Hyperthyroidism

Abstract

ImportanceOvert hyperthyroidism, defined as suppressed thyrotropin (previously thyroid-stimulating hormone) and high concentration of triiodothyronine (T3) and/or free thyroxine (FT4), affects approximately 0.2% to 1.4% of people worldwide. Subclinical hyperthyroidism, defined as low concentrations of thyrotropin and normal concentrations of T3 and FT4, affects approximately 0.7% to 1.4% of people worldwide. Untreated hyperthyroidism can cause cardiac arrhythmias, heart failure, osteoporosis, and adverse pregnancy outcomes. It may lead to unintentional weight loss and is associated with increased mortality.ObservationsThe most common cause of hyperthyroidism is Graves disease, with a global prevalence of 2% in women and 0.5% in men. Other causes of hyperthyroidism and thyrotoxicosis include toxic nodules and the thyrotoxic phase of thyroiditis. Common symptoms of thyrotoxicosis include anxiety, insomnia, palpitations, unintentional weight loss, diarrhea, and heat intolerance. Patients with Graves disease may have a diffusely enlarged thyroid gland, stare, or exophthalmos on examination. Patients with toxic nodules (ie, in which thyroid nodules develop autonomous function) may have symptoms from local compression of structures in the neck by the thyroid gland, such as dysphagia, orthopnea, or voice changes. Etiology can typically be established based on clinical presentation, thyroid function tests, and thyrotropin-receptor antibody status. Thyroid scintigraphy is recommended if thyroid nodules are present or the etiology is unclear. Thyrotoxicosis from thyroiditis may be observed if symptomatic or treated with supportive care. Treatment options for overt hyperthyroidism from autonomous thyroid nodules or Graves disease include antithyroid drugs, radioactive iodine ablation, and surgery. Treatment for subclinical hyperthyroidism is recommended for patients at highest risk of osteoporosis and cardiovascular disease, such as those older than 65 years or with persistent serum thyrotropin level less than 0.1 mIU/L.Conclusions and RelevanceHyperthyroidism affects 2.5% of adults worldwide and is associated with osteoporosis, heart disease, and increased mortality. First-line treatments are antithyroid drugs, thyroid surgery, and radioactive iodine treatment. Treatment choices should be individualized and patient centered.

Treatment for Hyperthyroidism During Pregnancy—Reply

“…In Reply We agree that overt Graves disease hyperthyroidism requires treatment during pregnancy. As described in our review, risks for preeclampsia, low birth weight, miscarriage, and preterm delivery are increased without therapy, and as noted by Dr Watkins and colleagues, congenital anomaly risk is higher without treatment than when propylthiouracil is taken. For individuals who need treatment with antithyroid drugs during pregnancy, propylthiouracil is preferred over methimazole during the period of organogenesis.…”

Treatment for Hyperthyroidism During Pregnancy

“…To the Editor Although the recent review of hyperthyroidism by Lee and Pearce was comprehensive, as specialists in maternal-fetal medicine, we have concerns regarding the authors’ overview of antithyroid medications during pregnancy.…”

“…First, Lee and Pearce discussed the teratogenicity of both propylthiouracil and methimazole. The risk of birth defects associated with these antithyroid drugs has been an area of concern since the 1970s.…”

“…However, 2 well-designed studies evaluating the risks of propylthiouracil during pregnancy found no increased risk of congenital anomalies . Lee and Pearce cited the meta-analysis by Agrawal et al noting their finding of an increased relative risk of birth defects with propylthiouracil exposure (adjusted relative risk, 1.16; 95% CI, 1.08-1.25). However, they did not mention that untreated hyperthyroidism was associated with significantly higher rates of congenital anomalies compared with patients treated with propylthiouracil.…”

Black Race and Hepatitis C—a New Focus for JAMA Narrative Reviews

“…Narrative reviews, an important component of JAMA ’s Clinical Review and Education section, provide evidence-based and timely summaries of topics relevant for the practicing generalist clinician. Recent JAMA narrative reviews have covered prediabetes, hyperthyroidism, and care of adults who survived childhood cancer …”