Management of Subclinical Hypothyroidism: A Focus on Proven Health Effects in the 2023 Korean Thyroid Association Guidelines

Subclinical hypothyroidism (SCH) is characterized by elevated thyroid-stimulating hormone (TSH) and normal free thyroxine levels. The Korean Thyroid Association recently issued a guideline for managing SCH, which emphasizes Korean-specific TSH diagnostic criteria and highlights the health benefits of levothyroxine (LT4) treatment. A serum TSH level of 6.8 mIU/L is presented as the reference value for diagnosing SCH. SCH can be classified as mild (TSH 6.8 to 10.0 mIU/L) or severe (TSH >10.0 mIU/L), and patients can be categorized as adults (age <70 years) or elderly (age ≥70 years), depending on the health effects of LT4 treatment. An initial increase in serum TSH levels should be reassessed with a subsequent measurement, including a thyroid peroxidase antibody test, preferably 2 to 3 months after the initial assessment. While LT4 treatment is not generally recommended for mild SCH in adults, it is necessary for severe SCH in patients with underlying coronary artery disease or heart failure and it may be considered for those with concurrent dyslipidemia. Conversely, LT4 treatment is generally not recommended for elderly patients, regardless of SCH severity. For those SCH patients who are prescribed LT4 treatment, the dosage should be personalized, and serum TSH levels should be regularly monitored to maintain the optimal LT4 regimen.

A Case of an Elderly Graves’ Patient with Fatal Pulmonary Embolism

In elderly Graves’ patients, thyrotoxicosis may have vague or atypical clinical features. It could delay the detection of Graves’ disease itself, and also other combined diseases. Here, we report a case of a 73-year-old Graves’ patient who complained of several atypical symptoms such as chest discomfort, pain in the lower calf, severe agitation, depression, sense of impending doom, myalgia etc. Despite these discomforts, they had previously been ignored as vague clinical features of Graves’ disease. After 4 months with hemoptysis, serious pulmonary embolism was confirmed by computed tomography of the chest, and the patient suddenly died. Clinicians should remember that the atypical symptoms in elderly Graves’ patients can suggest hidden comorbidities. This is especially critical in case of acute cardiovascular diseases such as pulmonary embolism, which can be fatal to elderly patients.

Subclinical Hypothyroidism: Prevalence, Health Impact, and Treatment Landscape

Subclinical hypothyroidism (sHypo) is defined as normal serum free thyroid hormone levels coexisting with elevated serum thyroid-stimulating hormone (TSH) levels. sHypo is a common condition observed in clinical practice with several unique features. Its diagnosis should be based on an understanding of geographic and demographic differences in biochemical criteria versus a global reference range for TSH that is based on the 95% confidence interval of a healthy population. During the differential diagnosis, it is important to remember that a considerable proportion of sHypo cases are transient and reversible in nature; the focus is better placed on persistent or progressive forms, which mainly result from chronic autoimmune thyroiditis. Despite significant evidence documenting the health impacts of sHypo, the effects of levothyroxine treatment (LT4-Tx) in patients with sHypo remains controversial, especially in patients with grade 1 sHypo and older adults. Existing evidence suggests that it is reasonable to refrain from immediate LT4-Tx in most patients if they are closely monitored, except in women who are pregnant or in progressive cases. Future research is needed to further characterize the risks and benefits of LT4-Tx in different patient cohorts.

A Case of an Elderly Graves’ Patient with Fatal Pulmonary Embolism

In elderly Graves’ patients, thyrotoxicosis may have vague or atypical clinical features. It could delay the detection of Graves’ disease itself, and also other combined diseases. Here, we report a case of a 73-year-old Graves’ patient who complained of several atypical symptoms such as chest discomfort, pain in the lower calf, severe agitation, depression, sense of impending doom, myalgia etc. Despite these discomforts, they had previously been ignored as vague clinical features of Graves’ disease. After 4 months with hemoptysis, serious pulmonary embolism was confirmed by computed tomography of the chest, and the patient suddenly died. Clinicians should remember that the atypical symptoms in elderly Graves’ patients can suggest hidden comorbidities. This is especially critical in case of acute cardiovascular diseases such as pulmonary embolism, which can be fatal to elderly patients.

