The apolipoprotein A-IV-360His polymorphism determines the dietary fat clearance in normal subjects

Apolipoprotein IV (apo A-IV) has been related to fat absorption and to the activation of some of the enzymes involved in lipid metabolism. Several pol ymorphic sites within the gene locus for apo A-IV have been detected. Previ ous studies have shown that the A-IV-2 isoform produces a different plasma lipid response after the consumption of diets with different fat and choles terol content. The present study was designed to evaluate whether the apo A -IV 360His polymorphism could explain, at least in part, the interindividua l variability observed during postprandial lipemia. Fifty-one healthy male volunteers (42 homozygous for the apo A-IV 360Gln allele (Gln/Gln) and nine carriers of the A-IV-360His allele), homozygous for the apo E3 allele, wer e subjected to a vitamin A-fat load test consisting of 1 g of fat/kg body w eight and 60 000 IU of vitamin A. Blood was drawn at time 0 and every hour for 11 h. Plasma cholesterol (C), triacylglycerol (TG), and C, TG, apo B-10 0, apo B-48, apo A-IV and retinyl palmitate (RP) were determined in lipopro tein fractions. Data of postprandial lipemia revealed that subjects with th e apo A-IV 360His allele had significantly greater postprandial levels in s mall triacylglycerol rich lipoproteins (TRL)-C (P < 0.02), small TRL-TG (P < 0.01) and large TRL-TG (P < 0.05) than apo A-IV 360Gln/Gln subjects. In c onclusion, the modifications observed in postprandial lipoprotein metabolis m in subjects with the A-IV 360His allele could be involved in the differen t low density lipoprotein (LDL)-C responses observed in these subjects foll owing a diet rich in cholesterol and saturated fats. (C) 2000 Elsevier Scie nce Ireland Ltd. All rights reserved.