Endocrine Abstracts

Objectives: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is causing coronavirus disease (COVID-19), enters host cells via the angiotensin-converting enzyme 2 receptor. Its expression is higher in thyroid gland than in lungs. In the literature, an association between SARS-CoV-2 infection and subacute thyroiditis/autoimmune thyroid disease has been implicated. Therefore, we aimed to explore the influence of COVID-19 pandemic on the incidence of subacute thyroiditis, Hashimoto’s thyroiditis and Graves’ disease.

Methods: In our retrospective study we reviewed medical records of all patients who were referred for the first time to our thyroid department from 1 April 2019 to 31 May 2019 (before COVID-19) and from 1 April 2020 to 31 May 2020 (during COVID-19). Our institution has a stable catchment area of 1,000,000 inhabitants. Therefore, number of new cases may be considered the incidence of the disease. In each patient, thyroid specialists performed clinical examination and thyroid ultrasound. Levels of thyrotropin (TSH), free thyroxine, free triiodothyronine, thyroid peroxidase antibodies, thyroglobulin antibodies and, if applicable, TSH receptor antibodies as well as sedimentation rate were measured.

Results: In the two months period before COVID-19, we examined 946 patients (224 men/722 women) with the mean age 52.0 19.0 years, and in the two months period during COVID-19, we examined 576 patients (154 men/422 women) with the mean age 53.7 18.3 years. Between the two periods, patients did not differ with respect to sex and age (P = 0.201 and P = 0.438, respectively). Before COVID-19, we found 8 patients with subacute thyroiditis (0.8% from all in that period), while during COVID-19, we found 10 patients with COVID-19 (1.7% from all in that period). The incidence of subacute thyroiditis did not differ significantly between the two periods (P = 0.189). Before COVID-19, we diagnosed 435 (46% from all) patients with Hashimoto’s thyroiditis and 51 (5.4% from all) patients with Graves’ disease, while during COVID-19, we diagnosed 273 (47.4%) patients with Hashimoto’s thyroiditis and 22 (3.8% from all) patients with Graves’ disease. Incidence of Hashimoto’s thyroiditis and Graves’ diseases did not differ significantly between the period before and during COVID-19 (P = 0.629 and P = 0.205, respectively).

Conclusions: Although we diagnosed absolutely and relatively more patients with subacute thyroiditis during COVID-19 than before, the results were not statistically significant and cannot be easily attributed to SARS-CoV-2 infection. A longer observation period would probably yield different results. In addition, we did not find any difference in the incidence of Hashimoto’s thyroiditis and Graves’ disease during COVID-19 pandemic.