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Learning Objectives
By the end of this review, you will be able to:
1. Understand, describe and list normal thyroid function.
2. Explain the pathophysiology of Graves' disease and be able to list presenting signs and symptoms.
3. List diagnostic and monitoring laboratory tests specific for Graves' disease.
4. List the available treatment options and agents for Graves' disease, and list pros and cons for each therapy.
5. Describe indications, contraindications, dosing and side effects of available treatments.
6. Know the special conditions that need to be monitored in Graves' disease and how they are treated.
Graves' disease is an autoimmune disorder, accounting for up to 80% of all hyperthyroidism cases.1 Affecting 0.5% of the worldwide population, thyroid gland enlargement, excessive thyroid hormone secretion and extrathyroidal issues ranging from ophthalmopathy to thyroid acropathy are all indicative of Graves' disease. Onset usually occurs between the ages of 20 to 50 affecting females five to 10 times more often than men. A younger age of onset may occur in people who have a family history of maternal relatives with Graves' disease. While exact etiology of Graves' disease is unknown, genetics, gender and environmental triggers such as smoking, stressful life events, childbirth, and infection are thought to play a major role.1-5 This article will focus on the clinical presentation of Graves' disease, available treatment options, and treatment in special patient populations.
Normal Thyroid Hormone Production and Release
Thyroid hormone is critical to maintain normal function in most every organ system. The body uses thyroid hormone for normal growth and development in children and metabolic stability in adults.2 Located in the lower part of the neck, the thyroid gland requires daily dietary intake of 100 to 150 micrograms of iodine for normal thyroid hormone synthesis of triiodothyronine (T3) and thyroxine (T4). Dietary intake of iodine is absorbed intestinally and transported to the thyroid gland as iodide. Approximately 80% of hormone released from the thyroid gland is in the form of T4. However, the more potent thyroid hormone, T3, is peripherally converted from T4 by deiondinase enzymes located in the kidney and liver.2,5
Thyroglobulin, a large glycoprotein formed in thyroid cells, is needed for the formation of T3 and T4. Tyrosine residues in thyroglobulin use the iodide to synthesize...