Effects of the human apolipoprotein A-I promoter G-A mutation on postprandial lipoprotein metabolism.
BACKGROUND
There is considerable interindividual variability in the postprandial lipid response to a fat-rich meal, and genetic factors have been considered to account for some of these effects. We previously showed that the G-A mutation 5' to the apolipoprotein (apo) A-I gene was significantly associated with the LDL-cholesterol response to diet.


OBJECTIVE
We evaluated whether this effect is mediated by mechanisms involving postprandial lipoprotein metabolism.


METHODS
Twenty-eight G/G and 23 G/A healthy male subjects, homozygotes for the apo E3 allele, were subjected to a vitamin A fat-loading test. Blood was drawn at time 0 and every hour for 11 h.


RESULTS
There was a significant postprandial decrease in plasma cholesterol, LDL cholesterol, and apo B in G/G subjects but not in G/A subjects. A greater postprandial response in large triacylglycerol-rich lipoproteins (TRLs) and a smaller postprandial response in large TRL apo A-IV was observed in G/A than in G/G subjects. Retinyl palmitate in large and small TRL concentrations was similar for both genotypes. No significant genotype effects were detected for triacylglycerol concentrations in plasma, small TRL fraction, and apo A-I and HDL-cholesterol concentrations.


CONCLUSIONS
Our data suggest that the G-A mutation affects the LDL-cholesterol response to diet by mechanisms involving postprandial lipoprotein cholesterol metabolism.
Marín
Carmen
C
Unidad de Lipidos y Arteriosclerosis, Hospital Universitario Reina Sofía, Cordoba, Spain.
López-Miranda
José
J
Gómez
Purificación
P
Paz
Elier
E
Pérez-Martínez
Pablo
P
Fuentes
Francisco
F
Jiménez-Perepérez
José Antonio
JA
Ordovás
José María
JM
Pérez-Jiménez
Francisco
F
D000328:Adult; D016632:Apolipoprotein A-I / Q000235:genetics*; D053299:Apolipoprotein B-100; D053283:Apolipoprotein B-48; D001055:Apolipoproteins B / Q000097:blood*; D002784:Cholesterol / Q000097:blood*; D005838:Genotype; D006801:Humans; D008074:Lipoproteins / Q000378:metabolism*; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D019518:Postprandial Period; D014801:Vitamin A / Q000008:administration & dosage / Q000494:pharmacology*
D016632:Apolipoprotein A-I; D053299:Apolipoprotein B-100; D053283:Apolipoprotein B-48; D001055:Apolipoproteins B; D008074:Lipoproteins; D014801:Vitamin A; D002784:Cholesterol