Abstract 289: Chronic Systemic Insulin Treatment Attenuates Atherosclerotic Lesion Development in Cholesterol-Fed ApoE -/- Mice.
Diabetes mellitus and metabolic syndrome, which are states of insulin resistance, are both well-known to increase the risk of atherosclerosis. However, it is still debated whether this increased risk is due to excess or lack of insulin action. Here, we present evidence that insulin is anti-atherogenic and decreases atherosclerosis independent of its effects on glycemia. ApoE -/- mice were fed a 1.25% (w/w) high cholesterol diet for 1 week pre-treatment then implanted with either control pellets or insulin pellets (0.05U/day which achieves a mild 4-fold elevation of circulating insulin without significantly lowering plasma glucose) subcutaneously for 12 weeks thereafter. At the end of the treatment, the mice were perfused and the aortas were harvested. Using en face Oil-Red O staining, the atherosclerotic plaque in the descending aorta was evaluated by measuring lesion area over total area. Insulin-treated mice (n=7) showed a significant decrease in atherosclerotic plaque (9.0 ± 2%) compared to control (n=11; 17.6 ± 2.5%). There was no significant difference in glycemia between the two groups. Based on our results, insulin is anti-atherogenic in the context of euglycemia.
- © 2012 by American Heart Association, Inc.