Diagnosis and management of thyrotoxicosis

Comparison of agranulocytosis and anti-neutrophil cytoplasmic antibody-associated vasculitis caused by two antithyroid drugs: A pharmacovigilance study using the WHO international database

BACKGROUND

Methimazole (MMI) and propylthiouracil (PTU) are commonly used for patients with thyrotoxicosis. Agranulocytosis and antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is associated with high morbidity and mortality, requiring appropriate interventions. In this study, we compared adverse drug effects associated with MMI and PTU using a real-world large pharmacovigilance database.

METHODS

We searched all Individual Case Safety Reports reported to be associated with MMI and PTU, from VigiBase between 1967 and June 2, 2021. We conducted disproportionality analysis (case/non-case analysis) to analyze the difference in reported adverse drug reactions (ADRs) between antithyroid drugs (case) and the entire database (non-cases). We further analyzed information for the cases of agranulocytosis and AAV.

RESULTS

Among 11 632 cases of ADRs reported after MMI intake, agranulocytosis occurred in 1633 cases and AAV occurred in 41 cases. For 5055 cases of ADRs reported after PTU intake, agranulocytosis occurred in 459 cases and AAV occurred in 110 cases. Agranulocytosis occurred after a median of 28 days after PTU intake and 33 days after MMI intake. More than 95% of the agranulocytosis cases were classified as serious, but most of them (65.1% for PTU and 70.4% for MMI) were reported to have recovered after dechallenge actions; mostly drug withdrawal. AAV occurred after a median of 668 days after PTU intake, and 1162 days after MMI intake.

CONCLUSIONS

This is a pharmacoepidemiological study investigating agranulocytosis and AAV caused by MMI and PTU. Through this research, we could provide more specific insights into a safe prescription of antithyroid drugs in a real-world setting.

Rare Presentation of Thyrotoxicosis Defying Methimazole Treatment: A Case Series

Thyrotoxicosis, also known as hyperthyroidism, is a condition characterized by the excessive production of thyroid hormones by the thyroid gland. Besides Graves' disease, other common causes of thyrotoxicosis include toxic multinodular goiter, toxic adenoma, and subacute thyroiditis. The treatment of thyrotoxicosis depends on the underlying cause and may include medications (e.g., antithyroid drugs, beta-blockers), radioactive iodine therapy, or surgical removal of the thyroid gland (thyroidectomy). In this report, we present two instances of thyrotoxicosis where conventional high doses of antithyroid treatment failed to control the condition effectively. This failure prompted the exploration of alternative therapeutic interventions. These cases highlight the intricacies involved in managing thyrotoxic crises that do not respond to methimazole (MMI), emphasizing the necessity for innovative approaches such as plasmapheresis and thyroidectomy. Understanding such scenarios is vital for enhancing the care provided to patients encountering resistance to standard treatments. The distinct clinical pathways and treatment strategies adopted in these cases offer valuable insights into this disease management, particularly concerning resistance to MMI.

Factors predicting remission in hyperthyroid patients after low-dose I-131 therapy: 20 years retrospective study from a tertiary care hospital

OBJECTIVE

To assess the therapeutic outcome and factors predicting remission in hyperthyroid patients treated with low-dose I-131 (radioactive iodine) from a tertiary care hospital in South India.

METHODS

This 20-year single-institutional retrospective study was carried out on 3891 hyperthyroid adult patients. Only those patients with complete clinical records were audited. Selection criteria were based on patients with scintigraphic diagnosis of either Graves' disease (GD), toxic multinodular goitre (TMNG) or autonomous toxic nodule (ATN) and the records of those who received low-dose I-131 therapy (LDT) between March 2000 and 2020 at Amrita Institute, Cochin were analysed. SPSS 10 software was used for statistical analysis.

RESULTS

The records of 3891 hyperthyroid predominantly female patients were analysed. 65% patients had GD, 33% had TMNG and 3% were ATN. High rates of remission as early as 12 weeks (in 61% patients) was observed with a single dose of LDT while on strict iodine-free diet for 3-4 weeks prior to LDT. Study reveals that those with lower free T4 (fT4), small goitre (thyroid volume < 25 cm3), < 15% thyroid trapping function, shorter time duration from onset of hyperthyroidism to LDT, and treatment-naïve patients were factors determining high remission rates. Mann Whitney U test and Chi-square test was used to correlate variables in the remission and relapse groups. We found a positive correlation between fT4, thyroid volume (r = 0.35, p < 0.01) and trapping function (r = 0.34, p < 0.01), which were independent of age, sex, body mass index and TSH levels in our study.

CONCLUSION

High therapeutic outcome was observed with a single dose of LDT while on iodine-free diet. Remission with single dose of LDT occurred in 90% patients by 5th month. Of them 56% patients were treatment naive prior to LDT. LDT is thus a safe and effective therapy in hyperthyroid patients and can be recommended as a primary modality of management.

Thyrotoxicosis

Hyperthyroidism is a diagnosis existing along a spectrum of severity. Patients present with a variety of signs and symptoms: tachycardia, elevated heart rate, anxiety, changes in mental status, gastrointestinal disturbances, and hyperthermia. Management of subclinical hyperthyroidism and thyrotoxicosis without thyroid storm is heavily dependent on outpatient evaluation. Thyroid storm is the most severe form of hyperthyroidism with the highest mortality. Management of thyroid storm follows a stepwise approach, with resuscitation and detection of the precipitating cause being paramount. Special attention should be paid to cardiac function in patients with thyroid storm before treatment, as these patients may develop cardiac collapse.

Prevalence, Treatment Status, and Comorbidities of Hyperthyroidism in Korea from 2003 to 2018: A Nationwide Population Study

BACKGRUOUND

This study aimed to investigate the changes of incidence and treatment of choice for hyperthyroidism from 2003 to 2018 and explore the treatment-related complications and concomitant comorbidities in South Korea using data from the National Health Insurance Service.

METHODS

This is a retrospective observational study. Hyperthyroidism was defined as a case having two or more diagnostic codes of thyrotoxicosis, with antithyroid drug intake for more than 6 months.

RESULTS

The average age-standardized incidence of hyperthyroidism from 2003 to 2018 was 42.23 and 105.13 per 100,000 men and women, respectively. In 2003 to 2004, hyperthyroidism was most often diagnosed in patients in their 50s, but in 2017 to 2018, people were most often diagnosed in their 60s. During the entire period, about 93.7% of hyperthyroidism patients were prescribed with antithyroid drugs, and meanwhile, the annual rates of ablation therapy decrease from 7.68% in 2008 to 4.56% in 2018. Antithyroid drug-related adverse events, mainly agranulocytosis and acute hepatitis, as well as complications of hyperthyroidism such as atrial fibrillation or flutter, osteoporosis, and fractures, occurred more often in younger patients.

