Metformin use may be safe in patients with type 2 diabetes (T2D) at estimated glomerular filtration rate (eGFR) 30 to 60 mL/min/1.73 m2 and was associated with acidosis only at eGFR <30 mL/min/1.73 m2, a recent study found. In 2 large retrospective cohorts of patients with diabetes mellitus (Geisinger Health System, n=75,413 and MarketScan, n=82,017), researchers sought to quantify the association between metformin use and hospitalization with acidosis across the range of eGFR, accounting for change in eGFR stage over time. They found:
- There were 2,335 hospitalizations with acidosis over a median follow-up of 5.7 years.
- Compared with alternative diabetes management, time-dependent metformin use was not significantly associated with incident acidosis overall (adjusted HR, 0.98) or in patients with eGFR 45 to 59 mL/min/1.73 m2 (adjusted HR, 1.16) and eGFR 30 to 44 mL/min/1.73 m2 (adjusted HR, 1.09).
- Conversely, metformin use was associated with an increased risk of acidosis at eGFR <30 mL/min/1.73 m2 (adjusted HR, 2.07).
Lazarus B, Wu A, Shin J, et al. Association of metformin use with risk of lactic acidosis across the range of kidney function. A community-based cohort study. JAMA Intern Med. 2018;178(7):903–910. doi:10.1001/jamainternmed.2018.0292.