Radioiodine treatment for benign thyroid disorders: results of a nationwide survey of UK endocrinologists

Characteristics of specialists treating hypothyroid patients: the "THESIS" collaborative

Introduction

Thyroid specialists influence how hypothyroid patients are treated, including patients managed in primary care. Given that physician characteristics influence patient care, this study aimed to explore thyroid specialist profiles and associations with geo-economic factors.

Methods

Thyroid specialists from 28 countries were invited to respond to a questionnaire, Treatment of Hypothyroidism in Europe by Specialists: an International Survey (THESIS). Geographic regions were defined according to the United Nations Statistics Division. The national economic status was estimated using World Bank data on the gross national income per capita (GNI per capita).

Results

5,695 valid responses were received (response rate 33·0%). The mean age was 49 years, and 65·0% were female. The proportion of female respondents was lowest in Northern (45·6%) and highest in Eastern Europe (77·2%) (p <0·001). Respondent work volume, university affiliation and private practice differed significantly between countries (p<0·001). Age and GNI per capita were correlated inversely with the proportion of female respondents (p<0·01). GNI per capita was inversely related to the proportion of respondents working exclusively in private practice (p<0·011) and the proportion of respondents who treated >100 patients annually (p<0·01).

Discussion

THESIS has demonstrated differences in characteristics of thyroid specialists at national and regional levels, strongly associated with GNI per capita. Hypothyroid patients in middle-income countries are more likely to encounter female thyroid specialists working in private practice, with a high workload, compared to high-income countries. Whether these differences influence the quality of care and patient satisfaction is unknown, but merits further study.

Gamma camera-specific reference standards for radioactive iodine uptake measurements

BACKGROUND

Current guidelines of the radioiodine uptake (RAIU) test allow the use of different equipment, isotopes, activity and region-of-interest (ROI). We evaluated presence and extent of these differences in clinical practice and evaluated the effect of some of these variations on RAIU outcomes. Also, gamma camera-specific reference standards were calculated and retrospectively compared with measurements obtained during clinical RAIU tests.

MATERIALS AND METHODS

First, questionnaires were sent to Dutch nuclear medicine departments requesting information about equipment usage, isotope, isotope formulation, activity and measurement techniques. Secondly, a neck phantom containing a range of activities in capsule or water-dissolved formulation was scanned. Counts were measured using automatic ROI, square box ROI or all counts in the image. Thirdly, clinical RAIU data were collected during 2015-2018 using three different gamma cameras. Reference standards for each scanner were calculated using regression analysis between reference activity and measured counts. Uptake measurements using this gamma camera-specific reference standard were compared with original measurements.

RESULTS

The survey demonstrated significant differences in isotope, isotope formulation, activity, use of neck phantoms, frequency and duration of reference measurements, distance to collimator, use of background measurements and ROI delineation. The phantom study demonstrated higher counts for the water-dissolved formulation than capsules using both automatic and square box ROI. Also, higher counts were found using a square box ROI than an automatic ROI. The retrospective study showed feasibility of RAIU calculations using camera-specific reference standards and good correlation with the original RAIU measurements.

CONCLUSIONS

This study demonstrated considerable technical variation in RAIU measurement in clinical practice. The phantom study demonstrated that these differences could result in differences in count measurements, potentially resulting in different dose calculations for radioactive iodine therapy. Retrospective data suggest that camera-specific reference standards may be used instead of individual reference measurements using separate activity sources, which may thus eliminate some sources of variation.

The management and metabolic characterization: hyperthyroidism and hypothyroidism

Hyperthyroidism and hypothyroidism are common diseases resulting from thyroid dysfunction, and are simple to diagnose and treat. The traditional treatment for hypothyroidism is thyroid hormone replacement therapy. The traditional treatments for hyperthyroidism include antithyroid drug, iodine radiotherapy, and surgery. Thyroid disease can be fatal in severe cases if untreated. Current statistical reference ranges used for diagnosis based on relevant biochemical parameters have been debated, and insufficient treatment can result in long-term thyroid hormone deficiency, which is associated with increased risk of cardiovascular disease and persistent symptoms. In contrast, overtreatment can result in heart disease and osteoporosis, particularly in older people and pregnant women. Therefore, under- or over-treatment should be avoided and treatment regimens should be monitored closely. A significant proportion of patients who achieve biochemical treatment goals still complain of significant symptoms. Systematic literature review was performed through the Embase (Elsevier), PubMed and Web of Science databases, and studies summarized evidence regarding treatment and management of hypothyroidism and hyperthyroidism, and reviewed clinical practice guidelines. We also reviewed the latest research on the metabolic mechanisms of hyperthyroidism and hypothyroidism, which contributed to understanding of thyroid diseases in the clinic. A reliable algorithm is needed to management, assessment, and treatment patients with hyperthyroidism and hypothyroidism, which can not only improve management efficiency, but also providing a broad application. In addition, the thyroid disorder showed a lipid metabolism tissue specificity in the Ventromedial Hypothalamus, and effect oxidative stress and energy metabolism of whole body. This review summarizes an algorithm for thyroid disease and the latest pathogenesis that would be useful to generalist and subspecialty physicians and others providing care for patients with this condition.

Postradioiodine Graves' management: The PRAGMA study

OBJECTIVE

Thyroid status in the months following radioiodine (RI) treatment for Graves' disease can be unstable. Our objective was to quantify frequency of abnormal thyroid function post-RI and compare effectiveness of common management strategies.

DESIGN

Retrospective, multicentre and observational study.

PATIENTS

Adult patients with Graves' disease treated with RI with 12 months' follow-up.

MEASUREMENTS

Euthyroidism was defined as both serum thyrotropin (thyroid-stimulating hormone [TSH]) and free thyroxine (FT4) within their reference ranges or, when only one was available, it was within its reference range; hypothyroidism as TSH ≥ 10 mU/L, or subnormal FT4 regardless of TSH; hyperthyroidism as TSH below and FT4 above their reference ranges; dysthyroidism as the sum of hypo- and hyperthyroidism; subclinical hypothyroidism as normal FT4 and TSH between the upper limit of normal and <10 mU/L; and subclinical hyperthyroidism as low TSH and normal FT4.

RESULTS

Of 812 patients studied post-RI, hypothyroidism occurred in 80.7% and hyperthyroidism in 48.6% of patients. Three principal post-RI management strategies were employed: (a) antithyroid drugs alone, (b) levothyroxine alone, and (c) combination of the two. Differences among these were small. Adherence to national guidelines regarding monitoring thyroid function in the first 6 months was low (21.4%-28.7%). No negative outcomes (new-onset/exacerbation of Graves' orbitopathy, weight gain, and cardiovascular events) were associated with dysthyroidism. There were significant differences in demographics, clinical practice, and thyroid status postradioiodine between centres.

CONCLUSIONS

Dysthyroidism in the 12 months post-RI was common. Differences between post-RI strategies were small, suggesting these interventions alone are unlikely to address the high frequency of dysthyroidism.

Observational Study on Outcomes after Radioiodine Ablation in Hyperthyroid Patients

INTRODUCTION

Radio-active Iodine (RAI) is a safe, definitive, and cost-effective modality of treatment that is used as the first line of treatment for Graves' hyperthyroidism by most endocrinologists. Very few reports are available from India, observational follow-up data is needed to determine the meaningful prognostic outcomes of RAI ablation in the Indian population.

AIMS

To study the outcomes in hyperthyroid patients undergoing RAI ablation.

MATERIALS AND METHODS

This observational cohort study was conducted at Department of Endocrinology at Indraprastha Apollo Hospital, New Delhi. A total of 82 hyperthyroid patients who underwent RAI ablation between June 2014 to June 2018 were enrolled. RAI dose was calculated arbitrarily in most cases; often by an empirical fixed dose based on the goiter size and RAIU. The patients were reviewed at 1, 3 and 6 months post-RAI ablation. During follow-up, along with a detailed clinical examination, free T4, free T3 and TSH were checked.

