neonatal hypoglycaemia (RR 3.07, 95% CI 0.90 to 10.52; 4 studies; 671 infants; very low-certainty evidence). However, myo-inositol may be associated with a reduction in the incidence of preterm birth (RR 0.35, 95% CI 0.17 to 0.70; 4 studies; 829 infants). There were insufficient data for a number of maternal and neonatal secondary outcomes, and no data were reported for any of the long-term childhood or adulthood outcomes, or for health service utilisation outcomes.

AUTHORS' CONCLUSIONS

Evidence from seven studies shows that antenatal dietary supplementation with myo-inositol during pregnancy may reduce the incidence of gestational diabetes, hypertensive disorders of pregnancy and preterm birth. Limited data suggest that supplementation with myo-inositol may not reduce the risk of a large-for-gestational-age infant.  The current evidence is based on small studies that were not powered to detect differences in outcomes such as perinatal mortality and serious infant morbidity. Six of the included studies were conducted in Italy and one in Ireland, which raises concerns about the lack of generalisability to other settings. There is evidence of inconsistency among doses of myo-inositol, the timing of administration and study population. As a result, we downgraded the certainty of the evidence for many outcomes to low or very low certainty. Further studies for this promising antenatal intervention for preventing gestational diabetes are encouraged and should include pregnant women of different ethnicities and varying risk factors. Myo-inositol at different doses, frequency and timing of administration, should be compared with placebo, diet and exercise, and pharmacological interventions. Long-term follow-up should be considered and outcomes should include potential harms, including adverse effects.

The protective role of nutritional antioxidants against oxidative stress in thyroid disorders

An imbalance between pro-oxidative and antioxidative cellular mechanisms is oxidative stress (OxS) which may be systemic or organ-specific. Although OxS is a consequence of normal body and organ physiology, severely impaired oxidative homeostasis results in DNA hydroxylation, protein denaturation, lipid peroxidation, and apoptosis, ultimately compromising cells' function and viability. The thyroid gland is an organ that exhibits both oxidative and antioxidative processes. In terms of OxS severity, the thyroid gland's response could be physiological (i.e. hormone production and secretion) or pathological (i.e. development of diseases, such as goitre, thyroid cancer, or thyroiditis). Protective nutritional antioxidants may benefit defensive antioxidative systems in resolving pro-oxidative dominance and redox imbalance, preventing or delaying chronic thyroid diseases. This review provides information on nutritional antioxidants and their protective roles against impaired redox homeostasis in various thyroid pathologies. We also review novel findings related to the connection between the thyroid gland and gut microbiome and analyze the effects of probiotics with antioxidant properties on thyroid diseases.

The Relationship between Gastrointestinal Health, Micronutrient Concentrations, and Autoimmunity: A Focus on the Thyroid

Currently, there is a lack of understanding of why many patients with thyroid dysfunction remain symptomatic despite being biochemically euthyroid. Gastrointestinal (GI) health is imperative for absorption of thyroid-specific nutrients as well as thyroid function directly. This comprehensive narrative review describes the impact of what the authors have conceptualized as the “nutrient–GI–thyroid axis”. Compelling evidence reveals how gastrointestinal health could be seen as the epicenter of thyroid-related care given that: (1) GI conditions can lower thyroid-specific nutrients; (2) GI care can improve status of thyroid-specific nutrients; (3) GI conditions are at least 45 times more common than hypothyroidism; (4) GI care can resolve symptoms thought to be from thyroid dysfunction; and (5) GI health can affect thyroid autoimmunity. A new appreciation for GI health could be the missing link to better nutrient status, thyroid status, and clinical care for those with thyroid dysfunction.

The impact of vitamin D on thyroid autoimmunity and hypothalamic-pituitary-thyroid axis activity in myo-inositol-treated and myo-inositol-naïve women with autoimmune thyroiditis: A pilot study

WHAT IS KNOWN AND OBJECTIVE

Vitamin D and myo-inositol reduce thyroid antibody titers in subjects with autoimmune thyroiditis. No previous study has investigated interactions between these agents. The aim of the current study was to determine whether the impact of exogenous vitamin D on thyroid autoimmunity and thyroid function in women with Hashimoto's thyroiditis depends on myo-inositol supplementation.

METHODS

The study population consisted of three thyroid antibody- and insulin sensitivity-matched groups of women with autoimmune thyroiditis and high-normal or slightly elevated TSH levels. Forty-one women (21 in group A and 20 in group C) had been treated for at least 6 months with myo-inositol (group A), while 21 women (group B) had not received myo-inositol preparations. Over the entire study period (6 months), groups A and C continued treatment with myo-inositol (2 g daily), while groups A and B received exogenous vitamin D (4000 IU daily). Plasma titers of thyroid peroxidase and thyroglobulin antibodies, as well as plasma concentrations of glucose, insulin, TSH, free thyroid hormones, prolactin, and 25-hydroxyvitamin D (25-OH-D) were assessed at entry and 6 months later. Moreover, baseline and follow-up values of the structure parameters of thyroid homeostasis were calculated RESULTS AND DISCUSSION: In groups A and B, vitamin D improved insulin sensitivity and increased 25-OH-D levels. Although follow-up antibody titers in both these groups were lower than baseline ones, the impact of vitamin D on thyroid peroxidase and thyroglobulin antibodies was stronger in group A than in group B. Only in group A, vitamin D decreased TSH levels and increased SPINA-GT. There were no differences between baseline and follow-up free values of glucose, thyroid hormones, prolactin, Jostel's index, and SPINA-GD. The impact of vitamin D treatment on antibody titers correlated with treatment-induced changes in 25-OH-D levels and the degree of improvement in insulin sensitivity. In group C, glucose homeostasis markers, antibody titers and hormone levels remained at a similar level throughout the study period.

WHAT IS NEW AND CONCLUSION

The obtained results suggest that the impact of vitamin D on thyroid autoimmunity and hypothalamic-pituitary-thyroid axis activity in subjects with autoimmune thyroiditis is more pronounced if they receive myo-inositol.

Differences in levothyroxine action on thyroid autoimmunity and hypothalamic-pituitary-thyroid axis activity between metformin- and myo-inositol-treated women with autoimmune subclinical hypothyroidism

WHAT IS KNOWN AND OBJECTIVE

Insulin resistance impairs the impact of levothyroxine on thyroid autoimmunity and hypothalamic-pituitary-thyroid axis activity. Both metformin and myo-inositol were found to improve insulin sensitivity and to reduce thyrotropin levels in individuals with hypothyroidism. The aim of the present study was to compare the effect of levothyroxine on thyroid autoimmunity and hypothalamic-pituitary-thyroid axis activity between women receiving metformin and myo-inositol.