CONCLUSION

In Korea, hyperthyroidism occurred about 2.5 times more in women than in men, and antithyroid drugs were most preferred as the first-line treatment. Compared to the general population, hyperthyroid patients may have a higher risk of atrial fibrillation or flutter, osteoporosis, and fractures at a younger age.

High risk and low prevalence diseases: Thyroid storm

INTRODUCTION

Thyroid storm is a rare but serious condition that carries a high rate of morbidity and even mortality.

OBJECTIVE

This review highlights the pearls and pitfalls of thyroid storm, including presentation, diagnosis, and management in the emergency department (ED) based on current evidence.

DISCUSSION

Thyroid storm is a challenging condition to diagnose and manage in the ED. It is characterized by exaggerated signs and symptoms of thyrotoxicosis and evidence of multiorgan decompensation, usually occurring in the presence of an inciting trigger. Clinical features of thyroid storm may include fever, tachycardia, signs of congestive heart failure, vomiting/diarrhea, hepatic dysfunction, and central nervous system disturbance. There are several mimics including sympathomimetic overdose, substance use disorders, alcohol withdrawal, acute pulmonary edema, aortic dissection, heat stroke, serotonin syndrome, and sepsis/septic shock. Ultimately, the key to diagnosis is considering the disease. While laboratory assessment can assist, there is no single laboratory value that will establish a diagnosis of thyroid storm. Clinical criteria include the Burch-Wartofsky point scale and Japan Thyroid Association diagnostic criteria. ED treatment focuses on diagnosing and managing the trigger; resuscitation; administration of steroids, thionamides, iodine, and cholestyramine; and treatment of hyperthermia and agitation. Beta blockers should be administered in the absence of severe heart failure. The emergency clinician should be prepared for rapid clinical deterioration and employ a multidisciplinary approach to treatment that involves critical care and endocrinology specialists.

CONCLUSIONS

An understanding of thyroid storm can assist emergency clinicians in diagnosing and managing this potentially deadly disease.

Thyrotoxic Crisis in the Absence of Risk Factors: A Case Report

Thyrotoxic crisis is a severe, life-threatening form of thyrotoxicosis characterized by elevated circulating thyroid hormone that can lead to profound complications. Early diagnostic interventions include a thorough physical examination, laboratory assessments of thyroid hormone levels, and the utilization of quantifying assessment tools to grade the severity of the condition. A targeted therapeutic regimen involving a combination of thioamides, beta-blocking agents, and iodide therapies is administered to combat each stage of the physiological process involved in a thyroid storm. The prompt recognition of clinical manifestations and systemic complications of thyrotoxic crisis is of paramount significance to prevent therapeutic delay and reduce patient mortality. Here, we report an atypical case of a new-onset thyrotoxic crisis in a patient without apparent underlying predisposing factors.

Cardiothyreosis: Epidemiological, clinical and therapeutic approach

Introduction

Cardiothyreosis corresponds to the cellular effects of free thyroid hormones on the vascular wall and the myocardium. We aim to describe the clinical, para-clinical and therapeutic aspects of cardiothyreosis and to detail prognostic factors.

Methods

We conducted a descriptive retrospective study at the Endocrinology-Diabetology Department of the Hedi Chaker University Hospital in Sfax-Tunisia. We collected medical records of 100 patients with cardiothyreosis between January 1999 and December 2019. We included patients with cardiothyreosis who underwent adequate cardiac evaluation. We excluded patients with cardiac abnormalities related to conditions other than hyperthyroidism, patients who died and patients without cardiothyreosis.

Results

We included 100 adult patients (43 men and 57 women). The mean age was 49.3 ±12.9 years (20-79 years). The diagnosis of cardiothyreosis was concomitant with that of hyperthyroidism in 72% of cases. Weight loss and palpitations were the two most frequently reported signs in 91% of cases each. Hypertension was systolic in 15 patients. The average heart rate was 103.1 beats/min (52-182 bpm). The mean TSH and FT4 levels were 0.042 μIU/ml and 59.6 pmol/l, respectively. Rhythm disorders and heart failure were the most common cardiac complications with 81 and 56 cases, respectively. Cardiac ultrasound showed dilatation of the left atrium in 28.3% of patients. Pulmonary arterial hypertension was present in 43% of cases. 57 patients had been treated with benzylthiouracil at a mean dose of 157.45 mg/day. Radical treatment with radioactive iodine was indicated in 81 patients. The evolution of cardiothyreosis was favourable in 58 patients.

Conclusion

Cardiothyreosis is a serious complication of hyperthyroidism. Future prospective studies will be of great help to better characterise and manage cardiothyreosis.

Thyrotoxicosis in Africa: a systematic review and meta-analysis of the clinical presentation

Background

Thyrotoxicosis is a common endocrine disorder. The clinical presentation is variable, and it is often misdiagnosed or diagnosed late in Africa. This study was aimed at collating and analyzing the clinical characteristics of the disease across the continent so as to enhance correct and timely diagnosis.

Methods

The study is a systematic review with a meta-analysis. Studies, done in Africa, which documented the clinical features of thyrotoxicosis were selected. African Journal Online (AJOL), PubMed, SCOPUS and Google Scholar, Research Square, SciELO, and medRxiv were systematically searched using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The study quality was assessed using the Newcastle-Ottawa scale. Heterogeneity was determined using I2 statistic and Cochran’s Q test. LFK index and the symmetry of the Doi plot were used to assess publication bias.

Results

The eligible studies were 59 and the total sample size was 9592. The most common symptoms of thyrotoxicosis on the continent included palpitations (69%), weight loss (65%), heat intolerance (64%), tiredness (49%), increased appetite (49%), hyperhidrosis (48%), and insomnia (47%). The most common signs were thyromegaly (88%), tachycardia (67%), sweaty palms (54%), hand tremor (49%), and exophthalmos (49%). Atrial fibrillation, heart failure, and thyrotoxic heart disease were found in 9, 12, and 22% respectively. Other findings were hypertension (25%) and diabetes (9%).

Conclusion

Clinical presentation of thyrotoxicosis varies, and understanding these peculiarities would mitigate misdiagnosis and delayed diagnosis in Africa.