RESULTS

The dose of I-131 varied from 6 mCi to 14 mCi. Most of the patients were given RAI in the dose of 7.1-10 mci. About 63.4% of patients achieved hypothyroidism in 6 months, 6.1% in 1 month, 37.8% in 3 months, and 19.5% in 6 months. Gender, age, etiology of hyperthyroidism, baseline thyroid function, goiter, and ophthalmopathy did not affect outcomes after RAI ablation. Those who were not treated with antithyroid drugs prior to RAI therapy were found to have higher rates of conversion to a hypothyroid state.

CONCLUSION

RAI can be given safely as the first line of treatment in Graves' disease and antithyroid drug naïve patients respond better to therapy.

Thyroid dysfunction and breast cancer risk among women in the UK Biobank cohort

This study aimed to evaluate the association between thyroid dysfunction and breast cancer risk. We included 239,436 females of the UK Biobank cohort. Information on thyroid dysfunction, personal and family medical history, medications, reproductive factors, lifestyle, and socioeconomic characteristics was retrieved from baseline self-reported data and hospital inpatient databases. Breast cancer diagnoses were identified through population-based registries. We computed Cox models to estimate hazard ratios (HRs) of breast cancer incidence for thyroid dysfunction diagnosis and treatments, and examined potential confounding and effect modification by comorbidities and breast cancer risk factors. In our study, 3,227 (1.3%) and 20,762 (8.7%) women had hyper- and hypothyroidism prior to the baseline. During a median follow-up of 7.1 years, 5,326 (2.2%) women developed breast cancer. Compared to no thyroid dysfunction, there was no association between hypothyroidism and breast cancer risk overall (HR = 0.93, 95% confidence interval (CI): 0.84-1.02, 442 cases), but we found a decreased risk more than 10 years after hypothyroidism diagnosis (HR=0.85, 95%CI 0.74-0.97, 226 cases). There was no association with hyperthyroidism overall (HR=1.08, 95%CI 0.86-1.35, 79 cases) but breast cancer risk was elevated among women with treated hyperthyroidism (HR=1.38, 95%CI: 1.03-1.86, 44 cases) or aged 60 years or more at hyperthyroidism diagnosis (HR=1.74, 95%CI: 1.01-3.00, 113 cases), and 5-10 years after hyperthyroidism diagnosis (HR=1.58, 95%CI: 1.06-2.33, 25 cases). In conclusion, breast cancer risk was reduced long after hypothyroidism diagnosis, but increased among women with treated hyperthyroidism. Future studies are needed to determine whether the higher breast cancer risk observed among treated hyperthyroidism could be explained by hyperthyroidism severity, type of treatment or aetiology.

Treatment of patients with Graves' disease in Sweden compared to international surveys of an 'index patient'

Introduction

The treatment strategies for a 42‐year‐old female index patient with moderate Graves’ disease (GD) vary according to several international surveys. The important question whether surveys of treatment preferences in theoretical patient cases also match how real patients are treated has not yet been addressed.

Materials and Methods

From a Swedish cohort of 1186 GD patients (TT‐12 cohort), 27 women were identified using the same criteria as from the index patient surveys from the European and American Thyroid Associations. This ‘index patient cohort’ was age 40–45, otherwise healthy female, with two children and uncomplicated GD. The applied first‐line treatment of the patients in the index cohort, together with its variations, was compared with the treatment preferences according to international surveys. A comparison with the TT‐12 cohort was also performed.

Results

In the ‘Index cohort’, 77.8% were treated with antithyroid drugs (ATD), and 22.2% were treated with radioiodine (¹³¹I). This preference for ATD is in line with most countries/regions, with the exception of USA and the Middle East/North Africa, where ¹³¹I was preferred. The distribution of treatment in the TT‐12 cohort did not significantly differ from the index cohort. ATD was the preferred treatment in male and young (age 19–22) patients, as was RAI in old (age 69–73) patients. The age‐related, but not the gender‐related, cases differed significantly from the entire TT‐12 cohort.

Conclusion

The treatment choice in an index patient in Sweden seems in line with European practice, where ATD is the preferred first choice. This differs compared to US and North African survey intentions, where ¹³¹I is more often used. Age more than gender influences the treatment choice of GD patients. This is, to our best knowledge, the first time an index patient from ‘real life’ has been presented and compared to treatment preferences of international thyroid association surveys.

Antithyroid drugs in Graves' hyperthyroidism: differences between "block and replace" and "titration" regimes in frequency of euthyroidism and Graves' orbitopathy during treatment

PURPOSE

Whereas antithyroid drugs (ATD) are the preferred treatment modality for Graves' hyperthyroidism (GH), there is still controversy about the optimal regimen for delivering ATD. To evaluate whether 'Block and Replace' (B + R) and 'Titration' (T) regimes are equivalent in terms of frequency of euthyroidism and Graves' Orbitopathy (GO) during ATD therapy.

METHODS

A prospective multicentre observational cohort study of 344 patients with GH but no GO at baseline. Patients were treated with ATD for 18 months according to B + R or T regimen in line with their institution's policy.

RESULTS

Baseline characteristics were similar in both groups. In the treatment period between 6 and 18 months thyrotropin (TSH) slightly increased in both groups, but TSH was on average 0.59 mU/L (95% CI 0.27-0.85) lower in the B + R group at all time points (p = 0.026). Serum free thyroxine (FT4) remained stable during the same interval, with a tendency to higher values in the B + R group. The point-prevalence of euthyroidism (TSH and FT4 within their reference ranges) increased with longer duration of ATD in both groups; it was always higher in the T group than in the B + R group: 48 and 24%, respectively, at 6 months, 81 and 58% at 12 months, and 87 and 63% at 18 months (p < 0.002). There were no significant differences between the B + R and T regimens with respect to the fall in thyrotropin binding inhibiting immunoglobulins (TBII) or thyroid peroxidase antibodies (TPO-Ab). GO developed in 15.9% of all patients: 9.1 and 17.8% in B + R group and T group, respectively, (p = 0.096). GO was mild in 13% and moderate-to-severe in 2%.

CONCLUSION

The prevalence of biochemical euthyroidism during treatment with antithyroid drugs is higher during T compared to B + R regimen. De novo development of GO did not differ significantly between the two regimens, although it tended to be higher in the T group. Whether one regimen is clinically more advantageous than the other remains unclear.

Effect of Different 131I Dose Strategies for Treatment of Hyperthyroidism on Graves' Ophthalmopathy

PURPOSE

The study aims to define the effect of different dose strategies on ophthalmic complications in patients with Graves' disease (GD).

METHODS

All the patients with GD and no or inactive ophthalmopathy (clinical activity score; CAS < 3) underwent Snellen chart examination, measurement of proptosis, thyroid volume, and radioactive iodine uptake, and randomized into 1 of 3 groups. In group 1, all the patients received fixed low dose (FLD) of 259 MBq of I, whereas in group 2, all the patients received fixed high dose (FHD) of 555 MBq, and in group 3, calculated dose (CD) was administered to deliver 5.55 MBq/g (thyroid weight) of I. All examinations were repeated 6 months after treatment. The measurement of thyroid function tests and clinical examination were repeated after 12 months.

RESULTS

We studied 92 patients (58 female and 34 male) with mean age of 38.2 ± 12.0 years. Overall, 29, 32, and 31 patients were studied in FLD, FHD, and CD groups, respectively. The patients in CD received a mean activity of 240.5 MBq. The 3 groups were not significantly different regarding age, sex ratio, radioactive iodine uptake, smoking, visual acuity, and proptosis. The response rate 12 months after radioactive iodine therapy was 66.7%, 94.4%, and 92.9% in FLD, FHD, and CD groups, respectively (P = 0.05). Overall, CAS was increased significantly after treatment. Delta proptosis and delta CAS were increased significantly in FHD group compared with other groups (P < 0.05). The highest increment in proptosis was seen in FHD group.

CONCLUSIONS

The administration of 5.55 MBq/g of I has fewer ophthalmic complications compared with high fixed dose model and is more effective than low fixed dose strategy.

