Insulin resistance is associated with high-risk coronary artery plaque composition in asymptomatic men between 65 and 75 years and no diabetes: A DANCAVAS cross-sectional sub-study

Background and aims: Insulin resistance (IR) and pre-diabetes are associated with an increased risk of cardiovascular disease (CVD). We aimed to investigate vulnerable plaque composition in relation to IR and pre-diabetes in asymptomatic non-diabetic men.Methods: All participants underwent a contrast-enhanced coronary computed tomography angiography (CCTA) to evaluate coronary artery plaque burden and plaque composition (necrotic core, dense calcium, fibrotic and fibrous-fatty volume). Homeostasis model assessment of IR (HOMA-IR) was used, and participants were stratified into tertiles. Participants underwent a standard oral glucose tolerance test (OGTT) and were categorized into 2 groups (normal glucose tolerance (NGT) or pre-diabetes). A multivariable linear regression model was used to evaluate the association between vulnerable plaque composition and IR or glycemic group.Results: Four-hundred-and-fifty non-diabetic men without known CAD were included. The mean age was 70 +/- 3 years. Participants in the higher HOMA-IR tertile (H-IR) had higher median necrotic plaque volume compared to the lower HOMA-IR tertile (L-IR) (18.2 vs. 11.0 mm(3), p = 0.02). H-IR tertile (beta 0.37 [95% CI 0.10-0.65], p = 0.008), pack-years (beta 0.07 [95% CI 0.007-0.14], p = 0.03) and total atheroma volume (TAV) (beta 0.47 [95% CI 0.36-0.57], p < 0.001) remained associated with necrotic plaque volume in the multivariable linear regression model.Conclusions: IR was associated with necrotic plaque volume in asymptomatic men without diabetes. Thus, even in asymptomatic men without diabetes, IR seems to have an incremental effect on necrotic plaque volume and vulnerable plaque composition.