A systematic review and meta-analysis of the etiology and treatment patterns of thyrotoxicosis in Africa

INTRODUCTION

Thyrotoxicosis is one of the most common endocrine disorders seen in clinical practice. This study aims to determine the etiologies and treatment modalities of thyrotoxicosis in Africa.

AREAS COVERED

The study design is a systematic review with a meta-analysis. Medical databases and the gray literature were systematically searched following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies done in Africa on the etiology and treatment of thyrotoxicosis were selected.

EXPERT OPINION

In Africa, it is still believed that autoimmune diseases, generally, are not as common as what is seen in the western world. The frequency of Graves' disease is reportedly lower in Africa. The treatment of thyrotoxicosis depends on the cause. Therefore, it is of substantial importance to establish the etiology following the diagnosis of the clinical syndrome.

Interplay between cardiovascular and thyroid dysfunctions: A review of clinical implications and management strategies

Cardiovascular diseases (CVD) and thyroid dysfunction are two of the most prevailing disorders in the world that are closely interlinked. Actions of thyroid hormones are mediated via thyroid receptors present in the myocardium and the vascular tissue. Primary mechanism that links thyroid dysfunction with CVD is the modification of cardiovascular risk factors (dyslipidemia, blood pressure, coagulation parameters, etc.) resulting in endothelial and left ventricular systolic and diastolic dysfunction.

Both overt and subclinical hyperthyroidism and hypothyroidism may cause adverse alterations in cardiac function. Hyperthyroidism gives rise to palpitation, atrial fibrillation, systolic hypertension, and heart failure, whereas hypothyroidism increases diastolic hypertension, pericardial effusion, and the risk of ischemic heart disease via altering lipid and coagulation parameters. Early recognition and treatment of thyroid dysfunction may prevent adverse cardiovascular events in patients with or without pre-existing CVD.

Certain cardiac conditions and medications can cause alterations in thyroid function that may predispose an individual to higher morbidity and mortality. In certain situations, thyroid dysfunction treatment may have cardiovascular benefits. This study deals with the interplay between cardiovascular and thyroid dysfunctions associated with clinical implications and management strategies.

PCGA: a comprehensive web server for phenotype-cell-gene association analysis

Most complex disease-associated loci mapped by genome-wide association studies (GWAS) are located in non-coding regions. It remains elusive which genes the associated loci regulate and in which tissues/cell types the regulation occurs. Here, we present PCGA (https://pmglab.top/pcga), a comprehensive web server for jointly estimating both associated tissues/cell types and susceptibility genes for complex phenotypes by GWAS summary statistics. The web server is built on our published method, DESE, which represents an effective method to mutually estimate driver tissues and genes by integrating GWAS summary statistics and transcriptome data. By collecting and processing extensive bulk and single-cell RNA sequencing datasets, PCGA has included expression profiles of 54 human tissues, 2,214 human cell types and 4,384 mouse cell types, which provide the basis for estimating associated tissues/cell types and genes for complex phenotypes. We develop a framework to sequentially estimate associated tissues and cell types of a complex phenotype according to their hierarchical relationships we curated. Meanwhile, we construct a phenotype-cell-gene association landscape by estimating the associated tissues/cell types and genes of 1,871 public GWASs. The association landscape is generally consistent with biological knowledge and can be searched and browsed at the PCGA website.

Cost-Effectiveness Analysis of Antithyroid Drug (Propylthiouracil) Compared to Radioactive Iodine for the Treatment of Graves’ Disease in Ethiopia

Background

Graves’ disease is an autoimmune disorder caused by stimulating antibodies. The peak incidence of Graves’ disease occurs among patients aged 30 to 60 years. Radioactive iodine (RAI) and antithyroid drug (ATD) have been well-established therapies for the treatment of Graves’ disease for several decades. However, there remain large variations in practice among physicians in the preferred modality and the method of administration.

Objective

To assess the cost-effectiveness of ATD (propylthiouracil) compared to RAI from a health care payer perspective in Ethiopia.

Methods

Markov model was constructed by using TreeAge software 2021 with different parameters, such as ATD, RAI, treatment failure, treatment success, hypothyroidism, and supplemental thyroxine to conduct a cost-effectiveness analysis. A hypothetical 40-year-old female patient with symptomatic Graves’ hyperthyroidism was simulated to estimate expected lifetime health outcomes, quality-adjusted life years (QALYs) and costs, discounted at 3%.

Results

RAI has lesser QALYs (14.19) and is less expensive (US$ 3583.22), while ATD has higher QALYs (16.54) and is more expensive (US$ 12531.68). The result showed that there was no dominant treatment option. The incremental cost-effectiveness ratio was US$ 3811.6 per QALY which was greater than one to three times the cost-effectiveness threshold of Ethiopia (US$ 783).

Conclusion

In this cost-effectiveness analysis, RAI was the preferred treatment strategy for Graves’ disease, since the cost needed to get one extra QALY through ATD was greater than one to three times the cost-effectiveness threshold of Ethiopia.

Effect of iodine-therapy on hyperthyroidism patients without pre-administration of anti-thyroid therapeutic options

Anti-thyroid treatment and radioiodine are mainly used treatments for patients with thyrotoxicosis. The effect of anti-thyroid drugs (ATDs) on radioactive iodine's therapeutic effectiveness in hyperthyroidism remains controversial. This study aimed to determine the treatment effectiveness and complications in patients with thyrotoxicosis receiving radioiodine treatment with or without adjunctive anti-thyroid drugs in a tertiary endocrinology center in Ahvaz, Iran. A total of 165 patients with thyrotoxicosis (50 males and 115 females) were recruited in this retrospective clinical study. These patients were divided into two groups: one group underwent natural iodine therapy without being treated with anti-thyroid drugs (N= 86), and the other group was first treated with anti-thyroid drugs and then treated with iodine (N= 79). Then, the frequency of euthyroidism, thyroid storm, thyroiditis, hypothyroidism and the time to reach euthyroidism is evaluated. The results showed no difference between the two groups when reaching the euthyroid and the mean numerical mean TSH at the time of hypothyroidism. However, the average dose of iodine received in the concomitant drug group was lower. No thyroid storm was observed in the two groups regarding complications after treatment. Also, the prevalence of hypothyroidism and thyroiditis were not significantly different between the two groups. Iodine therapy with and without the use of anti-thyroid drugs (ATD) in low-risk patients with thyrotoxicosis has no difference in treatment outcomes, response to treatment, and subsequent complications.

