Association of Increased Risk of Pneumonia and Using Proton Pump Inhibitors in Patients With Type II Diabetes Mellitus

BACKGROUND: This study explored the possible association between the use of proton pump inhibitors (PPIs) and the increased incidence of pneumonia in patients with type 2 diabetes mellitus (T2DM). METHODS: We selected 4940 patients with T2DM of whom 988 and 3952 were enrolled in PPI and propensity score-matched control cohorts, respectively. All patients were followed from the index date until admission with pneumonia, withdrawal from the National Health Insurance program or the end of 2013. The PPIs associated with risk of incident pneumonia were examined. Furthermore, we assessed the risk of pneumonia according to annual defined daily doses in the PPI cohort. RESULTS: After a 14-year follow-up, the cumulative incidence of pneumonia in the PPI users was 11.4% higher than that in the controls (30.3% vs 18.9%). Compared to the controls, the PPI users had a 1.70-fold higher risk of pneumonia in the Cox proportional hazards model after adjustment for matched pairs. The risk of pneumonia increased with the annual PPI defined daily dose. CONCLUSION: The results of this population-based retrospective cohort study suggest that PPI use increased the risk of pneumonia in patients with T2DM. The effects were more prominent in patients administered higher doses of PPIs.