Hyperthyroidisme pada Kehamilan

Hyperthyroidism is defined by abnormally high levels of thyroid hormones caused by increased synthesis and secretion of thyroid hormones from the thyroid gland. Physiological changes in pregnancy affect the function of the thyroid gland. The sharp increase in human chorionic gonadotropin (hCG) from early pregnancy stimulates the thyroid gland to increase thyroid hormone production. hCG is a glycoprotein synthesized and released from the placenta, and stimulates the TSH receptor due to its structural similarity to TSH. Normal pregnancy produces a number of important physiological and hormonal changes that alter thyroid function. These changes mean that laboratory tests of thyroid function should be interpreted with caution during pregnancy. Thyroid function tests change during pregnancy due to the influence of two main hormones: human chorionic gonadotropin (hCG), the hormone measured in pregnancy tests and estrogen, the main female hormone. The treatment of choice in pregnancy is antithyroid drugs (ATD). These drugs are effective in controlling maternal hyperthyroidism, but they all cross the placenta, thus requiring careful management and control during the second half of pregnancy taking into account the risk of fetal hyperthyroidism or hypothyroidism. An important aspect in early pregnancy is that the main side effect of taking ATD at 6-10 weeks of gestation is birth defects which can develop after exposure to the types of ATD available and may be severe. This review focuses on the management of overt hyperthyroidism in pregnancy, including the etiology and incidence of the disease, how the diagnosis is made, the consequences of untreated or inadequately treated disease, and finally how to treat overt hyperthyroidism in pregnancy. This review discusses the etiology, pathophysiology, and initial evaluation of hyperthyroidism in pregnancy, followed by a discussion of its treatment, management, and complications.

Isfahan Thyroid Cohort Study (ITCS)

Background: The Isfahan Thyroid Cohort Study (ITCS) is one of the few population-based epidemiological studies in Iran that investigates the prevalence and incidence of thyroid disorders including hypothyroidism, hyperthyroidism, goiter, nodule, and iodine status. Methods: This cohort is located in Isfahan, Iran. The first phase was initiated in 2006 with 2523 participants (1275 males, 1248 females). The participants were selected using multi-stage cluster sampling from the general residents of Isfahan, Iran. The study had two phases (2006 and 2011) and its third stage is planned for 2020–2021. Results: The prevalence of thyroid function states was euthyroid (89.3%, 95% CI: 88%–90%), overt hypothyroidism (2.8%, 95% CI: 2%‒3%), subclinical hypothyroidism (5.8%, 95% CI: 4%–6%), overt hyperthyroidism (0.8%, 95% CI: 0.4%‒1%), and subclinical hyperthyroidism (0.99%, 95% CI: 0.6%–1%). Hypothyroidism and hyperthyroidism were significantly associated with goiter. The incidence of thyroid dysfunction was reported as follows: overt hypothyroidism (2.7, 95% CI: 1.6–3.7), subclinical hypothyroidism (20.6, 95% CI: 18–23), overt hyperthyroidism (1.9, 95% CI: 1–2.7) and subclinical hyperthyroidism (2.7, 95% CI: 1.6–3.7) per 1000 (person-year). Conclusion: We assessed the prevalence and incidence of thyroid disorders in Isfahan in the first and second phase, respectively. We are conducting the third phase of the ITCS in order to study the associations between thyroid peroxidase antibody (TPOAb) level and environmental factors such as infection.

The relationship between ultrasound findings and thyroid function in children and adolescent autoimmune diffuse thyroid diseases

To evaluate the association between thyroid echogenicity and heterogeneity seen on ultrasonography (US) and thyroid function in pediatric and adolescent populations with autoimmune diffuse thyroid diseases (AITD). From 2000 to 2020, we reviewed thyroid ultrasound (US) images and thyroid function statuses in 133 children and adolescent AITD patients. Our review of the images focused on decreased echogenicity and heterogeneity, which were classified into four grades. Among patients with overt hypothyroidism or overt hyperthyroidism, 94.2% (65/69) showed a US grade of 3 or 4. In patients with subclinical hyper/hypothyroidism or euthyroidism, 45.3% (29/64) showed grades 1 or 2. There were no overt hyper/hypothyroidism patients with US grade 1. When we compared US grades according to thyroid status, more severe thyroid dysfunction was significantly associated with higher US grade (p = 0.047). Thyroid stimulating hormone (TSH) level differed significantly according to US grades when we evaluated hyperthyroid (p = 0.035) and hypothyroid (p = 0.027) states independently. 11 patients showed both US grade and thyroid function status changes on follow-up US. In children and adolescent AITD patients, there was an association between decreased echogenicity and heterogeneity on US and thyroid dysfunction.

