Increased mortality associated with hypermagnesemia in severe COVID-19 illness

BACKGROUND: While electrolyte abnormalities are common among patients with COVID-19, very little has been reported on magnesium homeostasis in these patients. Here we report the incidence of hypermagnesemia and its association with outcomes among patients admitted with COVID-19. METHODS: We retrospectively identified all patients with a positive test result for SARS-CoV-2 who were admitted to a large quaternary care center in New York City in spring 2020. Details of the patients9 demographics and hospital course were obtained retrospectively from the medical record. Patients were defined as having hypermagnesemia if their median magnesium over the course of their hospitalization was >2.4 mg/dL. RESULTS: A total of 1685 patients hospitalized with COVID-19 had magnesium levels checked during their hospitalization and were included in the final study cohort, among whom 355 (21%) had hypermagnesemia. Hypermagnesemic patients had a higher incidence of shock requiring pressors (35 vs 27%, p