Mortality after the treatment of hyperthyroidism with radioactive iodine

Visceral Fat Area and Subcutaneous Fat Area Increase in Hyperthyroidism Patients After Treatment-A Single-Group Repeated-Measures Trial

Purpose

There is evidence that long-term vascular risk remains increased in patients with hyperthyroidism even after normalization of thyroid function, and the mechanisms that regulate this risk are unclear. The aim of this study was to assess how visceral fat area and subcutaneous fat area change after hyperthyroidism treatment, and to further explore the relationship between thyroid hormones, abdominal fat area (visceral fat area and subcutaneous fat area), and lipids.

Patients and Methods

50 patients with newly diagnosed Graves' disease were selected. Anthropometric parameters (weight, height, body mass index, waist circumference, neck circumference), laboratory parameters (thyroid hormones, lipid metabolism indices), abdominal fat area (visceral fat area and subcutaneous fat area), and drug dose were collected. Measurements were made at baseline, 6 and 12 months after treatment. We used linear mixed-effects models for analysis.

Results

The results showed that the following indexes changed significantly at different time points: visceral fat area, subcutaneous fat area, free triiodothyronine, free thyroxine, thyroid stimulating hormone, total cholesterol, high-density lipoprotein, low-density lipoprotein, body weight, neck circumference, body mass index, waist circumference, and drug dose (All P<0.001). We found that free triiodothyronine and free thyroxine were significantly negatively associated with abdominal fat area (P<0.01). There was no significant correlation between drug dose and abdominal fat area (P>0.05). Total cholesterol and low-density lipoprotein were significantly positively associated with abdominal fat area (P<0.01). However, high-density lipoprotein (P=0.06) was not correlated with abdominal fat area. Moreover, the results showed a significant negative correlation between thyroid hormones and lipids (P<0.001).

Conclusion

After anti-thyroid medicine treatment, patients had elevated visceral fat area and subcutaneous fat area and altered lipid profiles. These changes may be one of the reasons why metabolic and cardiovascular diseases remain increased after thyroid function is restored.

Association between thyroid cancer and cardiovascular disease: A meta-analysis

Objective

To determine the association between thyroid cancer and coronary artery disease, atrial fibrillation, cerebrovascular disease, and cardiovascular disease mortality.

Methods

The PubMed, Embase, and Cochrane Library databases were searched for eligible studies from inception to September 22, 2022. Keywords included "thyroid cancer", "atrial fibrillation", "coronary artery disease", "cerebrovascular disease", and "mortality". Primary outcomes included the incidence of coronary artery disease, cerebrovascular disease, atrial fibrillation, and cardiovascular disease mortality among patients with thyroid cancer. Secondary outcomes included cardiovascular disease events among those with thyroid cancer that received or did not receive radioactive iodine or lenvatinib. Estimates were pooled using fixed- and random-effects meta-analysis.

Results

A total of 771,220 patients who underwent thyroidectomy in 15 studies were included. Risk for cerebrovascular disease (risk ratio [RR] 1.15 [95% confidence interval (CI) 1.10-1.21]) and atrial fibrillation [RR 1.59 (95% CI: 1.45-1.73)] were significantly increased. Risk for coronary artery disease was significantly increased [RR 1.12 (95% CI: 1.08-1.17)] in the common effect model. Cardiovascular disease mortality associated with thyroid cancer was not significant [RR 0.93 (95% CI: 0.59-1.45)]. Radioactive iodine had a neutral effect on cardiovascular disease [RR 1.00 (95% CI: 0.87-1.16)], and there was no beneficial nor harmful effect among different RAI doses.

Conclusions

Thyroid cancer was significantly associated with a higher risk for cerebrovascular disease and atrial fibrillation; however, the hazard risk was not different between patients with and without radioactive iodine treatment. Thyroid cancer treatment should be individualized considering the potential harms and benefits to cardiovascular health.

Cardiovascular and Neuronal Consequences of Thyroid Hormones Alterations in the Ischemic Stroke

Ischemic stroke is one of the leading global causes of neurological morbidity and decease. Its etiology depends on multiple events such as cardiac embolism, brain capillaries occlusion and atherosclerosis, which ultimately culminate in blood flow interruption, incurring hypoxia and nutrient deprivation. Thyroid hormones (THs) are pleiotropic modulators of several metabolic pathways, and critically influence different aspects of tissues development. The brain is a key TH target tissue and both hypo- and hyperthyroidism, during embryonic and adult life, are associated with deranged neuronal formation and cognitive functions. Accordingly, increasing pieces of evidence are drawing attention on the consistent relationship between the THs status and the acute cerebral and cardiac diseases. However, the concrete contribution of THs systemic or local alteration to the pathology outcome still needs to be fully addressed. In this review, we aim to summarize the multiple influences that THs exert on the brain and heart patho-physiology, to deepen the reasons for the harmful effects of hypo- and hyperthyroidism on these organs and to provide insights on the intricate relationship between the THs variations and the pathological alterations that take place after the ischemic injury.

Approach to the Patient: Management and the Long-term Consequences of Graves' Disease in Children

In children, Graves' disease (GD) is the most common cause of hyperthyroidism. Most pediatric patients with GD will not go into lasting remission, even following many years of antidrug therapy. Thus, most pediatric patients will require radioactive iodine (RAI) or surgery. When antithyroid drugs are used, methimazole is the drug of choice. When methimazole is used in children, up to 20% will have minor adverse reactions and serious adverse events occur in up to 1%. RAI is an effective form of therapy when the thyroid size is less than 80 g. Because of concerns of whole-body radiation exposure, it is recommended that RAI be avoided in children under 5 years of age, and dosages less than 10 mCi be used between 5 and 10 years of age. Surgery is an effective treatment in children if performed by a high-volume thyroid surgeon. Because of the scarcity of high-volume pediatric thyroid surgeons, a multidisciplinary approach using pediatric surgeons and endocrine surgeons can be considered. Whereas there is a trend toward long-term antithyroid drug therapy in adults, for several reasons, this approach may not be practical for children. Determining the optimal treatment for the pediatric patient with GD, requires consideration of the risks and benefits relating to age and likelihood of remission.

Management of Graves' hyperthyroidism: present and future

INTRODUCTION

Graves' disease (GD) is an autoimmune disorder due to loss of tolerance to the thyrotropin receptor (TSHR) and ultimately caused by stimulatory TSHR antibodies (TSHR-Ab). GD may be associated with extrathyroidal manifestations, mainly Graves' orbitopathy. Treatment of GD relies on antithyroid drugs (ATDs), radioactive iodine (RAI), thyroidectomy. The major ATD limitation is the high recurrence rate after treatment. The major drawback of RAI and thyroidectomy is the inevitable development of permanent hypothyroidism.

AREAS COVERED

Original articles, clinical trials, systematic reviews, meta-analyses from 1980 to 2021 were searched using the following terms: Graves' disease, management of Graves' disease, antithyroid drugs, radioactive iodine, thyroidectomy, Graves' orbitopathy, thyroid-eye disease.

EXPERT OPINION

ATDs are the first-line treatment worldwide, are overall safe and usually given for 18-24 months, long-term treatment may decrease relapses. RAI is safe, although associated with a low risk of GO progression, particularly in smokers. Thyroidectomy requires skilled and high-volume surgeons. Patients play a central role in the choice of treatment within a shared decision-making process. Results from targeted therapies acting on different steps of the autoimmune process, including iscalimab, ATX-GD-59, rituximab, blocking TSHR-Ab, small molecules acting as antagonists of the TSHR, are preliminary or preclinical, but promising in medium-to-long perspective.

Immobile crystallization of radioactive iodide by redox transformation of a low crystalline copper phase

Here we show an innovative way to effectively scavenge highly mobile radioiodide and to dramatically reduce its waste volume through a spontaneous phase transformation. Under an anaerobic condition, as metallic copper (II) was favorably associated with bicarbonate (HCO₃^-) in solution, a cupriferous carbonate compound (malachite) quickly formed, which was redox-sensitive and transformable to a compact crystal of CuI (marshite). The formation of CuI crystal was principally led by the spontaneous Cu-I redox reaction centering around the copper phase over the presence of sulfate (SO₄^2-). The completely transformed CuI crystal was poorly soluble in water and grew to large microcrystals (∼μm) via a remarkable selectivity for I^-. Interestingly, this redox-induced iodide crystallization was rather promoted over the existence of anionic competitors (e.g., HCO₃^- and SO₄^2-), which usually exist in wastewater and natural water. Unlike the conventional methods, these competing anions positively behaved in our system by supporting that the initial malachite was more apt to be reactive to largely attract highly mobile I^-. Under practical environments with various anions, such a selective I^- uptake and fixation within a compact crystalline space will be a promising way to effectively remove I^- in a great capacity.

Mortality Risk After Radioiodine Therapy for Hyperthyroidism: A Systematic Review and Meta-Analysis

OBJECTIVE

Radioiodine has been increasingly used to treat hyperthyroidism for many years. Although widely regarded as an effective therapy, radioiodine treatment for hyperthyroidism has been suspected to be associated with the risk of mortality. This study aimed to quantify the mortality outcomes in patients who were treated for hyperthyroidism with radioiodine.