Subclinical Hypothyroidism: Prevalence, Health Impact, and Treatment Landscape

Subclinical hypothyroidism (sHypo) is defined as normal serum free thyroid hormone levels coexisting with elevated serum thyroid-stimulating hormone (TSH) levels. sHypo is a common condition observed in clinical practice with several unique features. Its diagnosis should be based on an understanding of geographic and demographic differences in biochemical criteria versus a global reference range for TSH that is based on the 95% confidence interval of a healthy population. During the differential diagnosis, it is important to remember that a considerable proportion of sHypo cases are transient and reversible in nature; the focus is better placed on persistent or progressive forms, which mainly result from chronic autoimmune thyroiditis. Despite significant evidence documenting the health impacts of sHypo, the effects of levothyroxine treatment (LT4-Tx) in patients with sHypo remains controversial, especially in patients with grade 1 sHypo and older adults. Existing evidence suggests that it is reasonable to refrain from immediate LT4-Tx in most patients if they are closely monitored, except in women who are pregnant or in progressive cases. Future research is needed to further characterize the risks and benefits of LT4-Tx in different patient cohorts.

Cardiac Arrest Related to Torsades de Pointes in a Patient Recovering from Diabetic Ketoacidosis / 대한내과학회지

Diabetic ketoacidosis (DKA) is an acute complication related to severe hyperglycemia. While the mortality rate for DKA is low with appropriate therapy, several complications may lead to deterioration of the clinical course. Here, we report a case of a 23-year-old patient with DKA who suffered from a rare but hemodynamically unstable cardiac arrhythmia, polymorphic ventricular tachycardia with prolonged QT interval, or Torsades de Pointes. During the recovery phase of DKA, three episodes of Torsades de Pointes suddenly occurred, and were recovered by immediate defibrillation. The patient did not have structural heart disease or a genetic predisposition. To the best of our knowledge, this is the first report of an adult with DKA complicated with QT prolongation related to Torsades de Points after correction of ketosis. To manage DKA, more attention may be needed on changes in the QT interval as well as risk factors for Torsades de Points.

The Management of Thyroid Disease in COVID-19 Pandemic

The novel viral disease COVID-19 is spreading globally, causing countless infected individuals and deaths. There are active discussions and debates on how to manage patients with chronic illnesses in the COVID-19 pandemic era. Since thyroid diseases are chronic and associated with autoimmune diseases as well as high tumors, there is a need to assess the association between thyroid diseases and COVID-19. Recently, the American Thyroid Association and European Thyroid Association published a statement on thyroid disease management during the COVID-19 pandemic. Further, clinical data from COVID-19 patients also indicate that COVID-19 may affect thyroid functions. Therefore, we reviewed published literature on COVID-19 and thyroid diseases and discussed approaches to proper management of thyroid diseases during the COVID-19 pandemic.

Medical Treatment of Graves' Disease

Among the three treatment modalities of Graves' disease which include antithyroid drug (ATD), radioactive iodine and surgery, the ATD is most commonly preferred in Korea due to ease of use and definite curative effects on the thyrotoxic symptoms. However, several uncertainties about ATD remain: for example, the mechanism of actions on immune modulation, differences in the effects of drugs among individuals and associated factors in the view of remission. In recent years, long-term ATD treatment has been confirmed as an effective and safe therapy modality in adults, and several treatment guidelines have been released which accept long-term ATD therapy as an acceptable alternative to ablative therapy in Graves' patients. In this review, we summarize the recent progress in understanding the clinical role of ATD and emerging new antithyroid drugs focusing on immunomodulation.

