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

Effects of dietary fat quantity and composition on fasting and postprandial levels of coagulation factor VII and serum choline-containing phospholipids

Dietary fat influences plasma levels of coagulation factor VII (FVII) and serum phospholipids (PL). It is, however, unknown if the fat-mediated changes in FVII are linked to PL. The present study aimed to investigate the effects of dietary fat on fasting and postprandial levels of activated FVII (FVIIa), FVII coagulant activity (FVIIc), FVII protein (FVIIag) and choline-containing PL (PC). In a randomized single-blinded crossover-designed study a high-fat diet (HSAFA), a low-fat diet (LSAFA), both rich in saturated fatty acids, and a high-fat diet rich in unsaturated fatty acids (HUFA) were consumed for 3 weeks. Twenty-five healthy females, in which postprandial responses were studied in a subset of twelve, were included. The HSAFA diet resulted in higher levels of fasting FVIIa and PC compared with the LSAFA and the HUFA diets (all comparisons P< or =0.01). The fasting PC levels after the LSAFA diet were also higher than after the HUFA diet (P<0.001). Postprandial levels of FVIIa and PC were highest on the HSAFA diet and different from LSAFA and HUFA (all comparisons P< or =0.05). Postprandial FVIIa was higher on the HUFA compared with the LSAFA diet (P<0.03), whereas the HUFA diet resulted in lower postprandial levels of PC than the LSAFA diet (P<0.001). Significant correlations between fasting levels of PC and FVIIc were found on all diets, whereas FVIIag was correlated to PC on the HSAFA and HUFA diet. The present results indicate that dietary fat, both quality and quantity, influences fasting and postprandial levels of FVIIa and PC. Although significant associations between fasting FVII and PC levels were found, our results do not support the assumption that postprandial FVII activation is linked to serum PC.

High intakes of trans monounsaturated fatty acids taken for 2 weeks do not influence procoagulant and fibrinolytic risk markers for CHD in young healthy men

Dietary trans fatty acids are associated with increased risk of CHD. We hypothesized that the changes in plasma lipids associated with a high intake of trans fatty acids would cause adverse effects on procoagulant and fibrinolytic activities. A randomized crossover controlled feeding study was conducted in twenty-nine men. A trans-rich diet supplying 10 % energy as trans- 18:1 was compared with diets in which the trans fatty acids were replaced either with carbohydrate or oleate; each diet was taken for 2 weeks in random order. Fasting fibrinogen and d-dimer concentrations and factor VII coagulant, plasminogen activator inhibitor type 1 and tissue plasminogen activator did not differ between diets. Postprandially, tissue plasminogen activator activity increased and plasminogen activator inhibitor type 1 activity decreased on all diets. Factor VIIc increased postprandially by 15 and 17 % on the trans and oleate diets respectively, compared with an 11 % increase on the carbohydrate diet; the mean difference between oleate and carbohydrate diets was 6 (95 % CI 0.2, 11.9) %. The LDL-cholesterol:HDL-cholesterol and apolipoprotein B : apolipoprotein A-I ratios increased by 13 (95 % CI 5.7, 21.8) and 10 (95 % CI 3.1, 17.2) % respectively on the trans diet compared with the oleate diet and by 6 (95 % CI 0.1,12.7) and 7 (95 % CI 0, 13.5) % respectively compared with the carbohydrate diet. Plasma HDL2-cholesterol concentration was 18 (95 % CI 0.7, 35.9) % lower on the trans diet compared with the oleate diet. The results confirm adverse effects of trans fatty acids on HDL-cholesterol concentrations, but suggest that trans fatty acids do not have any specific effects on known haemostatic risk markers for cardiovascular disease in healthy young men in the short-term.

Effect of individual dietary fatty acids on postprandial activation of blood coagulation factor VII and fibrinolysis in healthy young men

BACKGROUND

Hypertriglyceridemia may represent a procoagulant state involving disturbances to the hemostatic system. Plasminogen activator inhibitor type 1 (PAI-1) is increased in the presence of hypertriglyceridemia. Free fatty acids (FFAs) in plasma may promote factor VII (FVII) activation.