Essentiality, relevance, and efficacy of adjuvant/combinational therapy in the management of thyroid dysfunctions

Thyroid dysfunction is the most prevalent endocrine disorder worldwide having an epidemiology of 11% in Indians, 4.6% in the United Kingdom, and 2% in the United States of America among the overall population. The common thyroid disorders include hypothyroidism, hyperthyroidism, Hashimoto's thyroiditis, and thyroid cancer. This review briefly elaborates the molecular regulation and mechanism of thyroid hormone, and its associated thyroid disorders. The thyroid hormones regulate critical biochemical functions in brain development and function. Hypothyroidism is mainly associated with dysregulation of cytokines, increased ROS production, and altered signal transduction in major regions of the brain. In addition, it is associated with reduced antioxidant capacity and increased oxidative stress in humans. Though 70% of thyroid disorders are caused by heredity, environmental factors have a significant influence in developing autoimmune thyroid disorders in people who are predisposed to them. This drives us to understand the relationship between environmental factors and thyroid dysregulated disorders. The treatment option for the thyroid disorder includes antithyroid medications, receiving radioactive iodine therapy, or surgery at a critical stage. However, antithyroid drugs are not typically used long-term in thyroid disease due to the high recurrence rate. Adjuvant treatment of antioxidants can produce better outcomes with anti-thyroid drug treatment. Thus, Adjuvant therapy has been proven as an effective strategy for managing thyroid dysfunction, herbal remedies can be used to treat thyroid dysfunction in the future, which in turn can reduce the prevalence of thyroid disorders.

Cardiovascular Involvement in Thyrotoxicosis Resulting in Heart Failure: The Risk Factors and Hemodynamic Implications

Thyrotoxicosis is a clinical syndrome with persistently elevated concentrations of free triiodothyronine, free thyroxine, or both, which correlates with an increased thyroid metabolic function. This article has discussed the direct effect of increased thyroid hormone on the heart, as the thyroid hormone physiologically exhibits a close harmony with hormones of the cardiovascular system. This action can lead to disturbances in hemodynamic stability, exacerbating the possibility of developing complications such as heart failure and life-threatening arrhythmias. This article has also explored the multifaceted pathogenesis of thyrotoxicosis and various pharmacological treatment options, including beta-blockers and anti-thyroid drugs. This article has reviewed numerous studies that have concluded that the main goal of therapy should always aim to normalize thyroid hormone levels based on the etiology of the thyrotoxicosis, although cardiovascular conditions are associated with a higher rate of mortality.

Thyroid Function During and After COVID-19 Infection: A Review

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can lead to multiorgan dysfunction through pulmonary and systemic inflammation. Infection also affects the thyroid gland directly via cytopathological effects of the virus or indirectly through cytokines, complement systems and coagulation mechanisms. The thyroid gland regulates innate and adaptive immune systems by genomic and nongenomic pathways. During or after SARS-CoV-2 infection, Graves' disease and subacute thyroiditis might be triggered, resulting in hyperthyroidism; alternatively, the effect of the virus on the hypophyseal.hypothalamic axis might cause central hypothyroidism. Severe cases of coronavirus disease 2019 (COVID-19) can present with hypoxia, which requires the use of dexamethasone. This can depress basal serum concentrations of 3,5,3'-triiodothyronine. Thyroid function should be monitored when using dexamethasone in patients with COVID-19. This article briefly reviews the direct and indirect effects of SARS-CoV-2 on the thyroid gland and function.

Extrapolating In Vitro Screening Assay Data for Thyroperoxidase Inhibition to Predict Serum Thyroid Hormones in the Rat

Thyroperoxidase (TPO) is an enzyme essential for thyroid hormone (TH) synthesis and a target site for a number of xenobiotics that disrupt TH homeostasis. An in vitro high-throughput screening assay for TPO inhibition, the Amplex UltraRed-TPO (AUR-TPO), has been used to screen the ToxCast chemical libraries for this action. Output from this assay would be most useful if it could be readily translated into an in vivo response, namely a reduction of TH in serum. To this end, the relationship between TPO inhibition in vitro and serum TH decreases was examined in rats exposed to 2 classic TPO inhibitors, propylthiouracil (PTU) and methimazole (MMI). Serum and gland PTU, MMI, and TH levels were quantified using tandem liquid chromatography mass spectrometry. Thyroperoxidase activity was determined in thyroid gland microsomes treated with PTU or MMI in vitro and ex vivo from thyroid gland microsomes prepared from exposed animals. A quantitative model was constructed by contrasting in vitro and ex vivo AUR-TPO results and the in vivo time-course and dose-response analysis. In vitro:ex vivo correlations of AUR-TPO outputs indicated that less than 30% inhibition of TPO in vitro was sufficient to reduce serum T4 by 20%, a degree of regulatory significance. Although further testing of model estimates using other TPO inhibitors is essential for verification of these initial findings, the results of this study provide a means to translate in vitro screening assay results into predictions of in vivo serum T4 changes to inform risk assessment.

A remarkable case of thyrotoxicosis initially caused by graves' disease followed by a probable TSHoma - a case report

BACKGROUND

Graves' disease is the commonest cause of thyrotoxicosis whilst thyrotropin (TSH)-producing pituitary adenomas (thyrotropinomas, TSHomas) are very rare and account for just 1-2% of all pituitary adenomas. Coexistence of a TSHoma and Graves' disease has been very rarely reported. Here, we report a case of a patient whose initial presentation with primary thyrotoxicosis due to Graves' disease, was subsequently followed by a relapse of thyrotoxicosis due to a probable TSHoma.

CASE

A sixty-eight year old woman was referred to our department with classical features of thyrotoxicosis. Initial biochemistry confirmed hyperthyroxinaemia [free thyroxine (fT4) 20.4 pmol/L (reference range 7.0-16.0)] and a suppressed TSH [< 0.02mIU/L (0.50-4.20)]. A technetium pertechnetate uptake scan was consistent with Graves' Disease. She was treated with carbimazole for 18 months and remained clinically and biochemically euthyroid. After stopping carbimazole her fT4 started to rise but TSH remained normal. Laboratory assay interference was excluded. A TRH stimulation test demonstrated a flat TSH response and pituitary MRI revealed a microadenoma. Remaining pituitary hormones were in the normal range other than a slightly raised IGF-1. An ¹¹C-methionine PET/CT scan coregistered with volumetric MRI (Met-PET-MRI^CR) demonstrated high tracer uptake in the left lateral sella region suggestive of a functioning adenoma. The patient declined surgery and was unable to tolerate cabergoline or octreotide. Thereafter, she has elected to pursue a conservative approach with periodic surveillance.

