Dysnatremia and Endocrine Alterations in Hospitalized COVID-19 Patients: Markers of Systemic Stress Rather than Independent Predictors of Outcomes

Background: COVID-19 is a multisystem disorder associated with inflammatory, metabolic, electrolyte, and endocrine disturbances. However, the clinical relevance of dysnatremia and acute hormonal alterations remains uncertain, particularly when assessed alongside established clinical risk factors. Methods: This prospective cohort study included 252 adults hospitalized with confirmed COVID-19. Clinical, laboratory, hormonal, and metabolic parameters were assessed at admission, and their associations with disease severity, intensive care unit (ICU) admission, and in-hospital mortality were analyzed. Results: The median age was 73 years, 50.4% of patients were female, and severe or critical disease was present in 81.7%. Dysnatremia and/or endocrine alterations were detected in 55.2% of patients, including hyponatremia in 16.7%, while thyroid-function alterations were observed in 40.9%. Dysnatremia was associated with higher glucose levels and inflammatory-cell changes. Several hormonal and metabolic parameters showed statistically significant univariate associations with adverse outcomes; however, their discriminative performance was weak, with AUC values below clinically meaningful thresholds. After adjustment for major clinical confounders, dysnatremia and endocrine alterations were not independent predictors of disease severity, ICU admission, or mortality. Conclusions: These findings suggest that electrolyte and endocrine abnormalities in hospitalized COVID-19 patients primarily reflect systemic stress physiology and acute disease burden rather than functioning as independent prognostic biomarkers.