METHODS

Systematic search and meta-analysis were performed to determine the risk of mortality in patients treated with radioiodine for hyperthyroidism. Relevant studies were searched through August 2020 and selected in accordance with the inclusion criteria.

RESULTS

A total of 13 studies were identified. The summary odds ratios (ORs) showed an increased risk of all-cause mortality in patients who were treated with radioiodine for hyperthyroidism (OR = 1.20; 95% CI = 1.07-1.35). The risk of death attributed to all forms of circulatory, respiratory, and endocrine and metabolic diseases was significantly increased, with summary ORs of 1.23 (95% CI, 1.12-1.35), 1.43 (95% CI, 1.17-1.75), and 2.38 (95% CI, 1.85-3.06), respectively. The summary ORs revealed no significant association between radioiodine treatment for hyperthyroidism and the risk of cancer mortality (OR = 1.03; 95% CI, 0.98-1.09). Radioiodine treatment for hyperthyroidism was not associated with the risk of mortality from breast, respiratory system, gastrointestinal, and genitourinary cancers.

CONCLUSION

Radioiodine treatment for hyperthyroidism is associated with the risk of all-cause mortality but not cancer mortality. Future research needs to address the causes of hyperthyroidism, effects of radioiodine therapy, and potential effects of confounding to identify causality.

The Association of Overt and Subclinical Hyperthyroidism with the Risk of Cardiovascular Events and Cardiovascular Mortality: Meta-Analysis and Systematic Review of Cohort Studies

BACKGROUND

Whether hyperthyroidism is an independent risk factor for cardiovascular events remains controversial. We aimed to evaluate the association of overt and subclinical hyperthyroidism with the risk of ischemic heart disease (IHD), stroke, heart failure, and cardiovascular mortality.

METHODS

Studies regarding the association between hyperthyroidism and cardiovascular events were searched on PubMed and Embase databases. The cardiovascular disease (CVD) risk was classified as high and low, based on pre-existing diseases, including history of coronary, cerebral, or peripheral artery disease; heart failure; atrial fibrillation; diabetes mellitus; or chronic kidney disease.

RESULTS

Thirty-seven cohort studies were included in this meta-analysis. The pooled hazard ratio for subjects with overt hyperthyroidism compared with the control group was 1.11 (95% confidence interval [CI], 1.03 to 1.19) for IHD, 1.35 (95% CI, 1.03 to 1.75) for stroke, and 1.20 (95% CI, 1.00 to 1.46) for cardiovascular mortality. For subjects with subclinical hyperthyroidism, the pooled hazard ratio was 1.24 (95% CI, 1.07 to 1.45) for IHD, when compared with the control group. Subgroup analysis by CVD risk showed that the risk of stroke in overt hyperthyroidism was increased in the low CVD risk group; however, these association was not observed in the high CVD risk group. Similarly, the risk of IHD in subjects with subclinical hyperthyroidism was significantly increased in the low CVD risk group.

CONCLUSION

Overt hyperthyroidism is associated with increased risk of IHD, stroke, and cardiovascular mortality, and subclinical hyperthyroidism is associated with increased risk of IHD. These associations were particularly observed in the low risk CVD group without underlying CVD.

Effects of radioactive iodine treatment on cardiovascular disease in thyroid cancer patients: a nationwide cohort study

Background

Radioactive iodine (RAI) treatment is a standard treatment in differentiated thyroid cancer (TC). However, its adverse effects on cardiovascular diseases (CVDs) have not been clearly elucidated.

Methods

In this retrospective cohort study based on the Korean National Health Insurance Service-National Health Screening Cohort (2002–2015), we analyzed 4,845 patients with TC with a median follow-up of 66 months. We evaluated and compared the risk of CVD between patients treated with and without RAI therapy. The primary CVD outcome was defined as a composite of ischemic stroke (IS), ischemic heart disease (IHD), hemorrhagic stroke (HS), or heart failure (HF).

Results

Overall, 2,533 patients (52.3%) received RAI treatment with a median cumulative dosage of 103 mCi [interquartile range (IQR), 40–162 mCi]. The incidence of the primary CVD outcome in patients who did not receive RAI therapy and those who did was 17.32 [95% confidence interval (CI), 15.07–19.90] and 13.96 (95% CI, 12.17–16.01) per 1,000 person-years, respectively, indicating an adjusted hazard ratio (HR) of 0.87 (95% CI, 0.71–1.07) after multivariate adjustments for variable confounding factors. The risks of IS (HR, 0.83; 95% CI, 0.51–1.34), IHD (HR, 0.90; 95% CI, 0.71–1.13), HS (HR 1.01; 95% CI, 0.49–2.09), and HF (HR 0.89; 95% CI, 0.49–1.63) were comparable between the patients who received RAI therapy and those who did not. There was no cumulative dose-dependent risk for CVD in TC patients who received RAI treatment.

Conclusions

RAI treatment is a prevalent and crucial treatment for TC, and has been used in more than half of TC patients in Korea from 2004 to 2015. This study found no significant between-group difference for the CVD risk in patients with TC who received RAI treatment and those who did not, giving further evidence to allay concerns related to the adverse effects of RAI.

Cancer incidence and mortality following treatment of hyperthyroidism with radioactive iodine

PURPOSE OF REVIEW

Hyperthyroidism is a commonly encountered clinical issue. Radioactive iodine is one of the treatment modalities employed over the last 80 years. Prior studies are conflicting as to whether radioactive iodine is associated with an increased risk of subsequent malignancy and associated mortality. The present article reviews recent publications on this subject.

RECENT FINDINGS

Two recent studies make meaningful contributions to the existing literature; however, data remain inconsistent. The first, conducted using the Clalit Health Services database, evaluated solid tumor incidence after radioactive iodine and found no association with increased risk of solid tumor malignancy. The second, which is an updated analysis of the Cooperative Thyrotoxicosis Therapy Follow-up Study, concluded that there is a dose-dependent increased risk of solid tumor mortality using a novel method of estimating organ-specific radiation exposure.

SUMMARY

In patients with hyperthyroidism, radioactive iodine is a popular and effective treatment option. Prior studies reach conflicting conclusions on the potential relationship between radioactive iodine and both subsequent cancer incidence and mortality. We review recent publications that add to our understanding of this important clinical question.

Cardiovascular Outcomes of Thyroidectomy or Radioactive Iodine Ablation for Graves' Disease

BACKGROUND

Treatment options for Graves' disease (GD) include medical management with antithyroid medications, radioactive iodine (RAI) ablation, or total thyroidectomy (TT). Definitive treatment with RAI ablation may be associated with worse cardiovascular morbidity and mortality than TT. We sought to determine the rate of cardiovascular morbidity before and after definitive treatment for GD.

METHODS

This study is a retrospective single-institution study of sequential adult patients with GD from 2012 to 2018 treated with RAI ablation or TT. Patients with prior thyroid surgery or RAI ablation with subsequent thyroidectomy were excluded. Demographic and clinical variables were collected from diagnosis of GD to last follow-up. Data analysis was performed with descriptive statistics, univariate analysis with Fisher's exact test for categorical variables and the Mann-Whitney U test for continuous variables.

RESULTS

One-hundred and eighty-four patients underwent definitive treatment for GD during the study period, of which 164 met inclusion criteria. One hundred and ten patients (67%) in the study group had TT and 54 (33%) had RAI ablation with a mean dose of 18.4 mCi (standard deviation 6.1). There were no differences in clinical or demographic factors in patients undergoing RAI ablation versus TT for definitive treatment including age, sex, thyroid-stimulating hormone level, free thyroxine level, or thyroid-stimulating immunoglobulin level at time of diagnosis, nor was there any difference in pretreatment cardiovascular comorbidity. Patients with TT had higher rates of resolution of arrhythmia after treatment than those undergoing RAI ablation, P = 0.02. There were no differences in treatment-related complications between the groups.

CONCLUSIONS

For patients undergoing definitive treatment for GD, TT is associated with improved rate of resolution of cardiac arrhythmia compared with RAI ablation.

Comparison of 24-Hour Electrocardiogram Parameters in Patients with Graves' Disease Before and After Anti-Thyroid Therapy

BACKGROUND

We aimed prospectively to investigate the laboratory and electrocardiographic parameters (heart rate, QRS, QT, QTc, Tpe, Tpe/QTc, and arrhythmia prevalence) in patients with Graves' disease before and after antithyroid therapy.

METHODS

Seventy-one patients (48 female, and 23 male), of age between 18-50 years (mean±SD: 36.48±12.20) with GD were included in the study. Patients were treated with antithyroid therapy (thioamides and/or surgical therapy) to maintain euthyroid status. Patients were examined in terms of electrocardiographic parameters before and after the treatment.

RESULTS

Mean TSH, free thyroxin (fT4), and tri-iodothyrionine (fT₃) levels of all patients were 0.005±0.21, 3.27± 1.81, 11.42±7.44, respectively. While 9 patients (group 2) underwent surgical therapy, had suspicious malignant nodule or large goiter, and unresponsiveness to medical treatment; the other patients (n=62, group 1) were treated with medical therapy. Patients with surgical therapy had more increased serum fT4 (p=0.045), anti-thyroglobulin value (p=0.018) and more severe graves orbitopathy (n=0.051) before treatment when compared to a medical therapy group. Baseline Tpe duration and baseline Tpe/QTc ratio and frequency of supraventricular ectopic beats were found to be significantly higher in group 2 when compared to group 1 (p=0.00, p=0.005). Otherwise, the baseline mean heart rate, QRS duration, QTc values of both groups were similar. Although the patients came at their euthyroid status, group 2 patients still suffered from more sustained supraventricular ectopics beats than group 1.

