Cross sectional and postprandial phenotypes of human subjects with the T54 variant of fatty acid-binding protein 2 (FABP2) gene and the effect of different fat sources.
Published: 2004
Language: eng
Number of pages: 142
Description: In conclusion, the A54T polymorphism results in a diet-gene interaction with the T54 group having increased chylomicron cholesterol after the olive oil-containing test only; however, the proportions of fatty acids within chylomicrons were not affected. Nevertheless, the greater hepatic insulin clearance in T54 carriers suggests that the polymorphism may not be deleterious in nonobese subjects.Fifty-two nonobese subjects were screened for the T54 variant of  FABP2 and there were no significant mean differences in body mass index (BMI), fasting plasma insulin, or lipids in the A54 and T54 groups. However, there were positive correlations between triacylglycerols (TGs) and BMI (r = 0.72) and TGs and insulin (r = 0.67), and a negative correlation between high-density lipoprotein cholesterol and insulin (r = -0.63) in T54 subjects, which were not significant in the A54 homozygotes. Thus, phenotypic associations vary with FABP2 genotype in a nonobese group despite the absence of mean differences between FABP2 genotypes.Twenty-two of the above subjects, eleven A54 homozygotes and 11 T54 carriers, ingested 3 oral fat-tolerance tests (butter, safflower, and olive oils) and postprandial lipids, glucose and insulin were measured. There was no effect of FABP2 genotype for chylomicron TG, glucose, or C-peptide. Insulin area under the curve (AUC) and insulin to C-peptide ratio were lower in T54 carriers compared to A54 homozygotes, suggesting greater hepatic insulin clearance. The association of genotype with chylomicron cholesterol was seen only after olive oil, with T54 carriers having greater chylomicron cholesterol than A54 homozygotes. The main effect of fat was significant for chylomicron cholesterol and TG with safflower and olive oils producing a greater response than butter. Peak chylomicron fatty acid proportions did reflect those of the ingested fats; however, there was no effect of genotype. These results indirectly support improved intracellular trafficking, increased chylomicron formation, and decreased portal fat absorption in T54 carriers.
Notes: Adviser:  Thomas M. S. Wolever.

Thesis (Ph.D.)--University of Toronto, 2004.

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Source: Dissertation Abstracts International, Volume: 65-05, Section: B, page: 2349.