Visual Abstract: Metformin use based on kidney function. Over ~1 million patients are not on guideline-directed therapy of metformin due to abnormal kidney function. Thee present study studies the relationship of metformin with lactic acidosis over a wide range of eGFR in patients. Patients were followed up for years and were assesed for decline in kidney function via eGFR calculation and risk of development of lactic acidosis due to metformin use. The results were consistent with previously stated guidelines as to which metformin is safe to use in eGFR > 30 over all ranges while risk of lactic acidosis doubles once eGFR drops below 30  mL/min/1.73 m2

Source: JAMA Intern Med