METHODS

The study included two groups of women with autoimmune hypothyroidism, treated for at least 6 months with either metformin (group A; n = 25) or myo-inositol (group B; n = 25). Both groups were matched for age, insulin sensitivity, hormone levels and antibody titers. For the following 6 months, all women received levothyroxine. Plasma levels of glucose, insulin, thyrotropin, free thyroid hormones, prolactin, 25-hydroxyvitamin D and high-sensitivity C-reactive protein (hsCRP), as well as titers of thyroid peroxidase and thyroglobulin antibodies were assessed at the beginning and at the end of the study.

RESULTS AND DISCUSSION

At baseline there were not differences between the study groups. Although levothyroxine reduced thyrotropin levels, increased free thyroid hormone levels and decreased antibody titers in both study groups, these effects were more pronounced in group A than group B. Only in group A, levothyroxine increased 25-hydroxyvitamin D, decreased hsCRP and improved insulin sensitivity. The impact of levothyroxine on thyrotropin and free thyroid hormones correlated with treatment-induced changes in insulin sensitivity, antibody titers, 25-hydroxyvitamin D and hsCRP.

WHAT IS NEW AND CONCLUSION

The present study suggests that the impact of levothyroxine on thyroid autoimmunity and hypothalamic-pituitary-thyroid axis activity is stronger in women receiving metformin than in women treated with myo-inositol.

Myoinositol in Autoimmune Thyroiditis

Myoinositol (Myo) is an isoform of inositol, a cyclic polyol with 6 hydroxyl groups. Myo is mainly derived from dietary intake while its endogenous production is generated from glucose by enzymatic reactions. Moreover, Myo is also synthesized de novo by catabolism of phosphatidylinositol (PI), phosphoinositides (PIP), and inositol phosphates (IP). Myo has a determinant role in thyroid function and autoimmune diseases as it regulates iodine organification and thyroid hormone biosynthesis by the formation of hydrogen peroxide (H₂O₂) in thyrocytes. Depletion of Myo that is involved in the thyroid stimulating hormone (TSH) signaling pathway, may cause the development of thyroid diseases such as hypothyroidism. TSH levels significantly decreased in patients with subclinical hypothyroidism, with or without autoimmune thyroiditis, after treatment with Myo plus Selenium (Myo+Se). In addition to TSH, antithyroid autoantibodies are reduced. This review summarizes the role of Myo in the thyroidal physiology and its role in the management of some thyroid diseases.

Supplementation with myo-inositol and Selenium improves the clinical conditions and biochemical features of women with or at risk for subclinical hypothyroidism

PURPOSE

The present study aims to evaluate the effect of myo-Inositol plus Selenium supplementation in patients affected by subclinical hypothyroidism.

METHODS

One hundred and forty-eight patients were included in the study from 8 different centers of Slovakia, and treated for 6 months with a daily dose of 600 mg myo-Ins plus 83 mcg Se. The patients included at the enrollment were women of reproductive age (18-50), who exhibit values of TSH in the range 2.5-5 mU/l and positivity to antibodies TPO-Ab/TG-Ab, or otherwise values of TSH in the range 5-10 mU/l both with and without positivity to antibodies TPO-Ab/TG-Ab.

RESULTS

Patients affected by subclinical hypothyroidism exhibited a significant improvement of their condition when treated for 6 months with a combination of myo-Inositol and Selenium. The TSH values significantly ameliorated along with the index of autoimmunity and the thyroid status. In a sub-class of patients, the auto-antibody titer decreased after myo-inositol + Selenium administration. The treatment also induces a regularization of the menstrual cycle and a reduction of the cholesterol in the patients enrolled for the study. Furthermore, a significant improvement is observed in the perception of the symptoms associated with subclinical hypothyroidism over the treatment period.

CONCLUSION

A dietary supplementation with of myo-Inositol and Selenium in the treatment of patients affected by subclinical hypothyroidism exhibits a beneficial role in the recovery of TSH values, in the improvement of the symptoms associated to this condition and in the maintenance of the thyroid functions.The trial was approved by the Ethical Committee from National Institute of Endocrinology and Diabetology of Lubochna, Slovakia, date 18.12.2018, registration number: 3124/2018.

Fish and the Thyroid: A Janus Bifrons Relationship Caused by Pollutants and the Omega-3 Polyunsaturated Fatty Acids

Benefits of the omega-3 polyunsaturated fatty acids (PUFA) on a number of clinical disorders, including autoimmune diseases, are widely reported in the literature. One major dietary source of PUFA are fish, particularly the small oily fish, like anchovy, sardine, mackerel and others. Unfortunately, fish (particularly the large, top-predator fish like swordfish) are also a source of pollutants, including the heavy metals. One relevant heavy metal is mercury, a known environmental trigger of autoimmunity that is measurable inside the thyroid. There are a number of interactions between the omega-3 PUFA and thyroid hormones, even at the level of the thyroid hormone transport proteins. Concerning the mechanisms behind the protection from/amelioration of autoimmune diseases, including thyroiditis, that are caused by the omega-3 PUFA, one can be the decreased production of chemokines, a decrease that was reported in the literature for other nutraceuticals. Recent studies point also to the involvement of resolvins. The intracellular increase in resolvins is associated with the tissue protection from inflammation that was observed in experimental animals after coadministration of omega-3 PUFA and thyroid hormone. After having presented data on fish consumption at the beginning, we conclude our review by presenting data on the market of the dietary supplements/nutraceuticals. The global omega-3 products market was valued at USD 2.10 billion in 2020, and was projected to go up at a compound annual growth rate of 7.8% from 2020 to 2028. Among supplements, fish oils, which are derived mainly from anchovies, are considered the best and generally safest source of omega-3. Taking into account (i) the anti-autoimmunity and anti-cancer properties of the omega-3 PUFA, (ii) the increasing incidence of both autoimmune thyroiditis and thyroid cancer worldwide, (iii) the predisposing role for thyroid cancer exerted by autoimmune thyroiditis, and (iv) the risk for developing metabolic and cardiovascular disorders conferred by both elevated/trendwise elevated serum TSH levels and thyroid autoimmunity, then there is enough rationale for the omega-3 PUFA as measures to contrast the appearance and/or duration of Hashimoto's thyroiditis as well as to correct the slightly elevated serum TSH levels of subclinical hypothyroidism.

Precision Medicine in Autoimmune Thyroiditis and Hypothyroidism

Autoimmune thyroid diseases (AITD) are T-cell-mediated organ specific autoimmune disorders, deriving from an altered response of the immune system that leads to the immune attack to the thyroid. Hashimoto’s thyroiditis (HT) and Graves’ disease (GD) are the two principal AITD clinical presentations. Hypothyroidism and thyrotoxicosis are, respectively, the clinical hallmarks of HT and GD. Patients with autoimmune thyroiditis are treated daily with synthetic L-thyroxine (L-T4) at the dose of 1.5–1.7 μg/kg. Various L-T4 formulations are commercially available (tablet, liquid solution, or soft gel capsule). L-T4 in tablets is generally prescribed to treat hypothyroidism, whereas the liquid formulation, or soft gel capsules, can be administered in hypothyroid patients in case of malabsorption or in patients in therapy with drugs interfering with L-T4 absorption. Furthermore, myoinositol has a crucial role in thyroid autoimmunity and function. Clinical studies reported a significant decline in TSH and antithyroid autoantibodies levels after treatment with myoinositol + selenium in patients with subclinical hypothyroidism and autoimmune thyroiditis. Moreover, thyroidectomy can be rarely recommended in patients with autoimmune thyroiditis, with cosmetic reasons for a goiter, or with important signs or symptoms of local compression, or nodular disease with a “suspicious” cytology for malignancy. Furthermore, a recent randomized trial suggested that total thyroidectomy can improve quality of life and fatigue, while medical therapy did not. In this review, we overview currently available evidence in personalized medicine in patients with autoimmune thyroiditis and hypothyroidism. Further research is needed in larger population to investigate the effect of these new treatments on quality of life.

