The prognostic value of hyponatremia severity in predicting clinical outcomes of COVID-19 patients; a retrospective cohort study

Abstract

Introduction: Hyponatremia, a common electrolyte disturbance, has been increasingly recognized as a potential prognostic marker in patients with COVID-19. Objectives: This retrospective cohort study aimed to evaluate the predictive value of hyponatremia severity in predicting clinical outcomes among patients with COVID-19. Patients and Methods: This retrospective cohort study included 315 adult COVID-19 patients with hyponatremia admitted to Khorshid hospital in Isfahan, Iran, from May to December 2020. Data were extracted from electronic health records using a standardized form, including demographics, clinical data, and laboratory results within 24 hours of admission. Patients were categorized by hyponatremia severity, and clinical outcomes such as intensive care unit (ICU) admission, need for mechanical ventilation, and mortality were recorded. The primary outcome of this study was to assess the relationship between the severity of hyponatremia and adverse clinical outcomes in COVID-19 patients. Results: Severe or moderate hyponatremia was correlated with increased odds of ICU admission compared to mild hyponatremia, with an unadjusted odds ratio (OR) of 2.69 and an adjusted OR of 2.05. The association was even stronger for mechanical ventilation, where severe or moderate hyponatremia increased the odds substantially, with an unadjusted OR of 10.12 and an adjusted OR of 9.40. Regarding mortality, severe or moderate hyponatremia was associated with the highest increase in risk, demonstrating an unadjusted OR of 12.56 and an adjusted OR of 13.30. Conclusion: The results indicated that severe or moderate hyponatremia in COVID-19 patients is strongly associated with worse clinical outcomes. These findings highlight hyponatremia severity as a robust predictor of disease severity and poor prognosis in COVID-19, emphasizing the importance of monitoring and managing sodium levels in affected patients to improve outcomes.