Hyperthyroidism Prevalence in China After Universal Salt Iodization.

Background: Universal salt iodization (USI) was implemented in mainland China in 1996. The prevalence of hyperthyroidism and its risk factors now require examination. Methods: Data were acquired from a nationwide Thyroid, Iodine, and Diabetes Epidemiological survey (TIDE 2015-2017) of 78,470 subjects from 31 provinces. Iodine status, and thyroid hormones and antibodies were measured. Results: After two decades of USI, the prevalence of overt hyperthyroidism (OH), Graves' disease (GD), severe subclinical hyperthyroidism (severe SCH), and mild subclinical hyperthyroidism (mild SCH) in mainland China was 0.78%, 0.53%, 0.22%, and 0.22%, respectively. OH and GD prevalence were higher in women than in men (OH: 1.16% vs. 0.64%, P<0.001; GD: 0.65% vs. 0.37%, P<0.001).Prevalence was significantly decreased after 60 years-of-age compared with 30-39 years-of-age (OH:0.61% vs. 0.81%, P<0.001; GD: 0.38% vs. 0.57%, P<0.001).Excessive iodine(EI) and deficient iodine(DI) were both related to increased prevalence of OH (odds ratio [OR] 2.09, 95% confidence interval [CI] 1.68-2.59; OR1.35, 95%CI 1.07-1.72, respectively); however, only deficient iodine was associated with increased prevalence of GD (OR1.67, 95%CI 1.30-2.15). Increased thyroid peroxidase antibody and thyroglobulin antibody levels were significantly associated with prevalence of OH and GD, but not severe SCH and mild SCH. Although hyperthyroidism was more prevalent in women, the association disappeared after adjusting for other factors such as antibody levels. Conclusion: OH and GD prevalences in mainland China are stable after two decades of USI. Iodine deficiency, elevated thyroid antibody levels, and middle age are the main risk factors for OH and GD. The severe SCH population, rather than the mild SCH population, shows similar characteristics to the OH population.

Inverse Association between Metformin and Amiodarone-Associated Extracardiac Adverse Events.

Background: The association between metformin and amiodarone-induced adverse events was examined using spontaneous adverse event database. Additionally, the association between other antidiabetic drugs and amiodarone-induced adverse events were also examined. Methods: A total of 6,153,696 reports from the first quarter of 2004 through the fourth quarter of 2015 were downloaded from the US Food and Drug Administration adverse event reporting system. Reporting odds ratio (ROR) and information component (IC) were used to detect associations between antidiabetic drugs and amiodarone-associated adverse events. Additionally, subset data analysis was performed to investigate whether the use of antidiabetic drugs further increased or decreased the risk of adverse events in patients receiving amiodarone therapy. Next, the RORs were adjusted for coadministered antidiabetic drugs using logistic regression analysis. Results: By whole dataset analysis, significant inverse associations were found between metformin and interstitial lung disease (ROR 0.84, 95% confidence interval [CI] 0.79-0.90; IC -0.24, 95% CI -0.33 to -0.15). In the subset data analysis, metformin (ROR 0.62, 95%CI 0.43-0.89; IC -0.63, 95%CI -1.14 to -0.11), sulfonylureas (ROR 0.53, 95%CI 0.32-0.85; IC -0.85, 95%CI -1.53 to -0.17), and dipeptidyl peptidase-4 (DPP-4) inhibitors (ROR 0.25, 95%CI 0.08-0.78; IC -1.66, 95%CI -3.08 to -0.23) were inversely associated with hyperthyroidism. Additionally, metformin (ROR 0.43, 95%CI 0.33-0.57; IC -1.09, 95%CI -1.49 to -0.69), sulfonylureas (ROR 0.64, 95%CI 0.48-0.86; IC -0.59, 95%CI -1.00 to -0.17), and DPP-4 inhibitors (ROR 0.47, 95%CI 0.27-0.81; IC -0.99, 95%CI -1.76 to -0.22) were inversely associated with interstitial lung disease. In the logistic regression analyses, DPP-4 inhibitors (adjusted ROR 0.32, 95% CI 0.10-1.00) and metformin (adjusted ROR 0.46, 95% CI 0.34-0.62) were inversely associated with amiodarone-associated hyperthyroidism and interstitial lung disease, respectively. Conclusion: Metformin is a candidate drug to reduce the risk of amiodarone-induced hyperthyroidism and interstitial lung disease.

