Cardiovascular Safety of Metformin in Patients with Low Renal Function

In 2016, the FDA loosened restrictions on metformin use in patients with mild renal impairment. To assess cardiovascular (CV) outcomes in metformin recipients with declining renal function, U.S. Veterans Affairs researchers conducted this retrospective cohort study of 25,000 metformin monotherapy users and 25,000 propensity-score–matched sulfonylurea monotherapy users (median age, 70) who continued their monotherapies after estimated glomerular filtration rates declined to <60 mL/minute/1.73 m² or after serum creatinine levels reached or exceeded 1.5 mg/dL.

During median follow-up of roughly 1 year, incidence of major adverse CV events, including death, myocardial infarction, stroke, or transient ischemic attack, was significantly lower in m…