Current controversies in the management of Graves' hyperthyroidism

Introduction: The management of Graves' disease centers on the use of effective and well-established therapies, namely thionamide antithyroid drugs, radioactive iodine, and thyroidectomy. Optimal treatment strategies are however controversial and vary significantly across centers.Areas covered: This review addresses specific controversies in Graves' disease management including the choice of primary therapy, the approach to women planning pregnancy, and optimal strategies for antithyroid drug and radioiodine therapy.Expert opinion: Important considerations in choosing therapy include treatment efficacy, adverse effects, patient convenience, and resource settings. Recent data suggest that early and effective control of hyperthyroidism is key to improving cardiovascular morbidity and mortality. Studies addressing cancer risk in radioiodine-treated patients face methodological challenges and require clarification in appropriately designed studies. Remission rates with antithyroid drugs are comparable when thionamides are used alone (titration-regimen) or in combination with levothyroxine (block and replace) and can be optimized by extending treatment for at least 12-18 months. Fixed and calculated radioiodine activity regimens are both effective but entail a trade-off between convenience and precision in the administered activity. Optimal preconception strategies are still evolving but ablative treatment in advance of pregnancy offers the most pragmatic means of reducing adverse effects of hyperthyroidism in subsequent pregnancy.

Radioiodine therapy and Graves' disease - Myths and reality

Introduction

Autoimmune reactions in Graves’ disease (GD) occur not only in the thyroid gland, but also in the orbital connective tissue, eyelids, extraocular muscles. The occurrence of orbitopathy in the course of GD is influenced by environmental factors, e.g. cigarette smoking.

Objectives

The aim of the study was to analyze the effect of cigarette smoking on the efficacy of activity of radioiodine(131I) therapy in patients with GD. We also studied the influence of cigarette smoking and the efficacy of prednisone prophylaxis on the risk of thyroid-associated ophthalmopathy (TAO) development after radioiodine therapy (RIT) during two years of follow-up.

Patients and methods

Medical records of hyperthyroid patients treated with radioiodine had been included. Patients were scheduled to visit outpatient clinics at baseline and 1, 3, 6, 9, 12, 18, and 24 months after RIT.

Results

The studied group consisted of 336 patients (274 women, 62 men) diagnosed with GD and treated with RIT; 130 patients received second therapeutic dose of ¹³¹I due to recurrent hyperthyroidism. Among all studied patients, 220 (65.5%) were smokers and 116 (34.5%) non-smokers. In the group of smokers 115 (52.2%) of patients received single RIT, 105 (47.8%) received second dose of RAI due to recurrent hyperthyroidism. In non-smokers 91 (78.6%) received single activity of RAI, while 25 (21.4%) patients required second RIT due to recurrent hyperthyroidism. The ophthalmic symptoms in the group of smokers after RIT were less frequent, if the patient received preventative treatment in the form of oral prednisone (P = 0.0088).

Conclusions

The results of our study suggest that cigarette smoking reduces the efficacy of treatment with ¹³¹I in patients with GD. The study also confirmed the effectiveness of steroid prophylaxis against TAO development or exacerbation after RIT.

The success rate of radioactive iodine therapy for Graves' disease in iodine-replete area and affecting factors: a single-center study

OBJECTIVE

Initial treatment options for Graves' disease include antithyroid drugs, radioactive iodine (RAI), and surgery. Because of similar effects of three modalities, initial treatment preferences differ by country to country. In Korea, iodine-replete area, RAI was used as a second-line option. For these reasons, the RAI success rate in Korea might differ from other countries.

METHODS

A total of 247 patients were enrolled. The primary outcome was cumulative success rate in the first year, and the secondary outcome was factors that affected the success. Delayed response, which included patients who attained successful RAI during the follow-up, after the first year without further RAI, and factors that affected the delayed response were reviewed.

RESULTS

The cumulative success rate in the first year was 62.8%. Higher RAI activity [odds ratio (OR) 2.56, P = 0.02], longer disease duration (OR 0.43, P = 0.01), larger goiter (OR 0.31, P = 0.01), and higher post-RAI fT4 (fT4 between upper normal limit (UNL) to 1.5 × UNL; OR 0.24; P < 0.01, 1.5 × UNL<; OR 0.08; P < 0.01) were associated with RAI success. Twenty-seven patients showed delayed response, and goiter size (P < 0.05), pre-RAI TSH receptor Ab (TRAb) level (P < 0.01) and post-RAI fT4 (P < 0.01) were associated.

CONCLUSION

The success rate of the first RAI in Korea was lower than that in other countries. Delayed response was observed in patients with smaller goiter, low pre-RAI TRAb, and low post-RAI fT4. In these patients, clinical follow-up with monitoring could be an option, and decision of optimal timing of first RAI is crucial.

Safety of long-term antithyroid drug treatment? A systematic review

Continued low-dose MMI treatment for longer than 12-18 months may be considered in patients not in remission. However, ATDs are not free from adverse effects. We undertook a systematic review to clarify safety of long-term ATD treatment. Medline and the Cochrane Library for trials published between 1950 and Nov 2018 were systematically searched. We included original studies containing data for long-term (> 18 months) ATD treatment. Two reviewers independently extracted data from included trials and any disagreement was adjudicated by consensus. Of 615 related articles found, 12 fulfilled the criteria. Six articles had data for adults, five for non-adults and one article had data for both groups. The sample sizes ranged between 20 and 249 individuals, and the mean duration of ATD treatment ranged between 2.1 and 14.2 years. Considering all data from 1660 patients treated with ATD for a mean duration of 5.8 years (around 10,000 patient-years), major complications occurred only in 14 patients: 7 severe agranulocytosis, 5 severe liver damage, one ANCA-associated glomerulonephritis and one vasculitis with small cutaneous ulcerations. Minor complications rates were between 2 and 36%, while more complications were in higher doses and in the children. The most reported AE was cutaneous reaction; the other adverse events were elevated liver enzymes, leukocytopenia, arthritis, arthralgia, myalgia, thrombocytopenia, fever, nausea and oral aphthous. Long-term ATD treatment is safe, especially in low dose and in adults, indicating that it should be considered as an earnest alternative treatment for GD.

How do paediatricians use and monitor antithyroid drugs in the UK? A clinician survey

OBJECTIVE

We aimed to document current practice in the medical management of paediatric hyperthyroidism in the UK and compare to international recommendations.

DESIGN

A 27-question online survey distributed via an electronic newsletter in August 2018.

PARTICIPANTS

Responses from 48 members (11%) of the British Society for Paediatric Endocrinology and Diabetes.

MEASUREMENTS

Information about antithyroid drug (ATD) preference, treatment duration, monitoring of full blood count (FBC), management of neutropaenia, agranulocytosis screening and patient education.

RESULTS

Carbimazole is favoured by 98% of respondents and a "dose titration" regimen preferred over "block and replace" (65% vs 29%). TRAbs (thyroid-stimulating hormone receptor antibodies) are used for diagnostic purposes by 85% and by 33% to look for evidence of disease remission. The majority (81%) treat for a minimum of 2 years before considering a trial off ATD. All respondents reported that they "always/usually" warn their patients about the risk of agranulocytosis before starting ATD, but written information is "rarely/never" provided by 63%. Sore throat (98%) and fever (92%) are the most commonly cited symptoms used to alert a patient to possible agranulocytosis. FBC is measured prior to treatment by 65% and measured periodically during treatment by 70%.

CONCLUSIONS

The management of paediatric hyperthyroidism with ATDs in the UK is not consistent with all international recommendations because a block and replace ATD regimen remains widely used. TRAbs are utilized at presentation, but underused for detecting disease remission. National consensus guidelines and written patient information may refine the management of paediatric patients on ATDs.

Treatment choice, satisfaction and quality of life in patients with Graves' disease

BACKGROUND

Thyrotoxicosis, most often caused by Graves' disease (GD), when treated inadequately may result in premature mortality. There is little consensus as to which of the 3 treatment options available - antithyroid drugs (ATD), radioactive iodine (RAI) and surgery, is better.

