When SARS CoV-2 meets thyroid - short-term and long-term patients’ outcomes

Abstract Purpose: The interaction between thyroid and SARS CoV-2 is complex and not yet fully understood. The aim of this study was to identify a possible association of the previous thyroid disease and serum TSH level on the short-term and long-term outcomes of patients hospitalised for COVID-19.Methods: We retrospectively analysed the data of 1423 patients aged 18 years or older, with known previous thyroid status who were admitted for COVID-19 to Clinical Hospital Dubrava, Zagreb, Croatia, between March 2020 and June 2021. For 614 patients whose serum TSH was determined during hospitalisation we examined short-term outcomes, including the required level of oxygen supplementation, admission to the ICU and death. The MSCT image of the chest and TSH was recorded in the post-COVID outpatient clinic six to eight weeks after the discharge from the hospital and was used to estimate the long-term COVID-19 complications. Patients were divided into three groups according to measured TSH levels.Results: Those with lower/suppressed TSH (<0.4 mIU/L) had worse short-term outcomes and were more frequently admitted to the ICU (p<0.011), needed mechanical ventilation (p<0.001) or died (p=0.03). In the post-COVID period, there was an overall increase in the TSH levels when compared to TSH during hospitalisation. The greatest increase was detected among the patients with suppressed/lowered TSH level during hospitalisation, and it correlated significantly with MSCT finding of higher pulmonary involvement (p<0.001).Conclusion: Changes in the serum TSH level may be an important indicator for the course of COVID-19 and its long-term outcomes.