Influence of fatty acid chain length and cis/trans isomerization on postprandial lipemia and factor VII in healthy subjects (postprandial lipids and factor VII).

Exaggerated postprandial lipemia is believed to be atherogenic and to influence risk of thrombosis. The postprandial effects on plasma triacylglycerol concentration, factor VII coagulant activity (FVII(c)) and activated FVII concentration (FVII(a)) of five high fat meals (5.2 MJ, 90 g fat) enriched with medium triacylglycerols (MCT, 8:0+10:0), palmitate(16:0), stearate (18:0), elaidate(18:1 trans) and oleate(18:1 cis) were compared with those following a low fat meal (5.2 MJ,10 g fat) in 16 healthy subjects using a randomized crossover design. Postprandial lipemia measured as the area under the curve (AUC arbitrary units) for plasma triacylglycerol concentration (mean+/-SE) was greater following the oleate (5.8+/-1. 05), elaidate (4.3+/-0.79) and palmitate (4.1+/-0.64) meals compared with stearate (2.0+/-0.45) and MCT (1.1+/-0.47) meals. Fatty acid analyses of the chylomicron lipids suggested that approximately one fifth of the dietary stearate was not absorbed. FVII(c) increased following the oleate, elaidate and palmitate meals and fell following the low fat meal; the increase in FVII(c) was correlated with the AUC for plasma TAG (r=0.34; P=0.001). FVII(a) concentration increased following all high fat meals but not following the low fat meal. The increase in FVII(a) at 7 h was greater after the oleate meal than after the stearate and MCT meals. These results do not support the hypothesis that dietary stearate and elaidate are responsible for the postprandial increases in FVII associated with high fat intakes.