title: Proton-pump inhibitor use is associated with lower urinary magnesium excretion.
abstract: OBJECTIVE
  Although multiple recent studies have confirmed an association between chronic proton-pump inhibitor (PPI) use and hypomagnesaemia, the physiologic explanation for this association remains uncertain. To address this, we investigated the association of PPI use with urinary magnesium excretion.
  
  
  METHODS
  We measured 24-hour urine magnesium excretion in collections performed for nephrolithiasis evaluation in 278 consecutive ambulatory patients and determined PPI use from contemporaneous medical records.
  
  
  RESULTS
  There were 50 (18%) PPI users at the time of urine collection. The mean daily urinary magnesium was 84.6 ± 42.8 mg in PPI users, compared with 101.2 ± 41.1 mg in non-PPI users (P = 0.01). In adjusted analyses, PPI use was associated with 10.54 ± 5.30 mg/day lower daily urinary magnesium excretion (P = 0.05). Diuretic use did not significantly modify the effect of PPI on urinary magnesium. As a control, PPI use was not associated with other urinary indicators of nutritional intake.
  
  
  CONCLUSIONS
  Our findings suggest that PPI use is associated with lower 24-hour urine magnesium excretion. Whether this reflects decreased intestinal uptake due to PPI exposure, or residual confounding due to decreased magnesium intake, requires further study.
authors.affiliation: Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA; Division of Nephrology, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA.
authors.forename: Jeffrey H
authors.initials: JH
authors.lastname: William
authors.forename: Rachel
authors.initials: R
authors.lastname: Nelson
authors.forename: Najwah
authors.initials: N
authors.lastname: Hayman
authors.forename: Kenneth J
authors.initials: KJ
authors.lastname: Mukamal
authors.forename: John
authors.initials: J
authors.lastname: Danziger
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000652:urine; D001900:Boston; D015536:Down-Regulation; D005260:Female; D006801:Humans; D007668:Kidney / Q000187:drug effects* / Q000378:metabolism; D008274:Magnesium / Q000652:urine*; D008297:Male; D008875:Middle Aged; D054328:Proton Pump Inhibitors / Q000009:adverse effects*; D065667:Renal Elimination / Q000187:drug effects*
chemical_list: D015415:Biomarkers; D054328:Proton Pump Inhibitors; D008274:Magnesium
keywords: electrolytes; hypomagnesaemia; magnesium; proton-pump inhibitors