Table 1.

Overview of studies on prevalence and relevance of thyroid dysregulation in COVID-19.

Number of COVID-19 patients in the study	Patients with abnormal TH values (%)	Focus of the study	Type of alterations in TH levels; control groups	Reference
191	13.1	Specificity of TH level changes for COVID-19	TSH decreased (5.2%); fT3 decreased (5.2%); COVID-19 vs non-COVID-19 hospitalized patients	(44)
334	13.7	Specificity of TH level changes for COVID-19	TSH and fT4 decreased; COVID-19 vs non-COVID-19 hospitalized patients	(45)
52	21	Role of TH levels for the severity of COVID-19	TSH decreased and T4 increased (15%); critically ill COVID-19 vs critically ill non-COVID-19 patients	(46)
60	35	Role of TH levels for the severity of COVID-19	TSH and T3 decreased (18.3%); TSH decreased and T4 increased (9.1%); critically ill vs non-severe COVID-19	(47)
50	58	Specificity of TH level changes for COVID-19	TSH and total T3 decreased and T4 normal; COVID-19 vs non-COVID-19 pneumonia and healthy individuals	(48)
84	61.9	Specificity of TH level changes for COVID-19	TSH and total T3 decreased; COVID-19 vs non-COVID-19 pneumonia and healthy individuals	(49)
48	75	Specificity of TH level changes for COVID-19	TSH and total T4 increased, total T3 decreased; COVID-19 pneumonia vs non-COVID-19 pneumonia	(50)
100	na	Role of TH levels for the severity of COVID-19	TSH and fT3 decreased; critically ill vs to non-severe COVID-19	(51)
113	na	Role of TH levels for the severity of COVID-19	TSH and fT3 decreased: deceased COVID-19 vs survivors	(52)