Abnormal TSH level as a predictor of severe outcomes among patients hospitalized with COVID-19

Objective: To assess the association between thyroid dysfunction and mortality among patients hospitalized with COVID-19. Design: This is a retrospective multi-center study, which examined all patients admitted with Covid-19 diagnoses, and thyroid function results in absence of known thyroid disease. Results: 10,933 hospitalized COVID-19 positive patients were included in the study. These patients were without prior diagnosis or treatment of thyroid disease. Outcomes assessed were mortality, ICU admission, Ventilator use, length of stay, readmission and complications during hospital stay. Patients with low TSH and Low free T4 had odds of mortality of 10.07(95% CI [7.44-13.6]) compared to patients with Normal TSH and any free T4 levels. Patients with Low TSH and High free T4 also had odds of mortality of 1.38 (95% CI [1.19-1.59]) compared to patients with Normal TSH and Any free T4 level. Patients with Low TSH and Normal free T4 levels also had an Odds of mortality of 1.46 (95% CI [1.31-1.62]) compared to patients with Normal TSH and any free T4 level. Patients with Low TSH also had higher odds of ICU admission and Ventilator use when compared to patients with normal TSH. Conclusions: This study shows that patients with low TSH, regardless of free T4 level, indicates poor prognosis for hospitalized patients with SARS-CoV-2 infection and offers further insights into possible prognostic value of TSH levels for severe COVID-19 outcomes.