CONCLUSION

Distinct from the medical treatment group, surgical treatment group with euthyroidism for at least 3 months still suffered from an arrhythmia (Tpe, Tpe/QTc, supraventricular and ventricular ectopic beats).

Incidence and Mortality of Myocardial Infarction and Stroke in Patients with Hyperthyroidism: A Nationwide Cohort Study in Korea

Background: Hyperthyroidism is associated with various cardiovascular risk factors. However, the relationship between hyperthyroidism and myocardial infarction (MI) or stroke has not been fully elucidated; only a few studies have investigated the association of hyperthyroidism with survival after MI or stroke. Methods: We included 59,021 hyperthyroid patients and a control cohort with 1,180,420 age- and sex-matched subjects from the Korean National Health Insurance database. Blood pressure, body mass index (BMI), glucose and cholesterol levels, and smoking history were obtained during National Health screening examination. We compared the incidence of MI, stroke, and survival after cardiovascular events between subjects with hyperthyroidism and the control cohort. Results: Subjects with hyperthyroidism had higher blood pressure, fasting glucose, and smoking rate, but lower cholesterol levels and a lower obesity rate compared with the control cohort. After adjusting these differences, as well as atrial fibrillation, hyperthyroidism was associated with increased risk of MI and ischemic stroke. Adjusted hazard ratios (HRs) for MI and ischemic stroke with hyperthyroidism was 1.16 [95% confidence interval, CI 1.03-1.30] and 1.12 [CI 1.04-1.20], respectively. In age-, sex-, and BMI-stratified analyses, an increased risk of MI and ischemic stroke remained significant in females, the older age group (≥50 years), and nonobese subjects (BMI <25 kg/m²), but not in males, the younger age group (<50 years), and obese subjects (BMI ≥25 kg/m²). The risk of hemorrhagic stroke was not different between subjects with hyperthyroidism and controls. Adjusted HRs for mortality in subjects with hyperthyroidism who developed MI, ischemic stroke, and hemorrhagic stroke were 1.11 ([CI 0.86-1.43], p = 0.44), 0.89 ([CI 0.75-1.05], p = 0.16), and 1.13 ([CI 0.88-1.47], p = 0.34), respectively. Conclusions: Hyperthyroidism is associated with increased risk of MI and ischemic stroke, independent of cardiovascular risk factors. This association is prominent in subjects with age ≥50 years, in females, and in the nonobese group. Hyperthyroidism did not significantly affect the mortality secondary to cardiovascular events.

Arterial Stiffness and Blood Pressure in Patients Newly Diagnosed with Graves' Disease Compared with Euthyroid Controls

INTRODUCTION AND OBJECTIVE

The excess cardiovascular morbidity and mortality in hyperthyroidism and Graves' disease (GD) is inadequately understood. We aimed to elucidate whether well-established cardiovascular risk factors such as arterial stiffness in terms of pulse wave velocity (PWV) and blood pressure differ in GD and controls.

METHODS

This was a cross-sectional study comparing 55 hyperthyroid patients with newly diagnosed GD and 55 euthyroid, population-based controls matched for age, sex and menopausal status. PWV and blood pressure were measured in office (SphygmoCor Xcel) and 24-h ambulatory settings (Arteriograph). Differences between groups were assessed using adjusted linear regression analysis.

RESULTS

Compared to controls, GD patients showed higher PWV in the 24-h but not in the office setting with an adjusted 24-h PWV difference of 1.0 (95% CI: 0.6-1.5) m/s. PWV was higher in GD at both day and night, and nightly PWV dipping was lower (-5.5, 95% CI: -10.4 to -0.6%). Furthermore, central and brachial pulse pressure was significantly higher in both the office and 24-h setting, whereas nightly central pulse pressure dipping was significantly lower in GD (-5.4, 95% CI: -10.5 to -0.2%). Mean arterial pressure did not differ between the groups.

CONCLUSIONS

Despite comparable blood pressure, GD is associated with a higher 24-h PWV that was not detected in the office setting. Pulse pressure was higher in GD, whereas mean arterial pressure did not differ between the groups. Longitudinal studies should pursue whether higher PWV might be a piece to the puzzle of understanding the increased risk of cardiovascular disease in hyperthyroidism and GD.

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.

Should radioiodine now be first line treatment for Graves' disease?

Background

Radioiodine represents a cost-effective treatment option for Graves’ disease. In the UK, it is traditionally reserved for patients who relapse after initial thionamide therapy. In a change from current practice, the new guidelines of the National Institute for Health and Care Excellence (NICE) recommends that radioiodine should now be first line therapy for Graves’ disease. However, the safety of radioiodine with respect to long-term mortality risk has been the subject of recent debate. This analysis examines evidence from treatment related mortality studies in hyperthyroidism and discusses their implications for future Graves’ disease treatment strategies.

Main body

Some studies have suggested an excess mortality in radioiodine treated cohorts compared to the background population. In particular, a recent observational study reported a modest increase in cancer-related mortality in hyperthyroid patients exposed to radioiodine. The interpretation of these studies is however constrained by study designs that lacked thionamide control groups or information on thyroid status and so could not distinguish the effect of treatment from disease. Two studies have shown survival advantages of radioiodine over thionamide therapy, but these benefits were only seen when radioiodine was successful in controlling hyperthyroidism. Notably, increased mortality was associated with uncontrolled hyperthyroidism irrespective of therapy modality.

Conclusions

Early radioiodine treatment will potentially reduce mortality and should be offered to patients with severe disease. However, thionamides are still suitable for patients with milder disease, contraindications to radioiodine, or individuals who choose to avoid permanent hypothyroidism. Ultimately, a patient individualised approach that prioritises early and sustained control of hyperthyroidism will improve long-term outcomes regardless of the therapy modality used.

Primary therapy of Graves' disease and cardiovascular morbidity and mortality: a linked-record cohort study

BACKGROUND

Graves' disease is routinely treated with antithyroid drugs, radioiodine, or surgery, but whether the choice of initial therapy influences long-term outcomes is uncertain. We evaluated cardiovascular morbidity and mortality according to the method and effectiveness of primary therapy in Graves' disease.

METHODS

In this retrospective cohort study, we identified patients with hyperthyroidism, diagnosed between Jan 1, 1998, and Dec 31, 2013, from a thyroid-stimulating hormone (TSH)-receptor antibody (TRAb) test register in south Wales, UK, and imported their clinical data into the All-Wales Secure Anonymised Information Linkage (SAIL) Databank (Swansea University, Swansea, UK). Patients with Graves' disease, defined by positive TRAb tests, were selected for the study, and their clinical data were linked with outcomes in SAIL. We had no exclusion criteria. Patients were matched by age and sex to a control population (1:4) in the SAIL database. Patients were grouped by treatment within 1 year of diagnosis into the antithyroid drug group, radioiodine with resolved hyperthyroidism group (radioiodine group A), or radioiodine with unresolved hyperthyroidism group (radioiodine group B). We used landmark Kaplan-Meier and Cox regression models to analyse the association of treatment with the primary outcome of all-cause mortality and the secondary outcome of major adverse cardiovascular events (myocardial infarction, heart failure, ischaemic stroke, or death) with the landmark set at 1 year after diagnosis. We analysed the association between outcomes and concentration of TSH using Cox regression and outcomes and free thyroxine (FT4) concentration using restricted cubic-spline regression models.

FINDINGS

We extracted patient-level data on 4189 patients (3414 [81·5%] females and 775 [18·5%] males) with Graves' disease and 16 756 controls (13 656 [81·5%] females and 3100 [18·5%] males). In landmark analyses, 3587 patients were in the antithyroid drug group, 250 were in radioiodine group A, 182 were in radioiodine group B. Patients had increased all-cause mortality compared with controls (hazard ratio [HR] 1·22, 95% CI 1·05-1·42). Compared with patients in the antithyroid drug group, mortality was lower among those in radioiodine group A (HR 0·50, 95% CI 0·29-0·85), but not for those in radioiodine group B (HR 1·51, 95% CI 0·96-2·37). Persistently low TSH concentrations at 1 year after diagnosis were associated with increased mortality independent of treatment method (HR 1·55, 95% CI 1·08-2·24). Spline regressions showed a positive non-linear relationship between FT4 concentrations at 1 year and all-cause mortality.

INTERPRETATION

Regardless of the method of treatment, early and effective control of hyperthyroidism among patients with Graves' disease is associated with improved survival compared with less effective control. Rapid and sustained control of hyperthyroidism should be prioritised in the management of Graves' disease and early definitive treatment with radioiodine should be offered to patients who are unlikely to achieve remission with antithyroid drugs alone.

FUNDING

National Institute for Social Care and Health Research, Wales.

