Fig. 5.

Correlations of plasma ACTH measured on the day of hospital admission (Day 1) with salivary cortisol levels measured during the next day (Day 2) in COVID-19 patients: a morning (8 a.m.), b mid-day (12-noon), c evening (6 p.m.), and d night (10 p.m.). Correlations were not statistically significant. COVID-19 patients are classified according to the severity of the disease (https://www.covid19treatmentguidelines.nih.gov/overview/clinical-spectrum/), and their clinical course during the 4-week follow-up period of the study. Spearman’s rank correlation coefficient was used for associations between the parameters tested. ACTH, adrenocorticotropin