Inositols Depletion and Resistance: Principal Mechanisms and Therapeutic Strategies

Inositols are natural molecules involved in several biochemical and metabolic functions in different organs and tissues. The term "inositols" refers to five natural stereoisomers, among which myo-Inositol (myo-Ins) is the most abundant one. Several mechanisms contribute to regulate cellular and tissue homeostasis of myo-Ins levels, including its endogenous synthesis and catabolism, transmembrane transport, intestinal adsorption and renal excretion. Alterations in these mechanisms can lead to a reduction of inositols levels, exposing patient to several pathological conditions, such as Polycystic Ovary Syndrome (PCOS), hypothyroidism, hormonal and metabolic imbalances, like weight gain, hyperinsulinemia, dyslipidemia, and metabolic syndrome. Indeed, myo-Ins is involved in different physiological processes as a key player in signal pathways, including reproductive, hormonal, and metabolic modulation. Genetic mutations in genes codifying for proteins of myo-Ins synthesis and transport, competitive processes with structurally similar molecules, and the administration of specific drugs that cause a central depletion of myo-Ins as a therapeutic outcome, can lead to a reduction of inositols levels. A deeper knowledge of the main mechanisms involved in cellular inositols depletion may add new insights for developing tailored therapeutic approaches and shaping the dosages and the route of administration, with the aim to develop efficacious and safe approaches counteracting inositols depletion-induced pathological events.

The Role of Inositol in Thyroid Physiology and in Subclinical Hypothyroidism Management

Myo-Inositol (MYO) is the most abundant stereoisomer of inositols' family, cyclic polyols with 6 hydroxyl groups. Myo-Inositol has a relevant role in thyroid function and autoimmune diseases, as a precursor of phosphoinositides that takes part in the phosphatidylinositol (PI) signal transduction pathway. Among phosphoinositides, phosphatidylinositol 4,5- bisphosphate (PIP2) is the precursor of inositol triphosphates (IP3), second messenger of several hormones including thyroid-stimulating hormone (TSH). As a second messenger in the phospholipase C (PLC)-dependent inositol phosphate Ca²⁺/DAG pathway, Myo-Inositol is essential to produce H₂O₂ required for the synthesis of thyroid hormones. Consequently, depletion of Myo-Inositol or impaired inositol dependent TSH signaling pathway may predispose to the development of some thyroid diseases, such as hypothyroidism. Many clinical studies have shown that after treatment with Myo-Inositol plus Selenium (MYO+Se), TSH levels significantly decreased in patients with subclinical hypothyroidism with or without autoimmune thyroiditis. The TSH reduction was accompanied by a decline of antithyroid autoantibodies. Moreover, Myo-Inositol supplementation seemed to be involved also in the management of thyroidal benign nodules, with a possible effect in the size reduction. This review proposes a summary of the role of inositol, especially of Myo-Inositol, in the thyroidal physiology and its contribution on the management of some thyroid diseases.

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.

Nutraceuticals in Thyroidology: A Review of in Vitro, and in Vivo Animal Studies

Nutraceuticals are defined as a food, or parts of a food, that provide medical or health benefits, including the prevention of different pathological conditions, and thyroid diseases, or the treatment of them. Nutraceuticals have a place in complementary medicines, being positioned in an area among food, food supplements, and pharmaceuticals. The market of certain nutraceuticals such as thyroid supplements has been growing in the last years. In addition, iodine is a fundamental micronutrient for thyroid function, but also other dietary components can have a key role in clinical thyroidology. Here, we have summarized the in vitro, and in vivo animal studies present in literature, focusing on the commonest nutraceuticals generally encountered in the clinical practice (such as carnitine, flavonoids, melatonin, omega-3, resveratrol, selenium, vitamins, zinc, and inositol), highlighting conflicting results. These experimental studies are expected to improve clinicians’ knowledge about the main supplements being used, in order to clarify the potential risks or side effects and support patients in their use.

Myo-Inositol and Its Derivatives: Their Emerging Role in the Treatment of Human Diseases

Myo-inositol has been established as an important growth-promoting factor of mammalian cells and animals. The role of myo-inositol as a lipotropic factor has been proven, in addition to its involvement as co-factors of enzymes and as messenger molecules in signal transduction. Myo-inositol deficiency leads to intestinal lipodystrophy in animals and "inositol-less death" in some fungi. Of late, diverse uses of myo-inositol and its derivatives have been discovered in medicinal research. These compounds are used in the treatment of a variety of ailments from diabetes to cancer, and continued research in this direction promises a new future in therapeutics. In different diseases, inositols implement different strategies for therapeutic actions such as tissue specific increase or decrease in inositol products, production of inositol phosphoglycans (IPGs), conversion of myo-inositol (MI) to D-chiro-inositol (DCI), modulation of signal transduction, regulation of reactive oxygen species (ROS) production, etc. Though inositol pharmacology is a relatively lesser-known field, recent years of research has generated a critical mass of information on the subject. This review aims to summarize our current understanding on the role of inositol derivatives in ameliorating the symptoms of different diseases.

Nutraceutical Supplements in the Thyroid Setting: Health Benefits beyond Basic Nutrition

In recent years, there has been a growing interest in nutraceuticals, which may be considered as an efficient, preventive, and therapeutic tool in facing different pathological conditions, including thyroid diseases. Although iodine remains the major nutrient required for the functioning of the thyroid gland, other dietary components play important roles in clinical thyroidology—these include selenium, l-carnitine, myo-inositol, melatonin, and resveratrol—some of which have antioxidant properties. The main concern regarding the appropriate and effective use of nutraceuticals in prevention and treatment is due to the lack of clinical data supporting their efficacy. Another limitation is the discrepancy between the concentration claimed by the label and the real concentration. This paper provides a detailed critical review on the health benefits, beyond basic nutrition, of some popular nutraceutical supplements, with a special focus on their effects on thyroid pathophysiology and aims to distinguish between the truths and myths surrounding the clinical use of such nutraceuticals.

