2021 Asia-Pacific Graves' Disease Consortium Survey of Clinical Practice Patterns in the Management of Graves' Disease

Radioactive Iodine-131 Therapy Reduced the Risk of MACEs and All-Cause Mortality in Elderly with Hyperthyroidism Combined with Type 2 Diabetes

Aim

This study aimed to assess the efficacy of antithyroid drugs (ATDs) and radioactive iodine-131 (RAI) therapies in reducing the risk of major adverse cardiovascular events (MACEs) and all-cause mortality in patients with hyperthyroidism complicated with type 2 diabetes mellitus (T2DM).

Methods

Between January 2013 and December 2021, 540 subjects were included in the analysis. All participants were followed up for 9 years, with a median of 54 months (2451 person-years). The subjects were categorized into two groups: the ATDs group (n = 414) and the RAI group (n = 126). According to the free triiodothyronine (FT3) tertiles, the patients receiving RAI were further grouped as follows: low-level (≤ 4.70 pmol/L, n = 42), moderate-level (4.70-12.98 pmol/L, n = 42), and high-level (≥ 12.98 pmol/L, n = 42). The efficacy of ATDs and RAI therapies in reducing the risk of MACEs and all-cause mortality was assessed.

Results

Of the 540 participants, 163 experienced MACEs (30.19%), 25 (15.34%) of whom died. Multivariate Cox regression analyses revealed that RAI was associated with a 38.5% lower risk of MACEs (P = 0.016) and a 77.1% lower risk of all-cause mortality (P = 0.046). Stratified analyses indicated that RAI had a protective effect on MACEs in patients aged ≥ 60 years (P = 0.001, P for interaction = 0.031) and patients with a duration of diabetes mellitus ≥ 6 years (P = 0.013, P for interaction = 0.002). Kaplan‒Meier analysis revealed a lower cumulative incidence of MACEs and all-cause mortality in the RAI group (log-rank, all P < 0.05). Moreover, the ROC curve suggested an optimal FT3 cut-off value of 5.4 pmol/mL for MACE (P < 0.001).

Conclusion

Our findings suggested that RAI therapy effectively reduced the risk of MACEs and all-cause mortality in elderly patients with hyperthyroidism combined with T2DM.

Treatment Patterns and Preferences for Graves' Disease in Korea: Insights from a Nationwide Cohort Study

Treatment patterns and preferences for patients with Graves' disease (GD) vary across countries. In this study, we assessed the initial therapies and subsequent treatment modalities employed for GD in real-world clinical practice in Korea. We analyzed 452,001 patients with GD from 2004 to 2020, obtained from the Korean National Health Insurance Service database. Initial treatments included antithyroid drug (ATD) therapy (98% of cases), thyroidectomy (1.3%), and radioactive iodine (RAI) therapy (0.7%). The rates of initial treatment failure were 58.5% for ATDs, 21.3% for RAI, and 2.1% for thyroidectomy. Even among cases of ATD treatment failure or recurrence, the rates of RAI therapy remained low. Regarding initial treatment, the 5-year remission rate was 46.8% among patients administered ATDs versus 91.0% among recipients of RAI therapy; at 10 years, these rates were 59.2% and 94.0%, respectively. Our findings highlight a marked disparity in the use of RAI therapy in Korea compared to Western countries. Further research is required to understand the reasons for these differences in treatment patterns.

Thyroid stimulating receptor autoantibodies

Thyroid-stimulating hormone receptor autoantibodies (TRAbs) play a crucial role as pathogenic antibodies in both the diagnosis and management of Graves' disease (GD). GD, an autoimmune disease resulting from a combination of genetic and environmental factors, is the most common cause of hyperthyroidism. With advancements in technology for TRAb detection and the availability of automated commercial kits, TRAb has become an essential clinical laboratory marker for the diagnosis of GD, as well as extra-thyroidal manifestations like Graves' ophthalmopathy (GO). This article provides a comprehensive review of TRAb, encompassing its clinical assays along with its significance in the clinical setting.

