Factors potentiating risk of higher lactate level associated with metformin therapy: a cross-sectional study in an ambulatory care setting

Background: Metformin is the first-line pharmacological treatment for type 2 diabetes mellitus. Metformin-associated lactic acidosis is uncommon; however, subclinical increases in lactate levels can yield considerable clinical consequences, warranting regular surveillance in high-risk patients. Limited data exist on the patterns of metformin dosing and specific patient factors that may elevate lactate levels, indicating a critical need for further investigation. Objectives: This study aimed to determine the patterns of metformin dosing and identify patient-specific factors associated with higher lactate levels. Design: A retrospective, cross-sectional study. Methods: Patients who attended the endocrinology and internal medicine clinic between January 2021 and December 2022 were included. Patients’ data, including demographics, comorbidities, prescribed medications, and laboratory tests, were collected from electronic health records. Patients were categorized based on age (middle-aged