Exercise training does not reduce hyperlipidemia in pigs fed a high-fat diet.

The pig is often used as a model for studying lipoprotein metabolism as it relates to human atherosclerosis, but few studies have examined the complete lipoprotein profile and related enzymes in swine ingesting an atherogenic diet. We examined whether exercise training would moderate the effects of an atherogenic diet on lipoproteins and lipoprotein lipase (LPL) activity in miniature swine. Male (n = 30) and female (n = 32) swine were initially divided into 2 dietary groups: one consumed low-fat (8%) pig chow, and one consumed pig chow supplemented with 2% cholesterol, 17.1% coconut oil, 2.3% corn oil, and.7% sodium cholate (46% kcal from fat). Following 30 days on the diets, pigs from each diet group were further divided into sedentary and exercise trained subgroups, each cell with 6 to 8 pigs. Training occurred 5 days per week on a treadmill in which the intensity and duration were progressively increased during the 16- to 20-week training period to 75 minutes of aerobic running per session. A 4-way analysis of variance (ANOVA) with repeated measures on time indicated that at the conclusion of the study the atherogenic diet caused significantly (P <.05) increased cholesterol, triglyceride (TG), high-density lipoprotein cholesterol (HDL-C) and subfractions, low-density lipoprotein cholesterol (LDL-C) and subfractions, and LPL activity in both genders. For cholesterol, TG, HDL-C, HDL(2)-C, LDL-C, LDL(1&2)-C, and hepatic lipase, the female response to the diet was exaggerated compared to the male response. Exercise training produced no group differences or interactions on any lipoprotein variable. These results suggest that an atherogenic diet has a greater impact on the lipoproteins of female miniature swine than males. Furthermore, under the conditions of this study, exercise training does not moderate the effects of an atherogenic diet on lipoproteins.