AIMS

(i) To assess factors involved in treatment choice and treatment satisfaction in patients treated for Graves' disease; (ii) To assess quality of life (QoL) following treatment of Graves' disease.

METHOD

Participants were selected from a prospective study cohort assessing thyrotoxicosis incidence and severity. Of the 172 eligible patients with Graves' disease, 123 treated patients participated (64% had received ATD only, 11% RAI and 25% total thyroidectomy, the latter 2 usually after a period of ATD), along with 18 untreated patients with newly diagnosed Graves' disease (overall participation rate, 73%). Consented patients completed a questionnaire detailing factors involved in treatment choice, QoL and satisfaction with treatment.

RESULTS

Participants reported that the most important factors in choosing a treatment were the following: the effects on activities of daily living, concern about use of radioiodine, possibility of depression or anxiety, and doctor's recommendations. Satisfaction levels were high across all 3 treatment types. QoL 1-year following treatment was higher than in untreated patients, and comparable with other international studies.

CONCLUSIONS

Patient satisfaction with therapy and QoL does not differ by treatment type. Therefore, clinical and social factors, in combination with patient choice and resource availability, should determine which treatment modality patients with Graves' disease should receive.

Global epidemiology of hyperthyroidism and hypothyroidism

Thyroid hormones are essential for growth, neuronal development, reproduction and regulation of energy metabolism. Hypothyroidism and hyperthyroidism are common conditions with potentially devastating health consequences that affect all populations worldwide. Iodine nutrition is a key determinant of thyroid disease risk; however, other factors, such as ageing, smoking status, genetic susceptibility, ethnicity, endocrine disruptors and the advent of novel therapeutics, including immune checkpoint inhibitors, also influence thyroid disease epidemiology. In the developed world, the prevalence of undiagnosed thyroid disease is likely falling owing to widespread thyroid function testing and relatively low thresholds for treatment initiation. However, continued vigilance against iodine deficiency remains essential in developed countries, particularly in Europe. In this report, we review the global incidence and prevalence of hyperthyroidism and hypothyroidism, highlighting geographical differences and the effect of environmental factors, such as iodine supplementation, on these data. We also highlight the pressing need for detailed epidemiological surveys of thyroid dysfunction and iodine status in developing countries.

Long-Term Antithyroid Drug Treatment: A Systematic Review and Meta-Analysis

BACKGROUND

Several studies have reported inconsistent findings on the advantages and disadvantages of long-term treatment with antithyroid drugs (ATD). A systematic review and meta-analysis was undertaken to clarify the numerous aspects of long-term treatment with ATD.

METHODS

Medline and the Cochrane Library for trials published between 1950 and May 2016 were systematically searched. Studies containing data for long-term (>24 months) ATD treatment were included. Summary estimates of pooled prevalence, odds ratio, and weighted mean difference were calculated with a random effects model.

RESULTS

Of 587 related articles found, six fulfilled the inclusion criteria. Long-term ATD treatment induced a remission rate of 57% [confidence interval (CI) 45-68%], a rate that was higher in adults than in non-adults (61% vs. 53%). The rate of complications was 19.1% [CI 9.6-30.9%], of which only 1.5% were major complications. The annual remission rate for each year of treatment was 16% [CI 10-27%], which was higher in adults than non-adults (19% vs. 14%). However, it should be noted that this is not a true linear correlation, but a positive relationship can be suggested between time and remission rate. Meta-regression revealed that smoking had a significant lowering effect on remission rate.

CONCLUSIONS

Long-term ATD treatment is effective and safe, especially in adults, indicating that it should be considered as an alternative treatment for Graves' disease.

Management of hyperthyroidism due to Graves' disease: frequently asked questions and answers (if any)

Graves' disease is the most common cause of hyperthyroidism in iodine-replete areas. Although progress has been made in our understanding of the pathogenesis of the disease, no treatment targeting pathogenic mechanisms of the disease is presently available. Therapies for Graves' hyperthyroidism are largely imperfect because they are bound to either a high rate of relapsing hyperthyroidism (antithyroid drugs) or lifelong hypothyroidism (radioiodine treatment or thyroidectomy). Aim of the present article is to offer a practical guidance to the reader by providing evidence-based answers to frequently asked questions in clinical practice.

Current trends in antithyroid drug treatment of Graves' disease

INTRODUCTION

Graves' hyperthyroidism is associated with significant morbidity and mortality risk. The thionamides, methimazole, its pro-drug derivative carbimazole, and propylthiouracil, remain a cornerstone of management. Yet despite decades of use, optimal strategies for maximising treatment response and curtailing adverse effect risk remains uncertain.

AREAS COVERED

We reviewed the current literature on the evidence based medical management of Graves' disease. Specifically, we evaluated current approaches to the use of thionamides, adjunctive therapies, and potential novel agents for controlling Graves' hyperthyroidism.

EXPERT OPINION

Primary medical therapy is successful in less than 50% of cases and so careful selection of patients for medical treatment based on a combination of pathological and pragmatic considerations is essential. Carbimazole or methimazole is the treatment of choice in the non-pregnant population driven by its more favourable pharmacokinetic and adverse effect profile over propylthiouracil. In pregnancy the choice of treatment is less straightforward and an approach that minimises undue fetal exposure to all thionamides should be adopted. Additional data is needed on the value of adjunctive therapies including potassium perchlorate, iodides, glucocorticoids, lithium, and cholestyramine. Novel agents directed against pathogenetic targets including TSH receptor blocking monoclonal antibodies and small molecule antagonists may hold promise for the future.

Predictive value of pyramidal lobe, percentage thyroid uptake and age for ablation outcome after 15 mCi fixed dose of radioiodine-131 in Graves' disease

PURPOSE

The purpose was to find out the efficacy of fixed 15 mCi radioactive iodine-131 (RAI) dose and predictive values of various factors for inducing hypothyroidism in Graves' disease (GD).

MATERIALS AND METHODS

Retrospective study conducted from January 2012 till August 2014. Patients with GD who had a technetium-99m thyroid scan, thyroid antibodies, received fixed 15 mCi RAI and did follow endocrine clinics for at least 6 months were selected. RAI was considered successful if within 6 months of RAI therapy patients developed hypothyroidism.

RESULTS

Of the 370 patients with GD who had RAI during study period, 210 (57%) qualified study criteria. Mean age of patients was 48 ± 15 years with female: male ratio of 69:31, positive thyroid antibodies in 61%, means thyroid uptake of 15.09 ± 11.23%, and presence of pyramidal lobe in 40% of total population. Hypothyroidism was achieved in 161 (77%) patients while 49 (23%) patients failed to achieve it (remained either hyperthyroid or euthyroid on antithyroid medication). Patients who became hypothyroid were significantly younger with higher proportion of presence of thyroid antibodies and pyramidal lobe and lower percentage thyroid uptake than those who failed. Multiple logistic regression analysis revealed that age (odds ratio; OR = 2.074), pyramidal lobe (OR = 3.317), thyroid antibodies (OR = 8.198), and percentage thyroid uptake (OR = 3.043) were found to be significant prognostic risk factors for post-RAI hypothyroidism. Gender was found to have nonsignificant association with the development of hypothyroidism. Receiver operating characteristic analysis revealed age <42 years and thyroid uptake <15% as threshold values for the development of post-RAI hypothyroidism.

CONCLUSION

We conclude that fixed (15 mCi) RAI dose is highly effective in rendering hypothyroidism in patients with GD. Age (≤42 years), thyroid uptake (≤15%) and presence of pyramidal lobe are strong predictors of hypothyroidism and must be considered for selecting optimal RAI dose.

