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/γ 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.