CONCLUSION

This is a very unusual case of thyrotoxicosis caused by two different processes occurring in the same patient. It highlights the importance of considering dual pathology when previously concordant thyroid function tests become discordant. It also highlights a potential role of Met-PET-MRI^CR in the localisation of functioning pituitary tumours.

Giant toxic multinodular goiter with dyspnea: A case report

•

This case report mainly focus on a case of 47-year old female with multinodular goiter.

•

Fine Needle Aspiration Cytology needs to be done from the suspicious nodule.

•

Toxic MNG is most effectively treated by total thyroidectomy, which achieves complete diminution from symptoms.

•

Surgery for huge goiter is challenging particularly on difficult intubation, altered anatomy, supraglottic edema and adhesions.

Introduction

Toxic multinodular goiter (MNG) involves an enlarged thyroid gland, is a common cause of hyperthyroidism and when it is accompanied by obstructive symptoms such as dyspnea, it carries an indication for surgery.

Case presentation

We present a case of 47-year old female with multinodular goiter with a rapid increase in size within 2 years. She also reported palpitation, breathlessness on exertion, tachycardia and hand tremor. Computed tomography scan of the neck shows a gross enlargement of thyroid gland across both sides of the neck. The fine needle aspiration cytology and final histopathological examination were suggestive of MNG with adenomatous nodules and toxic changes respectively. A total thyroidectomy was performed and the gland was dissected successfully.

Discussion

Toxic MNG is most effectively treated by total thyroidectomy, which achieves complete diminution from symptoms.

Conclusion

Surgery for huge goiter is challenging and one should be careful about difficult intubation, altered anatomy and adhesions to the surrounding structures. Recognizing and treating this kind of cases are important, as they constitute a preventable cause of mortality if timely diagnosed and treated.

Eosinophil/Monocyte Ratio Combined With Serum Thyroid Hormone for Distinguishing Graves' Disease and Subacute Thyroiditis

Background: Thyrotoxicosis is commonly classified into several entities according to different etiologies. Identifying the causes of thyroid dysfunction is critical for the subsequent selection of treatment. The free triiodothyronine to free thyroxine ratio (fT₃/fT₄) is widely used but is still a controversial diagnostic measurement. Methods: A total of 290 patients including 141 healthy control subjects, 86 patients with untreated Graves' disease (GD,) and 63 patients with subacute thyroiditis (SAT) were enrolled in the study. The main aim was to evaluate the diagnostic value of different indexes from serum testing including fT₃, fT₄, eosinophils (Eo) and monocytes (Mo). The diagnostic performance of multiple indexes was evaluated separately using receiver operating characteristic curve analysis. Results: Sensitivities and specificities of fT₄/fT₃, Mo/Eo ratios and Mo/Eo ratio + fT₄/fT₃ for diagnosing GD were 80.23 and 88.89, 82.56 and 60.32, and 74.4 and 87.3 with cut-off values of ≤ 2.841, ≤ 8.813 and >0.644, respectively. An equation of combined indicators including Mo, Eo, fT₃, and fT₄ data was developed to calculate a probability value and among all indexes studied the indicator combination formula gave the best diagnostic value, reaching sensitivity and specificity of 89.53 and 90.48%, respectively, with an optimum cut-off value at 0.561 for GD diagnosis. Conclusion: Compared to regular indexes (fT_4/fT₃ and Mo/Eo), a newly developed indicator combination formula provided a higher prediction probability and may serve as a simple, cost-effective tool for differentiating GD from SAT patients, especially in undeveloped regions of China.

[Hyperthyroidism and breast cancer: Is there a link?]

The objective of this review was to determine whether there is an association between hyperthyroidism and the risk of developing a breast cancer from the analysis of data in the literature.

METHOD

The analyzed articles were extracted from the PUBMED database from 2002 to 2017 using the following keywords "hyperthyroidism AND breast cancer" and "thyroid AND breast cancer".

RESULTS

A total of 22 studies were selected, including 8 cohort studies, 12 case-control studies and 2 meta-analyzes. Of these 22 studies, 15 have established a significant epidemiological or biological link between hyperthyroidism and breast cancer. Five of them were particularly interested in Graves' disease, and four demonstrated a positive association between this disease and the onset of breast cancer, especially within three years from the thyropathy diagnosis. These different studies also highlighted the increased risk of breast cancer seen in overweight or postmenopausal women. Contradictions persist over the types of mammary cancers observed and their prognosis.

CONCLUSION

This review reveals that women with hyperthyroidism appear to have a moderately high risk of breast cancer (RR<2). These data are corroborated by solid physiopathological hypotheses. Regardless of the type of thyropathy responsible for hyperthyroidism, care should be taken to ensure that these patients receive a clinical examination of the breasts on an annual basis and mammographic screening every 2 years from the age of 50 years.

Rescue pre-operative treatment with Lugol's solution in uncontrolled Graves' disease

BACKGROUND

Graves' disease is a common cause of hyperthyroidism. Three therapies have been used for decades: pharmacologic therapy, surgery and radioiodine. In case of adverse events, especially agranulocytosis or hepatotoxicity, pre-treatment with Lugol's solution containing iodine/potassium iodide to induce euthyroidism before surgery could be advocated, but this has rarely been reported.

METHODS

All patients hospitalised due to uncontrolled hyperthyroidism at the Karolinska University Hospital 2005-2015 and treated with Lugol's solution were included. All electronic files were carefully reviewed manually, with focus on the cause of treatment and admission, demographic data, and effects of iodine on thyroid hormone levels and pulse frequency.

RESULTS

Twenty-seven patients were included. Lugol's solution had been chosen due to agranulocytosis in 9 (33%), hepatotoxicity in 2 (7%), other side effects in 11 (41%) and poor adherence to medication in 5 (19%). Levels of free T4, free T3 and heart rate decreased significantly after 5-9 days of iodine therapy (free T4 53-20 pmol/L, P = 0.0002; free T3 20-6.5 pmol/L, P = 0.04; heart rate 87-76 beats/min P = 0.0007), whereas TSH remained unchanged. Side effects were noted in 4 (15%) (rash n = 2, rash and vomiting n = 1, swelling of fingers n = 1). Thyroidectomy was performed in 26 patients (96%) and one was treated with radioiodine; all treatments were without serious complications.