Therapeutic Effect of Quadruple Oral Hypoglycemic Agents in Patients with Type 2 Diabetes Mellitus Who Have Insulin Limitations / 임상당뇨병

BACKGROUND: Insulin therapy is the treatment of choice in type 2 diabetes mellitus (T2DM) patients who are not achieving glycemic goals despite triple oral hypoglycemic agent (OHA) combination therapy. However, there is still no additional treatment option for patients who cannot afford insulin therapy or who have various clinical limitations. The purpose of this study was to evaluate the clinical efficacy and safety of four OHA combination therapy in poorly controlled T2DM patients who could not afford insulin therapy. METHODS: Forty-seven T2DM patients were enrolled according to the following criteria: 1) glycosylated hemoglobin [HbA1c] > 8.5%, 2) ongoing treatment with 3 OHA combination therapy (metformin, sulfonylurea, dipeptidyl peptidase-4 inhibitor), or 3) combined limitations for applying insulin therapy. Patients were given the fourth OHA (pioglitazone) in addition to their previous treatment for 12 months. We evaluated changes in HbA1c, body weight, hypoglycemic events, and side effects. RESULTS: At study completion, mean HbA1c and fasting plasma glucose were significantly reduced from 9.6% to 8.04% and from 198.4 mg/dL to 161.5 mg/dL, respectively (P < 0.001). Mean body weight was significantly increased from 66.7 kg to 69.3 kg. Hypoglycemia and side effects were observed 18 times and only 3 cases showed abnormal liver function tests or edema. In addition, subjects with higher initial HbA1c levels and HOMA-beta showed an independent association with a greater reduction in HbA1c. CONCLUSION: The 4 OHA combination therapy is effective and safe when insulin is not feasible.

Modeling α-Synuclein Propagation with Preformed Fibril Injections

The aggregation of α-synuclein (α-syn) has been implicated in the pathogenesis of many neurodegenerative disorders, including Parkinson's disease (PD), dementia with Lewy bodies (DLB), and multiple system atrophy (MSA). Postmortem analyses of α-syn pathology, especially that of PD, have suggested that aggregates progressively spread from a few discrete locations to wider brain regions. The neuron-to-neuron propagation of α-syn has been suggested to be the underlying mechanism by which aggregates spread throughout the brain. Many cellular and animal models has been created to study cell-to-cell propagation. Recently, it has been shown that a single injection of preformed fibrils (PFFs) made of recombinant α-syn proteins into various tissues and organs of many different animal species results in widespread α-syn pathology in the central nervous system (CNS). These PFF models have been extensively used to study the mechanism by which aggregates spread throughout the brain. Here, we review what we have learned from PFF models, describe the nature of PFFs and the neuropathological features, neurophysiological characteristics, and behavioral outcomes of the models.

Recent Advances in Autoimmune Thyroid Diseases

Autoimmune thyroid disease (AITD) includes hyperthyroid Graves disease, hypothyroid autoimmune thyroiditis, and subtle subclinical thyroid dysfunctions. AITD is caused by interactions between genetic and environmental predisposing factors and results in autoimmune deterioration. Data on polymorphisms in the AITD susceptibility genes, related environmental factors, and dysregulation of autoimmune processes have accumulated over time. Over the last decade, there has been progress in the clinical field of AITD with respect to the available diagnostic and therapeutic methods as well as clinical consensus. The updated clinical guidelines allow practitioners to identify the most reasonable and current approaches for proper management. In this review, we focus on recent advances in understanding the genetic and environmental pathogenic mechanisms underlying AITD and introduce the updated set of clinical guidelines for AITD management. We also discuss other aspects of the disease such as management of subclinical thyroid dysfunction, use of levothyroxine plus levotriiodothyronine in the treatment of autoimmune hypothyroidism, risk assessment of long-standing antithyroid drug therapy in recurrent Graves' hyperthyroidism, and future research needs.

Two Cases of Graves' Disease Presented with Atypical Symptoms

We describe here two Graves' patients who have presented with atypical symptoms. Interestingly, both of them had symptoms related to imbalance of body fluid homeostasis. Chief complaint of a 35-year-old woman (case 1) was the ipsilateral edema of upper body. A 33-year-old man (case 2) who had severe polyuria has referred from urology department with impression of diabetes insipidus. Both of them denied any typical symptoms of Graves' disease at presentation. These rare extrathyroid manifestations of Graves' disease were completely subsided after antithyroid drug treatment. We introduce their clinical courses and possible pathophysiological mechanisms of the atypical symptoms of Graves' disease.

