Postprandial lipemia is modified by the presence of the polymorphism present in the exon 1 variant at the SR-BI gene locus

Abstract

It has recently been reported that carriers of the less common allele at the scavenger receptor class B type I (SR-BI) exon 1 polymorphism are more susceptible to the presence of saturated fatty acid in the diet because of a greater increase in LDL cholesterol. Our aim was to determine if this polymorphism could also influence postprandial lipoprotein metabolism, because the SR-BI has been described as a possible mediator in the intestinal absorption of triacylglycerols. Forty-seven normolipidemic volunteers who were homozygous for the E3 allele at the APOE gene were selected [37 homozygous for the common genotype (1/1) at the SR-BI exon 1 polymorphism and 10 heterozygous (1/2)]. They were given a fat-rich meal containing 1 g fat and 7 mg cholesterol per kg body weight and vitamin A 60 000 IU/m 2 body surface. Fat accounted for 60% of calories, and protein and carbohydrates accounted for 15% and 25% of energy respectively. Blood samples were taken at time 0, every 1 h until 6 h, and every 2·5 h until 11 h. Total cholesterol and triacylglycerols in plasma, and cholesterol, triacylglycerols and retinyl palmitate in triacylglycerol-rich lipoproteins (large and small triacylglycerol-rich lipoproteins) were determined. Postprandial responses for triacylglycerols and retinyl palmitate in small triacylglycerol-rich lipoproteins were higher in 1/1 individuals than in 1/2 individuals. No other significant differences were noted. Our data show that the presence of the genotype 1/2 is associated with a lower postprandial lipemic response.

Postprandial lipemia enhances the capacity of large HDL2 particles to mediate free cholesterol efflux via SR-BI and ABCG1 pathways in type IIB hyperlipidemia

“…Taken together, these observations strongly suggest that postprandial HDL metabolism is intimately related to SR-BI activity. In this context, it is relevant that SR-BI has been previously shown to modulate postprandial triglyceride response through its action on intravascular chylomicron metabolism ( 38,39 ) and more recently through its action on intestinal cholesterol absorption and TRL secretion ( 40 ).…”

Effects of amino acid substitutions at glycine 420 on SR-BI cholesterol transport function

“…Although it is well established that SR-BI's role in the reverse cholesterol transport pathway is particularly important for cholesterol metabolism in rodents, it is not clear whether this is true in humans. However, several recent studies have reported genetic polymorphisms that implicate SR-BI as a significant player in human HDL cholesterol metabolism as well (23)(24)(25)(26)(27)(28)(29)(30).…”

Peroxisome proliferator-activated receptor α polymorphisms and postprandial lipemia in healthy men

“…Although the magnitude of the genetic effect on variation in the postprandial lipid response is unknown, each of these genes seems to have a small, yet measurable, effect on postprandial lipid metabolism. Interestingly, polymorphisms in some of the PPARa-mediated genes, such as LPL, APOC3, APOA5, and SCARB1, modify the postprandial TG response (35)(36)(37)(38)(39). In this study, we report that PPARa is involved in the homeostasis of lipids in the fasted state as well as during the acute postprandial response to dietary fat.…”