Is Smaller Thyroid Gland Volume in COVID-19 Survivors Indicative of Chronic Thyroid Dysfunction?

Abstract

Purpose.Data about the effects of COVID-19 on the endocrine system are increasing, but COVID-19-associated thyroid dysfunctions are not known clearly. We investigated the effects of SARS-CoV-2 on the thyroid gland in COVID-19 survivors.Methods.64 adult COVID-19 survivors and 70 healthy adults were enrolled. The COVID-19 survivors were evaluated at median 5.7 months (IQR: 4-6.5) (range: 2-7 months) after acute infection. The blood tests were obtained for thyroid antibodies and function tests. Thyroid ultrasonography (USG) was done by the same physician. The ellipsoid formula was used for calculation of thyroid gland volume.Results. There was no significant difference between the groups for thyroid hormone levels. The mean thyroid gland volume was significantly lower in COVID-19 survivors (10.3 ± 3.4 ml) than in the controls (14 ± 5.3 ml) (p = 0.001). Mild TSH elevation was detected in 4 (6.2%) patients and all of the other patients (93.7%) were euthyroid. Thirty-one patients, who had pre-COVID thyroid hormone levels, were compared with their post-COVID thyroid hormone levels, and no significant difference was found. Twelve patients, who had acute-COVID infection were compared with their post-COVID thyroid function tests, and free triiodothyronine (FT3) values during acute-COVID infection were significantly lower than in their post-COVID period (p = 0.02).Conclusions.The effects of COVID-19 on the thyroid gland may have a variable course. Our results revealed that a significant decrease in thyroid gland volume in the early post-COVID compared to the healthy subjects and COVID-19 survivors may be candidates for thyroid gland disorders.