Interaction between the APOC3 gene promoter polymorphisms, saturated fat intake and plasma lipoproteins.
OBJECTIVE
To test the hypothesis that APOC3 gene polymorphisms modulate the effect of saturated fat (SAT) intake on plasma lipoproteins and LDL size.


METHODS
We studied 336 randomly selected residents from Costa Rica. APOC3 polymorphisms were genotyped in the promoter region (T-455C, T-625del) and the C3238G 3' untranslated region (UTR). Dietary intake was assessed by a validated food-frequency questionnaire (FFQ) and median saturated fat intake (11%) was used to define low and high exposure to saturated fat.


RESULTS
Allele frequencies were 0.49, 0.51 and 0.19 for the APOC3-455C, -625de1, and APOC3 3238G alleles, respectively. Significant gene-diet interactions were found for total (P<0.0004) and LDL cholesterol (P<0.01). In homozygotes for the APOC3-455T-625T alleles, saturated fat intake was associated with a 13% increase in total cholesterol (P<0.001) and a 20% increase in LDL cholesterol (P<0.001). In contrast, no association between plasma lipoproteins and saturated fat intake was found among carriers of the APOC3-455C-625del allele. The APOC3 3238G UTR allele did not modify the observed association.


CONCLUSIONS
Compared to a diet high in saturated fat, a habitually low saturated fat diet is associated with a beneficial lipoprotein profile only among homozygotes of the APOC3 promoter 455T-625T polymorphism.
Brown
Sherine
S
Department of Nutrition, Blg 2, Room 353a, Harvard School of Public Health, Boston, MA 02115, USA.
Ordovás
José M
JM
Campos
Hannia
H
D000328:Adult; D000368:Aged; D053305:Apolipoprotein C-III; D001056:Apolipoproteins C / Q000235:genetics*; D004041:Dietary Fats / Q000008:administration & dosage*; D005260:Female; D005787:Gene Frequency; D006801:Humans; D008074:Lipoproteins / Q000097:blood*; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic / Q000235:genetics*
D053305:Apolipoprotein C-III; D001056:Apolipoproteins C; D004041:Dietary Fats; D008074:Lipoproteins