Influences of lipid and non-lipid nutritional parameters on factor VII coagulant activity in normal subjects: the Nove study

Influence of stearic acid on postprandial lipemia and hemostatic function

It has been suggested that fats rich in stearic acid may result in exaggerated postprandial lipemia and have adverse effects on hemostatic function. The effects of test meals containing different saturated and monounsaturated FA were compared in healthy subjects in a series of studies to investigate this hypothesis. Stearic acid, when present as cocoa butter, resulted in similar postprandial lipemia and factor VII activation compared with a meal containing high-oleic sunflower oil. Stearic acid when presented as shea butter or as randomized stearate-rich TAG resulted in decreased postprandial lipemia and decreased postprandial activation of factor VII. Stearic acid-rich test meals did not result in impaired fibrinolytic activity compared with either a low-fat meal or a meal high in oleate. The difference in responses between the different stearic acid-rich fats appears to be due to varying solid fat contents of the fats at 37 degrees C.

Influence of a stearic acid-rich structured triacylglycerol on postprandial lipemia, factor VII concentrations, and fibrinolytic activity in healthy subjects

BACKGROUND

An elevated postprandial lipid concentration is believed to be atherogenic and to increase the risk of thrombosis.

OBJECTIVE

The objective was to test whether the consumption of a stearic acid-rich structured triacylglycerol has adverse effects on postprandial fibrinolytic activity and lipemia, factor VII coagulant (FVII:c) activity, and activated FVII (FVIIa) concentrations.

DESIGN

A randomized crossover design was used to compare the effects on middle-aged healthy men (n = 17) and women (n = 18) of meals enriched with cocoa butter, high-oleate sunflower oil (oleate), or a structured triacylglycerol containing stearic acid.

RESULTS

The mean increases from fasting in plasma triacylglycerol 3 h after the oleate, cocoa butter, and structured triacylglycerol meals were 1.36 (95% CI: 1.17, 1.56), 1.39 (1.17,1.63), and 0.65 (0.50, 0.82) mmol/L, respectively. Tissue plasminogen activator activity increased and plasminogen activator type 1 activity decreased after all 3 meals. Plasma FVII:c increased after the oleate and cocoa butter meals but not after the structured triacylglycerol meal. The values 6 h after the oleate and cocoa butter meals were 11.3% (7.0%, 15.6%) and 9.9% (4.7%, 15.2%), respectively, and were significantly different (P < 0.0001 and P = 0.001, respectively) from the value after the triacylglycerol meal [2.1% (-1.1%, 5.3%)]. Plasma FVIIa increased after all 3 meals, more so after the oleate and cocoa butter meals than after the structured triacylglycerol meal.

CONCLUSION

The consumption of stearic acid in the form of a structured triacylglycerol leads to less of an increase in plasma triacylglycerol and in FVII:c than does a meal enriched in cocoa butter or oleate.

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.

The effects of structurally defined triglycerides of differing fatty acid composition on postprandial haemostasis in young, healthy men

The aim of this study was to investigate whether a number of key haemostatic factors were altered when healthy young individuals were challenged with a fat load of physiological size contained within a meal composed of normal ingredients and whether this response was modified when the fatty acid composition of the meal was altered radically. Eight healthy male volunteers each randomly consumed four meals which were identical in terms of gross nutritional content (41% of energy provided as fat, 17% as protein and 42% as carbohydrate) but which differed in fatty acid composition. To reduce the possible influence of fatty acid position within the triglyceride molecule on lipid absorption and subsequent metabolic effects, the structural integrity of 91% of fat (test triglycerides such as 1,3 distearoyl-2-oleoyl glycerol (S-O-S), trioleine (O-O-O), and 1,3 dilinoleoyl-2-oleoyl glycerol, (L-O-L)) in the meals was controlled so that the principal fatty acid in the sn-2 position was oleic acid (18:1n-9). Meals rich in either a test triglyceride or a control oil provided 44+/-6 g of fat. No significant alterations from fasted values of elevated plasma factor VII coagulant activity (FVIIc) or F1 + 2 were observed. FVIIA varied significantly over the postprandial time course; however, when expressed as a percentage of the fasting value, the FVIIa responses to O-O-O and L-O-L differed significantly but this was not evident when the absolute values were analysed. Similarly, no difference in plasma fibrinopeptide A (FPA) concentrations were evident. After all four meals, chylomicron contained proportionately more palmitic acid and generally less oleic acid than the ingested lipids. This study clearly demonstrates that postprandial haemostatic responses of young healthy individuals to a physiological fat load are minimal, (irrespective of triglyceride structure).