Proton Pump Inhibitors and Hypomagnesemia in Older Inpatients: An Observational Study.

Purpose Proton pump inhibitors (PPIs) are prescribed frequently and can cause potentially severe hypomagnesemia. Researchers assessed the prevalence of hypomagnesemia and the association between PPI use and hypomagnesemia in hospitalized older patients. Methods Researchers conducted a single-center, observational, retrospective cohort study with patients admitted to a geriatric ward at the Jeroen Bosch Hospital in the period between June 24, 2016, and August 30, 2020. Patients were included if they were 65 years of age or older, had a serum magnesium measurement, and a complete overview of patient's current medication was present at the day of admission. The primary outcome was the occurrence of hypomagnesemia at hospital admission. Exposure to PPIs was the primary determinant investigated. Covariates were studied to identify risk factors and to adjust for potential confounding. The strength of the association between PPI and hypomagnesemia was evaluated with unconditional logistic regression, expressed as odds ratios (ORs) with 95% confidence intervals (CIs). Results The prevalence of hypomagnesemia was 21.9% in PPI users and 15.8% in non-PPI users. Overall, the use of PPIs was associated with hypomagnesemia (ORadj = 1.38, 95% CI 1.09-1.76). A trend for this association was most pronounced in male patients (ORadj = 1.88, 95% CI 1.27-2.79), smokers (ORadj = 3.95, 95% CI 1.52-10.28), and in patients using > 7 units alcohol a week (ORadj = 4.44, 95% CI 1.40-14.12). Conclusion Older patients who are taking a PPI have a higher risk of developing hypomagnesemia than nonusers; additional factors can contribute to the risk. Physicians should be aware of PPI-induced hypomagnesemia and routinely monitor serum magnesium levels in older patients.