Two Cases of Graves' Disease Presented with Atypical Symptoms

We describe here two Graves' patients who have presented with atypical symptoms. Interestingly, both of them had symptoms related to imbalance of body fluid homeostasis. Chief complaint of a 35-year-old woman (case 1) was the ipsilateral edema of upper body. A 33-year-old man (case 2) who had severe polyuria has referred from urology department with impression of diabetes insipidus. Both of them denied any typical symptoms of Graves' disease at presentation. These rare extrathyroid manifestations of Graves' disease were completely subsided after antithyroid drug treatment. We introduce their clinical courses and possible pathophysiological mechanisms of the atypical symptoms of Graves' disease.

Guidelines for the Diagnosis and Management of Thyroid Disease during Pregnancy and Postpartum / 대한갑상선학회지

No abstract available.

Letter: Association between Cardiac Autonomic Neuropathy, Diabetic Retinopathy and Carotid Atherosclerosis in Patients with Type 2 Diabetes (Endocrinol Metab 2013;28:309-19, Chan-Hee Jung et al.)

No abstract available.

Environmental Factors and Thyroid Dysfunction

No abstract available.

Letter: The Association between Type 2 Diabetes Mellitus and Colorectal Cancer

No abstract available.

Reversible Heart Failure and Rhabdomyolysis Caused by Primary Hypoparathyroidism during Lactation

Hypocalcemia can be complicated, on rare occasions, by congestive heart failure and may also be associated with labor and lactation in some cases. Herein, we report a 30-year-old woman with hypocalcemia-induced heart failure secondary to primary idiopathic hypoparathyroidism precipitated by lactation. The patient presented with chest pain and paresthesia in both arms and legs during breast-feeding after her second delivery. She had severe hypocalcemia and low parathyroid hormone levels. Hypocalcemia-induced rhabdomyolysis further aggravated her hypocalcemia symptoms. The echocardiogram showed global hypokinesia with an ejection fraction of 47%. After calcium and vitamin D replacement, her symptoms and ventricular function improved. Hypocalcemia needs to be considered in patients with heart failure, because it is readily reversible. To the best of our knowledge, this is the first report of a patient with heart failure and rhabdomyolysis induced by primary hypoparathyroidism during lactation.

Intrathyroidal Metastasis of Lung Adenocarcinoma Presenting as Subacute Thyroiditis

One of the rare diseases for differential diagnosis of subacute thyroiditis is metastases within the thyroid gland. We report here on a 72-year-old-woman with painful goiter and signs of hyperthyroidism. Her serum concentration of thyroid hormone was in the upper limit of normal, and the uptake of radioactive iodine by the thyroid was completely depressed. Although subacute thyroiditis was suspected, an additional work up that included a chest CT scan was done for the combined cough and chronic weakness. The result was lung cancer with metastatic involvement of the thyroid and multiple lymph nodes. She refused further anti-cancer therapy and died 5 months after the diagnosis. For the differential diagnosis of such a rare case, careful examination is important even in patients with the typical symptoms and laboratory findings of subacute thyroiditis.

Early Detection Of Asymptomatic Coronary Artery Disease In Patients With Type 2 Diabetes Mellitus

BACKGROUND/AIMS: In type 2 diabetic patients, coronary artery disease (CAD) is usually detected at an advanced stage due to a lack of symptoms. The aim of this study was to define which clinical parameters or non-invasive tests predict CAD in asymptomatic type 2 diabetic patients. METHODS: One hundred fourteen asymptomatic type 2 diabetic patients were divided into two groups based on the number of cardiovascular disease (CVD) risk factors (group A > or =2, group B or =10 years (OR=3.28; 95% CI, 1.29-8.84) were independent CAD risk factors in asymptomatic patients. CONCLUSIONS: We recommend a routine screening for CAD in type 2 diabetic patients who have a longer (> or =10 years) diabetic duration or a family history of CAD, even if they are asymptomatic for CAD.