Purpose: Proton pump inhibitor (PPI) may suppress adrenal cortical steroid synthesis and release, thereby leading to electrolyte disturbances. Both hyponatremia and hyperkalemia in the setting of PPI therapy have been documented in case reports. The objective of this study was to examine the association between serum potassium (K(+)) level and PPI use.
Methods: A retrospective data analysis of hospitalized adults aged > or = 65 years during 2006, including PPI users (N = 257) and PPI non-users (N = 388), was conducted. Multiple linear and logistic regression analyses were used to assess the association between PPI use and serum K(+) level.
Results: PPI users [mean age (SD):79.7 (8.0) years; 70% female] had significantly higher serum K(+) levels than PPI non-users [80.2 (8.8) years; 64% female] on admission [4.13 (0.62) vs. 3.97 (0.57) mmol/L; p < 0.001]. The linear regression model revealed that > or = 2 defined daily dose (DDD) units of PPI use were a significantly positive contributor to serum K(+) levels (p = 0.021) after adjusting for age, serum creatinine levels, sex, history of diabetes, and uses of the following drugs: angiotensin-converting enzyme (ACE) inhibitor, angiotensin receptor blocker, beta blocker, diuretics, spironolactone, K(+) supplement, non-steroidal anti-inflammatory drugs, atypical antipsychotics, and narcotics. However, multiple logistic regression model revealed that high dose PPI therapy was not associated with an increased risk for hyperkalemia occurrence (p = 0.762).
Conclusion: Higher serum K(+) levels were observed among PPI users when compared to PPI non-users. High daily dose PPI therapy may be an independent positive predictor of serum potassium levels.