Quantitative mRNA expression analysis of selected genes in patients with early-stage hypothyroidism induced by treatment with iodine-131

The present study aimed to investigate the molecular markers indicative of early-stage hypothyroidism induced by treatment with iodine-131, in order to assist in further investigations of radio iodine‑induced hypothyroidism. A total of 59 patients diagnosed with hyperthyroidism (male/female, 16/43; median age, 46.4 years) and 27 healthy subjects (male/female, 7/21; median age, 44.6 years) were included in the present study. All patients were treated with appropriate doses of iodine‑131 and, three months following treatment, the patients were subdivided into two groups: A group with early‑stage hypothyroidism symptoms, and a group with non‑early‑stage hypothyroidism, including euthyroid patients and patients remaining with hyperthyroidism. Tissue samples from the patients and healthy subjects were collected by fine needle biopsies, and the mRNA expression levels of B-cell lymphoma 2 (Bcl‑2), nuclear factor (NF)‑κB, Ku70, epidermal growth factor receptor (EGFR), early growth response 1 (Egr‑1), TP53 and ataxia telangiectasia mutated were analyzed using reverse transcription‑quantitative polymerase chain reaction prior to iodine‑131 treatment. The association of the variation of target genes with susceptibility to early‑stage hypothyroidism was analyzed. Compared with normal subjects, the mRNA expression levels of Ku70 (0.768, vs. 3.304, respectively; P<0.001) and EGFR (0.859, vs. 1.752, respectively; P<0.05) were significantly higher, whereas those of NF‑κB (0.884, vs. 0.578, respectively; P<0.05) and Bcl‑2 (1.235, vs. 0.834, respectively; P<0.05) were lower in the hyperthyroid patients. Following treatment with iodine‑131, 30 of the 59 (50.8%) patients with hyperthyroidism were diagnosed with early‑stage hypothyroidism, and in the early‑stage hypothyroidism group, the mRNA expression levels of Bcl‑2 were significantly decreased (P<0.05), whereas those of Egr‑1 (P<0.05) were significantly increased, compared with the non‑early‑stage hypothyroidism group. The association between the changes in the expression levles of Bcl‑2 and Egr‑1 and susceptibility to early‑stage hypothyroidism was supported by multivariate regression analysis. No significant changes in the expression levels of the other target genes were detected. The opposing changes in the mRNA expression levels of Bcl‑2 and Egr‑1 in patients with early‑stage hypothyroidism indicates their potential as prognostic markers of early-stage hypothyroidism induced by iodine-131 treatment.

Block & replace regime versus titration regime of antithyroid drugs for the treatment of Graves' disease: a retrospective observational study

CONTEXT

Two widely used antithyroid drug (ATD) regimes for Graves' disease (GD) include the 'block & replace' (B&R) regime (a fixed high-dose of ATD combined with levothyroxine) and the 'titration' regime (a titrating dose of ATD). Anecdotally, it is believed that B&R is less prone to fluctuating thyroid function.

OBJECTIVE

To study whether, in routine clinical practice, the B&R regime, compared with the titration regime, is associated with more stable thyroid function.

METHODS

We retrospectively analysed case-records for 450 patients treated with ATDs for GD at a secondary care hospital. Exclusion criteria included treatment with ATDs for <6 months, thyrotoxicosis due to other causes, treatment with radioiodine or thyroidectomy and pregnancy.

RESULTS

Two hundred and twenty three patients were treated with the B&R regime ('B&R group'), 149 with the titration regime ('titration group') and 78 with both regimes. The number of thyroid function tests (TFTs) performed per year (mean(SD): 3·2(1·2) vs 3·4(1·5); adjusted mean difference = -0·4; 95% CI: -0·7 to -0·1; and P = 0·008) and the number of hospital clinic visits per year (mean (SD): 2·9 (1·0) vs 3·2 (1·3); adjusted mean difference = -0·4; 95% CI: -0·7 to -0·2; and P = 0·002) were lower in the B&R group than the titration group. The number of abnormal TFT results per year was similar in the two groups (mean(SD): 1·8(1·3) vs 1·8(1·4); adjusted mean difference = 0·05; 95%CI: -0·3 to 0·4; and P = 0·74).

CONCLUSIONS

In this retrospective study, there was little evidence that patients under B&R have more stable thyroid function. Further data from prospective studies, however, are needed to confirm this finding.

Efficacy of different protocols of radioiodine therapy for treatment of toxic nodular goiter: systematic review and meta-analysis of the literature

CONTEXT

To evaluate treatment success and hypothyroidism following main methods of radioiodine therapy of toxic nodular goiter (TNG); calculated versus fixed dose and high versus low dose of radioiodine.

EVIDENCE ACQUISITIONS

We searched MEDLINE and SCOPUS databases from inception till July 2013, for clinical trials that compared two different methods of radioiodine administration in TNG. The trials were classified into two groups, those that compared fixed versus calculated dosimetry method and those that assessed high fixed dose versus low fixed dose method. Treatment response was defined as euthyroidism or hypothyroidism, one year after radioiodine administration. We calculated the risk ratio and risk difference of treatment response as well as permanent hypothyroidism as outcome variables. Random effects model was used for data pooling.

RESULTS

The literature search yielded 2538 articles. Two randomized and five non-randomized clinical trials with 669 patients met the eligibility criteria for the meta-analysis. Patients with TNG who were treated according to the calculated method had 9.6% higher cure rate (risk ratio=1.17) and only 0.3% more permanent hypothyroidism compared to patients treated with the fixed dose method. There was no significant difference in the amount of administered radio-iodine in the two groups. Patients treated with fixed high dose had 18.1% more cure rate (risk ratio = 1.2) and 23.9% more permanent hypothyroidism (risk ratio = 2.40) compared to patients treated by fixed low dose protocols.

CONCLUSIONS

Calculated radioiodine therapy may be preferred to fixed dose method in patients with TNG. High dose methods are associated with more response and more hypothyroidism.

Diagnosis and management of Graves disease: a global overview

Graves disease is an autoimmune disorder characterized by goitre, hyperthyroidism and, in 25% of patients, Graves ophthalmopathy. The hyperthyroidism is caused by thyroid hypertrophy and stimulation of function, resulting from interaction of anti-TSH-receptor antibodies (TRAb) with the TSH receptor on thyroid follicular cells. Measurements of serum levels of TRAb and thyroid ultrasonography represent the most important diagnostic tests for Graves disease. Management of the condition currently relies on antithyroid drugs, which mainly inhibit thyroid hormone synthesis, or ablative treatments ((131)I-radiotherapy or thyroidectomy) that remove or decrease thyroid tissue. None of these treatments targets the disease process, and patients with treated Graves disease consequently experience either a high rate of recurrence, if receiving antithyroid drugs, or lifelong hypothyroidism, after ablative therapy. Geographical differences in the use of these therapies exist, partially owing to the availability of skilled thyroid surgeons and suitable nuclear medicine units. Novel agents that might act on the disease process are currently under evaluation in preclinical or clinical studies, but evidence of their efficacy and safety is lacking.

Total thyroidectomy for safe and definitive management of Graves' disease

Background:

The role of total thyroidectomy in the management of patients with Graves' disease remains controversial. However, there is increasing evidence to support the role of the procedure as a safe and definitive treatment for Graves' disease.

Method:

Patients were identified from a prospective thyroid database of the multidisciplinary thyroid clinic at Hull Royal Infirmary. All case notes were independently reviewed to confirm the data held on the database.

Results:

Over a 7-year period, the senior author has performed 206 total thyroidectomies for Graves' disease. The incidence of temporary recurrent laryngeal nerve palsy and hypoparathyroidism was 3.4 per cent and 24 per cent respectively. There was one case of permanent unilateral recurrent laryngeal nerve palsy, and 3.9 per cent of patients developed permanent hypoparathyroidism. There has been no relapse of thyrotoxicosis.

Conclusion:

In the context of a multidisciplinary thyroid clinic, total thyroidectomy should be offered as a safe and effective first-line treatment option for Graves' disease.

Comparison of mortality in hyperthyroidism during periods of treatment with thionamides and after radioiodine

CONTEXT

Hyperthyroidism is common, but opinions regarding optimal therapy with antithyroid drugs or radioiodine (131-I) differ. There are no randomized trials comparing these options in terms of mortality.

OBJECTIVE

The aim of the study was to determine whether mortality associated with hyperthyroidism varies with treatment administered or other factors.

