- Initiation of metformin rather than a sulfonylurea reduces mortality risk in patients with type 2 diabetes (T2DM) and chronic kidney disease (CKD).
Why this matters
- Patients with moderately-severely reduced estimated glomerular filtration rate (eGFR) experienced the largest risk reduction.
- Findings support FDA guidance to consider metformin in patients with eGFR between 45 and 59 mL/min/1.73 m2.
- Veterans Health Administration study of 175,296 patients with CKD, followed ≥1 year before initiating metformin (52.4%) or sulfonylurea (47.6%) monotherapy during 2004-2009.
- Funding: National Heart, Lung, and Blood Institute.
- Mean monotherapy duration was 1.7 years; 22.6% and 28.8% of metformin- and sulfonylurea-treated patients later added a second agent.
- 5121 patients died during follow-up.
- Metformin yielded a 36% reduction in mortality risk vs sulfonylureas (HR, 0.64; 95% CI, 0.60-0.68).
- Among patients with eGFR ≥90 mL/min/1.73 m2, metformin reduced mortality risk by 41% (HR, 0.59; 95% CI, 0.50-0.70).
- A smaller effect was observed with eGFR between 45 and 59 mL/min/1.73 m2 (HR, 0.80; P<.001).
- The greatest absolute risk difference occurred among patients with eGFR between 30 and 44 mL/min/1.73 m2 (12.1 fewer deaths/1000 person-years [PY]).
- Risk differences with eGFR of ≥90, 60-89, and 45-59 mL/min/1.73 m2 were 3.0, 4.3, and 3.4 fewer deaths/1000 PY, respectively.
- Observational data, reliance on ICD-9 codes.