Cardiovascular and renal outcomes among patients with type 2 diabetes using SGLT2 inhibitors added to metformin: a population-based cohort study from the UK

INTRODUCTION: Large numbers of patients with type 2 diabetes receive treatment with a sodium-glucose co-transporter-2 inhibitor (SGLT2i). We investigated whether the cardiorenal preventative effects found in clinical trials are also seen in clinical practice where patient characteristics and adherence to treatment differ. RESEARCH DESIGN AND METHODS: Using UK primary care electronic health records, we followed two cohorts of patients with type 2 diabetes prescribed metformin: SGLT2is (N=12 978) and a matched comparator of patients not using an SGLT2i at the start of follow-up (N=44 286). Independent follow-ups were performed to identify the study outcomes: cardiovascular (CV) composite (comprising non-fatal myocardial infarction (MI)/ischemic stroke (IS) requiring hospitalization and CV death), severe renal disease, and all-cause mortality. Cox regression was used to estimate adjusted HRs. RESULTS: Mean follow-up was 2.3 years (SGLT2i cohort) and 2.1 years (comparison cohort). Mean age was 59.6 years (SD ±10.2, SGLT2i cohort) and 60.4 years (SD ±10.0, comparison cohort). SGLT2i new users were associated with a reduced risk of the CV composite (HR 0.75, 95% CI: 0.61 to 0.93), severe renal disease (HR 0.55, 95% CI: 0.46 to 0.67), and all-cause mortality (HR 0.56, 95% CI: 0.49 to 0.63), with risk reductions similar irrespective of baseline chronic kidney disease. Reduced risks were seen for IS (HR 0.51, 95% CI: 0.36 to 0.74) but not MI (HR 0.98, 95% CI: 0.74 to 1.28). Results were consistent in sensitivity analyses. CONCLUSIONS: In this population-based study, SGLT2is were associated with significant CV, renal and survival benefits among individuals with type 2 diabetes on metformin; the CV benefit was driven by a reduced risk of ischemic stroke.