title: Impact of proton pump inhibitor use on magnesium homoeostasis: a cross-sectional study in a tertiary emergency department.
abstract: BACKGROUND
  To date, the use of proton pump inhibitors (PPIs) has been associated with a low risk of hypomagnesaemia and associated adverse outcomes. We hypothesised that a better risk estimate could be derived from a large cohort of outpatients admitted to a tertiary emergency department (ED).
  
  
  METHODS
  A cross-sectional study was performed in 5118 patients who had measurements of serum magnesium taken on admission to a large tertiary care ED between January 2009 and December 2010. Hypomagnesaemia was defined as a serum magnesium concentration < 0.75 mmol/l. Demographical data, serum electrolyte values, data on medication, comorbidities and outcome with regard to length of hospital stay and mortality were analysed.
  
  
  RESULTS
  Serum magnesium was normally distributed where upon 1246 patients (24%) were hypomagnesaemic. These patients had a higher prevalence of out-of-hospital PPI use and diuretic use when compared with patients with magnesium levels > 0.75 mmol/l (both p < 0.0001). In multivariable regression analyses adjusted for PPIs, diuretics, renal function and the Charlson comorbidity index score, the association between use of PPIs and risk for hypomagnesaemia remained significant (OR = 2.1; 95% CI: 1.54-2.85). While mortality was not directly related to low magnesium levels (p = 0.67), the length of hospitalisation was prolonged in these patients even after adjustment for underlying comorbid conditions (p < 0.0001).
  
  
  CONCLUSIONS
  Use of PPIs predisposes patients to hypomagnesaemia and such to prolonged hospitalisation irrespective of the underlying morbidity, posing a critical concern.
authors.affiliation: Department of Emergency Medicine, Inselspital University of Bern, Bern, Switzerland.
authors.forename: G
authors.initials: G
authors.lastname: Lindner
authors.forename: G-C
authors.initials: GC
authors.lastname: Funk
authors.forename: A B
authors.initials: AB
authors.lastname: Leichtle
authors.forename: G M
authors.initials: GM
authors.lastname: Fiedler
authors.forename: C
authors.initials: C
authors.lastname: Schwarz
authors.forename: T
authors.initials: T
authors.lastname: Eleftheriadis
authors.forename: A
authors.initials: A
authors.lastname: Pasch
authors.forename: M G
authors.initials: MG
authors.lastname: Mohaupt
authors.forename: A K
authors.initials: AK
authors.lastname: Exadaktylos
authors.forename: S
authors.initials: S
authors.lastname: Arampatzis
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D004636:Emergency Service, Hospital; D005260:Female; D006706:Homeostasis / Q000187:drug effects*; D006801:Humans; D008274:Magnesium / Q000097:blood*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D054328:Proton Pump Inhibitors / Q000009:adverse effects / Q000627:therapeutic use*
chemical_list: D054328:Proton Pump Inhibitors; D008274:Magnesium