DESIGN, SETTING, AND PATIENTS

We conducted a prospective observational population-based study of 1036 subjects aged ≥ 40 years presenting to a single specialist clinic from 1989-2003 with a first episode of hyperthyroidism who were followed until June 2012.

INTERVENTIONS

Antithyroid drugs or radioiodine (131-I) were administered.

MAIN OUTCOME MEASURES

We compared causes of death with age-, sex-, and period-specific mortality in England and Wales and used within-cohort analysis of influence of treatment modality, outcome, disease etiology, severity and control, and comorbidities.

RESULTS

In 12 868 person-years of follow-up, 334 died vs 290.6 expected (standardized mortality ratio [SMR], 1.15 [95% confidence interval (CI),1.03-1.28]; P = .01). Increased all-cause mortality largely reflected increased circulatory deaths (SMR, 1.20 [95% CI, 1.01-1.43]; P = .04). All-cause mortality was increased for the person-years accumulated during thionamide treatment (SMR, 1.30 [95% CI, 1.05-1.61]; P = .02) and after 131-I not associated with hypothyroidism (SMR, 1.24 [95% CI, 1.04-1.46]; P = .01) but not during T₄ replacement for 131-I-induced hypothyroidism (SMR, 0.98 [95% CI, 0.82-1.18]; P = .85). Within-cohort analysis comparing mortality during thionamide treatment showed a similar hazard ratio (HR) for all-cause mortality when 131-I did not result in hypothyroidism (HR, 0.95 [95% CI, 0.70-1.29]), but reduced mortality with 131-I-induced hypothyroidism (HR, 0.70 [95% CI, 0.51-0.96]). Reduced mortality associated with hypothyroidism was seen only in those without significant comorbidities and not in those with other serious diseases. Atrial fibrillation at presentation (P = .02) and an increment of 10 pmol/L in serial free T₄ concentration during follow-up (P = .009) were independently associated with mortality.

CONCLUSIONS

Among hyperthyroid subjects aged 40 years or older, mortality was increased during periods of thionamide treatment and after radioiodine not resulting in hypothyroidism, but not during follow-up after radioiodine-induced hypothyroidism. Independent associations of mortality with atrial fibrillation and incomplete biochemical control during treatment indicate potential causative links with poor outcome.

Radioiodine therapy in benign thyroid diseases: effects, side effects, and factors affecting therapeutic outcome

Radioiodine ((131)I) therapy of benign thyroid diseases was introduced 70 yr ago, and the patients treated since then are probably numbered in the millions. Fifty to 90% of hyperthyroid patients are cured within 1 yr after (131)I therapy. With longer follow-up, permanent hypothyroidism seems inevitable in Graves' disease, whereas this risk is much lower when treating toxic nodular goiter. The side effect causing most concern is the potential induction of ophthalmopathy in predisposed individuals. The response to (131)I therapy is to some extent related to the radiation dose. However, calculation of an exact thyroid dose is error-prone due to imprecise measurement of the (131)I biokinetics, and the importance of internal dosimetric factors, such as the thyroid follicle size, is probably underestimated. Besides these obstacles, several potential confounders interfere with the efficacy of (131)I therapy, and they may even interact mutually and counteract each other. Numerous studies have evaluated the effect of (131)I therapy, but results have been conflicting due to differences in design, sample size, patient selection, and dose calculation. It seems clear that no single factor reliably predicts the outcome from (131)I therapy. The individual radiosensitivity, still poorly defined and impossible to quantify, may be a major determinant of the outcome from (131)I therapy. Above all, the impact of (131)I therapy relies on the iodine-concentrating ability of the thyroid gland. The thyroid (131)I uptake (or retention) can be stimulated in several ways, including dietary iodine restriction and use of lithium. In particular, recombinant human thyrotropin has gained interest because this compound significantly amplifies the effect of (131)I therapy in patients with nontoxic nodular goiter.

Increasing use of radioiodine in young people with thyrotoxicosis in Great Britain

OBJECTIVE

Radioiodine (RI) is an important therapeutic option in young patients with thyrotoxicosis. We wanted to determine whether RI is being used more frequently in this age group.

DESIGN

National survey of Great Britain (England, Wales and Scotland).

METHODS

Sixty-one medical physics departments were asked to provide the age and number of patients with thyrotoxicosis <21 years treated with RI (1990-2008). Information on the total number of RI treatments for thyrotoxicosis was also collected.

RESULTS

Forty-three departments (70%), with representation from 21 of the 25 most populous areas of Great Britain, provided data on 69,258 treatments. The number of treatments recorded on patients <21 years during this period was 560 (0.9%). The frequency of treatments in young people as a percentage of the total increased from 0.2% in 1990 to 1.5% in 2008 (P<0.001). When the 18 centres submitting at least 17 years of data were analysed, a similar pattern was observed. The maximum number of young people treated was greatest in 2008 (62) with a fall in the youngest age at which RI was administered from 18 years (1990) to 11 years (2008).

CONCLUSIONS

A rising proportion of patients with thyrotoxicosis receiving RI are in those <21 years. This is largely due to an increase in the number of young people treated with a reduction in the minimum age at RI administration. We suspect that European clinicians are becoming more comfortable with RI treatment in young people with thyrotoxicosis, although a changing incidence is a potential contributing factor.

The role of thyrotrophin receptor antibody assays in graves' disease

Thyrotrophin receptor antibodies (TRAb) exist as stimulating or blocking antibodies in the serum (neutral TRAb have been identified recently). The clinical features of GD occur when stimulating TRAb predominate. But the relationship of TRAb to clinical phenotype and outcome is not clear when current assay methods are used. Therefore no consensus exists about its utility in diagnosing and predicting outcome in GD. The most commonly used TRAb assays, measure thyroid binding inhibiting immunoglobulins (TBII or “receptor assays”) and don't differentiate between stimulating and blocking antibodies. However, the more expensive, technically demanding and less freely available “biological assays” differentiate between them by their ability to stimulate cyclic AMP or failure to do so. Failure to differentiate between TRAb types and its heterogeneous molecular and functional properties has limited TBII use to GD diagnosis and differentiating from other forms of thyrotoxicosis. The current 2nd-3rd generation receptor assays are highly sensitive and specific when used for this purpose. TRAb assays should also be done in appropriate pregnant women. Current data do not support its use in outcome prediction as there is a significant variability of assay methodology, population characteristics and study design in published data, resulting in a lack of consensus.

Thyroid disorders

All forms of thyroid diseases are much more frequently observed in women than men, although the reasons are still not completely elucidated.Hyperthyroidism is defined by elevated circulating free thyroid hormones. The prevalence is about 2 % in women and 0.2 % in men. The most frequent causes are various forms of thyroid autonomy in elderly women and Graves' disease, which occurs mostly in younger women.Hypothyroidism is defined by a lack of thyroid hormones. It is a common endocrine disorder caused by autoimmune thyroiditis (Hashimoto thyroiditis), iodine deficiency or following surgery or radioiodine therapy. Thyroxine requirements depend on fat-free mass and are, therefore, somewhat higher in males who are more often undersubstituted. In pregnancy lower TSH-reference ranges have to be considered and thyroid function should be monitored throughout pregnancy to avoid harm to the foetus caused by maternal thyroid dysfunctions. If overtreated women more often feature fractures, whereas males more often develop atrial fibrillation.

Endogenous subclinical hyperthyroidism: who, when and why to treat

Subclinical hyperthyroidism is defined as serum thyroid hormone levels within their respective reference ranges in the presence of low-undetectable serum thyrotropin-stimulating hormone levels. Subclinical hyperthyroidism is associated with important cardiovascular risk factors and negative effects on bone metabolism and structure. However, there are conflicting results on cardiovascular mortality and the risk of bone fractures. Treatment and management of subclinical hyperthyroidism is controversial. This article will address the necessity to treat this disorder in relation to the cause of hyperthyroidism, the patient's age, the degree of thyroid-stimulating hormone suppression and the presence of comorbidities.

