Thyroid Function Test Abnormalities in Children and Adolescents with COVID-19: A Case-Control Study

Background: There is a lack of conclusive evidence regarding thyroid function test (TFT) abnormalities in COVID-19, especially among children. Objectives: This study aimed to investigate TFT abnormalities in COVID-19 pediatric patients compared to healthy children. Methods: This study was conducted on 37 COVID-19-positive children who were admitted to Namazi Hospital from January 21 to March 1, 2022, compared with 37 healthy children. Within 48 h of positive real-time polymerase chain reaction (PCR) results for severe acute respiratory syndrome coronavirus 2, a blood sample was taken to measure serum levels of thyroid -stimulating hormone (TSH) and total thyroxine (tT4) in the two groups. Additional tests, including free and total triiodothyronine, free T4, and thyroperoxidase antibodies, were also conducted on cases. The chi-square, Pearson correlation coefficient, and analysis of variance tests were used for data analysis. Results: Twenty-five patients were male, and 49 were female, with a mean age of 7.99 +/- 5.02. The abnormal TFT and TSH frequency was significantly higher in the case group than in the control group. Nevertheless, there was no significant difference between the case and control groups regarding tT4 abnormalities. We could not establish an association between the mean of TSH and tT4 and age groups in the two groups and between abnormalities of TFTs and COVID-19 severity. Conclusions: Although abnormalities of TFT were significantly more common among COVID-19 children, they were not associated with the disease severity. However, studies with larger sample sizes are recommended to evaluate thyroid abnormalities and their clinical course in COVID-19 children.