Characterization of plasma lipoproteins in swine with different propensities for obesity.

Yorkshire (lean) and Ossabaw (obese) swine ca. one year of age were used to characterize the quantity and composition of plasma lipoproteins in animals with markedly different adiposity. While lean swine weighted more (175 vs 88 kg for obese), they had less backfat than obese swine (2.64 vs 5.97 cm; P < 0.05). Fasting plasma triacylglycerol (Tg) and cholesterol (CH) levels were elevated in obese swine. Swine plasma lipoproteins were fractionated into very low density lipoprotein (VLDL; d < 1.006), low density lipoprotein (LDL; d = 1.019-1.063), low density lipoprotein (LDL; d = 1.063-1.09), and high density lipoprotein (HDL; d = 1.09-1.21) by density ultracentrifugation. Obese VLDL-Tg, CH and protein (Pr) were elevated more than 2-fold. VLDL from obese swine were 2-fold larger than VLDL from lean swine. No alterations in LDL or LDL composition were observed. HDL-Tg, CH. Pr and phospholipid levels were significantly higher in obese swine. Plasma and VLDL-Tg levels were highly correlated with backfat thickness (r = 0.67 and r = 0.73, respectively). There was a positive correlation between adiposity and HDL-CH as well as VLDL-Tg and HDL-CH. These data indicate that (a) there are marked alterations in swine plasma lipoprotein composition between lean and obese swine; (b) that swine plasma lipoprotein levels may be useful parameters in estimating body composition; and (c) that HDL-CH is positively correlated with adiposity in swine.