Patients with type 2 diabetes treated with metformin have a better chance of living longer if they add an SGLT2 inhibitor rather than a sulfonylurea as second-line therapy, a large cohort study shows.

Furthermore, the combination of metformin and an SGLT2 inhibitor reduces all-cause mortality by 30% compared with SGLT2 treatment alone.

The researchers from St Louis University, Missouri, used data from 2016-2021 for more than 128,000 US veterans with type 2 diabetes (mean age 64.6 years, 95% men) who were taking metformin and then added in either an SGLT2 inhibitor (23,870 people) or a sulfonylurea (104,423).

During a mean of 2.2 years’ follow-up, the risk of all-cause mortality was 19% lower in patients who initiated SGLT2 inhibitors as a second-line compared to those who added in a sulfonylurea, the authors reported in JAMA Internal Medicine.