Cancer Risk in Graves Disease with Radioactive 131I Treatment: A Nationwide Cohort Study

Radioactive 131I (RAI) therapy has potential effects for the treatment of Graves disease (GD). However, whether RAI therapy for GD increases cancer risk remains controversial in medicine and public health. We aimed to investigate whether the risk of cancer increases in patients with GD receiving RAI therapy compared with those who did not. Methods: We used the Korean National Health Insurance Service's National Health Information Database from 2004 to 2020 and defined GD as prescribing antithyroid drugs, RAI, or thyroidectomy as a treatment for GD (International Classification of Diseases, 10th revision, E05 group). We investigated the hazard ratios (HRs) of overall and site-specific cancers associated with RAI in patients with GD. Subsequent cancer was defined as a primary malignancy treated at least 1 y after RAI therapy. Results: In total, 10,737 patients with GD who received RAI therapy (7,193 women, 67.0%; mean age, 43.7 ± 13.4 y) were matched to 53,003 patients with GD who had never received RAI treatment (35,471 women, 66.9%; mean age, 43.8 ± 13.2 y) in a 1:4-5 ratio by age, sex, and health checkup data. The median follow-up duration was 8.7 y (interquartile range, 5.2-12.1 y), and the median cumulative RAI dose was 555 MBq (interquartile range, 370-630 MBq) in the RAI therapy group. During 2004-2020, the overall subsequent cancer rates were 5.66 and 5.84 per 1,000 person-years in the RAI and non-RAI groups, respectively, with an unadjusted HR of 0.97 (95% CI, 0.88-1.06); this remained at 0.96 (95% CI, 0.83-1.10) after adjustment for multiple clinical confounding factors. For cancer subtypes, the risk of leukemia was significantly increased, with an HR of 2.39 (95% CI, 1.17-4.91). However, a loss of statistical significance was observed after adjusting for confounding factors, which may be attributed to the limited number of absolute events. Moreover, cancer-specific mortality was not different between the RAI and the non-RAI groups, with an adjusted HR of 0.99 (95% CI, 0.66-1.47). Conclusion: This study identified that the overall cancer risk in patients with GD who received RAI therapy compared with those who did not was not significant in Korea. Further long-term studies are needed to determine the risks and advantages of RAI therapy in patients with GD.

Unveiling Promising Modalities and Enhancing Patient Outcomes in Graves' Disease Treatment: A Systematic Review and Meta-Analysis

Graves' disease (GD) is an autoimmune condition of the thyroid. The hyperthyroidism manifested by patients affected by this disease is caused by the production of autoantibodies against the thyroid-stimulating hormone (TSH, or thyrotropin) receptor (TSHR), which mimic the effects of the hormone on thyroid cells, thereby stimulating autonomic production of thyroxine and triiodothyronine. Deciding on a therapeutic approach to this condition presents intricate dilemmas for both clinicians and patients. Each of the three available treatment modalities is grounded in evidence-based medicine, affirming its efficacy. This systematic review and meta-analysis aimed to assess the effect of carbimazole (CBM), radioactive iodine (RAI), and surgery in treating GD and provide evidence-based recommendations for healthcare providers regarding the optimal management of the condition based on a comprehensive analysis of effectiveness, safety, patient satisfaction, and recovery outcomes. This systematic review and meta-analysis adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We used the PubMed and Google Scholar databases to conduct a thorough web search for articles published between January 2019 and September 2023. The meta-analysis was carried out using Resource Manager (Revman) 5.4.1. The study found that propylthiouracil (PTU) or methimazole/carbimazole (MMI/CBM) treatment increases the risk of hyperlipidemia in patients with hyperthyroidism. Once in a euthyroid state, glucose tolerance increases; for children with GD, a computer model for customized dosing has been created. To sum up, CBM, surgery, and RAI are all useful treatment options for GD. Using steroids in conjunction with radiation therapy may help prevent Graves' ophthalmopathy (GO).

