Post-prandial effects of a dietary fat challenge on lipoprotein sub fractions measured by NMR spectroscopy. - (:unkn) unknown (Petaling Jaya : MPOB, 2005)
The study of post-prandial lipoproteins is a valuable tool for investigating the contribution of the reverse cholesterol transport pathway (RCT) to early events in HDL metabolismo Eight normocholesterolemic females (Age 23.5:1:2.2 yrs; BW 58:1:7.5 kg; BMI 21.5:1:2.2 kg/m2; Total plasma cholesterol (TC) 170:1:19 mg/dL; HDL-C 57:1:12 mg/dL; fasting glucose 91:1:11 mg/dL; x:l:SD) were subjected to an oral fat challenge with a high fat meal providing -800 kcal (60 9 test fat). The test fat was a blend of differing proportions of canola, safflower and palm olein to achieve two different ratios of palmitic/linoleic acid with constant amounts of oleic acid. Blood samples were taken 2, 4 and 8h fúllowing the "fat challenge". Plasma was isolated and lipoproteins and their various subfractions analyzed by NMR spectroscopy. Irrespective of diet, the data revealed no effects on TC, LDL cholesterol, LDL particle numbers, HDL cholesterol or HDL particle numbers. Two hours following the test meals, plasma TG concentrations were increased by 50 percent and remained elevated at 4 hrs. The values declined to baseline values by 8hrs. The changes in plasma TG were paralleled by corresponding changes in the TG content of TR-rich lipoproteins (chylomicrons and VLDL) of varying diameters (30 to 150 nm). Collectively the mea n diameters of the TG-rich lipoproteins increased - 40 percent over the first two hrs, whereas the subsequent increase over the next 6 hrs was less (16 percent). Although total HDL-C did not change over the course of the study, analyses of HDL subfractions revealed distinct changes in their cholesterol content. Thus, a progressive decrease in the cholesterol content of HDL particles of 7.5 nm diameter, was accompanied by a progressive increase in the cholesterol content of the HDL subfraction with diameters of 8.5 to 11 nm, indicative of the transformation of smaller HDL to larger HDL. These data suggest that NMR spectroscopy is a valuable tool for detecting changes in post-prandial lipoprotein subfractions. Effects of the different fatty acid ratios on HDL subfraction metabolism will be reported at the meeting.
The study of post-prandial lipoproteins is a valuable tool for investigating the contribution of the reverse cholesterol transport pathway (RCT) to early events in HDL metabolismo Eight normocholesterolemic females (Age 23.5:1:2.2 yrs; BW 58:1:7.5 kg; BMI 21.5:1:2.2 kg/m2; Total plasma cholesterol (TC) 170:1:19 mg/dL; HDL-C 57:1:12 mg/dL; fasting glucose 91:1:11 mg/dL; x:l:SD) were subjected to an oral fat challenge with a high fat meal providing -800 kcal (60 9 test fat). The test fat was a blend of differing proportions of canola, safflower and palm olein to achieve two different ratios of palmitic/linoleic acid with constant amounts of oleic acid. Blood samples were taken 2, 4 and 8h fúllowing the "fat challenge". Plasma was isolated and lipoproteins and their various subfractions analyzed by NMR spectroscopy. Irrespective of diet, the data revealed no effects on TC, LDL cholesterol, LDL particle numbers, HDL cholesterol or HDL particle numbers. Two hours following the test meals, plasma TG concentrations were increased by 50 percent and remained elevated at 4 hrs. The values declined to baseline values by 8hrs. The changes in plasma TG were paralleled by corresponding changes in the TG content of TR-rich lipoproteins (chylomicrons and VLDL) of varying diameters (30 to 150 nm). Collectively the mea n diameters of the TG-rich lipoproteins increased - 40 percent over the first two hrs, whereas the subsequent increase over the next 6 hrs was less (16 percent). Although total HDL-C did not change over the course of the study, analyses of HDL subfractions revealed distinct changes in their cholesterol content. Thus, a progressive decrease in the cholesterol content of HDL particles of 7.5 nm diameter, was accompanied by a progressive increase in the cholesterol content of the HDL subfraction with diameters of 8.5 to 11 nm, indicative of the transformation of smaller HDL to larger HDL. These data suggest that NMR spectroscopy is a valuable tool for detecting changes in post-prandial lipoprotein subfractions. Effects of the different fatty acid ratios on HDL subfraction metabolism will be reported at the meeting.
Keywords: Grasa; Lipoproteínas.; Nutrición.; Salud.