Evaluation of Hyponatremia and Predictors of Hyponatremia in Patients Hospitalized with the COVID-19

Abstract
Aim: The infection caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), called coronavirus disease-2019 (COVID-19), has been declared by the World Health Organization as a pandemic. Moderate and severe hyponatremia may develop in COVID-19 cases. This study aimed to evaluate the frequency and predictors of hyponatremia in patients hospitalized with COVID-19. Materials and Methods: This retrospective study included patients aged >18 years who were admitted to our hospital between August 1st, 2020, and September 30th, 2020, with positive RNA polymerase chain reaction (PCR) test. Patients' demographic data, comorbidities, vital signs, physical examination findings, laboratory results, sodium levels, and hospital outcomes were evaluated. Results: The study included 760 patients with positive PCR test results. Of all the patients, 47.6% were female, and the median age was 63 years. The in-hospital mortality rate was 11.7%. The median sodium level was 137 (134-140). Hyponatremia was present in 25.7% of the patients, and majority of the patients had mild hyponatremia. Hyponatremia was observed more frequently in patients with advanced age, male gender, diabetes, and severe pneumonia (p=0.041, p=0.003, p<0.001, p=0.002, respectively). Conclusion: In this study, hyponatremia is relatively common in patients admitted with COVID-19 pneumonia, and it is associated with higher disease severity. The incidence of hyponatremia increases in older patients, male patients, patients with severe pneumonia, and patients with diabetes.