Stable consumption of swordfish favors, whereas stable consumption of oily fish protects from, development of postpartum thyroiditis

PURPOSE

In 236 pregnant women, we showed that selective or predominant consumption of swordfish (group A) was associated with high rates of positivity for serum thyroid autoantibodies (TPOAb and TgAb) throughout day 4 postpartum. In contrast, selective or predominant consumption of oily fish (group B) was associated with TPOAb and TgAb negativity. Rates were intermediate in group C (scanty consumption of swordfish) and group D (consumption of fish other than swordfish and oily fish). Gestational TPOAb positivity is a risk factor for postpartum thyroiditis (PPT), which evolves into permanent hypothyroidism (PH) in about 50% of cases. Purpose of this study was to verify that the different rates of thyroid autoantibodies in the four groups translated into different PPT rates.

METHODS

We expanded our previous cohort (n = 412) and duration of follow-up (month 12 postpartum), and measured frequency of PPT and PH.

RESULTS

At first timester of gestation, we confirmed the different Ab positivity rates in group A vs. group B (TPOAb = 21.7% vs. 4.7%, P < 0.0001; TgAb = 14.1% vs. 2.4%, P < 0.05). Overall, PPT prevalence was 63/412 (15.3%), but 22/92 in group A (23.9%), 4/85 in group B (4.7%; P < 0.0001 vs. group A), 17/108 (15.7%) in group C, and 16/117 (13.7%) in group D. Approximately half of the PPT women had PH, regardless of fish group.

CONCLUSIONS

In conclusion, stable consumption of oily fish (which is enriched in polyunsaturated omega-3 fatty acids) protects from PPT, while stable consumption of swordfish (which is enriched in pollutants) favors PPT. Thus, a dietary prophylaxis of PPT is possible.

A pilot study on the beneficial effects of additional selenium supplementation to methimazole for treating patients with Graves’ disease

Background/aim

The aim of this study was to assess the effect of a combination use of methimazole (MMI) and selenium (Se) in the treatment of Graves’ disease (GD).

Materials and methods

A total of 103 newly diagnosed hyperthyroidism patients were randomized to MMI and MMI + Se combination groups. After treatment for 6 months, the levels of triiodothyronine (FT3), free thyroxine (FT4), thyrotropin receptor antibody (TRAb), thyroid peroxidase antibody (TPOAb), and thyroglobulin antibody (TGAb) were observed. An in vitro culture model of thyroid cells was established and the protein expression and mRNA levels of TRAb, TPOAb, and TGAb were determined by western blot and RT-PCR.

Results

A significant decrease in the levels of FT3, FT4, TRAb, TPOAb, and TGAb were observed in both groups along with a marked increase in TSH levels. Furthermore, the in vitro experiments showed that the protein expression and mRNA levels of TRAb, TPOAb, and TGAb decreased significantly. Also, compared to the MMI group, there was a greater improvement of these indices in the MMI + Se group.

Conclusion

We suggest that the combined use of MMI and Se could improve the thyroid activity in patients, which may provide an effective therapy for the treatment of GD in clinical settings.

Iodine and Myo-Inositol: A Novel Promising Combination for Iodine Deficiency

Despite universal salt iodization programmes implemented over the last decades, iodine deficiency remains a major public health problem in many countries worldwide. Endeavors are still required to ensure sufficient iodine intake in the populations at risk in order to eliminate deficiency. Iodine is crucial for the synthesis of thyroid hormones triiodothyronine (T₃) and thyroxine (T₄), as well as for the thyroid health. When iodine levels are insufficient, T₄ attests toward the lower limit of the physiological range, causing subtle fluctuations in the T₃:T₄ ratio. Monitoring these variations may be an accurate way to assess patient's iodine status. Recently, a number of published clinical studies documented a growing interest toward the use of myo-inositol in thyroid diseases. Myo-inositol, a carbocyclic polyol, regulates the generation of hydrogen peroxide (H₂O₂) in thyrocytes, crucial for iodine organification and thyroid hormone biosynthesis. Thus, combined supplementation of iodine and myo-inositol may promote higher iodine availability in thyrocytes improving thyroid functionality. This review presents novel strategies for the diagnosis and the management of iodine deficiency, focusing on the potential role of myo-inositol combined with iodine.

Inositol for subfertile women with polycystic ovary syndrome

BACKGROUND

Subfertile women are highly motivated to try different adjunctive therapies to have a baby, and the widespread perception is that dietary supplements such as myo-inositol (MI) and D-chiro-insoitol (DCI) are associated with only benefit, and not with harm. Many fertility clinicians currently prescribe MI for subfertile women with polycystic ovary syndrome (PCOS) as pre-treatment to in vitro fertilisation (IVF) or for ovulation induction; however no high-quality evidence is available to support this practice. This review assessed the evidence for the effectiveness of inositol in subfertile women with a diagnosis of PCOS.

OBJECTIVES

To evaluate the effectiveness and safety of oral supplementation of inositol for reproductive outcomes among subfertile women with PCOS who are trying to conceive.

SEARCH METHODS

We searched the following databases (to July 2018): Cochrane Gynaecology and Fertility Group (CGFG) Specialised Register, CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL, and AMED. We also checked reference lists and searched the clinical trials registries.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared any type, dose, or combination of oral inositol versus placebo, no treatment/standard treatment, or treatment with another antioxidant, or with a fertility agent, or with another type of inositol, among subfertile women with PCOS.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected eligible studies, extracted data, and assessed risk of bias. The primary outcomes were live birth and adverse effects; secondary outcomes included clinical pregnancy rates and ovulation rates. We pooled studies using a fixed-effect model, and we calculated odds ratios (ORs) with 95% confidence intervals (CIs). We assessed the overall quality of the evidence by applying GRADE criteria.

