Effect of Hypothalamic Adrenal Axis and Thyroid Function Alterations on Prognosis of Critically Ill COVID-19 Patients

Abstract

Aim: The aim of this study was to evaluate the effect of changes in adrenal, and thyroid functions on the prognosis of Coronavirus disease-2019 (COVID-19) patients admitted to the intensive care unit (ICU). Materials and Methods: This was a retrospective evaluation that included COVID-19 patients requiring ICU admission. Serum cortisol, adrenocorticotrophic hormone (ACTH), thyroid-stimulating hormone (TSH), free thyroxine (fT4) and triiodothyronine (fT3) levels were measured on admission and two more times during the hospitalization. Routine biochemistry, hemogram, C-reactive protein, procalcitonin, fibrinogen and D-dimer levels were also measured, along with hormones. All-cause mortality during ICU stay, inotropic drug and mechanical ventilation needs, and duration of hospitalization were recorded for each patient. Euthyroid sick syndrome (ESS) and hypocortisolism rates were determined. Deceased and surviving patients were compared in terms of hormone values, and logistic regression to determine independent associates of mortality was performed. Results: Overall, 124 patients (58% male, mean age 70.7±11.3 years) were included. During the ICU stay, both fT3 and fT4, but not TSH, showed a statistically significant decrease compared to admission values. Serum cortisol and ACTH values increased compared to admission values, but this increase was not significant. ESS was present in 89.5% of the patients. Two-thirds of the patients died in ICU. Serum fT3 values were significantly lower among decedents compared to survivors. Hypocortisolism was detected in 20.1% of the patients. Only the fT3 level could independently and significantly predict all-cause mortality. Conclusion: ESS was almost universal among critically ill COVID-19 patients. Serum fT3, but not other thyroid or adrenal hormones, could significantly predict all-cause mortality.

Keywords

• adrenal function
• euthyroid sick syndrome
• hypocortisolism
• prognosis
• thyroid function