Impaired Quality of Life After Radioiodine Therapy Compared to Antithyroid Drugs or Surgical Treatment for Graves' Hyperthyroidism: A Long-Term Follow-Up with the Thyroid-Related Patient-Reported Outcome Questionnaire and 36-Item Short Form Health Status Survey

BACKGROUND

Hyperthyroidism is known to have a significant impact on quality of life (QoL), at least in the short term. The purpose of the present study was to assess QoL in patients 6-10 years after treatment for Graves' disease (GD) with radioiodine (RAI) compared to those treated with thyroidectomy or antithyroid drugs (ATD) as assessed with both thyroid-specific Thyroid-Related Patient-Reported Outcome (ThyPRO) questionnaire and general (36-item Short Form Health Status) QoL survey.

METHODS

The study evaluated 1186 GD patients in a sub-cohort from an incidence study 2003-2005 who had been treated according to routine clinical practice at seven participating centers. Patients were included if they had returned the ThyPRO (n = 975) and/or the 36-item Short Form Health Status survey questionnaire (n = 964) and informed consent at follow-up. Scores from ThyPRO were compared to scores from a general population sample (n = 712) using multiple linear regression adjusting for age and sex as well as multiple testing. Treatment-related QoL outcome for ATD, RAI, and surgery were compared, including adjustment for the number of treatments received, sex, age, and comorbidity.

RESULTS

Regardless of treatment modality, patients with GD had worse thyroid-related QoL 6-10 years after diagnosis compared to the general population. Patients treated with RAI had worse thyroid-related and general QoL than patients treated with ATD or thyroidectomy on the majority of QoL scales. Sensitivity analyses supported the relative negative comparative effects of RAI treatment on QoL in patients with hyperthyroidism.

CONCLUSIONS

GD is associated with a lower QoL many years after treatment compared to the general population. In a previous small randomized controlled trial, no difference was found in patient satisfaction years after ATD, RAI, or surgery. Now, it is reported that in a large non-randomized cohort, patients who received RAI had adverse scores on ThyPRO and 36-item Short Form Health Status survey. These findings in a Swedish population are limited by comparison to normative data from Denmark, older age, and possibly a more prolonged course in those patients who received RAI, and a lack of information regarding thyroid status at the time of evaluation. The way RAI may adversely affect QoL is unknown, but since the results may be important for future considerations regarding treatment options for GD, they need to be substantiated in further studies.

Effects of thyrotropin suppression on lumbar bone mineral density in postmenopausal women with differentiated thyroid carcinoma

Purpose

The aim of this study was to evaluate the effect of postoperative thyroid-stimulating hormone suppression (TSHS) on bone mineral density (BMD) in Chinese postmenopausal women with differentiated thyroid carcinoma (DTC).

Patients and methods

A total of 225 postmenopausal women with DTC who had received TSHS were included in the study. Postmenopausal women with postoperative DTC undergoing thyroid residual ablation or metastasis treatment between 2009 and 2015 were enrolled and followed up for 2 years. They were divided into two groups: TSHS group (median thyroid-stimulating hormone [TSH] <0.3 μIU/mL) and postmenopausal control group (median TSH >0.3 μIU/mL). Lumbar 1–4 BMD levels were measured by a dual-energy X-ray absorptiometry (DXA) at baseline and 6, 12 and 24 months. All patients had calcium and vitamin D supplementation. The diagnosis of osteopenia (−1 SD > T >−2.5 SD) and osteoporosis (T <−2.5 SD) was made according to WHO guidelines.

Results

Thyroid cancers included 211 papillary carcinomas and 14 follicular carcinomas. One hundred and fifty-four patients were in the TSHS group, and 71 patients were in the non-suppressed TSH group (postmenopausal controls). No significant differences were found in the BMD of the lumbar spine between baseline and after 6, 12 and 24 months, pre and post treatment in TSHS and non-suppressed TSH patients. Compared with pre-TSHS, there was a reduction in the BMD of 1.9% in the lumbar spine at the 2-year follow-up. Significant difference in the number of osteopenia and osteoporosis patients at 24 months (χ²=2.88, P=0.004) was found between the TSHS (103/152) and postmenopausal control (32/68) groups. TSHS is not a significant risk of bone loss, but it is the incidence of osteopenia in postmenopausal women with DTC.

Conclusion

Our 2-year follow-up data indicated that TSHS had little effect on BMD in postmenopausal women with DTC. Large population with at least 5-year follow-up should be further investigated. BMD in postmenopausal women with DTC should be followed up regularly.

Cardiovascular Morbidity and Mortality After Treatment of Hyperthyroidism with Either Radioactive Iodine or Thyroidectomy

BACKGROUND

Hyperthyroid patients remain at an increased risk of cardiovascular diseases (CVDs) after restoring euthyroidism. The impact of the different treatment modalities of hyperthyroidism on future CVD risk remains unclear. The aims of this study were to assess cardiovascular morbidity and mortality in hyperthyroidism before and after treatment, and to compare the effects of two different treatment modalities: radioactive iodine (RAI) and thyroid surgery.

METHODS

A comparative cohort study was conducted among 6148 hyperthyroid patients treated with either RAI or thyroidectomy and 18,432 age- and sex-matched controls. First, hospitalizations due to CVDs prior to the treatment were analyzed. Second, the hazard ratios (HR) for any new hospitalization and mortality due to CVDs after treatment were estimated among all the hyperthyroid patients compared to the age- and sex-matched controls and also in the RAI-treated patients compared to the thyroidectomy-treated patients. The results were adjusted for prevalent CVDs at the time of treatment.

RESULTS

Before treatment for hyperthyroidism, hospitalizations due to all CVDs were more common in the hyperthyroid patients compared to the controls (odds ratio = 1.61 [confidence interval (CI) 1.49-1.73]). During the post-treatment follow-up, hospitalizations due to CVDs remained more frequent among the patients (HR = 1.15 [CI 1.09-1.21]), but there was no difference in CVD mortality (HR = 0.93 [CI 0.84-1.03]). Compared to the patients treated with thyroidectomy, the RAI-treated patients had a higher risk of hospitalization due to all CVDs (HR = 1.17), atrial fibrillation (HR = 1.28), as well as a higher CVD mortality rate (HR = 2.56). Yet, treatment with RAI resulting in hypothyroidism was not associated with increased CVD morbidity compared to thyroidectomy.

CONCLUSIONS

Hyperthyroidism increases the risk of CVD-related hospitalization, and the risk is sustained for up to two decades after treatment with RAI or surgery. Hyperthyroid patients treated with RAI remain at a higher CVD risk compared to patients treated with thyroidectomy. Hypothyroidism during follow-up, however, predicts better cardiovascular outcomes.

Risk Factors for Cardiovascular Disease Among Thyroid Cancer Survivors: Findings From the Utah Cancer Survivors Study

CONTEXT

Thyroid cancer survivors are at high risk of developing multiple cardiac and vascular conditions as consequence of cancer diagnosis and treatment. However, it is still unclear how the baseline and prognostic factors, as well as cancer treatments, play a role in increasing cardiac and vascular disease risk among thyroid cancer survivors.

OBJECTIVE

To investigate the association between potential risk factors, treatment effects, and cardiovascular disease (CVD) outcomes in thyroid cancer survivors.

DESIGN, SETTING, PATIENTS

Primary thyroid cancer survivors, diagnosed from 1997 to 2012 (n = 3822), were identified using the statewide Utah Population Database. The medical records were used to ascertain information on risk factors and CVD outcomes. Cox proportional hazards models were used to assess the risk of CVD with baseline demographic data and clinical factors.

RESULTS

Among thyroid cancer survivors, age and year at cancer diagnosis, cancer stage, sex, baseline body mass index, baseline comorbidities, and TSH suppression therapy were significantly associated with CVD risk 1 to 5 years after cancer diagnosis. Patients who were male, overweight or obese, older at cancer diagnosis, and diagnosed with cancer since 2005 had an increased risk of CVD compared with patients who were female, had a normal body mass index, were younger at cancer diagnosis, and diagnosed with cancer from 1997 to 1999. Administration of TSH suppression therapy, distant metastases at cancer diagnosis, and a higher Charlson comorbidity index score were associated with an increased CVD risk among thyroid cancer survivors.

CONCLUSIONS

Our findings suggest that examining the effect of thyroid cancer diagnosis, cancer treatment, and demographic characteristics on the risk of CVD is critical.

Association between radioiodine treatment for thyroid cancer and risk of stroke

BACKGROUND

The purpose of this study was to evaluate the association between radioiodine (I-131) therapy for thyroid cancer and the risk of stroke in Taiwan.

METHODS

A total of 10 104 of the patients aged 20 years or older, who were newly diagnosed with thyroid cancer during 2000-2010, were recruited and classified into 2 cohorts according to whether they received I-131 therapy through 1:1 propensity score matching. The cumulative Kaplan-Meier curves for the incidence of stroke in the 2 cohorts were compared using the log-rank test.

RESULTS

After adjustment for age, sex, and comorbidities, the I-131 therapy group showed no significantly higher risk of ischemic stroke (adjusted HR [aHR] = 1.05; 95% confidence interval [CI] = 0.82-1.34) or hemorrhagic stroke (aHR = 1.06; 95% CI = 0.58-1.93) than did the non-I-131 therapy group.

CONCLUSION

The I-131 treatment for thyroid cancer did not increase the risk of stroke during 10-year follow-up.

