Estimated glucose disposal rate and risk of first myocardial infarction in people with diabetes

Abstract Background The estimated glucose disposal rate (eGDR), calculated from glycated hemoglobin (HbA1c), hypertension status and BMI, is a proxy for insulin resistance. We examined the association between eGDR and the risk of first myocardial infarction (MI) and post-MI mortality in individuals with type 1 and type 2 diabetes. Methods Using nationwide health registry data (2006–2020), we identified individuals with type 1 and type 2 diabetes. Follow-up started at the first time a complete eGDR could be calculated. eGDR was then handled as a time-updated exposure until first MI, with person-time assigned according to the most recent available value. Among those with MI, follow-up for post-MI mortality started at the event, and covariates were fixed at their last value before MI. Hazard ratios (HRs) with 95% CIs were estimated using Cox regression with adjustment for blood lipids, albuminuria, estimated glomerular filtration rate and physical activity. Results We included 46,155 individuals with type 1 diabetes and 570,230 individuals with type 2 diabetes (both 43% women). During a median follow up of 7.7 person-years, 1997 (4.3%) and 34,237 (6.0%) experienced first MI, respectively. Adjusted HRs (95% CIs) for first MI across eGDR categories ≤4, 4–6, 6–8, and ≥8 mg/kg/min) were: 3.73 (3.35–4.16), 3.09 (2.85–3.35), 2.40 (2.15–2.69) and 0.96 (0.79–1.17) for type 1 diabetes, respectively. Corresponding HRs for type 2 diabetes were 1.71 (1.62–1.82), 1.54 (1.46–1.62), 1.43 (1.35–1.51) and 1 (reference). Similar associations were observed for post-MI mortality, however non-significant across all eGDR categories. Conclusions Lower eGDR, reflecting greater insulin resistance, was associated with a higher risk of first MI, with a stronger association observed in type 1 diabetes. These findings support insulin resistance as a potential modifiable cardiovascular risk factor in people with diabetes.