Proton Pump Inhibitor Use Increases Pyogenic Liver Abscess Risk: A Nationwide Cohort Study

BACKGROUND/AIMS: Proton pump inhibitors (PPIs) increase gastric pH and alter the gut microbiome. An increased risk for infectious diseases has been reported in PPI users. However, little is known about the association of PPI use with pyogenic liver abscess (PLA) incidence risk. METHODS: We conducted a population-based cohort study using data from a nationwide representative sample of the Korean general population followed up for 10 years (January 1, 2003 to December 31, 2013). We identified PPI prescriptions and considered PPI as a time-varying variable. Proportional hazards regression model was used for incident PLA comparing PPI use versus non-use. Propensity score matching was also conducted. RESULTS: During the 4 209 229 person-years of follow-up, 58 595 participants had at least 1 PPI prescription and 541 patients developed liver abscess. The age-, sex-, residential area-, and income-adjusted hazard ratio for PLA incidence with PPI use was 4.19 (95% CI, 2.54-6.92). The association was observed in fully adjusted models (hazard ratio 3.88; 95% CI, 2.33-6.44). The positive association between PPI use and PLA was consistent in all subgroups analyzed and in propensity score matching group. CONCLUSION: The present data indicate that PPI use is associated with an increased PLA risk. Therefore, it is necessary to prescribe PPIs with clear indication and to avoid improper use of PPIs.