Risk of new-onset diabetes across individual statins in secondary prevention: results from the Korean national health insurance service cohort

Introduction Statins are the cornerstone of secondary prevention in atherosclerotic cardiovascular disease (ASCVD), but their association with new-onset diabetes mellitus (NODM) remains incompletely defined. Whether the risk of NODM differs among individual statins within the same intensity class has not been well established. Methods Using the Korean National Health Insurance Service (NHIS) database, we identified 29,826 patients with established ASCVD who initiated statin therapy between 2009 and 2012 and were followed for up to five years. The primary endpoint was incident NODM, defined by new diagnostic coding plus antidiabetic medication use after a three-year window period. The secondary endpoint was major adverse cardiac and cerebrovascular events (MACCE). Results Overall, 11,918 patients (40.0%) developed NODM. The incidence of NODM was comparable between high- and moderate-intensity statins (42.9% vs. 41.1%). In the moderate-intensity group, rosuvastatin (adjusted HR 1.07, 95% CI 1.01–1.14), pravastatin (HR 1.19, 95% CI 1.02–1.38), and simvastatin (HR 1.15, 95% CI 1.06–1.20) were associated with higher NODM risk compared with atorvastatin, while fluvastatin and pitavastatin showed no significant differences. MACCE incidence was similar across statins. Discussion In this nationwide secondary prevention cohort, the risk of NODM differed across individual statins despite comparable cardiovascular outcomes. These findings suggest that the diabetogenic effect of statins may be agent-specific rather than a uniform class effect, highlighting the importance of individualized statin selection balancing metabolic and cardiovascular benefits.