Endocrine Abstracts

Background: Impaired insulin and glucose levels are implicated in the etiology of cardiovascular disease, however, their influence on the formation and composition of atherosclerotic plaque remains unclear.

Purpose: To investigate the association between fasting serum insulin and glucose levels with atherosclerotic plaque composition in the carotid artery.

Methods: In 1740 participants (mean age 72.9 years, 46% women, 14.4% diabetes mellitus) from the population-based Rotterdam Study, we performed carotid MRI to evaluate the presence of calcification, lipid core, and intraplaque hemorrhage in carotid atherosclerosis. All participants also underwent blood sampling to obtain information on serum insulin and glucose levels. Using logistic regression models, we assessed the association of serum insulin and glucose levels (per standard deviation (SD) and in tertiles) with the different plaque components, while adjusting for sex, age, intima-media thickness, and cardiovascular risk factors.

Results: High serum insulin levels were associated with the presence of intraplaque hemorrhage [adjusted odds ratio (OR) per 1-SD increase: 1.32 (95% confidence interval (CI) 1.01–1.75)] and with a lower frequency of lipid core [adjusted OR: 0.61 (95% CI: 0.54–0.88)]. We found no association with the presence of calcification. Sensitivity analyses restricted to individuals without diabetes mellitus yielded similar results. No associations were found between serum glucose levels and any of the plaque components.

Conclusions: Higher serum insulin levels are associated with the presence of intraplaque hemorrhage, and with a lower frequency of lipid core in carotid atherosclerosis. These findings suggest a complex role for serum insulin in the pathophysiology of carotid plaque vulnerability.