OBJECTIVE

We tested the hypothesis that FVII activation would be less after consumption of saturated fatty acids than after other fatty acids.

DESIGN

The effects of 6 matching dietary test fats, rich in stearic (S), palmitic (P), palmitic + myristic (M), oleic (O), trans 18:1 (T), and linoleic (L) acid, respectively, on the postprandial lipid and hemostatic profile (after 2, 4, 6, and 8 h) were investigated in 16 young men. High-fat meals (1 g fat/kg body wt; 43% from the test fatty acid) were served in the morning on 6 separate days.

RESULTS

All fats increased FVII activation. The S fat resulted in a lower increase in activated FVII (FVIIa) than did the T fat and in a lower FVII coagulant activity (FVII:c) than did the O fat (P < 0.02, diet x time interaction). When the data were pooled, the saturated (S, P, and M) test fats resulted in a smaller postprandial increase in FVIIa (P = 0.036, diet effect), a smaller increase in FVII:c (P < 0.001, diet x time interaction), a greater rise in tissue plasminogen activator concentrations (P = 0.028, diet effect), and a tendency to a greater postprandial decline in PAI-1 (P = 0.06, diet effect) compared with the unsaturated test fats (O, T, and L). The increase in FVIIa was not significantly associated with the level of lipemia, plasma FFAs, or plasma lipoprotein lipase activity.

CONCLUSION

Our results indicate a lesser increase in FVIIa after the consumption of saturated fats, especially the S fat, than after unsaturated test fats.

Influence of triacylglycerol structure on the postprandial response of factor VII to stearic acid-rich fats

BACKGROUND

The consumption of a synthetic, randomized, stearic acid-rich triacylglycerol results in decreased postprandial lipemia and activated factor VII (FVII:a) compared with cocoa butter (a nonrandomized, symmetrical, stearic acid-rich triacylglycerol). It was hypothesized that this difference is a consequence of the differences in structure between the 2 triacylglycerols.

OBJECTIVE

The objective was to test whether the consumption of randomized cocoa butter decreases postprandial lipemia and FVII:a.

DESIGN

A randomized crossover trial with 17 male subjects compared the effects of meals containing 50 g fat provided as a symmetrical (cocoa butter) or an asymmetrical (randomized cocoa butter) triacylglycerol on postprandial changes in lipids, chylomicron composition, and FVII:a.

RESULTS

After randomization, the postprandial area under the curve for plasma triacylglycerol decreased by 41% (P < 0.01). At 3 h the plasma concentrations of triacylglycerol, palmitic acid, stearic acid, and oleic acid were 26%, 18%, 34%, and 19% lower, respectively. The proportion of oleic acid in the sn-2 position of the chylomicron triacylglycerol was reduced from 67.4 mol% to 35.9 mol% and resulted in an increase in the proportion of stearic acid in the sn-2 position from 9.2 mol% to 25.4 mol%. FVII:a did not increase 6 h after consumption of the randomized cocoa butter (: 1.2; 95% CI: -2.7, 4.6 U/L) but increased significantly (: 7.7; 95% CI: 2.5,12.9 U/L) 6 h after consumption of the unrandomized cocoa butter.

CONCLUSIONS

Symmetrical stearic acid-rich triacylglycerol with oleic acid in the sn-2 position appears to be absorbed more rapidly than is asymmetrical triacylglycerols with long-chain saturated fatty acids in the sn-2 position, which leads to activation of FVII.

Boron supplementation and activated factor VII in healthy men

OBJECTIVE

The aim of the present study was to determine whether postprandial concentrations of the active component of serine protease coagulation factor VII (VIIa) were lowered by acute boron supplementation in vivo.

DESIGN

An acute, randomized, placebo-controlled, double blind, cross-over study.

SETTING

Free-living population.

SUBJECTS

Fifteen apparently healthy men, aged 45-65 y.