Efficacy and Safety of Long-Term Universal Salt Iodization on Thyroid Disorders: Epidemiological Evidence from 31 Provinces of Mainland China.

Background: Mandatory universal salt iodization (USI) has been implemented in China for 20 years. Although iodine deficiency disorders are effectively controlled, the risk of excess iodine have been debated. Methods: A nationally representative cross-sectional study with 78,470 enrolled participants, aged 18 years or older, from all 31 provincial regions of mainland China was performed. The participants were given a questionnaire and underwent B-mode ultrasonography of the thyroid. Serum concentrations of thyroid hormones, thyroid antibodies, and urine iodine concentration (UIC) were measured. Results: The median UIC of the adult population was 177.89 µg/L. The weighted prevalence of thyroid disorders in adults were as follows: 0.78% of overt hyperthyroidism, 0.44% of subclinical hyperthyroidism, 0.53% of Graves' disease, 1.02% of overt hypothyroidism, 12.93% of subclinical hypothyroidism, 14.19% of positive thyroid antibodies, 10.19% of positive thyroid peroxidase antibodies, 9.70% of positive thyroglobulin antibodies, 1.17% of goiter, and 20.43% of thyroid nodules. Iodine excess was only associated with higher odds of overt hyperthyroidism and subclinical hypothyroidism, while iodine deficiency was significantly associated with higher odds of most thyroid disorders. In addition, increased iodine intake was significantly associated with elevated serum thyrotropin levels but was inversely associated with thyroid antibodies and thyroid nodules. Conclusions: The long-term mandatory USI program with timely adjustments is successful in preventing iodine deficiency disorders, and it appears to be safe. The benefits outweigh the risks in a population with a stable median iodine intake level of up to 300 µg/L.

Thyroid disease: assessment and management

This guideline covers investigating all suspected thyroid disease and managing primary thyroid disease (related to the thyroid rather than the pituitary gland). It does not cover managing thyroid cancer or thyroid disease in pregnancy. It aims to improve quality of life by making recommendations on diagnosis, treatment, long-term care and support.

Role of Selenium Intake for Risk and Development of Hyperthyroidism.

Purpose: To investigate the importance of dietary selenium (Se) for hyperthyroidism. Methods: We performed a more in-depth analysis of a large cross-sectional study of 6152 participants from two counties within the Shaanxi Province, China. These counties are characterized by different habitual Se intake. We investigated the effects of a different dietary Se supply (0.02, 0.18, 0.6, or 2.0 ppm Se) on disease development in a mouse model of Graves disease (GD). Results: The cross-sectional study revealed a comparable prevalence of hyperthyroidism, irrespective of Se intake, in both counties. However, an unexpected sex-specific difference was noted, and Se deficiency might constitute a risk factor for hyperthyroidism, especially in males. In a mouse model, pathological thyroid morphology was affected, and greater Se intake exerted some protecting effects on the pathological distortion. Circulating thyroid hormone levels, malondialdehyde concentrations, total antioxidant capacity, and the titer of GD-causing TSH receptor autoantibodies were not affected by Se. Expression analysis of the transcripts in the spleen indicated regulatory effects on genes implicated in the immune response, erythropoiesis, and oxygen status. However, the humoral immune response, including the CD4/CD8 or T-helper 1/T-helper 2 cell ratio and the concentration of regulatory T cells, was similar between the experimental groups, despite the difference in Se intake. Conclusions: Our data have highlighted a sexual dimorphism for the interaction of Se and thyroid disease risk in humans, with indications of a local protective effects of Se on thyroid gland integrity, which appears not to be reflected in the circulating biomarkers tested.

Arecoline ameliorates hyperthyroid condition in mice under cold stress.

