Long-Term Mortality and SGLT2 Inhibitors in Type 2 Diabetes with and without Renal Impairment: An Observational Cohort Study

Aim: Sodium-glucose co-transporter 2 (SGLT2) inhibitors have emerged as a vital part of management of type 2 diabetes, as they have been shown to have both cardiovascular and renal benefits along with an improved survival rate in several randomized clinical trials. We designed a retrospective cohort study to investigate the impact of SGLT2 inhibitors on mortality among type 2 diabetes patients. Methods: Patients with type 2 diabetes who presented to the Dasman Diabetes Institute in Kuwait were followed from January 1st, 2015, until January 20th, 2023. To control for non-random allocation of SGLT2 inhibitors and measured confounders, we performed one-to-one propensity score matching and evaluated outcomes in the matched cohorts using a Cox proportional hazards model. The primary treatment variable was SGLT2 inhibitor use; time to mortality from any cause was used as the outcome of interest. Results: 1,551 patients were taking SGLT2 inhibitors, and 1,687 patients were not. After propensity score matching, 845 patients were on SGLT2 inhibitors, and 845 patients were not. In post-matching analysis, all-cause mortality was higher among patients who did not take SGLT2 inhibitors compared to patients taking SGLT2 inhibitors (5.2 vs. 2.1%, p = 0.0012). The hazard ratio of all-cause mortality in patients taking SGLT2 inhibitors was 0.42 (95% confidence interval [95% CI], 0.24-0.72). Additional adjustment of matching factors did not change the results. Conclusion: This observational study demonstrated substantial long-term reduction in mortality risk among patients with type 2 diabetes treated with SGLT2 inhibitors. This is irrespective of the stage of their renal diseases or GLP1 agonist. Highlights of the StudyThis study supplements the findings of the clinical trials and confirms the survival benefit of SGLT2 inhibitors.This survival benefit is long-term and can last for up to 8 years. This was not reported by the latest clinical trials.This study will encourage the long-term use of SGLT2 inhibitors.