Postprandial chylomicrons and VLDLs in severe hypertriacylglycerolemia arelowered more effectively than are chylomicron remnants after treatment with n-3 fatty acids

Background: n-3 Fatty acids lower plasma triacylglycerols not only in the f asting state but also in the postprandial state. However, it is not known w hether chylomicrons, chylomicron remnants, and VLDLs are all affected equal ly or whether some lipoprotein species are lowered preferentially. Objective: Lipoproteins, including large and small chylomicron remnants, we re determined specifically with the aid of a newly developed method involvi ng a combination of size-exclusion chromatography and fluorometric determin ation of retinyl palmitate, which served as a marker for exogenous fat. Design: Twelve hypertriacylglycerolemic men were treated for 6 wk with 4 ca psules containing 85% fish-oil concentrate/d; each capsule contained 850 mg n-3 fatty acid ethyl esters (49.1% eicosapentaenoic acid by wt and 32.2% d ocosahexaenoic acid by wt). Oral-fat-tolerance tests were performed before and after the treatment. Blood samples were drawn in the fasting state and until 8 h postprandially. Results: Treatment with n-3 fatty acids reduced the fasting VLDL-triacylgly cerol concentration by 44% (P < 0.05) and postprandial chylomicrons and VLD Ls at 4, 6, and 8 h (P < 0.05) by 49-64% and 36-43%, respectively. Chylomic ron remnants were reduced only in the late postprandial phase: large chylom icron remnants by 19% at 6 h and by 43% at 8 h (P < 0.05) and small chylomi cron remnants by 31% at 8 h (P < 0.05). Conclusion: n-3 Fatty acids effectively lower chylomicrons and VLDLs, but t heir effect on chylomicron remnants was observed only in the late postprand ial phase.