Betel nut of Areca catechu is chewed by millions of people for increased capacity to work and stress reduction, but it contains arecoline that causes hypothyroidism. The aim is to investigate the role of arecoline on thyroid activity in cold stress in mice. Arecoline treatment (10 mg/kg body wt/day, for 7 d) caused a reduction in thyroid weight and ultrastructural degeneration of thyro-follicular cells with depletion of T3 and T4 levels compared with the control mice. Cold stress (4 °C for 2 h, twice daily, for 7 d) stimulated thyroid activity ultrastructurally with an elevation of T3 and T4 levels. Arecoline treatment in cold stress suppressed thyroid activity by showing reversed changes to those of cold stress. In contrast, TSH concentrations were consistently increased under all experimental conditions. The findings suggest that cold stress causes hyperthyroidism which arecoline can ameliorate in mice.

Departamento de Tireoide da Sociedade Brasileira de Endocrinologia e Metabologia

Página do Departamento de Tireoide da Sociedade Brasileira de Endocrinologia e Metabologia contendo informações para a área científica e para o público sobre a glândula tireoide.

12-month efficacy of a single radiofrequency ablation on autonomously functioning thyroid nodules.

PURPOSE: Radiofrequency ablation has been advocated as an alternative to radioiodine and/or surgery for the treatment of autonomously functioning benign thyroid nodules. However, only a few studies have measured radiofrequency ablation efficacy on autonomously functioning benign thyroid nodules. The aim of this work was to evaluate the 12-month efficacy of a single session of radiofrequency ablation (performed with the moving shot technique) on solitary autonomously functioning benign thyroid nodules. METHODS: Thirty patients with a single, benign autonomously functioning benign thyroid nodules, who were either unwilling or ineligible to undergo surgery and radioiodine, were treated with radiofrequency ablation between April 2012 and May 2015. All the patients underwent a single radiofrequency ablation, performed with the 18-gauge needle and the moving shot technique. Clinical, laboratory, and ultrasound evaluations were scheduled at baseline, and after 1, 3, 6, and 12 months from the procedure. RESULTS: A single radiofrequency ablation reduced thyroid nodule volume by 51, 63, 69, and 75 % after 1, 3, 6, and 12 months, respectively. This was associated with a significant improvement of local cervical discomfort and cosmetic score. As for thyroid function, 33 % of the patients went into remission after 3 months, 43 % after 6 months, and 50 % after 12 months from the procedure. This study demonstrates that a single radiofrequency ablation allowed us to withdraw anti-thyroid medication in 50 % of the patients, who remained euthyroid afterwards. CONCLUSION: This study shows that a single radiofrequency ablation was effective in 50 % of patients with autonomously functioning benign thyroid nodules. Patients responded gradually to the treatment. It is possible that longer follow-up studies might show greater response rates.

Management of a pregnant woman with thyrotropinoma: a case report and review of the literature.

INTRODUCTION: Pituitary disorders during pregnancy are uncommon. The approach should include a close follow-up in order to reduce maternal and fetal risks associated with physiological changes during pregnancy or treatment side effects. MATERIALS AND METHODS: We report a 21-year-old woman with a thyroid-stimulating hormone-secreting pituitary macroadenoma and positive antithyroid antibodies. She was initially treated using transsphenoidal pituitary surgery. The patient relapsed 17-month post-surgery. Somatostatin analog therapy was started which rapidly controlled the hyperthyroidism. Eleven months later, while receiving octreotide, the patient reported to be pregnant and the medication was stopped. Gestation and delivery went well with a healthy full-term newborn. The patient developed a postpartum thyroiditis 15 weeks after giving birth. Twenty-eight months postpartum the patient remains euthyroid without medication. CONCLUSIONS: The overall positive outcomes of the four cases reported in literature, including this new case, suggest that pregnancy should not be absolutely contraindicated in women with thyrotropinomas. We emphasize the effectiveness of octreotide to control hyperthyroidism, as well as stopping medication when a patient is found to be pregnant. In our case, close observation following octreotide cessation had a positive outcome.

Early detection of biochemically occult autonomous thyroid nodules.

