American Board of Internal Medicine (ABIM) Certification Practice Exam

What could precipitate thyroid storm in patients with underlying Graves disease?

1. Increased physical activity

2. The iodine content in contrast media

3. Low thyroid hormone levels

4. Use of beta-blockers

The correct answer is: The iodine content in contrast media

Thyroid storm is a life-threatening condition characterized by an extreme increase in thyroid hormone levels, commonly seen in patients with untreated or inadequately managed hyperthyroidism, such as those with Graves' disease. The precipitating factors for thyroid storm often involve situations that lead to an abrupt increase in thyroid hormone release. The iodine content in contrast media can trigger thyroid storm in patients with Graves' disease due to the phenomenon known as the "Jod-Basedow effect." High levels of iodine can stimulate the thyroid gland to produce and release more thyroid hormones, exacerbating hyperthyroidism and potentially leading to a thyroid storm. This is particularly relevant in patients who have Graves' disease, as their thyroid tissue is already hyper-responsive to hormonal stimulation. Increased physical activity, while it can raise metabolic demands, is not a common direct trigger for thyroid storm in the way that elevated iodine exposure is. Low thyroid hormone levels would typically not lead to a thyroid storm, as the condition is defined by excess hormone production and release. The use of beta-blockers, on the other hand, is often used as supportive treatment to manage symptoms in cases of hyperthyroidism and does not precipitate a thyroid storm; in fact, they can help mitigate some of the cardiovascular effects associated