Thyroid Dysfunction in COVID-19

Background: Preliminary data suggest that thyroid dysfunction may occur in association with coronavirus disease-2019 (COVID-19). Objective: To clarify the link between COVID-19 and thyroid function. Methods: PubMed search of English literature until August 11, 2020. Since there is lack of randomized trials, case reports retrospective studies, and National guidelines are reviewed. Results: Retrospective studies suggest that 7-34% of patients with COVID-19 admitted to the hospital display thyroid hormone alterations consistent with non-thyroidal illness. Severity of thyroid hormonal abnormalities correlate with severity of COVID-19. Only 4 well-documented cases of subacute thyroiditis were reported in association with infection with COVID-19. Less commonly, de novo autoimmune Hashimoto’s hypothyroidism was reported in COVID-19. Conclusion: Alterations of thyroid hormones due to non-thyroidal illness are common in COVID-19, whereas other thyroid diseases seem uncommon or underreported. Evaluation of thyroid function should be considered in patients with COVID-19 with symptoms or signs pertinent to thyroid function.