MAIN RESULTS

We included 13 trials involving 1472 subfertile women with PCOS who were receiving myo-inositol as pre-treatment to IVF (11 trials), or during ovulation induction (two trials). These studies compared MI versus placebo, no treatment/standard, melatonin, metformin, clomiphene citrate, or DCI. The evidence was of 'low' to 'very low' quality. The main limitations were serious risk of bias due to poor reporting of methods, inconsistency, and lack of reporting of clinically relevant outcomes such as live birth and adverse events.We are uncertain whether MI improves live birth rates when compared to standard treatment among women undergoing IVF (OR 2.42, 95% CI 0.75 to 7.83; P = 0.14; 2 RCTs; 84 women; I² = 0%). Very low-quality evidence suggests that for subfertile women with PCOS undergoing pre-treatment to IVF who have an expected live birth rate of 12%, the rate among women using MI would be between 9% and 51%.We are uncertain whether MI may be associated with a decrease in miscarriage rate when compared to standard treatment (OR 0.40, 95% CI 0.19 to 0.86; P = 0.02; 4 RCTs; 535 women; I² = 66%; very low-quality evidence). This suggests that among subfertile women with PCOS with an expected miscarriage rate of 9% who are undergoing pre-treatment to IVF, the rate among women using MI would be between 2% and 8%; however this meta-analysis is based primarily on one study, which reported an unusually high miscarriage rate in the control group, and this has resulted in very high heterogeneity. When we removed this trial from the sensitivity analysis, we no longer saw the effect, and we noted no conclusive differences between MI and standard treatment.Low-quality evidence suggests that MI may be associated with little or no difference in multiple pregnancy rates when compared with standard treatment (OR 1.04, 95% CI 0.63 to 1.71; P = 0.89; 2 RCTs; 425 women). This suggests that among subfertile women with PCOS who are undergoing pre-treatment to IVF, with an expected multiple pregnancy rate of 18%, the rate among women using inositol would be between 12% and 27%.We are uncertain whether MI may be associated with an increased clinical pregnancy rate when compared to standard treatment (OR 1.27, 95% CI 0.87 to 1.85; P = 0.22; 4 RCTs; 535 women; I² = 0%; very low-quality evidence). This suggests that among subfertile women with PCOS who are undergoing pre-treatment to IVF, with an expected clinical pregnancy rate of 26%, the rate among women using MI would be between 24% and 40%. Ovulation rates were not reported for this comparison.Other comparisons included only one trial in each, so for the comparisons MI versus antioxidant, MI versus an insulin-sensitising agent, MI versus an ovulation induction agent, and MI versus another DCI, meta-analysis was not possible.No pooled evidence was available for women with PCOS undergoing ovulation induction, as only single trials performed comparison of the insulin-sensitising agent and the ovulation induction agent.

AUTHORS' CONCLUSIONS

In light of available evidence of very low quality, we are uncertain whether MI improves live birth rate or clinical pregnancy rate in subfertile women with PCOS undergoing IVF pre-treatment taking MI compared to standard treatment. We are also uncertain whether MI decreases miscarriage rates or multiple pregnancy rates for these same women taking MI compared to standard treatment. No pooled evidence is available for use of MI versus placebo, another antioxidant, insulin-sensitising agents, ovulation induction agents, or another type of inositol for women with PCOS undergoing pre-treatment to IVF. No pooled evidence is available for use of MI in women undergoing ovulation induction.

Myo-inositol in autoimmune thyroiditis, and hypothyroidism

Myo-inositol (Myo-Ins) plays an important role in thyroid function and autoimmunity. Myo-Ins is the precursor for the synthesis of phosphoinositides, which takes part in the phosphatidylinositol (PtdIns) signal transduction pathway, and plays a decisive role in several cellular processes. In the thyroid cells, PtdIns is involved in the intracellular thyroid-stimulating hormone (TSH) signaling, via Phosphatidylinositol (3,4,5)-trisphosphate (PtdIns(3,4,5)P3) (PIP-3). Moreover, the phosphatidyl inositol 3 kinases (PI3K) family of lipid kinases regulates diverse aspects of T, B, and Tregs lymphocyte behaviour. Different mouse models deficient for the molecules involved in the PIP3 pathway suggest that impairment of PIP3 signaling leads to dysregulation of immune responses and, sometimes, autoimmunity. Studies have shown that cytokines modulate Myo-Ins in thyroid cells. Moreover, clinical studies have shown that after treatment with Myo-inositol plus seleniomethionine (Myo-Ins + Se), TSH levels significantly declined in patients with subclinical hypothyroidism due to autoimmune thyroiditis. The treatment was accompanied by a decline of antithyroid autoantibodies. After treatment serum CXCL10 levels declined, confirming the immune-modulatory effect of Myo-Ins. Additional research is necessary in larger population to evaluate the effect on the quality of life, and to study the mechanism of the effect on chemokines.

The protective effect of myo-inositol on human thyrocytes

Patients affected by autoimmune thyroiditis reached positive effects on indices of thyroid autoimmunity and/or thyroidal function, after following a treatment with selenomethionine (Se) alone, or Se in combination with Myo-inositol (Myo-Ins). Our purpose was to investigate if Myo-Ins alone, or a combination of Se + Myo-Ins, is effective in protecting thyroid cells from the effects given by cytokines, or hydrogen peroxide (H₂O₂). We assessed the interferon (IFN)-γ-inducible protein 10 (IP-10/CXCL10) secretion by stimulating primary thyrocytes (obtained from Hashimoto's thyroiditis or from control patients) with cytokines in presence/absence of H₂O_2. Our results confirm: 1) the toxic effect of H₂O₂ in primary thyrocytes that leads to an increase of the apoptosis, to a decrease of the proliferation, and to a slight reduction of cytokines-induced CXCL10 secretion; 2) the secretion of CXCL10 chemokine induced by IFN-γ + tumor necrosis factor alpha (TNF)-α has been decreased by Myo + Ins, both in presence or absence of H₂O₂; 3) no effect has been shown by the treatment with Se. Therefore, a protective effect of Myo-Ins on thyroid cells has been suggested by our data, which exact mechanisms are at the basis of this effect need to be furtherly investigated.

The effect of vitamin D and selenomethionine on thyroid antibody titers, hypothalamic-pituitary-thyroid axis activity and thyroid function tests in men with Hashimoto's thyroiditis: A pilot study

BACKGROUND

Both selenium and vitamin D were found to reduce thyroid antibody titers in women with Hashimoto's thyroiditis.

METHODS

The study enrolled 37 young drug-naïve euthyroid men with autoimmune thyroiditis, who were treated for 6 months with either exogenous vitamin D (group A, n = 20) or selenomethionine (group B, n = 17). Serum titers of thyroid peroxidase and thyroglobulin antibodies, serum levels of thyrotropin and free thyroid hormones, serum levels of 25-hydroxyvitamin D, as well Jostel's thyrotropin, the SPINA-GT and the SPINA-GD indices were determined at the beginning and at the end of the study.

RESULTS

At baseline, there were no differences between the study groups. Both vitamin D and selenomethionine reduced antibody titers and increased the SPINA-GT index. Only selenomethionine affected the SPINA-GD index, while only vitamin D increased 25-hydroxyvitamin D levels. Neither selenomethionine nor vitamin D significantly affected thyrotropin and free thyroid hormone levels. The effect of vitamin D on antibody titers correlated with baseline and treatment-induced changes in serum levels of 25-hydroxivitamin D.

CONCLUSIONS

Both vitamin D and selenomethionine have a beneficial effect on thyroid autoimmunity in drug-naïve men with Hashimoto's thyroiditis.

Diagnosis of post-surgical fine-needle aspiration biopsies of thyroid lesions with indeterminate cytology using HRMAS NMR-based metabolomics

INTRODUCTION

Ultrasound examination coupled with fine-needle aspiration (FNA) cytology is the gold standard for the diagnosis of thyroid cancer. However, about 10-40% of these analyses cannot be conclusive on the malignancy of the lesions and lead to surgery. The cytological indeterminate FNA biopsies are mainly constituted of follicular-patterned lesions, which are benign in 80% of the cases.

OBJECTIVES

The development of a FNAB classification approach based on the metabolic phenotype of the lesions, complementary to cytology and other molecular tests in order to limit the number of patients undergoing unnecessary thyroidectomy.