INTERVENTIONS

Subjects visited the centre on two occasions, with the study days separated by a minimum of 2 weeks. Following collection of a fasting blood sample, subjects received either placebo or acute bolus of 11.6 mg boron (given as 102.6 mg sodium tetraborate decahydrate) together with a standard fat-rich meal. Blood samples were obtained at 1, 2, 4 and 6 h after the administration of the test meal, during which time subjects were at liberty to consume deionized water only. Blood samples were assayed for concentrations of insulin, glucose, lipids and boron. Measurement of the concentration of activated factor VIIa and of factor VII antigen, and of the activity of coagulation factors VII, IX and X was also carried out.

RESULTS

Plasma boron concentrations were significantly higher following consumption of the boron supplement compared with placebo (0.124+/-0.02 vs 0.008+/-0.01 mg/l; P< or =0.001). There was no significant effect of acute boron supplementation on plasma insulin and glucose concentration or on blood lipid or coagulation factor profile. Factor VIIa rose significantly following consumption of the high fat meal (1.05+/-0.07 vs 1.26+/-0.07; P< or =0.001), but this increase was not altered by boron supplementation.

CONCLUSIONS

Results from this study suggest that acute boron supplementation (at 11.6 mg boron) does not alter the activity of factor VIIa following consumption of a high-fat meal.

SPONSORSHIP

This work was funded by Borax Europe Ltd.

Trans monounsaturated fatty acids and saturated fatty acids have similar effects on postprandial flow-mediated vasodilation

OBJECTIVE

Several studies suggest that a fatty meal impairs flow-mediated vasodilation (FMD), a measure of endothelial function. We tested whether the impairment was greater for trans fats than for saturated fats. We did this because we previously showed that replacement of saturated fats by trans fats in a controlled diet decreased FMD after 4 weeks.

DESIGN

We fed 21 healthy men two different test meals with 0.9-1.0 g fat/kg body weight in random order: one rich in saturated fatty acids (Sat), mainly from palm kernel fat, and one rich in trans fatty acids (Trans) from partially hydrogenated soy bean oil. The study was performed in our metabolic ward. We had complete data for both diets of 21 men.

RESULTS

FMD increased from a fasting value of 2.3+/-2.0% of the baseline diameter to 3.0+/-1.7% after the Sat test meal (95% CI for change -0.33, 1.70) and from 2.7+/-2.3 to 3.1+/-2.0% after the Trans test meal (95% CI for change -0.57, 1.29). The increase after the Sat meal was 0.22 (-1.18-1.61) FMD% higher than after the Trans meal. Serum triacylglycerols increased by 0.46+/-0.36 mmol/l after the Sat test meal and by 0.68+/-0.59 mmol/l after the Trans test meal; a difference of 0.23 (0.07, 0.39) mmol/l. Serum HDL-cholesterol was hardly affected by the test meals. The activity of serum paraoxonase, an esterase bound to HDL, increased slightly after the two test meals but the difference between meals was not significant.

CONCLUSION

FMD was not impaired and not different after test meals with saturated or trans fatty acids. Thus, differences in long-term effects of these fats are not caused by differences in acute effects on the vascular wall.

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.

Fats, lipids and blood coagulation

Saturated and n-3 fatty acids, postprandial lipaemia, and the combined effects of fatty acids and lipid-lowering drugs have been of principal interest in recent studies in the field of dietary fats, lipids and haemostasis. The sex-specific effect of individual saturated fatty acids on coagulation factor VII activity has been discovered, and the significant effect of factor VII R353Q polymorphism on the postprandial response has also been found. An increased intake of n-3 fatty acids or fat reduction when combined with intensive lifestyle interventions may lead to reduced thrombotic potential in type 2 diabetic patients and obese individuals. Furthermore, positive effects on haemostasis by combined treatment with long-chain n-3 fatty acids and simvastatin indicate that n-3 fatty acids may be of some relevance with lipid-lowering drugs. The possible unfavourable effect of n-3 fatty acids on plasminogen activator inhibitor-1 activity is still a matter of dispute, but recent studies suggest that n-3 fatty acids, including alpha-linolenic acid, may have antithrombotic effects by enhancing protein C activity.