Diet induced obesity promotes aortic stiffness by impairing elastin functionality (LB695)

Abstract

Cardiovascular diseases (CVD) are the leading cause of mortality in the United States. Obesity is a primary risk factor for CVD resulting in greater large elastic artery stiffness. Importantly, stiffening of the aorta is an independent predictor of CV events and is a novel therapeutic target for attenuating CVD risk with obesity. The purpose was to determine if a high fat diet promotes aortic stiffening in mice that would result in a significant increase in aortic pulse wave velocity (aPWV) and intrinsic mechanical stiffness. Mice were randomly assigned into two groups receiving either a low fat (LF, 10% kcal fat) or high fat (HF, 60% kcal fat) diet. HF mice had greater aortic stiffness as assessed by aPWV (401 ± 26 vs. 304 ± 17 cm/s, P < 0.05) and in vitro aortic mechanical stiffening. Specifically, the elastic modulus of the elastin region was decreased in HF compared with LF mice (398 ± 6 vs. 615 ± 42 kPa, P < 0.05), whereas the collagen elastic modulus showed no difference between groups (3707 ± 694 vs. 3732 ± 403 kPa, P<0.05). Collectively, these data suggest that the decrease in aortic elastic modulus of the elastin region is due to loss of functionality of the elastin protein fiber. These results support the notion that high fat diets promote aortic stiffening thus increasing CVD risk.