Effect of gastrointestinal disorders in autoimmune thyroid diseases

Autoimmune thyroid diseases are highly prevalent, and many affected individuals may, at some point, require thyroid hormone replacement. Although most patients achieve normal thyroid levels by taking regular doses of levothyroxine, that is not the case in some patients, despite high doses. In many cases, poor adherence to treatment and misuse of medications are main causes of inadequate control. On the other hand, other autoimmune disorders, such as celiac disease and atrophic gastritis, are highly prevalent in patients with autoimmune thyroid disease. Those diseases can interfere in the treatment with thyroid hormone, and lead to inadequate thyroid hormone levels, despite full adherence to therapy. The objective of this paper is to discuss the major disorders of the gastrointestinal tract that affect patients with autoimmune thyroid disease, and its treatment with thyroid hormone.