(A1121) Impact of Metformin on Chronic Rhinosinusitis Development and Complications in Patients with Type 2 Diabetes

Introduction: Metformin is commonly prescribed for Type 2 Diabetes Mellitus (T2DM), although its effects on sinonasal mucosa are not fully understood. This study examines the impact of Metformin on the complications of Chronic Rhinosinusitis (CRS) in T2DM patients.

Methods: This study utilized TriNetX, a nationwide database containing de-identified electronic health records between 2004–2024. Patients were identified using ICD-10 codes for T2DM, Chronic Rhinosinusitis, and Metformin use. Propensity score matching was performed (1:1) based on demographics, BMI, and A1c levels to create control cohorts of patients with T2DM and Chronic Rhinosinusitis not taking Metformin. The primary outcome was the need for surgery, identified using CPT codes for surgical and endoscopic procedures on the accessory sinuses and nose. Kaplan–Meier analysis estimated diagnosis probabilities, with cohort comparisons using the log-rank test. Hazard ratios (HRs) with 95% confidence intervals (CI) were calculated using the Cox proportional hazards model, with significance set at p < 0.05.

Results: The analysis included 204,424 patients with T2DM and Chronic Rhinosinusitis on Metformin versus matched controls not on Metformin. Metformin users were less likely to require surgery (HR: 0.939, 95% CI: 0.915–0.964, p < 0.0001).

Conclusions: This retrospective cohort study suggests that Metformin may mitigate severe CRS complications, such as the need for surgery, for patients with Type 2 Diabetes.