UC San Diego

Objective

Western-type high-fat/high-cholesterol diets used to induce atherogenesis in low-density lipoprotein (LDL) receptor-deficient mice also lead to obesity with concomitant metabolic complications, eg, hypertriglyceridemia, hyperinsulinemia, and insulin resistance. Our aim was to design a diet inducing atherosclerosis through moderate hypercholesterolemia without associated parameters of the metabolic syndrome.

Methods and results

Male LDL receptor-deficient mice were fed regular chow (RC; 0.01% cholesterol/4.4% fat), cholesterol-enriched regular chow (HC; 1% cholesterol/4.4% fat), or Western diet (WD 0.06% cholesterol/21% milk fat) for 28 weeks. HC-feeding led to elevated plasma (approximately 20.7 mmol/L [800 mg/dL]) and LDL cholesterol and accelerated atherosclerosis. Plasma triglycerides were unaffected. Compared with RC-fed controls, HC-fed mice had normal body weight gain and normal fasting levels of glucose, free fatty acids, and insulin. In contrast, WD-fed mice were extremely hypercholesterolemic (>41.4 mmol/L), obese, hypertriglyceridemic, hyperinsulinemic, insulin resistant, and showed adverse health such as skin/fur abnormalities and hepatic steatosis. Although atherosclerotic surface areas in the entire aorta were similar in HC-fed and WD-fed mice, lesions in aortic origin cross sections were significantly larger in WD-fed mice. However, morphology was similar in lesions of equal size.

Conclusions

The HC diet induced moderate hypercholesterolemia and extensive atherosclerosis and should be useful to study specific aspects of atherogenesis in the absence of confounding effects of the metabolic syndrome.