OBJECTIVE: Autonomously functioning thyroid areas may be associated with subclinical or overt hyperthyroidism, but may exist even in the presence of normal TSH. This study was aimed at comparing the rate of autonomously functioning areas and their cardiac sequelae in patients with nodular goitre studied with the usual and a novel approach. DESIGN AND METHODS: In total 490 adult outpatients with thyroid nodular goitre, living in a mild iodine-deficient area, were selected in our referral centre for thyroid diseases from 2009 to 2014 on the basis of a suspicion of thyroid functional autonomy. They were divided in three groups according to a non-conventional approach (excessive response to thyroxine treatment: group 1) or conventional approach (low/normal TSH with clinical suspicion or low TSH: groups 2 and 3). All patients of the study with the suspicion of thyroid functional autonomy underwent thyroid scan with radioactive iodine (I131) uptake (RAIU). RESULTS: The percentage of confirmed thyroid functional autonomy was 319/490, being significantly higher in group 3 than in groups 1 and 2 (81.5 vs 64.7 vs 52.6%; chi-square P < 0.0001). However, the diagnosis with non-conventional approach was made at a significant earlier age (P < 0.0001). Cardiac arrhythmias as well as atrial fibrillation were similarly detected by conventional and non-conventional approaches (chi-square test: P = 0.2537; P = 0.8425). CONCLUSIONS: The hyper-responsiveness to thyroxine treatment should induce the suspicion of thyroid functional autonomy at an early stage, allowing to detect autonomous functioning areas in apparently euthyroid patients.

Physiological and Metabolic Changes During the Transition from Hyperthyroidism to Euthyroidism in Graves' Disease.

BACKGROUND: The serum metabolomic profile and its relationship to physiological changes during hyperthyroidism and restoration to euthyroidism are not known. This study aimed to examine the physiological, adipokine, and metabolomic changes that occur when subjects with Graves' disease transition from hyperthyroidism to euthyroidism with medical treatment. METHODS: Chinese women between 21 and 50 years of age and with newly diagnosed Graves' disease attending the endocrine outpatient clinics in a single institution were recruited between July 2012 and September 2014. All subjects were treated with thioamides to achieve euthyroidism. Clinical parameters (body weight, body composition via bioelectrical impedance analysis, resting energy expenditure and respiratory quotient via indirect calorimetry, and reported total energy intake via 24 h food diary), biochemical parameters (thyroid hormones, lipid profile, fasting insulin and glucose levels), serum leptin, adiponectin, and metabolomics profiles were measured during hyperthyroidism and repeated in early euthyroidism. RESULTS: Twenty four Chinese women with an average age of 36.3 ± 8.6 years were included in the study. The average duration of treatment that was required to reach euthyroidism for these subjects was 38 ± 16.3 weeks. There was a significant increase in body weight (52.6 ± 9.0 kg to 55.3 ± 9.4 kg; p < 0.001) and fat mass (14.3 ± 6.9 kg to 16.8 ± 6.5 kg; p = 0.005). There was a reduction in resting energy expenditure corrected for weight (28.7 ± 4.0 kcal/kg to 21.5 ± 4.1 kcal/kg; p < 0.001) and an increase in respiratory quotient (0.76 to 0.81; p = 0.037). Resting energy expenditure increased significantly with increasing free triiodothyronine levels (p = 0.007). Significant increases in total cholesterol, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol were noted. There was no significant change in leptin levels, but adiponectin levels increased significantly (p = 0.018). Significant reductions in fasting C2, medium-chain, long-chain, and total acylcarnitines were observed, but no changes in the fat-free mass, branched chain amino acid levels, or insulin sensitivity during recovery from hyperthyroidism were noted. CONCLUSIONS: Serum metabolomics profile changes complemented the physiological changes observed during the transition from hyperthyroidism to euthyroidism. This study provides a comprehensive and integrated view of the changes in fuel metabolism and energy balance that occur following the treatment of hyperthyroidism.

[Hyperthyroid and acute tonsillitis in a 23-year-old woman]. / Hyperthyreose und akute Tonsillitis bei einer 23-jährigen Patientin.