Hyperthyroidism, Hypothyroidism, and Cause-Specific Mortality in a Large Cohort of Women

BACKGROUND

The prevalence of hyperthyroidism and hypothyroidism is 0.5-4% in iodine-replete communities, but it is 5-10 times higher in women than in men. Those conditions are associated with a broad range of metabolic disorders and cardiovascular diseases. Biological evidence of a role of thyroid hormones in carcinogenesis also exists. However, the association between thyroid dysfunction and cardiovascular disease or cancer mortality risk remains controversial. In a large cohort of women, the associations of hyperthyroidism and hypothyroidism with cause-specific mortality were evaluated after nearly 30 years of follow-up.

METHODS

The prospective study included 75,076 women aged 20-89 years who were certified as radiologic technologists in the United States in 1926-1982, completed baseline questionnaires in 1983-1998 from which medical history was ascertained, and reported no malignant disease or benign thyroid disease except thyroid dysfunction. A passive follow-up of this cohort was performed through the Social Security Administration database and the National Death Index-Plus. Cause-specific mortality risks were compared according to self-reported thyroid status, with proportional hazards models adjusted for baseline year and age, race/ethnicity, body mass index, family history of breast cancer, and life-style and reproductive factors.

RESULTS

During a median follow-up of 28 years, 2609 cancer, 1789 cardiovascular or cerebrovascular, and 2442 other non-cancer deaths were recorded. Women with hyperthyroidism had an elevated risk of breast cancer mortality after 60 years of age (hazard ratio [HR] = 2.04 [confidence interval (CI) 1.16-3.60], 13 cases in hyperthyroid women) compared to women without thyroid disease. Hypothyroid women had increased mortality risks for diabetes mellitus (HR = 1.58 [CI 1.03-2.41], 27 cases in hypothyroid women), cardiovascular disease (HR = 1.20 [CI 1.01-1.42], 179 cases), and cerebrovascular disease (HR = 1.45 [CI 1.01-2.08], 35 cases, when restricting the follow-up to ≥10 years after baseline). Other causes of death were not associated with hyperthyroidism or hypothyroidism, though there was a suggestion of an elevated risk of ovarian cancer mortality in hyperthyroid women based on very few cases.

CONCLUSION

The excess mortality risks observed in a large, prospective 30-year follow-up of patients with thyroid dysfunction require confirmation, and, if replicated, further investigation will be needed because of the clinical implications.

Recovery following Thyroxine Treatment Withdrawal, but Not Propylthiouracil, Averts In Vivo and Ex Vivo Thyroxine-Provoked Cardiac Complications in Adult FVB/N Mice

Persistent cardiovascular pathology has been described in hyperthyroid patients even with effective antithyroid treatment. Here, we studied the effect of a well-known antithyroid drug, propylthiouracil (PTU; 20 mg/kg/day), on thyroxine (T4; 500 µg/kg/day)-induced increase in blood pressure (BP), cardiac hypertrophy, and altered responses of the contractile myocardium both in vivo and ex vivo after 2 weeks of treatment. Furthermore, the potential recovery through 2 weeks of T4 treatment discontinuation was also investigated. PTU and T4 recovery partially reduced the T4-prompted increase in BP. Alternatively, PTU significantly improved the in vivo left ventricular (LV) function with no considerable effects on cardiac hypertrophy or ex vivo right ventricular (RV) contractile alterations subsequent to T4 treatment. Conversely, T4 recovery considerably enhanced the T4-provoked cardiac changes both in vivo and ex vivo. Altogether, our data is in agreement with the proposal that hyperthyroidism-induced cardiovascular pathology could persevere even with antithyroid treatments, such as PTU. However, this cannot be generalized and further investigation with different antithyroid treatments should be executed. Moreover, we reveal that recovery following experimental hyperthyroidism could potentially ameliorate cardiac function and decrease the risk for additional cardiac complications, yet, this appears to be model-dependent and should be cautiously construed.

MANAGEMENT OF ENDOCRINE DISEASE: Subclinical thyrotoxicosis: prevalence, causes and choice of therapy

Subclinical thyrotoxicosis is a condition affecting up to 10% of the population in some studies. We have reviewed literature and identified studies describing prevalences, causes and outcomes of this condition. Treatment should be considered in all subjects if this biochemical abnormality is persistent, especially in case of symptoms of thyrotoxicosis or in the presence of any complication. In particular, treatment should be offered in those subclinically thyrotoxic patients with a sustained serum TSH below 0.1 U/L. However it is important to recognise that there are no large controlled intervention studies in the field and thus there is no high quality evidence to guide treatment recommendations. In particular, there is no evidence for therapy and there is weak evidence of harm from thyrotoxicosis if serum TSH is in the 0.1-0.4 IU/L range. In this review, we describe the different causes of subclinical thyrotoxicosis, and how treatment should be tailored to the specific cause. We advocate radioactive iodine treatment to be the first-line treatment in majority of patients suffering from subclinical thyrotoxicosis due to multinodular toxic goitre and solitary toxic adenoma, but we do generally not recommend it as the first-line treatment in patients suffering from subclinical Graves' hyperthyroidism. Such patients may benefit mostly from antithyroid drug therapy. Subclinical thyrotoxicosis in early pregnancy should in general be observed, not treated. Moreover, we advocate a general restriction of therapy in cases where no specific cause for the presumed thyroid hyperactivity has been proven.

Controversies in the management of Graves' disease in children

Graves' disease (GD) is the most prevalent cause of thyrotoxicosis in children. Because spontaneous and lasting resolution of this condition occurs in only a minority of patients, most pediatric patients with GD will need radioactive iodine treatment (¹³¹I) or thyroidectomy. Whereas the medication propylthiouracil (PTU) had been used in the past, only methimazole (MMI) should be now used in children, as PTU is associated with an unacceptable risk of liver failure. However, MMI may be associated minor and major side effects, which may be minimized using lower doses. An area of controversy involves the optimal duration of antithyroid drug (ATD) therapy. For some children, the prolonged use of antithyroid drugs is a valid approach, but for most, this will not increase the chance of remission. When ¹³¹I is administered, dosages should be greater than 150 uCi/gm of thyroid tissue, with higher dosages needed for larger glands. Considering that there will be low-level whole body radiation exposure associated with ¹³¹I, this treatment is viewed as controversial by some and should be avoided in young children. When surgery is performed, near-total or total thyroidectomy is the recommended procedure. Complications for thyroidectomy in children are considerably higher than in adults. Thus, an experienced thyroid surgeon is needed when children have surgery. Overall, when different treatment options for GD are considered, the benefits, risks and viewpoints of the family need to be considered and discussed in full.

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.

2016 American Thyroid Association Guidelines for Diagnosis and Management of Hyperthyroidism and Other Causes of Thyrotoxicosis

BACKGROUND

Thyrotoxicosis has multiple etiologies, manifestations, and potential therapies. Appropriate treatment requires an accurate diagnosis and is influenced by coexisting medical conditions and patient preference. This document describes evidence-based clinical guidelines for the management of thyrotoxicosis that would be useful to generalist and subspecialty physicians and others providing care for patients with this condition.

METHODS

The American Thyroid Association (ATA) previously cosponsored guidelines for the management of thyrotoxicosis that were published in 2011. Considerable new literature has been published since then, and the ATA felt updated evidence-based guidelines were needed. The association assembled a task force of expert clinicians who authored this report. They examined relevant literature using a systematic PubMed search supplemented with additional published materials. An evidence-based medicine approach that incorporated the knowledge and experience of the panel was used to update the 2011 text and recommendations. The strength of the recommendations and the quality of evidence supporting them were rated according to the approach recommended by the Grading of Recommendations, Assessment, Development, and Evaluation Group.

RESULTS

Clinical topics addressed include the initial evaluation and management of thyrotoxicosis; management of Graves' hyperthyroidism using radioactive iodine, antithyroid drugs, or surgery; management of toxic multinodular goiter or toxic adenoma using radioactive iodine or surgery; Graves' disease in children, adolescents, or pregnant patients; subclinical hyperthyroidism; hyperthyroidism in patients with Graves' orbitopathy; and management of other miscellaneous causes of thyrotoxicosis. New paradigms since publication of the 2011 guidelines are presented for the evaluation of the etiology of thyrotoxicosis, the management of Graves' hyperthyroidism with antithyroid drugs, the management of pregnant hyperthyroid patients, and the preparation of patients for thyroid surgery. The sections on less common causes of thyrotoxicosis have been expanded.

CONCLUSIONS

One hundred twenty-four evidence-based recommendations were developed to aid in the care of patients with thyrotoxicosis and to share what the task force believes is current, rational, and optimal medical practice.

