Variations in serum cholesteryl ester transfer and phospholipid transfer activities in healthy women and men consuming diets enriched in lauric, palmitic or oleic acids

Cholesteryl ester transfer protein (CETP) and phospholipid transfer protein (PLTP) activities were measured in sera from 32 normolipidemic women and m en consuming diets enriched in lauric, palmitic, or oleic acids. Serum CETP activity, measured as the rate of radiolabeled cholesteryl esters transfer red from HDL toward serum apo B-containing lipoproteins, was higher with th e palmitic acid diet (25.1 +/- 2.5%) than with the lauric acid (23.7 +/- 2. 4%) and the oleic acid (24.0 +/- 2.7%) diets (P = 0.0028 and 0.0283, respec tively). CETP mass concentrations, as measured with an enzyme-linked immuno sorbent assay were increased after the lauric acid diet (2.57 +/- 0.63 mg/l ) and the palmitic acid diet (2.49 +/- 0.64 mg/l) as compared with the olei c acid diet (2.34 +/- 0.45 mg/l) (P = 0.0035 and 0.0249, respectively). In contrast with CETP, serum PLTP activity, as measured as the rate of radiola beled phosphatidylcholine transferred From liposomes toward serum HDL, was significantly higher with the lauric acid diet (23.5 +/- 2.6%) than with th e palmitic acid diet (22.5 +/- 2.5%) (P = 0.0013), while no significant dif ferences were noted when comparing the saturated diets versus the oleic aci d diet (23.0 +/- 2.3%). No significant alterations in the mean apparent dia meter of LDL, and in the relative proportions of individual HDL subpopulati ons were observed from one dietary period to another. Nevertheless, lipid t ransfer activities correlated significantly with the relative abundance of HDL2b, HDL2a, HDL3b, and HDL3c, with opposite tendencies bring observed for cholesteryl eater transfer and phospholipid transfer activities. In genera l, serum CETP activity correlated negatively with HDL cholesterol, but posi tively with triglyceride concentrations after the dietary interventions, an d the relations with serum lipids were just the opposite for PLTP activity. In addition, CETP and PLTP activities correlated negatively when subjects consumed the standardized diets (P < 0.05 in all cases), but not when subje cts consumed their habitual diet. It is concluded that serum lipid transfer activities in normolipidemic subjects can be significantly affected by the fatty acid content of the diet, with differential effects on CETP and PLTP activities. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.