title: Dysmagnesemia in Hospitalized Patients: Prevalence and Prognostic Importance.
abstract: OBJECTIVE
  To examine the prevalence of serum magnesium (Mg) alterations and outcomes in hospitalized patients.
  
  
  METHODS
  All admissions to Mayo Clinic in Rochester, Minnesota, from January 1, 2009, through December 31, 2013 (288,120 patients), were screened. Admission Mg from each unique patient and relevant clinical data were extracted from the institutional electronic database.
  
  
  RESULTS
  After excluding patients aged less than 18 years, those without Mg measurement, and readmission episodes, a total of 65,974 patients were studied. Magnesium levels of 2.1 mg/dL or higher were found in 20,777 patients (31.5%), and levels less than 1.7 mg/dL were noted in 13,320 (20.2%). Hypomagnesemia was common in patients with hematologic/oncological disorders, and hypermagnesemia was common in those with cardiovascular disease. The lowest hospital mortality, assessed by restricted cubic spline and percentage death, occurred in patients with Mg levels between 1.7 and 1.89 mg/dL. An Mg level of less than 1.7 mg/dL was independently associated with an increased risk of hospital mortality after adjusting for all variables except the admission diagnosis; risk for longer hospital stay and being discharged to a care facility were increased in the fully adjusted model. An elevated Mg level of 2.3 mg/dL or higher was a predictor for all adverse outcomes. The magnitude of Mg elevations in patients with levels of 2.3 mg/dL or higher (N=7908) was associated with worse hospital mortality in a dose-response manner. In patients with cardiovascular diseases, Mg levels of 1.5 to 1.69 mg/dL and 2.3 mg/dL or higher both independently predicted poor outcomes including hospital mortality.
  
  
  CONCLUSIONS
  Dysmagnesemia in hospitalized patients is common, with hypermagnesemia being most prevalent. Compared with hypomagnesemia, hypermagnesemia is a stronger predictor for poor outcomes. Magnesium supplementation for patients without Mg deficiency should be avoided in the absence of randomized controlled trials documenting a benefit.
authors.affiliation: Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN.
authors.forename: Wisit
authors.initials: W
authors.lastname: Cheungpasitporn
authors.affiliation: Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN; Department of Anesthesiology, Mayo Clinic, Rochester, MN.
authors.forename: Charat
authors.initials: C
authors.lastname: Thongprayoon
authors.affiliation: Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN. Electronic address: qian.qi@mayo.edu.
authors.forename: Qi
authors.initials: Q
authors.lastname: Qian
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D005260:Female; D017052:Hospital Mortality; D006760:Hospitalization; D006801:Humans; D008274:Magnesium / Q000097:blood*; D008275:Magnesium Deficiency / Q000150:complications / Q000175:diagnosis* / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011379:Prognosis; D012307:Risk Factors
chemical_list: D008274:Magnesium