Safe disposal of radioactive iodide ions from solutions by Ag2O grafted sodium niobate nanofibers

Radioactive iodine isotopes are released into the environment by the nuclear industry and medical research institutions using radioactive materials, and have negative effects on organisms living within the ecosystem. Thus, safe disposal of radioactive iodine is necessary and crucial. For this reason, the uptake of iodide ions was investigated in Ag2O nanocrystal grafted sodium niobate nanofibers, which were prepared by forming a well-matched phase coherent interface between them. The resulting composite was applied as an efficient adsorbent for I(-) anions by forming an AgI precipitate, which also remained firmly attached to the substrates. Due to their one-dimensional morphology, the new adsorbents can be easily dispersed in liquids and readily separated after purification. This significantly enhances the adsorption efficiency and reduces the separation costs. The change in structure from the pristine sodium niobate to Ag2O anchored sodium niobate and to the used adsorbent was examined by using various characterization techniques. The effects of Ag(+) concentration, pH, equilibration time, ionic strength and competing ions on the iodide ion removal ability of the composite were studied. The Ag2O nanocrystal grafted sodium niobate adsorbent showed a high adsorption capacity and excellent selectivity for I(-) anions in basic solutions. Our results are useful for the further development of improved adsorbents for removing I(-) anions from basic wastewater.

Radioiodine Therapy Does Not Change the Atherosclerotic Burden of the Carotid Arteries

BACKGROUND AND AIM

Atherosclerosis evolves or accelerates when arteries are exposed to ionizing radiation, both early and late after exposure. Radioiodine therapy of benign thyroid disease exposes the carotid arteries to 4-50 Gy, and may thereby increase the risk of atherosclerosis. Increased risk of cerebrovascular events has been reported after radioiodine therapy. This study aimed to examine whether atherosclerosis develops early or late after radioiodine therapy of benign thyroid disease.

METHOD

Patients treated for benign thyroid disorders (nontoxic goiter, adenoma, and hyperthyroidism) were examined with ultrasound for the main outcome, carotid intima media thickness (CIMT), and for plaque presence (plaque presence only in late damage). Signs of early damage from radioiodine were studied in 39 radioiodine-treated patients, who were examined before treatment and at 1, 3, 6, and 12 months after treatment. Late changes were studied in a cross-sectional case-control design, with radioiodine-treated patients as cases (n = 193) and patients treated with surgery as controls (n = 95). Data were analyzed with repeated measurement for longitudinal data, and with multivariate regression for cross-sectional data. Results were adjusted for age, sex, cholesterol, smoking status, known atherosclerotic disease, and body mass index.

RESULTS

No changes in CIMT were found in the patients followed prospectively for one year after treatment with radioactive iodine for benign thyroid disease (p = 0.58). In the study on late effects, there was no difference in CIMT (p = 0.25) or presence of plaques (p = 0.70) between those treated with radioactive iodine and those treated with surgery (9.8 and 5.6 years since treatment, respectively). Furthermore, the level of thyrotropin (TSH) did not influence these atherosclerosis markers.

CONCLUSION

No early changes in CIMT were detected in patients treated with radioactive iodine for benign thyroid disease. No signs of late effects of radioactive iodine on CIMT or plaque presence were found after 10 years of follow-up. The radiation to the carotid arteries by radioactive iodine therapy for benign thyroid disease may therefore have no or low effect on atherosclerotic burden of the carotid arteries in general.

Role of prophylactic central compartment lymph node dissection in clinically N0 differentiated thyroid cancer patients: analysis of risk factors and review of modern trends

In the last years, especially thanks to a large diffusion of ultrasound-guided FNBs, a surprising increased incidence of differentiated thyroid cancer (DTC), "small" tumors and microcarcinomas have been reported in the international series. This led endocrinologists and surgeons to search for "tailored" and "less aggressive" therapeutic protocols avoiding risky morbidity and useless "overtreatment". Considering the most recent guidelines of referral endocrine societies, we analyzed the role of routine or so-called prophylactic central compartment lymph node dissection (RCLD), also considering its benefits and risks. Literature data showed that the debate is still open and the surgeons are divided between proponents and opponents of its use. Even if lymph node metastases are commonly observed, and in up to 90% of DTC cases micrometastases are reported, the impact of lymphatic involvement on long-term survival is subject to intensive research and the best indications of lymph node dissection are still controversial. Identification of prognostic factors for central compartment metastases could assist surgeons in determining whether to perform RLCD. Considering available evidence, a general agreement to definitely reserve RCLD to "high-risk" cases was observed. More clinical researches, in order to identify risk factors of meaningful predictive power and prospective long-term randomized trials, should be useful to validate this selective approach.

Role of Thyroid Hormones in Skeletal Development and Bone Maintenance

The skeleton is an exquisitely sensitive and archetypal T3-target tissue that demonstrates the critical role for thyroid hormones during development, linear growth, and adult bone turnover and maintenance. Thyrotoxicosis is an established cause of secondary osteoporosis, and abnormal thyroid hormone signaling has recently been identified as a novel risk factor for osteoarthritis. Skeletal phenotypes in genetically modified mice have faithfully reproduced genetic disorders in humans, revealing the complex physiological relationship between centrally regulated thyroid status and the peripheral actions of thyroid hormones. Studies in mutant mice also established the paradigm that T3 exerts anabolic actions during growth and catabolic effects on adult bone. Thus, the skeleton represents an ideal physiological system in which to characterize thyroid hormone transport, metabolism, and action during development and adulthood and in response to injury. Future analysis of T3 action in individual skeletal cell lineages will provide new insights into cell-specific molecular mechanisms and may ultimately identify novel therapeutic targets for chronic degenerative diseases such as osteoporosis and osteoarthritis. This review provides a comprehensive analysis of the current state of the art.

Radioiodine therapy versus antithyroid medications for Graves' disease

BACKGROUND

Graves' disease is the most common cause of hyperthyroidism. Both antithyroid medications and radioiodine are commonly used treatments but their frequency of use varies between regions and countries. Despite the commonness of the diagnosis, any possible differences between the two treatments with respect to long-term outcomes remain unknown.

OBJECTIVES

To assess the effects of radioiodine therapy versus antithyroid medications for Graves' disease.

SEARCH METHODS

We performed a systematic literature search in the Cochrane Library, MEDLINE and EMBASE and the trials registers ICTRP Search Portal and ClinicalTrials.gov. The date of the last search was September 2015 for all databases.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing the effects of radioiodine therapy versus antithyroid medications for Graves' disease with at least two years follow-up.

DATA COLLECTION AND ANALYSIS

Two authors independently screened titles and abstracts for relevance. One author carried out screening for inclusion, data extraction and 'Risk of bias' assessment and a second author checked this. We presented data not suitable for meta-analysis as descriptive data. We analysed the overall quality of evidence utilising the GRADE instrument.

MAIN RESULTS

We included two RCTs involving 425 adult participants with Graves' disease in this review. Altogether 204 participants were randomised to radioiodine therapy and 221 to methimazole therapy. A single dose of radioiodine was administered. The duration of methimazole medication was 18 months. The period of follow-up was at least two years, depending on the outcome measured. For most outcome measures risk of bias was low; for the outcomes health-related quality of life as well as development and worsening of Graves' ophthalmopathy risks of performance bias and detection bias were high in at least one of the two RCTs.Health-related quality of life appeared to be similar in the radioiodine and methimazole treatment groups, however no quantitative data were reported (425 participants; 2 trials; low quality evidence). The development and worsening of Graves' ophthalmopathy was observed in 76 of 202 radioiodine-treated participants (38%) and in 40 of 215 methimazole-treated participants (19%): risk ratio (RR) 1.94 (95% confidence interval (CI) 1.40 to 2.70); 417 participants; 2 trials; low quality evidence. A total of 35% to 56% of radioiodine-treated participants and 42% of participants treated with methimazole were smokers, which is associated with the risk of worsening or development of Graves' ophthalmopathy. Euthyroidism was not achieved by any participant being treated with radioiodine compared with 64/68 (94%) of participants after methimazole treatment (112 participants; 1 trial). In this trial thyroxine therapy was not introduced early in both treatment arms to avoid hypothyroidism. Recurrence of hyperthyroidism (relapse) in favour of radioiodine treatment showed a RR of 0.20 (95% CI 0.01 to 2.66); P value = 0.22; 417 participants; 2 trials; very low quality evidence. Heterogeneity was high (I² = 91%) and the RRs were 0.61 or 0.06 with non-overlapping CIs. Adverse events other than development of worsening of Graves' ophthalmopathy for radioiodine therapy were hypothyroidism (39 of 41 participants (95%) compared with 0% of participants receiving methimazole, however thyroxine treatment to avoid hypothyroidism was not introduced early in the radioiodine group - 104 participants; 1 trial; very low quality evidence) and drug-related adverse events for methimazole treatment (23 of 215 participants (11%) reported adverse effects likely related to methimazole therapy - 215 participants; 2 trials; very low quality evidence). The outcome measures all-cause mortality and bone mineral density were not reported in the included trials. One trial (174 participants) reported socioeconomic effects: costs based on the official hospital reimbursement system in Sweden for patients without relapse and methimazole treatment were USD 1126/1164 (young/older methimazole group) and for radioiodine treatment USD 1862. Costs for patients with relapse and methimazole treatment were USD 2284/1972 (young/older methimazole group) and for radioiodine treatment USD 2760.

AUTHORS' CONCLUSIONS

The only antithyroid drug investigated in the two included trials was methimazole, which might limit the applicability of our findings with regard to other compounds such as propylthiouracil. Results from two RCTs suggest that radioiodine treatment is associated with an increased risk of Graves' ophthalmopathy. Our findings suggest some benefit from radioiodine treatment for recurrence of hyperthyroidism (relapse) but there is uncertainty about the magnitude of the effect size.

