Effects of western diet and wheel access on lipid profiles in mice selectively bred for high voluntary wheel running

Abstract

Increased consumption of high‐fat foods and a sedentary lifestyle are viewed as two key factors in the ongoing trends for increased rates of human obesity and cardiovascular disease. However, in experimental studies with both humans and rodents, both diet and exercise have shown varying effects on metabolic syndrome risk factors, sometimes depending on genetic background. To examine potential interactive effects of diet, exercise, and genetic background on components of the metabolic syndrome, we studied mice bred for high voluntary wheel running and their respective controls. A standard chow (14% kcal from fat) or Western diet (WD, 42% kcal from fat plus added sucrose) was given to male mice housed with or without wheels for 60 days starting at 24 days of age. Neither genetic selection history nor wheel access had an appreciable impact on the final blood lipid profile. WD was obesogenic for both HR and C, leading to increased retroperitoneal fat and liver mass, even after accounting for wheel running and calories consumed. As expected from results of previous studies with diets high in saturated fats, WD also decreased plasma triglyceride levels. WD significantly increased fasting glucose levels, but raised total and HDL cholesterol concentrations, leading to an improved total/HDL ratio, which may offset some of the negative aspects of the diet. Supported by MSU Seed Grant to JCE and NSF IOB‐0543429 to TG