METHODS

We explored the potential of a NMR-based metabolomics approach to improve the quality of the diagnosis from FNABs, using thyroid tissues collected post-surgically.

RESULTS

The NMR-detected metabolites were used to produce a robust OPLSDA model to discriminate between benign and malignant tumours. Malignancy was correlated with amino acids such as tyrosine, serine, alanine, leucine and phenylalanine and anti-correlated with myo-inositol, scyllo-inositol and citrate. Diagnosis accuracy was of 84.8% when only indeterminate lesions were considered.

CONCLUSION

These results on model FNAB indicate that there is a clear interest in exploring the possibility to export NMR metabolomics to pre-surgical diagnostics.

Marked improvement of thyroid function and autoimmunity by Aloe barbadensis miller juice in patients with subclinical hypothyroidism

Some natural compounds decrease serum levels of thyroid autoantibodies, but results are inconsistent and thyroid function has been evaluated infrequently; moreover, the effects of Aloe on thyroid autoimmunity and function have been examined in very few studies. This study stems from the observation of one co-author, who has Hashimoto’s thyroiditis (HT)-related subclinical hypothyroidism (SCH). Upon checking her biochemical thyroid panel when taking daily Aloe barbardensis Miller juice (ABMJ) for thyroid-unrelated reasons, she noticed a decrease in serum thyroperoxidase autoantibodies (TPOAb) and thyrotropin (TSH) and an increase in serum free thyroxine (FT4). Based on this observation, we enrolled 30 consecutive HT women with levothyroxine-untreated SCH and high TPOAb levels. All of them took ABMJ (50 ml daily) for nine months and were tested for serum TSH, FT4, free triiodothyronine (FT3) and TPOAb. Measurements were performed at baseline and at months 3 and 9. TSH, FT4 and TPOAb improved significantly already at month 3 and further (−61%, +23% and −56%) at month 9. However, FT3 decreased significantly at month 3 (−16%) with no further decrease at month 9, so that the FT4:FT3 ratio increased significantly (+33% and + 49%). At baseline, 100% of women had TSH > 4.0 mU/L and TPOAb > 400 U/ml, but frequencies fell to 0% and 37%, respectively, at month 9. In contrast, a control group (namely, 15 untreated SCH women of comparable age and baseline levels of TSH, FT4, FT3 and TPOAb) had no significant changes in any index. We conclude that the daily intake of 100 ml ABMJ for 9 months in women with HT-related SCH decreases the burden of thyroid autoimmune inflammation. In addition, ABMJ rescues thyrocyte function, with decreased need for conversion of the prohormone T4 into the more active T3 through ABMJ-induced inhibition of T4 deiodination.

Serum selenium and selenoprotein-P levels in autoimmune thyroid diseases patients in a select center: a transversal study

OBJECTIVE

Selenium (Se) supplementation has been used to help prevent the progression of Graves' ophthalmopathy (GO) and autoimmune thyroid diseases (AITD) patients. We investigated Se serum and selenoprotein P (SePP) levels in Graves' disease (GD) with and without GO, Hashimoto's thyroiditis (HT) patients and in 27 control individuals (C).

SUBJECTS AND METHODS

We studied 54 female and 19 male patients: 19 with GD without GO, 21 GD with GO, 14 with HT and 19 with HT+LT4. Se values were measured using graphite furnace atomic absorption spectrophotometry. Serum SePP levels were measured by ELISA.

RESULTS

Median Se levels were similar among all groups; GD patients: 54.2 (46.5-61.1 μg/L), GO: 53.6 (43.5-60.0 μg/L), HT: 51.9 (44.6-58.5 μg/L), HT+LT4 54.4 (44-63.4) and C group patients: 56.0 (52.4-61.5 μg/L); P = 0.48. However, serum SePP was lower in GO patients: 0.30 (0.15-1.05 μg/mL) and in HT patients: 0.35 (0.2-1.17 μg/mL) compared to C group patients: 1.00 (0.564.21 μg/mL) as well as to GD patients: 1.19 (0.62-2.5 μg/mL) and HT+LT4 patients: 0.7 (0,25-1.95); P = 0.002. Linear regression analysis showed a significant relationship between SePP and TPOAb values (r = 0.445, R2 = 0.293; P < 0.0001). Multiple regression analysis found no independent variables related to Se or SePP.

CONCLUSION

A serum Se concentration was lower than in some other countries, but not significantly among AITD patients. The low serum SePP levels in GO and HT patients seems to express inflammatory reactions with a subsequent increase in Se-dependent protein consumption remains unclear.

Treatment with Myo-Inositol and Selenium Ensures Euthyroidism in Patients with Autoimmune Thyroiditis

Clinical evidences have highlighted the efficacy of myo-inositol and selenium in the treatment of autoimmune thyroiditis. Aim of this study was to further analyze the role of myo-inositol plus selenium (Myo-Ins-Se) in restoring a normal thyroid function of Hashimoto's patients with subclinical hypothyroidism. Eighty-six patients with Hashimoto's thyroiditis having thyroid-stimulating hormone (TSH) levels between 3 and 6 mIU/L, elevated serum antithyroid peroxidase (TPOAb) and/or antithyroglobulin (TgAb), and normal free thyroxine (fT4) and free triiodothyronine (fT3) levels were enrolled in the study: one hyperthyroid subject with TSH about 0.14 μU/ml was included in this trial as a single case. Patients were assigned to receive Myo-Ins-Se. TSH, TPOAb, and TgAb levels were significantly decreased in patients treated with combined Myo-Ins-Se after 6 months of treatment. In addition, a significant fT3 and fT4 increase, along with an amelioration of their quality of life, was observed. Remarkably, TSH values of the hyperthyroid patient increased from 0.14 μU/ml up to 1.02 μU/ml, showing a complete restoration of TSH values at a normal range. In conclusion, the administration of Myo-Ins-Se is significantly effective in decreasing TSH, TPOAb, and TgAb levels, as well as enhancing thyroid hormones and personal wellbeing, therefore restoring euthyroidism in patients diagnosed with autoimmune thyroiditis.