Better adherence to antithyroid drug is associated with decreased risk of stroke in hyperthyroidism patients

BACKGROUND

An increased risk for ischaemic stroke has been reported in young hyperthyroidism patients independent of atrial fibrillation (AF). However, whether the use of antithyroid drugs in hyperthyroidism patients can reduce the occurrence of ischaemic stroke remains unclear.

METHODS

A total of 36,510 newly diagnosed hyperthyroidism patients during 2003-2006 were identified from the Taiwan National Health Insurance Research database. Each patient was individually tracked for 5 years from their index date (beginning the antithyroid drugs) to identify those who suffered from new episode of ischaemic stroke. Medication possession ratio (MPR) was used to represent the antithyroid drug compliance. The association between the MPR and the risk of stroke was examined.

RESULTS

The stroke incidence rates for hyperthyroidism patients with age < 45 years and age ≥ 45 years were 0.42 and 3.76 per 1000 person-years, respectively. The patients aged < 45 years with MPR < 0.2 (adjusted hazard ratio, HR, 2.30; 95% CI, 1.13-4.70; p = 0.02) and 0.2 ≤ MPR < 0.4 (adjusted HR, 2.24; 95% CI, 1.06-4.72; p = 0.035) had a significantly increased risk of ischaemic stroke as compared to those with ≥ 0.6. In patients of the age ≥ 45 years, only the patients with MPR < 0.2 (adjusted HR, 1.44; 95% CI, 1.03-2.01; p = 0.036) had a significantly higher risk of ischaemic stroke as compared to those with MPR ≥ 0.6. In hyperthyroidism patients without AF, good antithyroid drugs compliance also reduced the incidence of stroke significantly (adjusted HR, range: 1.52-1.61; p = 0.02); but not in hyperthyroidism with AF.

CONCLUSION

Hyperthyroidism patients with good antithyroid drug compliance had a lower risk of ischaemic stroke than patients with poor compliance.

Severe Hyperthyroidism Presenting with Acute ST Segment Elevation Myocardial Infarction

Introduction. Acute myocardial infarction is life-threatening. A cardiac troponin rise accompanied by typical symptoms, ST elevation or depression is diagnostic of acute myocardial infarction. Here, we report an unusual case of a female who was admitted with chest pain. However, she did not present with a typical profile of an acute myocardial infarction patient. Case Presentation. A 66-year-old Han nationality female presented with chest pain. The electrocardiogram (ECG) revealed arched ST segment elevations and troponin was elevated. However, the coronary angiography showed a normal coronary arterial system. Thyroid function tests showed that this patient had severe hyperthyroidism. Conclusion. Our case highlights the possibility that hyperthyroidism may cause a large area of myocardium injury and ECG ST segment elevation. We suggest routine thyroid function testing in patients with chest pain.

Radioiodine therapy increases the risk of cerebrovascular events in hyperthyroid and euthyroid patients

BACKGROUND AND OBJECTIVE

Hyperthyroid patients treated with radioiodine have increased morbidity and mortality from cerebrovascular events. This risk has until now has been attributed to the hyperthyroidism. However, radioiodine therapy of benign thyroid diseases exposes the carotid arteries to radiation and is capable of inducing atherosclerosis. The objective of the study was to elucidate whether ionizing radiation from radioiodine might contribute to cerebrovascular morbidity.

METHODS

In a retrospective register cohort study, 4000 hyperthyroid and 1022 euthyroid goitre patients treated with radioiodine between 1975 and 2008 were matched 1:4 on age and sex with random controls. The cohort was followed from the date of treatment until hospitalization due to cerebrovascular event, death, 20 years of follow-up or March 2013. Data were analyzed in competing risk models adjusting for age, sex, Charlson's comorbidity score, atrial fibrillation and previous cerebrovascular events.

RESULTS

Mean follow-up time was 11.5 years, mean age 61 years, with a total number of 3228 events. Comparing all radioiodine-treated patients with controls, the fully adjusted model showed increased risk of cerebrovascular events among all treated patients, hazard ratio (HR) 1.18 (95% CI 1.09-1.29). The risk was increased among hyperthyroid (HR 1.17; 95% CI 1.07-1.28) as well as euthyroid patients (HR 1.21; 95% CI 1.02-1.44).

CONCLUSIONS

We report an increased risk of cerebrovascular events in hyperthyroid as well as euthyroid patients treated with radioiodine for benign thyroid disorders. That these patient groups have similar risks suggests the possibility that radiation from radioiodine contributes to cerebrovascular morbidity via acceleration or initiation of atherosclerosis.

Italian Association of Clinical Endocrinologists (AME) & Italian Association of Clinical Diabetologists (AMD) Position Statement : Diabetes mellitus and thyroid disorders: recommendations for clinical practice

Thyroid disease and diabetes mellitus, the most common disorders in endocrine practice, are not infrequently associated in the same subject. An altered thyroid function may affect glucose tolerance and worsen metabolic control in patients with diabetes. Thyrotoxicosis increases the risk of hyperglycemic emergencies, while a clinically relevant hypothyroidism may have a detrimental effect on glycemic control in diabetic patients. The association of alterations in thyroid function with diabetes mellitus may adversely affect the risk of cardiovascular and microvascular complications resulting from diabetes. Moreover, the treatments used for both diabetes and thyroid disease, respectively, can impact one other. Finally, multinodular goiter, but not thyroid carcinoma, was shown to be more prevalent in type 2 diabetes mellitus. Aim of the present Position Statement is to focus on the evidence concerning the association of thyroid disease and diabetes mellitus and to provide some practical suggestions for an updated clinical management.

Systemic oxidative stress to nucleic acids is unaltered following radioiodine therapy of patients with benign nodular goiter

BACKGROUND

Little is known about the whole body oxidative stress burden following radioactive iodine ((131)I) therapy of thyroid diseases.

METHODS

We studied 17 patients with benign nodular goiter treated with (131)I therapy. The targeted thyroid dose was 50 Gy in 11 patients pretreated with 0.1 mg of recombinant human TSH (rhTSH). In 6 patients, the applied thyroid dose was 100 Gy without rhTSH prestimulation. Well-established biomarkers of oxidative stress to RNA (8-oxo-7,8-dihydroguanosine; 8-oxoGuo) and DNA (8-oxo-7,8-dihydro-2'-deoxyguanosine; 8-oxodG) were measured in freshly voided morning urine (normalized against the creatinine concentration) at baseline, and 7 and 21 days after rhTSH (not followed by (131)I), and 7 and 21 days after (131)I therapy, respectively.

RESULTS

The baseline urinary excretions of 8-oxoGuo and 8-oxodG were 2.20 ± 0.84 and 1.63 ± 0.70 nmol/mmol creatinine, respectively. We found no significant changes in the excretion of any of the metabolites, neither after rhTSH stimulation alone nor after (131)I therapy. Also, no significant differences were found between the rhTSH group (low dose, median (131)I: 152 MBq) and the non-rhTSH group (high dose, median (131)I: 419 MBq; 8-oxoGuo: p = 0.66, 8-oxodG: p = 0.71).

CONCLUSION

Systemic oxidative stress, as detected by nucleic acids metabolites in the urine, is not increased after thyroid stimulation with 0.1 mg of rhTSH, or after (131)I therapy. Our method cannot quantify the oxidative stress induced locally in the thyroid gland, but the study supports that (131)I therapy of benign nodular goiter carries no or only a minute risk of developing subsequent malignancies. It remains to be explored whether our findings also apply to hyperthyroid disorders.

The role of surgery in the current management of differentiated thyroid cancer

In the last decades, a surprising increased incidence of differentiated thyroid cancer (DTC), along with a precocious diagnosis of "small" tumors and microcarcinomas have been observed. In these cases, better oncological outcomes are expected, and a "tailored" and "less aggressive" multimodal therapeutic protocol should be considered, avoiding an unfavorable even if minimal morbidity following an "overtreatment." In order to better define the most suitable surgical approach, its benefits and risks, we discuss the role of surgery in the current management of DTCs in the light of data appeared in the literature. Even if lymph node metastases are commonly observed, and in up to 90 % of DTC cases micrometastases are reported, the impact of lymphatic involvement on long-term survival is still argument of intensive research, and indications and extension of lymph node dissection (LD) are still under debate. In particular, endocrine and neck surgeons are still divided between proponents and opponents of routine central LD (RCLD). Considering the available evidence, there is agreement about total thyroidectomy, therapeutic LD in clinically node-positive DTC patients, and RCLD in "high risk" cases. Nevertheless, indications to the best surgical treatment of clinically node-negative "low risk" patients are still subject of research. Considering on the one hand, the recent trend toward routine central lymphadenectomy, avoiding radioactive treatment, and on the other hand, the satisfactory results obtained reserving prophylactic LD to "high risk" patients, we think that further prospective randomized trials are needed to evaluate the best choice between the different surgical approaches.

Duration of thyroid dysfunction correlates with all-cause mortality. the OPENTHYRO Register Cohort

Introduction and Aim

The association between thyroid dysfunction and mortality is controversial. Moreover, the impact of duration of thyroid dysfunction is unclarified. Our aim was to investigate the correlation between biochemically assessed thyroid function as well as dysfunction duration and mortality.

