DIETARY AND GENETIC-EFFECTS AN LDL SIZE MEASURES IN BABOONS

Genetic and dietary effects on LDL phenotypes, including predominant L DL particle diameter, LDL size distribution, and non-HDL cholesterol a nd apoB concentrations, were investigated in 150 pedigreeed baboons th at are members of 19 sire groups. Baboons were fed a sequence of three defined diets differing in levels of fat and cholesterol. Increasing dietary fat had relatively little effect on two measures of LDL partic le size. However, increasing the level of cholesterol in the diet resu lted in larger increases of the predominant LDL particle diameters and in the proportion of stain on LDLs >29 nm. As expected apoB and non-H DL cholesterol concentrations significantly increased when levels of d ietary fat and cholesterol were increased. Correlations among the LDL phenotypes suggested that several different aspects of the LDL phenoty pe were captured by the four LDL measures across the three diets. Gene tic effects indicated by sire group membership were significant both f or expression of the LDL phenotypes and for response to changes in die t.