CONCLUSION

Treatment of uncontrolled hyperthyroidism with Lugol's solution before definitive treatment is safe and it decreases thyroid hormone levels and heart rate. Side effects were limited. Lugol's solution could be recommended pre-operatively in Graves' disease with failed medical treatment, especially if side effects to anti-thyroid drugs have occurred.

Normothermic thyroid storm: an unusual presentation

Thyroid storm is a rare life-threatening emergency due to thyrotoxicosis. A 30-year-old female presented with restlessness, tachycardia and vomiting but with normothermia which is an unusual presentation. There is the need for clinicians to be aware of atypical clinical features that can make the diagnosis of thyroid storm difficult.

Mechanisms of Action of TSHR Autoantibodies

The availability of human monoclonal antibodies (MAbs) to the TSHR has enabled major advances in our understanding of how TSHR autoantibodies interact with the receptor. These advances include determination of the crystal structures of the TSHR LRD in complex with a stimulating autoantibody (M22) and with a blocking type autoantibody (K1-70). The high affinity of MAbs for the TSHR makes them particularly suitable for use as ligands in assays for patient serum TSHR autoantibodies. Also, M22 and K1-70 are effective at low concentrations in vivo as TSHR agonists and antagonists respectively. K1-70 has important potential in the treatment of the hyperthyroidism of Graves' disease and Graves' ophthalmopathy. Small molecule TSHR antagonists described to date do not appear to have the potency and/or specificity shown by K1-70. New models of the TSHR ECD in complex with various ligands have been built. These models suggest that initial binding of TSH to the TSHR causes a conformational change in the hormone. This opens a positively charged pocket in receptor-bound TSH which attracts the negatively charged sulphated tyrosine 385 on the hinge region of the receptor. The ensuing movement of the receptor's hinge region may then cause activation. Similar activation mechanisms seem to take place in the case of FSH and the FSHR and LH and the LHR. However, stimulating TSHR autoantibodies do not appear to activate the TSHR in the same way as TSH.

Relevance of a thyroid phantom in estimating thyroid radioiodine uptake values using a gamma camera

The objective of this work was to evaluate the necessity of a thyroid phantom in counting a standard capsule during estimation of iodine-131 thyroid uptake using gamma camera methods. For this, camera-based uptake was calculated taking a standard capsule within a thyroid phantom, as well as a standard capsule (without phantom) placed at 5, 10, and 15 cm from the face of the collimator. The values obtained in each setting were compared with the traditional standard thyroid probe-based method. Among these four sets of values, that with the phantom was the closest to the reference probe-based uptake values. Among those without the phantom, the camera-based uptake with the standard at 15 cm from the face of the collimator was closer to the standard probe method. However, as the image at 15 cm would give poor resolution, it would not be feasible to adopt this method for clinical routine. Thus, to conclude, for calculating camera-based uptake, a standard capsule in the phantom gives the best comparable values to the standard probe-based method, indicating the need for the phantom when adopting the gamma camera-based methodology.

Preoperative Preparation with Lugol's Iodine in Thyroidectomy of Euthyroid Patients-Is it Really Mandatory?-An Otorhinolaryngologist's View

OBJECTIVE

To elucidate the necessity of Lugol's iodine in preoperative preparation of patients undergoing thyroidectomy.

MATERIALS AND METHODS

Hundred and five euthyroid patients who underwent surgery without preoperative preparation of patients with Lugol's iodine were enrolled in this retrospective study conducted during the period May 2009 to August 2013 in Teaching Hospital. Indication of surgery was ranging from suspected malignancy to cosmetic reasons and compressive features like dysphagia , dyspnoea and hoarseness of voice.

RESULTS

All patients were operated by the same surgeon where in hemi, total and subtotal thyroidectomies were performed without any usage of Lugol's iodine preoperatively. During the postoperative period the following events occurred, five patients (4.7%) had incurred recurrent laryngeal nerve palsy (RLNP) which was confirmed with postoperative indirect laryngoscopic examination and two patients (1.9%) with hypocalcemia (serum calcium less than 8mg/dl) which was managed conservatively and effectively. Among these five patients, three patients had (Right RLNP) and two patients had (Left RLNP) palsies. Of these four RLNP (3.8%) were temporary which improved with conservative management within 3weeks-6months duration and one (0.9%) was a permanent Rt RLNP with no improvement even after six months.

CONCLUSION

Hence, we conclude that it is not of much importance to use Lugol's iodine preoperatively in patients undergoing thyroidectomy. There does not appear any convincing evidence of advantages of preoperative preparation of patients with lugol's iodine in euthyroid state undergoing surgery.

The Brazilian consensus for the diagnosis and treatment of hyperthyroidism: recommendations by the Thyroid Department of the Brazilian Society of Endocrinology and Metabolism

INTRODUCTION

Hyperthyroidism is characterized by increased synthesis and release of thyroid hormones by the thyroid gland. Thyrotoxicosis refers to the clinical syndrome resulting from excessive circulating thyroid hormones, secondary to hyperthyroidism or due to other causes. This article describes evidence-based guidelines for the clinical management of thyrotoxicosis.

OBJECTIVE

This consensus, developed by Brazilian experts and sponsored by the Department of Thyroid Brazilian Society of Endocrinology and Metabolism, aims to address the management, diagnosis and treatment of patients with thyrotoxicosis, according to the most recent evidence from the literature and appropriate for the clinical reality of Brazil.

MATERIALS AND METHODS

After structuring clinical questions, search for evidence was made available in the literature, initially in the database MedLine, PubMed and Embase databases and subsequently in SciELO - Lilacs. The strength of evidence was evaluated by Oxford classification system was established from the study design used, considering the best available evidence for each question.

RESULTS

We have defined 13 questions about the initial clinical approach for the diagnosis and treatment that resulted in 53 recommendations, including the etiology, treatment with antithyroid drugs, radioactive iodine and surgery. We also addressed hyperthyroidism in children, teenagers or pregnant patients, and management of hyperthyroidism in patients with Graves' ophthalmopathy and various other causes of thyrotoxicosis.

CONCLUSIONS

The clinical diagnosis of hyperthyroidism usually offers no difficulty and should be made with measurements of serum TSH and thyroid hormones. The treatment can be performed with antithyroid drugs, surgery or administration of radioactive iodine according to the etiology of thyrotoxicosis, local availability of methods and preferences of the attending physician and patient.

