Renal outcomes of combination therapy with sodium-glucose cotransporter 2 inhibitors plus renin-angiotensin system blockers in patients with type 2 diabetes mellitus: A population-based cohort study

Background: Sodium-glucose cotransporter 2 inhibitors (SGLT2i) can benefit patients with type 2 diabetes mellitus by reducing hazardous renal outcomes. This study aimed to evaluate whether the combination of sodium-glucose cotransporter 2 inhibitors (SGLT2i) and conventional renin-angiotensin system blockers (RASB) provides a synergistic effect on renal outcomes in patients with type 2 diabetes mellitus, compared to the combination of RASB and dipeptidyl peptidase 4 inhibitors (DPP4i). Methods: This is a retrospective cohort study. The study utilized data from the Taiwan National Health Insurance Research Database (NHIRD), including patients with type 2 diabetes mellitus enrolled between January 1, 2016, and December 31, 2016. Participants were divided into two groups: the case group (n = 3,622) receiving RASB plus SGLT2i and the comparison group (n = 3,622) receiving RASB plus DPP4i. The groups were matched 1:1 based on gender, age, and Charlson comorbidity index. Additionally, TriNetX was used for external validation. Results: Prior to matching, unadjusted hazard ratios (HRs) showed significant differences favoring the SGLT2i group for chronic kidney disease (CKD) (HR: 0.66; 95% CI, 0.58–0.74), advanced kidney failure (HR: 0.64; 95% CI, 0.44–0.93), and initiation of long-term dialysis (HR: 0.61; 95% CI, 0.38–0.97). These differences remained significant post-matching: CKD (HR: 0.74; 95% CI, 0.65–0.84), advanced kidney failure (HR: 0.62; 95% CI, 0.42–0.92), and commencement of long-term dialysis (HR: 0.53; 95% CI, 0.32–0.87). The renal benefits of the combination therapy were consistently observed in the TriNetX dataset. Limitations: NHIRD lacks key clinical factors (e.g., physical features, lab data), potential baseline disparities due to retrospective design, and limited generalizability beyond Taiwanese patients, despite TriNexT validation. Conclusions: In patients with type 2 diabetes mellitus, combination therapy with SGLT2i and RASB yielded better renal outcomes.