Endocrine Abstracts

Context: A variety of thyroid disorders have been documented in COVID-19 patients, including non-thyroidal illness syndrome (NTIS), subacute thyroiditis (SAT) and thyrotoxicosis.

Objectives: To investigate the relationship between thyroid dysfunctions observed during hospitalisation and COVID-19-related morbidity and mortality.

Study design and setting: Prospective cohort study on patients admitted in a tertiary hospital for COVID-19 pneumonia. Thyroid function tests (TFTs) and thyroid autoantibodies were assessed during hospitalisation and 4 months after discharge (FU1).

Patients and Methods: We enrolled 376 patients between March 2020 and June 2021, including 121 subjects requiring intensive care unit (ICU). Sixty-eight and 13 patients were excluded because they were affected with thyroid diseases or were taking amiodarone.

Results: None of the 295 patients included in the study had subacute thyroiditis during hospitalisation. An undiagnosed primary hypothyroidism was found in four patients (1.3%), two of them with positive TPO-Ab. A transient reduction of TSH, fT3 and fT4 levels compatible with NTIS was found in 62 (21%), 67 (23%) and 14 (5%) patients, respectively. Treatment with steroids during or before the admission did not significantly influence these findings. Thirty-seven out of 295 (13%) patients died during hospitalisation. Risk factors for in-hospital mortality were age >65, obesity, history of cardiac disease, severe ARDS, disseminated intravascular coagulation, cardiac complications, coinfections, liver dysfunctions, low T4 and low T3 levels (P < 0.05), but not low TSH levels. Conversely, age >65, history of cardiac diseases or Parkinson’s disease, severe ARDS requiring intubation, coinfections and low T4 were risk factors for decreased patients’ autonomy after hospitalisation. After discharge 104/258 (40%) of participants decided to withdraw from the study. At FU1, the remaining 154 patients had normal TFTs, except two men with borderline high TSH (<5 mU/l) and negative TPO- or Tg-Ab. TRAb were negative in all patients. None of patients with negative thyroid autoantibodies at admission developed thyroid autoimmunity at FU1. Long-COVID symptoms including fatigue, dyspnea and palpitations, cognitive dysfunctions, depression, balance instability, taste and smell dysfunctions, hair loss were reported by 88/154 (57%) patients at FU1. Interestingly, age> 65 years and low TSH during admission, but not low T3 or T4 were significantly associated with long-covid symptoms such as asthenia and muscular weakness (P = 0.012 and 0.048), but not with neurological or cognitive impairment. Females reported symptoms of long-COVID more frequently than males (P = 0.008).

Conclusions: Biochemical finding in euthyroid patients with severe SARS-CoV 2 infections correlate with in-hospital outcomes and long-term consequences of COVID-19.