Should We Treat for Subclinical Hypothyroidism?: Grand Rounds Discussion From Beth Israel Deaconess Medical Center

In May 2015, the U.S. Preventive Services Task Force issued a guideline on screening for thyroid disease that included a systematic evidence review and an update of its 2004 recommendations. The review assessed the effect of treating screen-detected subclinical thyroid dysfunction on health outcomes. It found adequate evidence that treating subclinical hypothyroidism does not provide clinically meaningful improvements in blood pressure, body mass index, bone mineral density, lipid levels, or quality-of-life measures. The review also concluded that evidence was inadequate to determine whether screening for thyroid dysfunction reduced cardiovascular disease or related morbidity and mortality. In separate guidelines, the American Association of Clinical Endocrinologists and American Thyroid Association advocated aggressive case-finding and recommended screening persons with certain clinical conditions or characteristics rather than the general population. These societies argue that subclinical hypothyroidism adversely affects cardiovascular outcomes and thus merits case-finding. Here, 2 experts discuss their perspectives on whether treating subclinical hypothyroidism reduces morbidity and mortality, whether there are harms of treatment, and how they would balance the benefits and harms of treatment both in general and for a specific patient.