Resting Energy Expenditure and Cold Induced Thermogenesis in Patients with Overt Hyperthyroidism

Context Thyroid hormone is crucial for the adaptation to cold. Objective To evaluate the effect of hyperthyroidism on resting energy expenditure (REE), cold-induced thermogenesis (CIT) and changes in body composition and weight. Design Prospective cohort study. Setting Endocrine outpatient clinic at tertiary referral center. Patients Eighteen patients with overt hyperthyroidism. Main Outcome Measures We measured REE during hyperthyroidism, after restoring euthyroid TH levels and after 3 months of normal thyroid function. In fourteen patients energy expenditure (EE) was measured before and after a mild cold exposure of two hours and CIT was the difference between EEcold and EEwarm. Skin temperatures at eight positions were recorded during the study visits. Body composition was assessed by dual X-ray absorption. Results Free T4 (fT4) and free T3 (fT3) decreased significantly over time (fT4, p=0.0003; fT3, p=0.0001). REE corrected for lean body mass (LBM) decreased from 42 ± 6.7 kcal/24h/kg LBM in the hyperthyroid to 33±4.4 kcal/24h/kg LBM (-21%, p<0.0001 vs hyperthyroid) in the euthyroid state and three months later to 33 ± 5.2 kcal/24h/kg LBM (-21%, p=0.0022 vs. hyperthyroid, overall p<0.0001). Free T4 (p=0.0001) and free T3 (p<0.0001) were predictors of REE. CIT did not change from the hyperthyroid to the euthyroid state (p=0.96). Hyperthyroidism led to increased skin temperature at warm ambient conditions but did not alter core body temperature, nor skin temperature after cold exposure. Weight regain and body composition were not influenced by REE and CIT during the hyperthyroid state. Conclusions CIT is not increased in patients with overt hyperthyroidism.

Incidence, risk factors, natural history and outcomes of heart failure in patients with Graves’ disease

ObjectiveGraves’ disease (GD) can both aggravate pre-existing cardiac disease and cause de novo heart failure (HF), but large-scale studies are lacking. We aimed to investigate the incidence, risk factors and outcomes of incident GD-related HF.MethodsPatients with GD (2009–2019) were retrospectively included. HF with reduced ejection fraction (HFrEF) was defined by left ventricular ejection fraction <50% and Framingham criteria, while HF with preserved ejection fraction (HFpEF) was defined according to the HFA-PEFF criteria. HF due to ischaemia, valve disorder or other structural heart disease was excluded. Proportional hazards regression was used to analyse risk factors and outcomes.ResultsOf 1371 patients with GD, HF occurred in 74 (5.4%) patients (31 (2.3%) HFrEF; 43 (3.1%) HFpEF). In HFrEF, atrial fibrillation (AF) (HR 10.5 (3.0–37.3), p<0.001) and thyrotropin receptor antibody (TRAb) level (HR 1.05 (1.01–1.09) per unit, p=0.007) were independent risk factors. In HFpEF, the independent risk factors were chronic obstructive pulmonary disease (HR 7.2 (3.5–14.6), p<0.001), older age (HR 1.5 (1.2–2.0) per 10 years, p=0.001), overt hyperthyroidism (HR 6.4 (1.5–27.1), p=0.01), higher body mass index (BMI) (HR 1.07 (1.03–1.10) per unit, p=0.001) and hypertension (HR 3.1 (1.3–7.2), p=0.008). The risk of cardiovascular hospitalisations was higher in both HFrEF (HR 10.3 (5.5–19.4), p<0.001) and HFpEF (HR 6.7 (3.7–12.2), p<0.001). However, only HFrEF was associated with an increased risk of all-cause mortality (HR 5.17 (1.3–19.9), p=0.02) and ventricular tachycardia/fibrillation (HR 64.3 (15.9–259.7), p<0.001).ConclusionDe novo HF occurs in 5.4% of patients with GD and is associated with increased risk of cardiovascular hospitalisations and mortality. Risk factors include AF, higher TRAb, higher BMI and overt hyperthyroidism.

