Insulin resistance is a well-known driver of cardiovascular risk in diabetes, but its direct impact on first myocardial infarction (MI) remains under investigation. Presented at the European Association for the Study of Diabetes 2025, this large registry-based study evaluated the relationship between estimated glucose disposal rate (eGDR), a clinical proxy for insulin sensitivity, and cardiovascular outcomes in 46,155 individuals with type 1 diabetes and 570,230 individuals with type 2 diabetes. 

Participants were categorized by eGDR (<4, 4-5.99, 6-7.99, >8 mg/kg/min) and followed for first MI and post-MI mortality. The incidence of first MI increased significantly with lower eGDR, especially in type 1 diabetes, where hazard ratios for MI reached 3.73 (95% CI: 3.35–4.16) in the lowest category compared to the highest. Type 2 diabetes participants also showed elevated risk with lower eGDR, though the association was less pronounced. 

No link was found between eGDR and post-MI mortality in either group. These findings highlight the critical role of insulin resistance in precipitating first MI, particularly in type 1 diabetes, and support targeting metabolic control to prevent cardiovascular events.