Current safety practices relating to I-131 administration for diseases of the thyroid: a survey of physicians and allied practitioners

BACKGROUND

There is little information about the individual safety instructions provided by healthcare professionals to patients receiving radioactive iodine (I-131) therapy for the treatment of benign and malignant thyroid disorders or about whether these instructions are consistent across medical specialties. Currently, no national guidelines exist to standardize safety instructions related to I-131 administration. Here, we examine the spectrum of I-131 safety practices in contemporary use.

METHODS

Members of major societies of physicians and allied specialists who treat patients with thyroid disorders were invited to complete a 27-question online survey about safety practices related to I-131 administration. Data from questionnaires were analyzed by type of safety recommendation and grouped according to provider specialty and geographic location.

RESULTS

A total of 311 endocrinologists, surgeons, nuclear medicine radiologists, and allied health professionals completed questionnaires. They indicated that patients often receive instruction from more than one treating specialist. The decision to hospitalize a patient for treatment and the length of stay were determined by the patient's social situation and the dose of I-131 administered. Starting at I-131 doses between 259 and 1073 MBq (7 and 29 mCi), over 60% of respondents advised avoiding contact with children, sexual activity, and breastfeeding, with the latter recommendation continuing beyond 48 hours after treatment. Personal hygiene, laundry, and meal preparation precautions varied across respondents. Over 90% of respondents used serum or urine testing to screen for pregnancy status. Precautions to delay parenthood were given more often to female than male patients (90% vs. 60%), with a minimum recommended delay of 6 months. About 20% of respondents considered insurance coverage as a factor in selecting outpatient versus inpatient I-131 therapy, and this consideration varied geographically.

CONCLUSION

A wide variety of safety recommendations are given to patients who receive I-131. To our knowledge, this survey represents the first organized inquiry into safety practices related to I-131 administration. The diversity of responses suggests an opportunity for multispecialty collaboration in defining more uniform recommendations for patient safety instructions during and after I-131 treatment.

Risk factors for persistent atrial fibrillation following successful hyperthyroidism treatment with radioiodine therapy

OBJECTIVE

To investigate the predicting factors for persistent atrial fibrillation (AF) following radioiodine therapy for hyperthyroidism.

METHODS

Standard 12-lead ECG and 24-h Holter monitoring were performed in 94 patients (38 males, mean age 46.1±8.2 years) with persistent AF following radioiodine therapy for hyperthyroidism. Left ventricular (LV) function was assessed with two-dimensional echocardiography.

RESULTS

Euthyroidism or hypothyroidism was achieved in 81% and 19% of the patients, respectively, after radioiodine therapy. At the end of follow-up (1.6±1.3 years), LV ejection fraction in the 52 patients with LV dysfunction was increased from 39.3±3.3% to 59.0±5.5% (p<0.01). In the 38 patients with pre-treatment paroxysmal AF, no AF was documented during the follow-up. In the 45 patients with pre-treatment persistent AF, AF was found in 27 (60%) during the follow-up. Multivariate logistic regression analysis showed that more than 55 years old in age (RR 2.76, 95% CI: 1.16-8.79, p<0.01), duration of hyperthyroidism (RR 3.08, 95% CI: 1.22-11.41, p<0.01) and duration of pre-treatment atrial fibrillation (RR 2.96, 95% CI: 1.31-7.68, p<0.01) were independent predictors for persistent AF following radioiodine therapy.

CONCLUSION

Older age, duration of hyperthyroidism and pre-treatment duration of AF are risk factors for persistent AF following radioiodine therapy.

Subclinical thyroid disorders: significance and clinical impact

Subclinical thyroid diseases are defined by abnormal serum thyroid stimulating hormone (TSH) levels associated with normal thyroid hormone concentrations. The diagnosis of these conditions depends on defining the 'normal' euthyroid TSH range; in this review, arguments for and against lowering the upper limit of TSH are summarised. Although, subclinical hypothyroidism and subclinical hyperthyroidism are frequently encountered, their long-term consequences are debated due to conflicting results from many observational studies. The causes, effects and outcomes of treatment of both subclinical diseases are described, and the direction of future research in these conditions is outlined.

The tale of radioiodine and Graves' orbitopathy

BACKGROUND

Autoimmunity against the thyrotropin receptor (TSH-R) is a key pathogenic element in Graves' disease (GD) and the autoimmune aberration may be modified by antithyroid treatment. An association between radioactive iodine (RAI) therapy for GD and the development or worsening of Graves' orbitopathy (GO) is widely quoted. RAI-associated leakage of thyroid antigen(s) leads to an increased production of TSH-R antibodies that may initiate the eye injury.

SUMMARY

RAI therapy leads to prolonged worsening of autoimmunity against the TSH-R, and the number of patients entering remission of TSH-R autoimmunity is considerably lower than with other antithyroid therapies. Scientific evidence has indicated that RAI treatment for GD is associated with increased risk of occurrence or progression of GO compared with antithyroid drugs (ATD) and thyroid surgery. The risks of developing new GO or worsening of preexisting GO is around 20% after RAI and around 5% after ATD. The risk of developing severe GO after RAI is around 7%. Smoking, high levels of pretreatment serum triiodothyronine, and post-RAI hypothyroidism are associated with increased risk of GO, whereas a high TSH-R autoantibody titer is an independent risk factor for the progression of GO. In patients with mild preexisting GO, steroid prophylaxis is effective in preventing deterioration of GO. Also, routine use of prophylactic oral steroids with RAI therapy should be considered in GD patients without overt GO, but even more so in those at higher risks of eye complications such as smokers, old men, and those with severe hyperthyroidism or high TSH-R antibody titers.

CONCLUSION

In contrast to ATD, remission of TSH-R autoimmunity after RAI therapy is less common, and RAI for GD is associated with definite increased risk of GO. Oral steroids are beneficial for patients with preexisting GO, particularly smokers.

Glucocorticoid administration for Graves' hyperthyroidism treated by radioiodine. A questionnaire survey among members of the European Thyroid Association

BACKGROUND

Glucocorticoid prophylaxis is required in some instances after radioiodine (RAI) treatment for Graves' hyperthyroidism to prevent progression of Graves' orbitopathy (GO). However, no randomized clinical trial has been performed to ascertain the optimum glucocorticoid therapy.

AIM AND METHODS

Aim of this study was to perform a questionnaire-based survey of glucocorticoid prophylaxis among European thyroidologist members of the European Thyroid Association.

RESULTS

Eighty-two responses from 25 European Countries were received. Two respondents did not prescribe steroids in any clinical scenario, while 8 gave the drug to all patients receiving RAI therapy. The majority of respondents only gave glucocorticoids to patients showing some degree of ocular involvement or if risk factors for the progression of GO after RAI were present (e.g., cigarette smoking); 24% of responses indicated that clinicians would not give glucocorticoids if patients were thought to have no GO or inactive GO. Ninety-one percent of clinicians used prednisone (53%) or prednisolone (38%). The mean starting dose [given for 16 days (range 2-60 days)] was 37.6 mg prednisone or prednisone-equivalent (range 15-80 mg). Overall, the results of this survey showed a wide diversity in the regimens used, in terms of timing of initiation of treatment, duration of treatment, cumulative doses of administered glucocorticoids and monitoring of side-effects of glucocorticoid treatment.

CONCLUSIONS

The results of this study underscore the need for randomized clinical trials to ascertain the optimum regimen of prophylactic glucocorticoid therapy.

Older subjects with hyperthyroidism present with a paucity of symptoms and signs: a large cross-sectional study

CONTEXT

The absence of classical symptoms and signs of hyperthyroidism often results in delayed diagnosis and treatment.

OBJECTIVES

The objective of the study was to determine the prevalence of symptoms and signs of hyperthyroidism according to patients' age and gender as well as severity and type of hyperthyroidism.

DESIGN, PARTICIPANTS AND SETTING

This was a cross-sectional study of 3049 consecutive patients with hyperthyroidism presenting to a single secondary/tertiary care clinic.