MACE and Hyperthyroidism Treated With Medication, Radioactive Iodine, or Thyroidectomy

Importance

Excessive thyroid hormones from hyperthyroidism increase cardiovascular risks. Among 3 available treatments for hyperthyroidism, comparisons of long-term outcomes associated with antithyroid drugs (ATDs), radioactive iodine (RAI), and surgery to treat newly diagnosed hyperthyroidism are lacking.

Objective

To compare risks of major adverse cardiovascular events (MACE) and all-cause mortality among patients with hyperthyroidism treated with ATDs, RAI, or surgery.

Design, Setting, and Participants

This nationwide cohort study used the Taiwan National Health Insurance Research Database. Patients aged 20 years or older with newly diagnosed hyperthyroidism between 2011 and 2020 were enrolled. Treatment groups were determined within 18 months from diagnosis, with follow-up until the development of MACE, death, or the end date of the database, whichever came first. Data were analyzed from October 2022 through December 2023.

Exposures

The ATD group received ATDs only. RAI and surgery groups could receive ATDs before treatment. Anyone who underwent thyroid surgery without RAI was classified into the surgery group and vice versa.

Main Outcomes and Measures

The primary outcomes included MACE (a composite outcome of acute myocardial infarction, stroke, heart failure, and cardiovascular mortality) and all-cause mortality.

Results

Among 114 062 patients with newly diagnosed hyperthyroidism (mean [SD] age, 44.1 [13.6] years; 83 505 female [73.2%]), 107 052 patients (93.9%) received ATDs alone, 1238 patients (1.1%) received RAI, and 5772 patients (5.1%) underwent surgery during a mean (SD) follow-up of 4.4 (2.5) years. Patients undergoing surgery had a significantly lower risk of MACE (hazard ratio [HR] = 0.76; 95% CI, 0.59-0.98; P = .04), all-cause mortality (HR = 0.53; 95% CI, 0.41-0.68; P < .001), heart failure (HR = 0.33; 95% CI, 0.18-0.59; P < .001), and cardiovascular mortality (HR = 0.45; 95% CI, 0.26-0.79; P = .005) compared with patients receiving ATDs. Compared with ATDs, RAI was associated with lower MACE risk (HR = 0.45; 95% CI, 0.22-0.93; P = .03). Risks for acute myocardial infarction and stroke did not significantly differ between treatment groups.

Conclusions and Relevance

In this study, surgery was associated with lower long-term risks of MACE and all-cause mortality, while RAI was associated with a lower MACE risk compared with ATDs.

Hyperthyroidism

Thyrotoxicosis causes a variety of symptoms and adverse health outcomes. Hyperthyroidism refers to increased thyroid hormone synthesis and secretion, most commonly from Graves' disease or toxic nodular goitre, whereas thyroiditis (typically autoimmune, viral, or drug induced) causes thyrotoxicosis without hyperthyroidism. The diagnosis is based on suppressed serum concentrations of thyroid-stimulating hormone (TSH), accompanied by free thyroxine and total or free tri-iodothyronine concentrations, which are raised (overt hyperthyroidism) or within range (subclinical hyperthyroidism). The underlying cause is determined by clinical assessment, detection of TSH-receptor antibodies and, if necessary, radionuclide thyroid scintigraphy. Treatment options for hyperthyroidism include antithyroid drugs, radioactive iodine, and thyroidectomy, whereas thyroiditis is managed symptomatically or with glucocorticoid therapy. In Graves' disease, first-line treatment is a 12-18-month course of antithyroid drugs, whereas for goitre, radioactive iodine or surgery are preferred for toxic nodules or goitres. Evidence also supports long-term treatment with antithyroid drugs as an option for patients with Graves' disease and toxic nodular goitre.