A 23-year-old woman with preexisting Graves' disease who received thiamazole treatment presented with fever, dysphagia, hyperthyroidism and leukopenia. With suspicion of thyreotoxicosis accompanied by drug-induced agranulocytosis she was successfully managed by plasmapheresis, G­CSF administration and inhibition of periphereal conversion of thyroid hormones. In due course she underwent thyroidectomy. Thiamazole is frequently associated with drug-induced agranulocytosis. Long-term therapy with thiamazole requires critical evaluation and alternatives should be considered early. Plasmapheresis is an adequate treatment option to achieve normal thyroid hormonal status.

Prospective Intervention of a Novel Levothyroxine Dosing Protocol Based on Body Mass Index after Thyroidectomy.

BACKGROUND: Weight-based postoperative levothyroxine (LT4) dosing often fails to appropriately dose overweight and underweight patients. Previously, we created an LT4-dosing algorithm based on BMI. We hypothesize that more patients will achieve euthyroidism at their postoperative visit with the use of the protocol. STUDY DESIGN: A prospective evaluation was performed of our previously published BMI-based LT4 dosing. All adults who underwent thyroidectomy for benign disease between January 1, 2011 and December 31, 2013 were included; the new protocol was implemented in October 2012. Serum TSH was measured for all patients 6 to 8 weeks postoperatively, and adjustments were based on TSH. RESULTS: Three hundred and thirty patients were included, with 54% undergoing thyroidectomy after institution of the protocol. The groups were well matched. Before protocol implementation, LT4 was dosed solely by weight and 25% of patients were euthyroid at initial follow-up. After the protocol, 39% of patients were euthyroid (p = 0.01). The percentage of patients who were given too high a dose of LT4 remained the same (46% vs 42%), and there was a significant reduction in the number of patients who were given too little (29% vs 19%; p = 0.05). The effect was most profound in patients with low and normal BMI, and there were slight differences between sexes. CONCLUSIONS: Although correct initial dosing of LT4 remains challenging, this dosing protocol that we developed and implemented has improved patient care by increasing the number of patients who achieve euthyroidism at the first postoperative visit. We have made a change to our original protocol to incorporate sex differences into the calculation.

Change of maternal thyroid function in twin-twin transfusion syndrome.

Human chorionic gonadotropin (hCG) has weak thyroid-stimulating activity because of its homology with thyroid stimulating hormone (TSH). In twin-twin transfusion syndrome (TTTS), which is a severe complication of monochorionic twin pregnancies, a close association between maternal serum hCG concentration and TTTS has been reported. And, TTTS can be treated by fetoscopic laser coagulation of the communicating vessels. To clarify the relationship between maternal serum hCG and maternal thyroid function in TTTS, the present study investigated the change in thyroid hormone and hCG levels after laser therapy. The protocol included collection of serial maternal blood samples in TTTS before laser therapy, and at two and four weeks after laser therapy. For 131 cases of TTTS, the following parameters were determined at each point: hCG, TSH, free triiodothyronine (fT3), and free thyroxine (fT4). The multiple of the median (MoM) of pre-operative hCG concentration in TTTS was 5.39 MoM (interquartile range, 2.83 - 8.64). There was a moderate positive correlation between hCG and fT3 in TTTS pre-operatively (R = 0.22, P = 0.030). fT4 was also positively correlated with hCG (R = 0.33, P < 0.001). Some cases showed very high concentration in fT3. When laser therapy for TTTS was effective, the hCG concentration significantly decreased, and fT3 and fT4 decreased progressively in concert with the decrease in hCG. The relationship between hCG and thyroid function in TTTS supports the finding of TTTS as a novel etiology of hCG-mediated hyperthyroidism during pregnancy.

Iodine deficiency and thyroid disorders.