Blocking type TSH receptor antibodies

TSH receptor (TSHR) autoantibodies (TRAbs) play a key role in the pathogenesis of Graves' disease. In the majority of patients, TRAbs stimulate thyroid hormone synthesis via activation of the TSHR (stimulating TRAbs, TSHR agonists). In some patients, TRAbs bind to the receptor but do not cause activation (blocking TRAbs, TSHR antagonists). Isolation of human TSHR monoclonal antibodies (MAbs) with either stimulating (M22 and K1-18) or blocking activities (5C9 and K1-70) has been a major advance in studies on the TSHR. The binding characteristics of the blocking MAbs, their interaction with the TSHR and their effect on TSHR constitutive activity are summarised in this review. In addition, the binding arrangement in the crystal structures of the TSHR in complex with the blocking MAb K1-70 and with the stimulating MAb M22 (2.55 Å and 1.9 Å resolution, respectively) are compared. The stimulating effect of M22 and the inhibiting effect of K1-70 on thyroid hormone secretion in vivo is discussed. Furthermore the ability of K1-70 to inhibit the thyroid stimulating activity of M22 in vivo is shown. Human MAbs which act as TSHR antagonists are potentially important new therapeutics. For example, in Graves' disease, K1-70 may well be effective in controlling hyperthyroidism and the eye signs caused by stimulating TRAb. In addition, hyperthyroidism caused by autonomous TSH secretion should be treatable by K1-70, and 5C9 has the potential to control hyperthyroidism associated with TSHR activating mutations. Furthermore, K1-70 has potential applications in thyroid imaging as well as targeted drug delivery to TSHR expressing tissues.

Thyrotoxicosis

Thyrotoxicosis is a common disorder, especially in women. The most frequent cause is Graves' disease (autoimmune hyperthyroidism). Other important causes include toxic nodular hyperthyroidism, due to the presence of one or more autonomously functioning thyroid nodules, and thyroiditis caused by inflammation, which results in release of stored hormones. Antithyroid drugs are the usual initial treatment (thionamides such as carbimazole or its active metabolite methimazole are the drugs of choice). A prolonged course leads to remission of Graves' hyperthyroidism in about a third of cases. Because of the low remission rate in Graves' disease and the inability to cure toxic nodular hyperthyroidism with antithyroid drugs alone, radioiodine is increasingly used as first line therapy, and is the preferred choice for relapsed Graves' hyperthyroidism. Total thyroidectomy is an option in selected cases. Future efforts are likely to concentrate on novel and safe ways to modulate the underlying disease process rather than stopping excess thyroid hormone production.

Resistant thyrotoxicosis in a patient with graves disease: a case report

Background. Conventional management of thyrotoxicosis includes antithyroid drugs, radioactive iodine, and surgery while adjunctive treatment includes beta-blockers, corticosteroids, inorganic iodide and iopanoic acid. Very rarely, patients may be resistant to these modalities and require additional management. Case Presentation. A 50-year-old lady presented with weight loss and palpitations diagnosed as atrial fibrillation. Her past history was significant for right thyroid lobectomy for thyrotoxicosis. Thyroid functions tests at this presentation showed free T4 of 6.63 ng/dl (normal range: 0.93–1.7) and TSH of <0.005 μIU/mL (normal range: 0.4–4.0). She was given aspirin, propranolol, heparin and carbimazole; however free T4 failed to normalize. Switching to propylthiouracil (PTU) did not prove successful. She was then given high doses of prednisolone (1 mg/kg/day) and lithium (400 mg twice daily) which prepared the patient for radioactive iodine treatment by reducing free T4 levels (2.82 ng/dl). Two doses of radioactive iodine were then administered 6 months apart. Subsequently she became hypothyroid and was started on thyroid replacement therapy. Conclusion. This case highlights management options in patients with resistant thyrotoxicosis. Radioactive iodine and surgery are definitive modes of treatment in such complex cases while steroids and lithium play an important role in preparing patients for more definitive treatment.

The effects of HIV-1 infection on endocrine organs

Early in the HIV epidemic, multiple endocrine and metabolic abnormalities were observed in HIV-infected patients. These abnormalities were either related glandular infection or infiltration with opportunistic diseases or the effects of systemic inflammation and severe illness on hormonal function and metabolic homeostasis. This review describes the epidemiology and pathogenesis of dyslipidemia, disorders of bone homeostasis, and dysfunction of the adrenal, gonadal, and thyroid axes in the untreated HIV-infected patient. While this review is most applicable to the HIV epidemic in the developing world where effective antiretroviral therapy is not available, understanding the effect of systemic inflammation on endocrine and metabolic function in the untreated HIV-infected person has valuable lessons for the pathogenesis of endocrine disease in HIV-infected patients receiving antiretroviral treatment.

Treatment options for Graves disease: a cost-effectiveness analysis

BACKGROUND

First-line treatment for Graves disease is frequently 18 months of antithyroid medication (ATM). Controversy exists concerning the next best line of treatment for patients who have failed to achieve euthyroidism; options include lifelong ATM, radioactive iodine (RAI), or total thyroidectomy (TT). We aim to determine the most cost-effective option.

STUDY DESIGN

We performed a cost-effectiveness analysis comparing these different strategies. Treatment efficacy and complication data were derived from a literature review. Costs were examined from a health-care system perspective using actual Medicare reimbursement rates to an urban university hospital. Outcomes were measured in quality-adjusted life-years (QALY). Costs and effectiveness were converted to present values; all key variables were subjected to sensitivity analysis.

RESULTS

TT was the most cost-effective strategy, resulting in a gain of 1.32 QALYs compared with RAI (at an additional cost of 9,594 US dollars) and an incremental cost-effectiveness ratio of 7,240 US dollars/QALY. RAI was the least costly option at 23,600 US dollars but also provided the least QALY (25.08 QALY). Once the cost of TT exceeds 19,300 US dollars, the incremental cost-effectiveness ratio of lifelong ATM and TT reverse and lifelong ATM becomes the more cost-effective strategy at 15,000US dollars/QALY.

CONCLUSIONS

This is the first formal cost-effectiveness study in the US of the optimal treatment for patients with Graves disease who fail to achieve euthyroidism after 18 months of ATM. Our findings demonstrate that TT is more cost effective than RAI or lifelong ATM in these patients; this continues until the cost of TT becomes > 19,300 US dollars.

Is rapid preparation for thyroidectomy in severe Graves' disease beneficial? The relationship between clinical and immunohistochemical aspects

BACKGROUND

To evaluate the effect of Lugol's Iodine (LI) on angiogenic characteristics and postthyroidectomy morbidity in patients with Graves' Disease (GD).