MAIN OUTCOME MEASURES

Calculation of adjusted odds ratios for presence/absence of symptoms/signs of hyperthyroidism simultaneously analyzing the influence of patients' age/gender, disease etiology/severity, symptom duration, and smoking.

RESULTS

The majority of patients older than 61 yr had two or more symptoms. The lowest proportion of subjects reporting five or more symptoms was found in those older than 61 yr. Increasing age was associated with reduced adjusted odds ratio for the presence of most classical symptoms except for weight loss and shortness of breath, independent of disease severity. Those with more severe hyperthyroidism and smokers had increased odds ratios for most symptoms. Older age, higher serum free T(4) concentrations at diagnosis, male gender, and toxic nodular hyperthyroidism were independently associated with risk of atrial fibrillation. Signs of ophthalmopathy were associated with increasing age, smoking, longer symptom duration, and female gender.

CONCLUSIONS

Classical symptoms and signs of hyperthyroidism are significantly less prevalent in older patients and more prevalent in smokers and subjects with higher free T(4) concentrations. We propose a lower threshold for performing thyroid function tests in patients older than 60 yr, especially in those presenting with atrial fibrillation, weight loss, or shortness of breath.

Lower dose prednisone prevents radioiodine-associated exacerbation of initially mild or absent graves' orbitopathy: a retrospective cohort study

CONTEXT

Radioiodine (RAI) therapy may cause progression of mild or absent Graves' orbitopathy (GO), preventable by oral prednisone. Optimal doses of prednisone are undefined.

OBJECTIVE

The aim of this study was to compare the effectiveness of reported doses [starting dose, >0.3 mg/kg body weight (bw)], and lower (<0.3 mg/kg bw)] doses of prednisone.

DESIGN AND SETTING

We conducted a retrospective matched cohort study at a University Center.

PATIENTS

Of 111 RAI-treated Graves' patients with mild or no GO, 35 received no steroid prophylaxis (absence of GO and/or risk factors for RAI-associated GO progression); 28 received low-dose prednisone (starting dose, 0.16-0.27 mg/kg bw; mean +/- sd, 0.22 +/- 0.03 mg/kg bw; group 1); and 48 received higher doses (group 2). Among the latter, 28 (starting dose, 0.32-0.56 mg/kg bw; mean +/- sd, 0.36 +/- 0.05 mg/kg bw) were matched with group 1 according to several relevant variables. Prednisone was started 1 d after RAI and withdrawn after 6 wk.

MAIN OUTCOME MEASURES

We assessed ocular changes (1, 3, and 6 months after RAI) and side effects of prednisone.

RESULTS

Two of 35 patients not receiving steroid prophylaxis (6%) developed mild-to-moderate GO (clinical activity score, 2/7 and 3/7) after RAI. No patients in group 1 or group 2 had GO progression. Side effects were very mild and inconstant, although more frequent in group 2. Both groups showed an increase in bw, an increase that was significantly higher in group 2.

CONCLUSION

Lower doses of oral prednisone (about 0.2 mg/kg bw) are as effective as previously reported doses (0.3-0.5 mg/kg bw). A shorter treatment period (6 wk) is probably sufficient. The increase in bw is less using lower doses of prednisone.

Current and emerging treatment options for Graves' hyperthyroidism

Radioiodine, antithyroid drugs and surgery have been well established therapies for Graves' hyperthyroidism for several decades. However there remain large variations in practice among physicians in the preferred modality and the method of administration. Patient choice and perceptions also play a big role in the choice of treatment. Radioiodine may be given using fixed high doses or by calculated doses following uptake studies. The risks of radioiodine including eye disease and the role of prophylactic steroid therapy are discussed. The commonly used antithyroid drugs include carbimazole, methimazole and propylthiouracil; however a number of other agents have been tried in special situations or in combination with these drugs. The antithyroid drugs may be given in high (using additional levothyroxine in a block-replace regimen) or low doses (in a titration regimen). This review examines the current evidence and relative benefits for these options as well as looking at emerging therapies including immunomodulatory treatments such as rituximab which have come into early clinical trials. The use of antithyroid therapies in special situations is also discussed as well as clinical practice issues which may influence the choices.

The patient experience of services for thyroid eye disease in the United Kingdom: results of a nationwide survey

BACKGROUND

A recent consensus statement from the European Group on Graves' Orbitopathy recommends referring all patients with thyroid eye disease (TED), except the mildest cases, to a specialist multidisciplinary clinic.

OBJECTIVE

To study the patients' experiences of accessing services for the treatment of TED in the UK.

METHODS

A postal questionnaire survey of 395 members of two patients support organisations for TED in the UK, the TED Charitable Trust and the British Thyroid Foundation.

RESULTS

The response rate was 67%. The majority of responders were females (91%) and aged above 45 (74%). There were delays in the diagnosis and referral. In 26% of responders, the time lapsed from the first symptoms to the diagnosis of TED for over 12 months. There was a wide variation in the type of clinic and healthcare professionals involved in the treatment of TED. Only 25% of the responders attended a specialist TED clinic. Out of these, 33% waited over 6 months from the first consultation with a doctor to being seen at a specialist TED clinic. Only 56% of responders were satisfied with the treatment they received for TED. More responders who had attended a specialist TED clinic were satisfied with the treatment than those who had not attended a specialist clinic (67 vs 52%, P<0.05).

CONCLUSION

Only a minority of patients with TED are treated at a specialist TED clinic in the UK. Those patients who are treated at a specialist TED clinic are more likely to be satisfied with the treatment.

Prediction of cure and risk of hypothyroidism in patients receiving 131I for hyperthyroidism

CONTEXT

There is little consensus regarding the most appropriate dose of radioiodine ((131)I) to be administered to patients with hyperthyroidism.

OBJECTIVE

To compare the efficacy of fixed dose regimens of (131)I in curing hyperthyroidism and to define simple clinical and biochemical factors that predict outcome in individual patients.

DESIGN

Consecutive series of hyperthyroid subjects treated with (131)I.

SETTING

Single Secondary/Tertiary Care Hospital Clinic.

PARTICIPANTS

A total of 1278 patients (1013 females and 262 males, mean age 49.7 years) presenting with hyperthyroidism between 1984 and 2006.

INTERVENTION

Treatment with (131)I using a fixed dose regimen.

MAIN OUTCOME MEASURES

Probability of cure and risk of development of hypothyroidism following a single dose of (131)I.

RESULTS

Patients given a single dose of (131)I of 600 MBq (n = 485) had a higher cure rate (84.1%) compared with those receiving either 370 MBq (74.9%, P < 0.001) or those given 185 Bq (63%, P < 0.001). An increased incidence of hypothyroidism by 1 year was evident with higher doses (600 MBq: 60.4%; 370 MBq: 49.2%, P = 0.001; 185 Bq: 38.1%, P < 0.001). Binary logistic regression analysis identified a 600 Bq dose of (131)I [adjusted odds ratio, AOR 3.33 (2.28-4.85), P < 0.001], female gender [AOR 1.75 (1.23-2.47), P = 0.002], lower presenting serum free T4 concentration [AOR 1.01 (1.01-1.02), P < 0.001] and absence of a palpable goitre [AOR 3.33 (2.00-5.56), P < 0.001] to be independent predictors of cure. Similarly, a 600 MBq dose [AOR 3.79 (2.66-5.38), P < 0.001], female gender [AOR 1.46 (1.05-2.02), P = 0.02], younger age [AOR 1.03 (1.02-1.04), P < 0.001], absence of a palpable goitre [AOR 3.85 (2.38-5.88), P < 0.001] and presence of ophthalmopathy [AOR 1.57 (1.06-2.31), P = 0.02] were identified as independent factors predicting the probability of development of hypothyroidism at one year. Based on these findings, formulae to indicate probability of cure and risk of hypothyroidism for application to individual patients were derived.

CONCLUSIONS

Simple clinical/biochemical criteria can be used to predict outcome after (131)I treatment. These factors determine that males, those with severe biochemical hyperthyroidism, and those with a palpable goitre require larger doses (600 MBq) in order to achieve cure.