Iodine deficiency early in life impairs cognition and growth, but iodine status is also a key determinant of thyroid disorders in adults. Severe iodine deficiency causes goitre and hypothyroidism because, despite an increase in thyroid activity to maximise iodine uptake and recycling in this setting, iodine concentrations are still too low to enable production of thyroid hormone. In mild-to-moderate iodine deficiency, increased thyroid activity can compensate for low iodine intake and maintain euthyroidism in most individuals, but at a price: chronic thyroid stimulation results in an increase in the prevalence of toxic nodular goitre and hyperthyroidism in populations. This high prevalence of nodular autonomy usually results in a further increase in the prevalence of hyperthyroidism if iodine intake is subsequently increased by salt iodisation. However, this increase is transient because iodine sufficiency normalises thyroid activity which, in the long term, reduces nodular autonomy. Increased iodine intake in an iodine-deficient population is associated with a small increase in the prevalence of subclinical hypothyroidism and thyroid autoimmunity; whether these increases are also transient is unclear. Variations in population iodine intake do not affect risk for Graves' disease or thyroid cancer, but correction of iodine deficiency might shift thyroid cancer subtypes toward less malignant forms. Thus, optimisation of population iodine intake is an important component of preventive health care to reduce the prevalence of thyroid disorders.

A critical review of food-associated factors proposed in the etiology of feline hyperthyroidism.

Since the first description of feline hyperthyroidism (HT) in 1979, several studies have been undertaken to define the etiology of the disease. Epidemiologic studies, after investigating non-food- and food-associated factors, suggest a multifactorial etiology. However, in the absence of prospective cohort studies that can confirm a cause-and-effect relationship between HT and associated risk factors, no causative factor for HT has been identified to date. Feline HT resembles toxic nodular goiter in humans, with autonomously functioning upregulated iodide uptake systems. Contribution of the diet to HT development remains controversial. The purpose of this paper is to review critically the reported food-associated risk factors for HT.

[Maternal autoimmune thyroid disease: relevance for the newborn]. / Enfermedad tiroidea autoinmunitaria materna: repercusión en el recién nacido.

BACKGROUND AND OBJECTIVE: Autoimmune thyroid disease is amongst the most frequent endocrine disorders during pregnancy. It is associated with an increase in perinatal morbidity, congenital defects, neurological damage, fetal and neonatal thyroid dysfunction. Maternal thyroid hormones play a key role in child neurodevelopment. We aimed to evaluate the thyroid function and the clinical course of neonates born from mothers with autoimmune thyroid disease during the first months of life in order to define the follow-up. PATIENTS AND METHOD: We monitored thyroid function and clinical status during the first months in 81 newborns of mothers with autoimmune thyroid disease; 16 had Graves disease and 65 autoimmune thyroiditis. RESULTS: A percentage of 4.93 newborns had congenital defects, and 8.64% neonates showed an increase in thyrotropin (TSH) (>9.5 µUI/mL 2 times) and required thyroxin within the first month of life. A 85.7% of these showed a negative newborn screening (due to a later increase of TSH). A higher TSH value in the newborn was related to an older age of the mother, higher levels of thyroid peroxidase (TPO) antibody during pregnancy and lower birth weight. A higher free thyroxine (FT4) value in the newborn was related to fewer days of life and mothers with Graves disease. CONCLUSIONS: We recommend the evaluation of TSH, T4 and TPO antibodies before 10 weeks in all pregnant women with follow-up if maternal thyroid autoimmunity or disorders is detected. It is also recommended to test children's serum TSH and FT4 at 48 h of life in newborns of mothers with autoimmune thyroid disease and repeat them between the 2nd and 4th week in children with TSH>6 µUI/mL. Careful endocrine follow-up is advised in pregnant women and children if hyperthyroidism is detected.

Adenoma tóxico de Plummer: relato de caso / Toxic adenoma of Plummer: case report

O termo hipertireoidismo refere-se ao aumento da síntese e liberação dos hormônios tireoidianos pela glândula tireoide. O bócio multinodular toxico e o adenoma toxico constituem as principais causas do hipertireoidismo no paciente idoso e são frequentes em regiões com ingestão insuficiente de iodo...(AU)

Adenoma tóxico de Plummer: relato de caso / Toxic adenoma of Plummer: case report

O termo hipertireoidismo refere-se ao aumento da síntese e liberação dos hormônios tireoidianos pela glândula tireoide. O bócio multinodular toxico e o adenoma toxico constituem as principais causas do hipertireoidismo no paciente idoso e são frequentes em regiões com ingestão insuficiente de iodo...