Thyroid Dysfunction in COVID-19.

Objective: The aim of this study was to evaluate thyroid dysfunction in COVID-19 and study its association with disease severity in COVID-19.

Methods: Patients with confirmed COVID-19 infection who were admitted to dedicated COVID hospital were recruited over 3 months period. Those with pre-existing thyroid disease were excluded. The thyroid function tests were performed and correlated with interleukin-6 levels.

Results: A total of 164 patients (14 children) with mean(SD) age 53.85 (19.54) years were recruited. The proportion of patients with mild, moderate and severe disease were 22 (13.4%), 78 (47.6%) and 64 (39.0%), respectively, among which 12 (54.5%), 56 (71.8%) and 43 (67.2%) patients had thyroid dysfunction, respectively; = 0.309. Eighty eight (53.7%) had sick euthyroid (84 had low fT3 only), 14 had overt hypothyroidism and 9 had thyroiditis. Median (IQR) levels of serum fT3 showed significant decline from mild category [4.54 (3.81, 5.27)], to moderate [3.95 (3.67, 4.24)] and severe category [3.56 (3.22, 3.89)]; = 0.011. Low fT3 had significant risk [odds ratio (95% CI)] of death [2.634 (1.01, 6.87); = 0.031] and elevated IL-6 [2.575 (1.084, 6.118); = 0.021].

Conclusion: Sick euthyroid was seen in the majority of patients hospitalized with COVID. Low fT3 was associated with death and increased inflammation, suggesting poor prognosis.