Selected observational studies reporting the risk of acidosis among metformin users with reduced kidney function
| Author | Year of publication | Country | N | Age | HR (95% CI) of acidosis outcome | Key findings |
| Ekström et al31 | 2012 | Swedish National Diabetes Register (Sweden) | 51 675 | Mean 65.3 years | 0.85 (0.74 to 0.97) (eGFR 45–60 mL/min/1.73 m2); 0.98 (0.79 to 1.21) (eGFR 30–45 mL/min/1.73 m2) | Compared with other oral antihyperglycemic agents and insulin, metformin use was associated with reduced risk of acidosis and serious infection and all-cause mortality in patients with eGFR of 45–60 mL/min/1.73 m2. Metformin use was not associated with increased risk of acidosis and serious infection and all-cause mortality in patients with eGFR of 30–45 mL/min/1.73 m2. |
| Lazarus et al29 | 2018 | Geisinger Health System (USA) | 75 413 | Mean 60.4 years | 1.16 (0.95 to 1.41)(eGFR 45–59 mL/min/1.73 m2); 1.09 (0.83 to 1.44) (eGFR 30–44 mL/min/1.73 m2); 2.07 (1.33 to 3.22) (eGFR <30 mL/min/1.73 m2) | Metformin use was not associated with incident acidosis among patients with eGFR of >30 mL/min/1.73 m2. Metformin use was associated with increased incident acidosis among patients with eGFR of <30 mL/min/1.73 m2. |
| Chu et al30 | 2020 | National Veterans Health Administration, Medicare, Medicaid, National Death Index (USA) | 49 204 | Median 70 years | 1.21 (0.99 to 1.50) (eGFR <60 mL/min/1.73 m2) | Among patients who developed reduced kidney function, the rate of lactic acidosis hospitalization was not statistically different between metformin users and sulfonylurea users. |
eGFR, estimated glomerular filtration rate.