Association between SGLT2 Inhibitors vs DPP-4 Inhibitors and Risk of Pneumonia Among Patients with Type 2 Diabetes

Context Patients with diabetes are at a higher risk of pneumonia and pneumonia mortality. Sodium-glucose co-transporter 2 inhibitors (SGLT2is), the latest class of glucose-lowering agents, were shown to reduce the risk of pneumonia in clinical trials. However, the real-world effectiveness of SGLT2is on the risk of pneumonia is largely unknown. Objective To investigate the associations between SGLT2is use and the risk of pneumonia and pneumonia mortality compared to dipeptidyl peptidase-4 inhibitors (DPP4is) using an electronic medical database in Hong Kong. Design A retrospective cohort study. The “prevalent new-user” design was adopted to account for the previous exposure to the study drugs being compared. Propensity score (PS) matching (1:4) was used to balance the baseline characteristics of the two groups. Setting and participants Electronic health data of type 2 diabetes patients using SGLT2is and DPP4is between 2015 and 2018 was collected from the Clinical Data Analysis and Reporting System (CDARS). Main Outcome Measures Pneumonia incidence and mortality. Results The PS-matched cohort consisted of 6,664 users of SGLT2is and 26,656 users of DPP4is, with a mean follow-up of 3.8 years. Poisson regression showed that SGLT2is use was associated with lower risk of pneumonia compared to DPP4is with an absolute rate difference of 4.05 per 1000 person-years (95% CI: 2.61-5.51). The corresponding IRR was 0.71 (95% CI: 0.62-0.81). Similar reduction in risk of pneumonia death was observed (HR: 0.57; 95% CI: 0.42-0.77). Conclusion Compared to DPP4is, SGLT2is use was associated with a reduced risk of pneumonia and pneumonia mortality in a real-world setting.