Polymorphism exon 1 variant at the locus of the scavenger receptor class B type I gene: influence on plasma LDL cholesterol in healthy subjects during the consumption of diets with different fat contents.
BACKGROUND
The association between polymorphisms in the scavenger receptor class B type I (SRB-I) gene and variations in basal plasma concentrations of cholesterol in humans has recently been described.


OBJECTIVE
The objective of the study was to determine whether the exon 1 variant (G-->A) at the SRB-I gene is associated with the lipid response to the content and quality of dietary fat in healthy subjects.


METHODS
We studied 97 healthy volunteers with exon 1 polymorphism [65 homozygous for allele 1 (1/1) and 32 heterozygous for allele 2 (1/2)]. Both groups consumed 3 diets lasting 4 wk each. The first was a saturated fatty acid (SFA)-rich diet (38% fat, 20% SFA), which was followed by a carbohydrate (Cho)-rich diet (30% fat, < 10% SFA, 55% carbohydrate) or a monounsaturated fatty acid (MUFA), olive oil-rich diet (38% fat, 22% MUFA) according to a randomized crossover design. At the end of each dietary period, plasma concentrations of triacylglycerol and of total, LDL, and HDL cholesterol were measured.


RESULTS
Carriers of the 1/2 genotype had a trend toward higher concentrations of LDL cholesterol (P < 0.11) after the SFA-rich diet than did those who were homozygous for 1/1. Carriers of the mutation showed a significantly greater (P = 0.007) decrease in LDL-cholesterol concentrations (-23%) in changing from an SFA-rich diet to a Cho-rich diet than did noncarriers of the mutation (-16%).


CONCLUSIONS
Carriers of the minority allele, 1/2, are more susceptible to the presence of SFA in the diet because of a greater increase in LDL cholesterol.
Pérez-Martínez
Pablo
P
Unidad de Lipidos y Arteriosclerosis, Hospital Universitario Reina Sofia, Córdoba, Spain.
Ordovás
José M
JM
López-Miranda
José
J
Gómez
Purificación
P
Marín
Carmen
C
Moreno
Juan
J
Fuentes
Francisco
F
Fernández de la Puebla
Rafael Angel
RA
Pérez-Jiménez
Francisco
F
D000483:Alleles; D018955:CD36 Antigens / Q000235:genetics*; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood*; D018592:Cross-Over Studies; D004040:Dietary Carbohydrates / Q000008:administration & dosage; D004041:Dietary Fats / Q000008:administration & dosage*; D005091:Exons; D005227:Fatty Acids / Q000008:administration & dosage; D005229:Fatty Acids, Monounsaturated / Q000008:administration & dosage; D006579:Heterozygote; D006720:Homozygote; D006801:Humans; D008565:Membrane Proteins; D009154:Mutation; D000069463:Olive Oil; D010938:Plant Oils; D011110:Polymorphism, Genetic; D011971:Receptors, Immunologic; D018110:Receptors, Lipoprotein; D051116:Receptors, Scavenger; D051122:Scavenger Receptors, Class B; D014280:Triglycerides / Q000097:blood
D018955:CD36 Antigens; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D005227:Fatty Acids; D005229:Fatty Acids, Monounsaturated; D008565:Membrane Proteins; D000069463:Olive Oil; D010938:Plant Oils; D011971:Receptors, Immunologic; D018110:Receptors, Lipoprotein; D051116:Receptors, Scavenger; C454739:Scarb1 protein, mouse; D051122:Scavenger Receptors, Class B; D014280:Triglycerides