Homeostasis model assessment of insulin resistance and survival in patients with diabetes and acute coronary syndrome

Objective Insulin resistance has been linked to development and progression of atherosclerosis and is present in most patients with type 2 diabetes. Whether the degree of insulin resistance predicts adverse outcomes in patients with type 2 diabetes and acute coronary syndrome (ACS) is uncertain. Design The Effect of Aleglitazar on Cardiovascular Outcomes after Acute Coronary Syndrome in Patients with Type 2 Diabetes Mellitus trial compared the peroxisome proliferator-activated receptor-α/ 3 agonist aleglitazar with placebo in patients with type 2 diabetes and recent ACS. In participants not treated with insulin, we determined whether baseline homeostasis model assessment of insulin resistance (HOMA-IR; n = 4303) or the change in HOMA-IR on assigned study treatment (n = 3568) was related to the risk of death or major adverse cardiovascular events (cardiovascular death, myocardial infarction, and stroke) in unadjusted and adjusted models. Because an inverse association of HOMA-IR with N-terminal pro-B-type natriuretic peptide (NT-proBNP) has been described, we specifically examined effects of adjustment for the latter. Results In unadjusted analysis, twofold higher baseline HOMA-IR was associated with lower risk of death [hazard ratio (HR): 0.79, 95% CI: 0.68 to 0.91, P = 0.002]. Adjustment for 24 standard demographic and clinical variables had minimal effect on this association. However, after further adjustment for NT-proBNP, the association of HOMA-IR with death was no longer present (adjusted HR: 0.99, 95% CI: 0.83 to 1.19, P = 0.94). Baseline HOMA-IR was not associated with major adverse cardiovascular events, nor was the change in HOMA-IR on study treatment associated with death or major adverse cardiovascular events. Conclusions After accounting for levels of NT-proBNP, insulin resistance assessed by HOMA-IR is not related to the risk of death or major adverse cardiovascular events in patients with type 2 diabetes and ACS.