Insufficient documentation for clinical efficacy of selenium supplementation in chronic autoimmune thyroiditis, based on a systematic review and meta-analysis

By a systematic review and meta-analysis to investigate clinically relevant effects of selenium supplementation in patients with chronic autoimmune thyroiditis. Controlled trials in adults (≥18 years) with autoimmune thyroiditis, comparing selenium with or without levothyroxine substitution, versus placebo and/or levothyroxine substitution, were eligible for inclusion. Identified outcomes were serum thyrotropin (thyroid stimulating hormone) levels in LT4-untreated patients, thyroid ultrasound and health-related quality of life. Eleven publications, covering nine controlled trials, were included in the systematic review. Random effects model meta-analyses were performed in weighted mean difference for thyroid stimulating hormone, ultrasound and health-related quality of life. Quality of evidence was assessed per outcome, using GRADE. Meta-analyses showed no change in thyroid stimulating hormone, or improvements in health-related quality of life or thyroid echogenicity (ultrasound), between levothyroxine substitution-untreated patients assigned to selenium supplementation or placebo. Three trials found some improvement in wellbeing in patients receiving levothyroxine substitution, but could not be synthesized in a meta-analysis. The quality of evidence ranged from very low to low for thyroid stimulating hormone as well as ultrasound outcomes, and low to moderate for health-related quality of life, and was generally downgraded due to small sample sizes. We found no effect of selenium supplementation on thyroid stimulating hormone, health-related quality of life or thyroid ultrasound, in levothyroxine substitution-untreated individuals, and sporadic evaluation of clinically relevant outcomes in levothyroxine substitution-treated patients. Future well-powered RCTs, evaluating e.g. disease progression or health-related quality of life, are warranted before determining the relevance of selenium supplementation in autoimmune thyroiditis.

Selenium Supplementation Significantly Reduces Thyroid Autoantibody Levels in Patients with Chronic Autoimmune Thyroiditis: A Systematic Review and Meta-Analysis

BACKGROUND

Selenium supplementation may decrease circulating thyroid autoantibodies in patients with chronic autoimmune thyroiditis (AIT), but the available trials are heterogenous. This study expands and critically reappraises the knowledge on this topic.

METHODS

A literature search identified 3366 records. Controlled trials in adults (≥18 years of age) with AIT, comparing selenium with or without levothyroxine (LT4), versus placebo and/or LT4, were eligible. Assessed outcomes were serum thyroid peroxidase (TPOAb) and thyroglobulin (TgAb) autoantibody levels, and immunomodulatory effects. After screening and full-text assessment, 16 controlled trials were included in the systematic review. Random-effects meta-analyses in weighted mean difference (WMD) were performed for 3, 6, and 12 months of supplementation in two different populations: one receiving LT4 therapy and one newly diagnosed and LT4-untreated. Heterogeneity was estimated using I², and quality of evidence was assessed per outcome, using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) guidelines.

RESULTS

In LT4-treated populations, the selenium group had significantly lower TPOAb levels after three months (seven studies: WMD = -271 [confidence interval (CI) -366 to -175]; p < 0.0001; I² = 45.4%), which was consistent at six months (three studies) and 12 months (one study). TgAb decreased at 12 months, but not at three or six months. In LT4-untreated populations, the selenium group showed a decrease in TPOAb levels after three months (three studies: WMD = -512 [CI -626 to -398]; p < 0.0001, I² = 0.0%), but not after 6 or 12 months. TgAb decreased at 3 months, but not at 6 or 12 months. Quality of evidence was generally assessed as low. Study participants receiving selenium had a significantly higher risk than controls of reporting adverse effects (p = 0.036).

CONCLUSIONS

Selenium supplementation reduced serum TPOAb levels after 3, 6, and 12 months in an LT4-treated AIT population, and after three months in an untreated AIT population. Whether these effects correlate with clinically relevant measures remains to be demonstrated.

Dietary supplementation with myo-inositol in women during pregnancy for treating gestational diabetes

BACKGROUND

Gestational diabetes mellitus (GDM) is any degree of glucose intolerance that first presents and is recognised during pregnancy and usually resolves after the birth of the baby. GDM is associated with increased short- and long-term morbidity for the mother and her baby. Treatment usually includes lifestyle modification and/or pharmacological therapy (oral antidiabetic agents or insulin) with the aim to maintain treatment targets for blood glucose concentrations. Finding novel treatment agents which are effective, acceptable and safe for the mother and her baby are important. One such emerging potential intervention is myo-inositol which is an isomer of inositol and occurs endogenously and is found in natural dietary sources such as fruits, vegetables, nuts and cereals.

OBJECTIVES

To assess if dietary supplementation with myo-inositol during pregnancy is safe and effective, for the mother and fetus, in treating gestational diabetes.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 April 2016), ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (7 April 2016), and reference lists of retrieved studies.

SELECTION CRITERIA

All published and unpublished randomised controlled trials or cluster-randomised controlled trials reporting on the use of myo-inositol compared with placebo, no treatment or another intervention for the treatment of women with gestational diabetes. Quasi-randomised and cross-over studies are not eligible for inclusion. Women with pre-existing diabetes were excluded.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy. For key outcomes (where data were available), we assessed the quality of the evidence using the GRADE approach.

MAIN RESULTS

We included two studies (142 women and infants), both were conducted in women in Italy and compared myo-inositol with a placebo control.None of the maternal primary outcomes pre-specified for this review were reported in the included studies: hypertensive disorders of pregnancy; caesarean section; development of subsequent type 2 diabetes mellitus. No data were reported for the majority of this review's maternal secondary outcomes. We could only perform meta-analysis for two secondary outcomes: fasting oral glucose tolerance test and additional pharmacological treatment. All other results are based on data from single studies. Overall, the risk of bias of the included studies was judged to be unclear due to lack of key methodological information.There was no evidence of a difference between treatment groups in need for additional pharmacotherapy or weight gain during pregnancy, although myo-inositol was associated with a lower body mass index (BMI) change (mean difference (MD) -1.50 kg/m2; 95% confidence interval (CI) -2.35 to -0.65; one trial, n = 73). Myo-inositol was associated with a reduction in the fasting blood glucose concentration at the end of treatment (MD -0.47 mmol/L; 95% CI -0.59 to -0.35; two trials, n = 142 women) compared with the control group. One small trial reported that myo-inositol was associated with a reduction in one-hour post-prandial blood glucose concentration at the end of treatment (MD -0.90 mmol/L; 95% CI -1.73 to -0.07; one trial, n = 73 women) compared with the control group. There was no difference between groups for the two-hour post-prandial blood glucose concentrations between groups (MD -0.70 mmol/L; 95% CI -1.46 to 0.06; one trial, n = 73 women). The one-hour and two-hour blood glucose concentrations show evidence of imprecision associated with wide CIs and small sample size.For the infant, there was no evidence of a difference in the risk for being born large-for-gestational age between the myo-inositol and the control group (risk ratio (RR) 0.36; 95% CI 0.02 to 8.58; one trial, n = 73 infants; low-quality evidence). The evidence was downgraded due to imprecision. This review's other primary outcomes were not reported in the included trials: perinatal mortality (stillbirth and neonatal mortality); mortality of morbidity composite (as defined by the trials); neurosensory disability. Infants in the myo-inositol group were less likely to have neonatal hypoglycaemia compared with the placebo group (RR 0.05; 95% CI 0.00 to 0.85; one study, n = 73 infants; low-quality evidence). There is evidence of imprecision for this outcome with low event rates and small sample size. There was no evidence of a difference between treatment and placebo groups for preterm birth or birthweight. Myo-inositol was associated with a later gestational age at birth compared with the placebo group (MD 2.10 weeks; 95% CI 1.27 to 2.93; one trial, n = 73 infants). No data were reported for any of the other neonatal outcomes for this review.No long-term outcomes were reported for the mother, infant as a child, infant as an adult, or health service outcomes.