METHODS

Medical records of 153 patients, who underwent thyroidectomies for GD between 1987 and 2006 were reviewed. LI in addition to antithyroid drugs (ATD) was administered to 16 toxic Graves' cases (group I), while 137 received ATD only (group II). In order to evaluate thyroid vascularity, immunohistochemical staining (IHS) for VEGF and CD31 for assessing microvessel density (MVD) were performed in group I, 20 random cases of group II, and 7 stochastic patients with non-toxic goiter (group III).

RESULTS

Early postoperative complications were significantly higher in group I compared to group II: (transient recurrent nerve palsy (P < 0.04), transient hypocalcemia (P < 0.02), and postoperative bleeding (P < 0.003)). Meanwhile permanent complications were not significantly different. VEGF-IHS revealed ten patients of group I (62.5%) to have positive staining compared to only 3 (15%) of group II. All patients of group III stained positive. The expression of VEGF was more intense in group I as compared to group II (P < 0.02). However, no significant difference of MVD among all groups was recorded.

CONCLUSION

Preoperative LI treatment may be associated with increased early postoperative morbidity and did not affect thyroid vascularity.

Atrial fibrillation induced by post-parathyroidectomy transient thyrotoxicosis

We describe a 59-year-old Japanese woman with post-parathyroidectomy transient thyrotoxicosis and atrial fibrillation. She underwent parathyroidectomy for secondary hyperparathyroidism due to chronic renal failure. Three days after surgery, she complained of palpitation and chest pain due to atrial fibrillation. Results of thyroid function tests were compatible with thyrotoxicosis. Twelve days after parathyroidectomy, the elevated level of free thyroxine decreased spontaneously to the normal range. These features were compatible with post-parathyroidectomy transient thyrotoxicosis. No further recurrences of thyrotoxicosis or atrial fibrillation were observed for one year. This is the first report of atrial fibrillation induced by post-parathyroidectomy transient thyrotoxicosis.

Avaliação da radioiodoterapia com doses fixas de 10 e 15 mCi em pacientes com doença de graves

As opções terapêuticas para a hipertireoidismo da doença de Graves são as drogas antitireoidianas, a cirurgia e o radioiodo, porém nenhuma delas é considerada ideal pois não atuam diretamente na etiopatogênese da doença. O radioiodo vem sendo cada vez mais utilizado como primeira escolha, sendo um tratamento definitivo, seguro e de fácil administração. Há autores que preferem doses mais altas para induzir deliberadamente o hipotireoidismo, enquanto outros recomendam doses mais baixas que, a curto prazo, implicam menor incidência de hipotireoidismo e maior de eutireoidismo. Não há consenso sobre o melhor esquema de doses fixas a ser utilizado, sendo esse o principal enfoque deste estudo, no qual comparamos doses de 10 e 15 mCi. Dos 164 pacientes analisados, 61 (37,2%) foram submetidos a 10 mCi e 103 (62,8%), a 15 mCi de 131I. Na análise longitudinal, observou-se que a remissão do hipertireoidismo foi estatisticamente diferente no sexto mês (p < 0,001), sendo maior no grupo em que foi empregada a dose de 15 mCi. Contudo, foi semelhante nos dois grupos após 12 e 24 meses. É possível concluir que doses fixas de 10 e 15 mCi promovem semelhante remissão do hipertireoidismo após 12 meses de tratamento. A remissão do hipertireoidismo não teve associação com idade, sexo ou uso prévio de drogas antitireoidianas.

Thyroid function abnormalities in HIV-infected patients

Abnormal thyroid function test results are common among human immunodeficiency virus (HIV)-infected patients. Although the prevalence of overt thyroid disease does not appear to be significantly increased in HIV-infected patients, compared with the general population, specific patterns of abnormal thyroid function test findings are more frequently identified among HIV-infected patients. Among patients with advanced acquired immunodeficiency syndrome, nonthyroidal illness (i.e., euthyroid sick syndrome) is common. During antiretroviral therapy, the prevalence of 2 generally asymptomatic conditions (subclinical hypothyroidism, which is characterized by isolated elevated thyroid-stimulating hormone levels, and isolated low free thyroxine levels) is increased. In addition, Graves disease, which is marked by low thyroid-stimulating hormone and elevated thyroxine levels, may occur during immune reconstitution. Testing for thyroid disease among symptomatic patients should begin with measurement of the thyroid-stimulating hormone level. However, there is insufficient evidence to recommend routine thyroid screening of asymptomatic HIV-infected individuals. This review summarizes the current evidence regarding the optimal laboratory evaluation of thyroid function; highlights the causes, presentation, and treatment of thyroid dysfunction in HIV-infected patients; and discusses the controversies regarding screening.

Effect of lugol solution on thyroid gland blood flow and microvessel density in the patients with Graves' disease

CONTEXT

Although some endocrine surgeons administer Lugol solution to decrease thyroid gland vascularity, there is still not an agreement on its effectiveness.

OBJECTIVE

The aims of this clinical trial are to evaluate thyroid blood flow and microvessel density in patients with Graves' disease who received Lugol solution treatment preoperatively.

DESIGN

This was a prospective clinical trial.

SETTING

This clinical trial took place at a tertiary referral center.

METHOD

Thirty-six patients were randomly assigned to receive either preoperative treatment with Lugol solution (group 1, n = 17) or no preoperative treatment with Lugol solution (group 2, n = 19).

MAIN OUTCOME MEASURES

Blood flow through the thyroid arteries of patients with Graves' disease was measured by color flow Doppler ultrasonography. The microvessel density (MVD) was assessed by immunohistochemical and Western blot analysis of the level of expression of CD-34 in thyroid tissue. The weight and blood loss of the thyroid gland were measured in all patients.

RESULTS

The mean blood flow, MVD, CD-34 expression, and blood loss in group 1 patients were significantly lower than those in group 2 patients. There was a negative correlation between Lugol solution treatment and blood flow (r(s) = -0.629; P = 0.0001), blood loss (r(s) = -0.621; P = 0.0001), MVD (r(s) = -0.865; P = 0.0001), and CD-34 expression (r(s) = -0.865; P = 0.0001). According to logistic regression analysis, Lugol solution treatment resulted in a 9.33-fold decreased rate of intraoperative blood loss.

CONCLUSION

Preoperative Lugol solution treatment decreased the rate of blood flow, thyroid vascularity, and intraoperative blood loss during thyroidectomy.