Metformin adherence and the risk of cardiovascular disease: a population-based cohort study
Shun-Fan Yu, Chien‐Tai Hong, Wan‐Ting Chen, Lung Chan, Li‐Nien Chien
Abstract
Background: Metformin is a potent antiglycemic agent, but its importance has receded owing to the launch of novel antidiabetic medications. The benefit of metformin includes not only blood sugar control but also anti-inflammation, autophagy activation, and neuroprotection. This study investigated the risk of cardiovascular disease (CVD) in people with type II diabetes mellitus (T2DM) who adhered to metformin after adding on a second-line antiglycemic agent. Objectives: The purpose of this study was to investigate the benefits of metformin in CVD prevention in patients with T2DM. Design: We designed the study by comparing the incident rate of CVD events in patients with T2DM who received metformin continually and who ceased metformin during 2002-2014. Methods: Medical information was obtained from the National Health Insurance Research Database, and patients with T2DM receiving second-line antiglycemic agents were categorized into metformin-adherent and nonadherent groups according to prescription claims. The study outcomes were the incidence of CVD hospitalization, including stroke (ischemic and hemorrhagic) and myocardial infarction (MI). Results: < 0.001). The risk reduction persisted in both ischemic and hemorrhagic strokes. Our subgroup analysis revealed that the protective effect on stroke and MI hospitalization persisted in metformin-adherent patients, both sexes, patients aged ⩽65 or >65 years, and patients with or without concurrent insulin treatment. Conclusions: This study revealed that metformin adherence in patients with T2DM who required a first-line treatment may reduce the risk of subsequent CVD. Despite the availability of numerous novel antiglycemic agents, metformin adherence by patients who require a combination of antiglycemic agents provides an additional benefit of CVD protection.