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 with 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 2 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.

Main outcome measures: Pneumonia incidence and mortality.

Results: The PS-matched cohort consisted of 6664 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 with DPP4is with an absolute rate difference of 4.05 per 1000 person-years (95% CI, 2.61-5.51). The corresponding incidence rate ratio was 0.71 (95% CI, 0.62-0.81). Similar reduction in risk of pneumonia death was observed (hazard ratio 0.57; 95% CI, 0.42-0.77).

Conclusion: Compared with DPP4is, SGLT2is use was associated with a reduced risk of pneumonia and pneumonia mortality in a real-world setting.