Prandial Hypertriglyceridemia in Metabolic Syndrome is due to an Overproduction of both Chylomicron and VLDL Triacylglycerol

Abstract

Abstract The aim was to determine whether fed very low density lipoprotein (VLDL) and chylomicron (CM) triacylglycerol (TAG) production rates are elevated in metabolic syndrome (MetS). Eight men with MetS (BMI 29.7± 1.1) and 8 lean age matched healthy men (BMI 23.1± 0.4) were studied using a frequent feeding protocol. After 4 hours of feeding an intravenous bolus of 2 H 5 -glycerol was administered to label VLDL1, VLDL2 and CM TAG. 13 C glycerol tripalmitin was administered orally as an independent measure of CM TAG metabolism. Hepatic and intestinal lipoproteins were separated by an immunoaffinity method. In MetS, fed TAG and the increment in TAG from fasting to feeding were higher (p=0.03, p<0.05 respectively) than in lean men. Fed CM, VLDL1 and VLDL2 TAG pool sizes were higher (p=0.006, p=0.03, p<0.02) and CM, VLDL1 and VLDL2 TAG production rates were higher (p<0.002, p<0.05, p=0.06) than in lean men. VLDL1, VLDL2 and CM TAG clearance rates were not different between groups. In conclusion prandial hypertriglyceridemia in men with MetS was due to an increased production rate of both VLDL and CM TAG. Since both groups received identical meals this suggests that in MetS the intestine is synthesising more TAG de novo for export in CMs.