COVID-19: hypernatremia is a significant predictor of mortality

ABSTRACT

Introduction: Coronavirus disease 2019 (COVID-19) pandemic spread rapidly, creating a worrisome scenario worldwide. In hospitalized patients, dysnatremia (hyponatremia and/or hypernatremia) is the most common electrolyte disturbance, reported in 30­40% of cases and associated with a poor prognosis. This study aimed to evaluate the association between dysnatremia and mortality in hospitalized patients infected with SARS-COV-2. Methods: Retrospective longitudinal study that analyzed data from hospital records of 1,000 patients with COVID-19 (median age, 62.5 years; 57.1% men), including 109 (10.9%) deaths. Kaplan-Meier survival curves and Cox proportional hazard models with Hazard Ratio (HR) with 95% confidence intervals (95%CI) were applied to confirm the association between dysnatremia (hyponatremia and/or hypernatremia) and death. Results: Hypernatremia was detected in 83 (76.1%) of the patients who died, with a cumulative reduction in survival (p < 0.01) and a 2.42-fold increased mortality risk (95%CI 1.45­2.91). In the multivariable analysis, hypernatremia was the main factor associated with increased mortality (HR 1.50; 95%CI 1.23­1.81). Long length of stay (LOS) (HR 1.54; 95%CI 1.21­1.78), old age (HR 1.63; 95%CI 1.28­1.88), and chronic kidney disease (HR 1.77; 95%CI 1.21­3.30) were also associated with death. Conclusion: Hypernatremia during hospitalization is an important risk factor for poor prognosis and an increased mortality risk. LOS, old age, and chronic kidney disease could also be used for risk stratification in patients with COVID-19.