A Chinese survey on clinical practice in hyperthyroidism management: comparison with recent studies and guidelines

Objective: To conduct a questionnaire survey of the current clinical practice for overt hyperthyroidism in China. Methods: An online questionnaire survey was conducted in July 2020. The two questionnaires covered 35 and 8 questions about nonpregnancy and pregnancy clinical practice for overt hyperthyroidism, respectively. Results: One thousand, two hundred fifty-six physicians participated. Chief physicians and associate chief physicians accounted for 58.6% of the participants. Approximately 95.2% of the respondents chose the thyrotropin receptor antibody (TRAb) test to clarify the etiology of thyrotoxicosis, while only 27.0% of them chose radioactive iodine uptake (RAIU). In terms of the treatment for nonpregnant patients, antithyroid drugs (ATDs) were the first choice, and most of the clinicians chose methimazole. Compared with clinicians in recent studies, Chinese physicians used serum TRAb to diagnose Graves’ disease more commonly, and there were obviously more physicians preferring ATDs. For maternal hyperthyroidism, most physicians preferred propylthiouracil administration before or during the first trimester, which is consistent with the 2016 American Thyroid Association (ATA) guidelines. In terms of the initial ATD dose, monitoring of the treatment process, indications for ATD withdrawal, and treatment of special cases, the preferences of Chinese physicians were generally consistent with the guidelines. Conclusion: Chinese physicians can generally follow the ATA guidelines for the diagnosis and treatment of hyperthyroidism. Moreover, there are small differences from foreign studies or the guidelines with respect to particular problems. These findings provide evidence for future clinical research in China.

Association between ultrasonography echogenicity and heterogeneity and thyroid function in autoimmune diffuse thyroid diseases in children and adolescents

Purpose: To evaluate the association between thyroid echogenicity and heterogeneity seen on ultrasonography (US) and thyroid function in pediatric and adolescent populations with autoimmune diffuse thyroid diseases (AITD).Methods: From 2000 to 2020, we reviewed thyroid ultrasound (US) images and thyroid function statuses in 133 children and adolescent AITD patients. Our review of the images focused on decreased echogenicity and heterogeneity, which were classified into four grades.Results: Among patients with overt hypothyroidism or overt hyperthyroidism, 94.2% (65/69) showed a US grade of 3 or 4. In patients with subclinical hyper/hypothyroidism or euthyroidism, 45.3% (29/64) showed grades 1 or 2. There were no overt hyper/hypothyroidism patients with US grade 1. When we compared US grades according to thyroid status, more severe thyroid dysfunction was significantly associated with higher US grade (p=0.047). Thyroid stimulating hormone (TSH) level differed significantly according to US grades when we evaluated hyperthyroid (p=0.035) and hypothyroid (p=0.027) states independently. 11 patients showed both US grade and thyroid function status changes on follow-up US.Conclusions: In children and adolescent AITD patients, there was an association between decreased echogenicity and heterogeneity on US and thyroid dysfunction.

Fracture in a girl with graves’ disease induced by osteoporosis: A case report

A 6-year-old girl with long-standing Graves’ Disease (GD) presented with a left oblique non-displaced humeral fracture. Examination reveals signs of thyrotoxicosis and mild swelling of her left humerus. Investigations confirmed severe overt hyperthyroidism due to GD. A dual-energy X-ray Absorptiometry (DXA) of the lumbar vertebrae (L1-4) and femoral neck revealed that Z-score were -2.9 and -2.1, respectively, representing below the expected range for age which is consistent with osteoporosis. The girl was commenced on carbimazole in a dose of 5 mg two times daily and propranolol 10 mg two times daily. After one year of treatment, she returned to a euthyroid state, and Bone Mineral Density (BMD) increase by 19% and 23% of the lumbar spine and femur neck, respectively Keywords: Osteoporosis; Graves’ disease; Fracture.