1. Western-type diets induce insulin resistance and hyperinsulinemia in LDL receptor-deficient mice but do not increase aortic atherosclerosis compared with normoinsulinemic mice in which similar plasma cholesterol levels are achieved by a fructose-rich diet.
- Author
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Merat, S, Casanada, F, Sutphin, M, Palinski, W, and Reaven, PD
- Subjects
Animals ,Mice ,Knockout ,Mice ,Rats ,Aortic Diseases ,Arteriosclerosis ,Hyperinsulinism ,Insulin Resistance ,Hypercholesterolemia ,Genetic Predisposition to Disease ,Body Weight ,Dietary Sucrose ,Fructose ,Dietary Fats ,Receptors ,LDL ,Species Specificity ,Research Design ,Male ,arteriosclerosis ,diabetes ,fructose ,hypercholesterolemia ,lipoproteins ,Cardiovascular System & Hematology ,Cardiorespiratory Medicine and Haematology ,Clinical Sciences - Abstract
The role of insulin resistance (IR) in atherogenesis is poorly understood, in part because of a lack of appropriate animal models. We assumed that fructose-fed LDL receptor-deficient (LDLR-/-) mice might be a model of IR and atherosclerosis because (1) fructose feeding induces hyperinsulinemia and IR in rats; (2) a preliminary experiment showed that fructose feeding markedly increases plasma cholesterol levels in LDLR-/- mice; and (3) hypercholesterolemic LDLR-/- mice develop extensive atherosclerosis. To test whether IR could be induced in LDLR-/- mice, 3 groups of male mice were fed a fructose-rich diet (60% of total calories; n=16), a fat-enriched (Western) diet intended to yield the same plasma cholesterol levels (n=18), or regular chow (n=7) for approximately 5.5 months. The average cholesterol levels of both hypercholesterolemic groups were similar (849+/-268 versus 964+/-234 mg/dL) and much higher than in the chow-fed group (249+/-21 mg/dL). Final body weights in the Western diet group were higher (39+/-6.2 g) than in the fructose- (27.8+/-2.7 g) or chow-fed (26.7+/-3.8 g) groups. Contrary to expectation, IR was induced in mice fed the Western diet, but not in fructose-fed mice. The Western diet group had higher average glucose levels (187+/-16 versus 159+/-12 mg/dL) and 4.5-fold higher plasma insulin levels. Surprisingly, the non-insulin-resistant, fructose-fed mice had significantly more atherosclerosis than the insulin-resistant mice fed Western diet (11.8+/-2.9% versus 7.8+/-2. 5% of aortic surface; P
- Published
- 1999