Methods

Register-based follow-up study of 239,768 individuals with a serum TSH measurement from hospitals and/or general practice in Funen, Denmark. Measurements were performed at a single laboratory from January 1st 1995 to January 1st 2011. Cox regression was used for mortality analyses and Charlson Comorbidity Index (CCI) was used as comorbidity score.

Results

Hazard ratios (HR) with 95% confidence intervals (CI) for mortality with decreased (<0.3 mIU/L) or elevated (>4.0 mIU/L) levels of TSH were 2.22; 2.14–2.30; P<0.0001 and 1.28; 1.22–1.35; P<0.0001, respectively. Adjusting for age, gender, CCI and diagnostic setting attenuated the risk estimates (HR 1.23; 95% CI: 1.19–1.28; P<0.0001, mean follow-up time 7.7 years, and HR 1.07; 95% CI: 1.02–1.13; P = 0.004, mean follow-up time 7.2 years) for decreased and elevated values of TSH, respectively. Mortality risk increased by a factor 1.09; 95% CI: 1.08–1.10; P<0.0001 or by a factor 1.03; 95% CI: 1.02–1.04; P<0.0001 for each six months a patient suffered from decreased or elevated TSH, respectively. Subdividing according to degree of thyroid dysfunction, overt hyperthyroidism (HR_overt 1.12; 95% CI: 1.06–1.19; P<0.0001), subclinical hyperthyroidism (HR_subclinical 1.09; 95% CI: 1.02–1.17; P = 0.02) and overt hypothyroidism (HR_overt 1.57; 95% CI: 1.34–1.83; P<0.0001), but not subclinical hypothyroidism (HR_subclinical 1.03; 95% CI: 0.97–1.09; P = 0.4) were associated with increased mortality.

Conclusions and Relevance

In a large-scale, population-based cohort with long-term follow-up (median 7.4 years), overt and subclinical hyperthyroidism and overt but not subclinical hypothyroidism were associated with increased mortality. Excess mortality with increasing duration of decreased or elevated serum TSH suggests the importance of timely intervention in individuals with thyroid dysfunction.

Hypothalamic control of bone metabolism

Bones are structures in vertebrates that provide support to organs, protect soft organs, and give them shape and defined features, functions that are essential for their survival. To perform these functions, bones are constantly renewed throughout life. The process through which bones are renewed is known as bone remodeling, an energy demanding process sensitive to changes in energy homeostasis of the organism. A close interplay takes place between the diversity of nutritional cues and metabolic signals with different elements of the hypothalamic circuits to co-ordinate energy metabolism with the regulation of bone mass. In this review, we focus on how mouse and human genetics have elucidated the roles of hormonal signals and neural circuits that originate in, or impinge on, the hypothalamus in the regulation of bone mass. This will help to understand the mechanisms whereby regulation of bone is gated and dynamically regulated by the hypothalamus.

Effects of radiation and temperature on iodide sorption by surfactant-modified bentonite

Bentonite, which is used as an engineered barrier in geological repositories, is ineffective for sorbing anionic radionuclides because of its negatively charged surface. This study modified raw bentonite using a cationic surfactant (i.e., hexadecyltrimethylammonium [HDTMA]-Br) to improve its sorption capability for radioactive iodide. The effects of temperature and radiation on the iodide sorption of surfactant-modified bentonite (SMB) were also evaluated under alkaline pH condition similar to that found in repository environments. Different amounts of surfactant, equivalent to the 50, 100, and 200% cation-exchange capacity of the bentonite, were used to produce the HDTMA-SMB for iodide sorption. The sorption reaction of the SMB with iodide reached equilibrium rapidly within 10 min regardless of temperature and radiation conditions. The rate of iodide sorption increased as the amount of the added surfactant was increased and nonlinear sorption behavior was exhibited. However, high temperature and γ-irradiation ((60)Co) resulted in significantly (∼2-10 times) lower iodide Kd values for the SMB. The results of FTIR, NMR, and XANES spectroscopy analysis suggested that the decrease in iodide sorption may be caused by weakened physical electrostatic force between the HDTMA and iodide, and by the surfactant becoming detached from the SMB during the heating and irradiation processes.

The role of radioiodine therapy in benign nodular goitre

For treatment of benign nodular goitre the choice usually stands between surgery and (131)I therapy. (131)I therapy, used for 30 years for this condition, leads to a goitre volume reduction of 35-50% within 1-2 years. However, this treatment has limited efficacy if the thyroid (131)I uptake is low or if the goitre is large. Recombinant human TSH (rhTSH)-stimulated (131)I therapy significantly improves goitre reduction, as compared with conventional (131)I therapy without pre-stimulation, and adverse effects are few with rhTSH doses of 0.1 mg or lower. RhTSH-stimulated (131)I therapy reduces the need for additional therapy due to insufficient goitre reduction, but the price is a higher rate of hypothyroidism. Another approach with rhTSH-stimulation is to reduce the administered (131)I activity by a factor that equals the increase in the thyroid (131)I uptake. Using this approach, radiation exposure is considerably reduced while the goitre reduction is similar to that obtained with conventional (131)I therapy.

Pediatric Graves' disease: management in the post-propylthiouracil Era

The most prevalent cause of thyrotoxicosis in children is Graves’ disease (GD), and remission occurs only in a modest proportion of patients. Thus most pediatric patients with GD will need treatment with radioactive iodine (RAI; ¹³¹I) or surgical thyroidectomy. When antithyroid drugs (ATDs) are prescribed, only methimazole (MMI) should be administered, as PTU is associated with an unacceptable risk of severe liver injury. If remission does not occur following ATD therapy, ¹³¹I or surgery should be contemplated. When ¹³¹I is administered, dosages should be greater than 150 uCi/gm of thyroid tissue, with higher dosages needed for large glands. Considering that there will be low-level whole body radiation exposure associated with ¹³¹I, this treatment should be avoided in young children. When surgery is performed near total or total-thyroidectomy is the recommended procedure. Complications for thyroidectomy in children are considerably higher than in adults, thus an experienced thyroid surgeon is needed when children are operated on. Most importantly, the care of children with GD can be complicated and requires physicians with expertise in the area.

The role of serum C-reactive protein measured by high-sensitive method in thyroid disease

The aim of this study was the evaluation of serum C-reactive protein (CRP) concentration as a marker of the inflammatory state in many different thyroid diseases and its dependence on the stage and duration of disease. We conducted a retrospective analysis of 444 randomly selected patients with different kinds of thyroid disease (106 men and 338 women, ranging 18-72 years of age; mean 56.2 ± 5.0 years; median 52 years). Group 1 (G1) comprised 250 patients with hyperthyroidism. Group 2 (G2) consisted of 72 euthyroid patients. Group 3 (G3) consisted of 122 patients with hypothyroidism. Free T4, free T3, and thyrotropin (TSH) levels were measured using the electrochemiluminescent method. Human serum thyroglobulin autoantibodies (Tg-Abs), thyroperoxidase autoantibodies (TPO-Abs), and autoantibodies against the thyrotropin receptor (TSHR-Abs) levels were measured by radioimmunoassay. The high-sensitive CRP (Hs-CRP) level (reference range <3 mg/L) was determined with a highly sensitive latex-based immunoassay. The mean value of Hs-CRP in G1 was 3.6 ± 2.8 mg/L, in G2 2.5 ± 1.5 mg/L and in G3 5.9 ± 5.8 mg/L. Hs-CRP (in mg/L) medians, interquartile and the total ranges in G1 were 3.0 (2.0 [0.1-21.0] 4.0); in G2: 2.3 [1.8 (0.2-9.2) 3.2]; and in G3: 4.3 [2.2 (0.3-31.5) 7.8]. We found statistically significant differences (Kruskal-Wallis test) in serum Hs-CRP values between G1 and G2 (P = 0.007), G1 and G3 (P = 0.001), G2 and G3 (P < 0.001). In G1, statistically significant correlation was confirmed between Hs-CRP and Tg-Abs (r = -0.22, P = 0.0016), CRP and TPO-Abs (r = -0.26, P < 0.001), and also between Hs-CRP and TSHR-Abs (r = -0.18, P = 0.02). In the remaining cases, differences between Hs-CRP and TSH levels (r = -0.09, P = 0.16) were not statistically significant. In G2, no statistically significant correlation was observed: Hs-CRP and Tg-Abs (r = -0.18, P = 0.13), Hs-CRP and TPO-Abs (r = -0.17, P = 0.15), Hs-CRP and TSH (r = 0.01, P = 0.91), Hs-CRP and TSHR-Abs (r = -0.19, P = 0.17). In G3, a statistically significant correlation was confirmed between Hs-CRP and Tg-Abs (r = 0.22, P = 0.012), Hs-CRP and TSH (r = -0.28, P = 0.001). No statistically significant correlation was observed between Hs-CRP and TPO-Abs (r = 0.20, P = 0.06) and between Hs-CRP and TSHR-Abs (r = -0.23, P = 0.11). Hs-CRP is increased in various types of hypothyroidism. This is particularly relevant in postpartum thyroiditis and in patients after radioiodine treatment. The impact of this situation on human health requires further research, however, one might assume that some types of thyroid disease may lead to systemic inflammatory reactions that are reflected in elevated CRP levels.