AUTHORS' CONCLUSIONS

There are insufficient data to evaluate the effect of myo-inositol for the treatment of gestational diabetes, with no data to examine the majority of outcomes in this review. There do not appear to be any benefits for the infant associated with exposure to myo-inositol such as reduced risk of being born large-for-gestational age. Although the risk of neonatal hypoglycaemia is reduced for the myo-inositol group, there is evidence of imprecision. Evidence from two studies suggested that myo-inositol was associated with a reduced change in maternal BMI and fasting blood sugar concentration compared with placebo. There is a lack of reporting of the clinically meaningful outcomes pre-specified for this review.Uncertainty of the effectiveness of myo-inositol as a treatment for GDM for key maternal and infant outcomes remains and further high- quality trials with appropriate sample sizes are required to further investigate the role of myo-inositol as a treatment or co-treatment for women with gestational diabetes. Future trials should report on the core outcomes for GDM identified in the methods section of this review. Participants of varying ethnicities and with varying risk factors for GDM should be included in future trials. In addition, further trials of myo-inositol for the treatment of GDM should explore the optimal dose, frequency and timing of supplementation, report on adverse effects and assess the long- term effects of this intervention. Economic analysis or health service use and costs should also be included.

Antenatal dietary supplementation with myo-inositol in women during pregnancy for preventing gestational diabetes

BACKGROUND

Gestational diabetes, glucose intolerance with onset or first recognition during pregnancy, is a rising problem worldwide. Both non-pharmacological and pharmacological approaches to the prevention of gestational diabetes have been, and continue to be explored. Myo-inositol, an isomer of inositol, is a naturally occurring sugar commonly found in cereals, corn, legumes and meat. It is one of the intracellular mediators of the insulin signal and correlated with insulin sensitivity in type 2 diabetes. The potential beneficial effect on improving insulin sensitivity suggests that myo-inositol may be useful for women in preventing gestational diabetes.

OBJECTIVES

To assess if antenatal dietary supplementation with myo-inositol is safe and effective, for the mother and fetus, in preventing gestational diabetes.

SEARCH METHODS

We searched the Pregnancy and Childbirth Group's Trials Register, ClinicalTrials.gov, WHO ICTRP (2 November 2015) and reference lists of retrieved studies.

SELECTION CRITERIA

We sought published and unpublished randomised controlled trials, including conference abstracts, assessing the effects of myo-inositol for the prevention of gestational diabetes mellitus (GDM). Quasi-randomised and cross-over trials were not eligible for inclusion, but cluster designs were eligible. Participants in the trials were pregnant women. Women with pre-existing type 1 or type 2 diabetes were excluded. Trials that compared the administration of any dose of myo-inositol, alone or in a combination preparation were eligible for inclusion. Trials that used no treatment, placebo or another intervention as the comparator were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion, risk of bias and extracted the data. Data were checked for accuracy.

MAIN RESULTS

We included four randomised controlled trials (all conducted in Italy) reporting on 567 women who were less than 11 weeks' to 24 weeks' pregnant at the start of the trials. The trials had small sample sizes and one trial only reported an interim analysis. Two trials were open-label. The overall risk of bias was unclear.For the mother, supplementation with myo-inositol was associated with a reduction in the incidence of gestational diabetes compared with control (risk ratio (RR) 0.43, 95% confidence interval (CI) 0.29 to 0.64; three trials; n = 502 women). Using GRADE methods this evidence was assessed as low with downgrading due to unclear risk of bias for allocation concealment in two of the included trials and lack of generalisability of findings. For women who received myo-inositol supplementation, the incidence of GDM ranged from 8% to 18%; for women in the control group, the incidence of GDM was 28%, using International Association of Diabetes and Pregnancy Study Groups Consensus Panel 2010 criteria to diagnose GDM.Two trials reported on hypertensive disorders of pregnancy, a primary maternal outcome of this review. There was no clear difference in risk of hypertensive disorders of pregnancy between the myo-inositol and control groups (average RR 0.43, 95% CI 0.02 to 8.41; two trials; n = 398 women; Tau(2) = 3.23; I(2) = 69%). Using GRADE methods, this evidence was assessed as very low, with downgrading due to wide confidence intervals with very low event rates, a small sample size, and lack of blinding and unclear allocation concealment methods, and a lack of generalisability. For women who received myo-inositol the risk of hypertensive disorders of pregnancy ranged from 0% to 33%; for women in the control group the risk was 4%.For the infant, none of the included trials reported on the primary neonatal outcomes of this systematic review (large-for-gestational age, perinatal mortality, mortality or morbidity composite).In terms of this review's secondary outcomes, there was no clear difference in the risk of caesarean section between the myo-inositol and control groups (RR 0.95, 95% CI 0.76 to 1.19; two trials; n = 398 women). Using GRADE methods, this evidence was assessed as low, with downgrading due to unclear risk of bias in one trial and lack of generalisability. For women who received myo-inositol supplementation, the risk of having a caesarean section ranged from 34% to 54%; for women in the control group the was 45%. There were no maternal adverse effects of therapy in the two trials that reported on this outcome (the other two trials did not report this outcome).Two trials found no clear difference in the risk of macrosomia between infants whose mothers received myo-inositol supplementation compared with controls (average RR 0.35, 95% CI 0.02 to 6.37; two trials; n = 398 infants;Tau(2) = 3.33; I(2) = 73%). Similarly, there was no clear difference between groups in terms of neonatal hypoglycaemia (RR 0.36, 95% CI 0.01 to 8.66) or shoulder dystocia (average RR 2.33, 95% CI 0.12 to 44.30, Tau(2) = 3.24; I(2) = 72%).There was a lack of data available for a large number of maternal and neonatal secondary outcomes, and no data for any of the long-term childhood or adulthood outcomes, or for health service cost outcomes.

AUTHORS' CONCLUSIONS

Evidence from four trials of antenatal dietary supplementation with myo-inositol during pregnancy shows a potential benefit for reducing the incidence of gestational diabetes. No data were reported for any of this review's primary neonatal outcomes. There were very little outcome data for the majority of this review's secondary outcomes. There is no clear evidence of a difference for macrosomia when compared with control.The current evidence is based on small trials that are not powered to detect differences in outcomes including perinatal mortality and serious infant morbidity. All of the included studies were conducted in Italy which raises concerns about the lack of generalisability of the evidence to other settings. There is evidence of inconsistency and indirectness and as a result, many of the judgements on the quality of the evidence were downgraded to low or very low quality (GRADEpro Guideline Development Tool).Further trials for this promising antenatal intervention for preventing gestational diabetes are encouraged and should include pregnant women of different ethnicities and varying risk factors and use of myo-inositol (different doses, frequency and timing of administration) in comparison with placebo, diet and exercise or pharmacological interventions. Outcomes should include potential harms including adverse effects.