Starting metformin treatment, rather than a sulfonylurea, for type 2 diabetes among patients with chronic kidney disease (CKD) is associated with decreased mortality risk, reported a study published in the Journal of General Internal Medicine.

Researchers at the University of Washington in Seattle assessed a cohort of 175,296 veterans who had received care for at least 1 year before starting monotherapy for type 2 diabetes with either metformin or a sulfonylurea from 2004 to 2009. Of these, 5121 patients died. Researchers noted that in comparison with patients starting on a sulfonylurea, those starting on metformin had a 36% lower risk of death, with the magnitude of risk reduction varying by eGFR. Among patients with an eGFR of 90 mL/min/1.73 m² or higher, those starting on metformin had a statistically significant 41% decreased risk of death compared to those starting on a sulfonylurea. Among those with an eGFR of 45–59 mL/min1.73 m², those starting on metformin had a statistically significant 20% decreased risk of death in comparison with those starting on sulfonylurea.

The study thus concluded that initiation of metformin in patients with type 2 diabetes and CKD was associated with a considerable reduction in mortality, in terms of both relative and absolute risk reduction, in comparison with initiation of a sulfonylurea.