Assessment of Diurnal Salivary Cortisol Production in COVID-19

In the year of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic several studies have focused on the effect of the COVID-19 on the adrenal cortex, demonstrating conflicting results. Herein, researchers sought to investigate the adrenal response in patients with COVID-19by assessing the diurnal rhythm of salivary cortisol and the adrenal androgen dehydroepiandrosterone (DHEA), as well as the plasma levels of aldosterone and adrenocorticotropic hormone (ACTH) in consecutive patients before the possible therapeutic administration of dexamethasone. To elucidate the potential association between the magnitude of individual immune response and the adrenal cortex response we included serum measurements of interleukin - 6 (IL-6).

All adult consecutive patients that visited the emergency department of the LAIKO General Hospital of Athens from May to July 2021 due to confirmed COVID-19 and related symptomatology were eligible for the study. Age and gender matched healthy individuals without COVID-19 who had never been treated with GCs and fulfilled the exclusion criteria were also recruited from the Hospital's personnel and included in the analysis as Controls. Blood samples were obtained immediately upon admission for the measurements of ACTH, IL-6 and aldosterone, which were performed by electrochemiluminescence assays on the cobas e 801 immunoassay analysers (Roche Diagnostics GmbH). Salivary samples for free cortisol and DHEAS were obtained during the next day using the Salivette (Sarstedt, Nümbrecht, Germany) at different time points 0800, 12.00, 18.00, and 22.00. Within 24h after saliva collection the salivettes were centrifuged at 2400 g for 20 min in 4 °C and aliquots were stored at -80 °C and analyzed by an Immunochemiluminescence assay in a Roche COBAS E411 analyzer.