Factor VIIa response to a fat-rich meal does not depend on fatty acid composition: a randomized controlled trial

Effects of two consecutive mixed meals high in palmitic acid or stearic acid on 8-h postprandial lipemia and glycemia in healthy-weight and overweight men and postmenopausal women: a randomized controlled trial

Purpose

Palmitic and stearic acids have different effects on fasting serum lipoproteins. However, the effects on postprandial lipemia and glycemia are less clear. Also, the effects of a second meal may differ from those of the first meal. Therefore, we studied the effects of two consecutive mixed meals high in palmitic acid- or stearic acid-rich fat blends on postprandial lipemia and glycemia.

Methods

In a randomized, crossover study, 32 participants followed 4-week diets rich in palmitic or stearic acids, At the end of each dietary period, participants consumed two consecutive meals each containing ± 50 g of the corresponding fat blend.

Results

Postprandial concentrations of triacylglycerol (diet-effect: − 0.18 mmol/L; p = 0.001) and apolipoprotein B48 (diet-effect: − 0.68 mg/L; p = 0.002) were lower after stearic-acid than after palmitic-acid intake. Consequently, total (iAUC_0–8 h) and first meal (iAUC_0–4 h) responses were lower after stearic-acid intake (p ≤ 0.01). Second meal responses (iAUC_4–8 h) were not different. Postprandial changes between the diets in non-esterified fatty acids (NEFA) and C-peptide differed significantly over time (p < 0.001 and p = 0.020 for diet*time effects, respectively), while those for glucose and insulin did not. The dAUC_0–8 h, dAUC_0–4 h, and dAUC_4–8 h for NEFA were larger after stearic-acid intake (p ≤ 0.05). No differences were observed in the iAUCs of C-peptide, glucose, and insulin. However, second meal responses for glucose and insulin (iAUC_4–8 h) tended to be lower after stearic-acid intake (p < 0.10).

Conclusion

Consumption of the stearic acid-rich meals lowered postprandial lipemia as compared with palmitic acid. After the second stearic acid-rich meal, concentrations of C-peptide peaked earlier and those of NEFA decreased more.

Clinical trial registry This trial was registered at clinicaltrials.gov as NCT02835651 on July 18, 2016.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00394-021-02530-2.

Palmitic Acid Versus Stearic Acid: Effects of Interesterification and Intakes on Cardiometabolic Risk Markers - A Systematic Review

Fats that are rich in palmitic or stearic acids can be interesterified to increase their applicability for the production of certain foods. When compared with palmitic acid, stearic acid lowers low-density lipoprotein (LDL)-cholesterol, which is a well-known risk factor for coronary heart disease (CHD), but its effects on other cardiometabolic risk markers have been studied less extensively. In addition, the positional distribution of these two fatty acids within the triacylglycerol molecule may affect their metabolic effects. The objective was to compare the longer-term and postprandial effects of (interesterified) fats that are rich in either palmitic or stearic acids on cardiometabolic risk markers in humans. Two searches in PubMed/Medline, Embase (OVID) and Cochrane Library were performed; one to identify articles that studied effects of the position of palmitic or stearic acids within the triacylglycerol molecule and one to identify articles that compared side-by-side effects of palmitic acid with those of stearic acid. The interesterification of palmitic or stearic acid-rich fats does not seem to affect fasting serum lipids and (apo) lipoproteins. However, substituting palmitic acid with stearic acid lowers LDL-cholesterol concentrations. Postprandial lipemia is attenuated if the solid fat content of a fat blend at body temperature is increased. How (the interesterification of) palmitic or stearic acid-rich fats affects other cardiometabolic risk markers needs further investigation.

Cardiovascular disease risk of dietary stearic acid compared with trans, other saturated, and unsaturated fatty acids: a systematic review

BACKGROUND

High stearic acid (STA) soybean oil is a trans-free, oxidatively stable, non-LDL-cholesterol-raising oil that can be used to replace trans fatty acids (TFAs) in solid fat applications.

OBJECTIVE

The objective was to assess the cardiovascular health effects of dietary STA compared with those of trans, other saturated, and unsaturated fatty acids.

DESIGN

We reviewed epidemiologic and clinical studies that evaluated the relation between STA and cardiovascular disease (CVD) risk factors, including plasma lipids and lipoproteins, hemostatic variables, and inflammatory markers.

RESULTS

In comparison with other saturated fatty acids, STA lowered LDL cholesterol, was neutral with respect to HDL cholesterol, and directionally lowered the ratio of total to HDL cholesterol. STA tended to raise LDL cholesterol, lower HDL cholesterol, and increase the ratio of total to HDL cholesterol in comparison with unsaturated fatty acids. In 2 of 4 studies, high-STA diets increased lipoprotein(a) in comparison with diets high in saturated fatty acids. Three studies showed increased plasma fibrinogen when dietary STA exceeded 9% of energy (the current 90th percentile of intake is 3.5%). Replacing industrial TFAs with STA might increase STA intake from 3.0% (current) to approximately 4% of energy and from 4% to 5% of energy at the 90th percentile. One-to-one substitution of STA for TFAs showed a decrease or no effect on LDL cholesterol, an increase or no effect on HDL cholesterol, and a decrease in the ratio of total to HDL cholesterol.

CONCLUSIONS

TFA intake should be reduced as much as possible because of its adverse effects on lipids and lipoproteins. The replacement of TFA with STA compared with other saturated fatty acids in foods that require solid fats beneficially affects LDL cholesterol, the primary target for CVD risk reduction; unsaturated fats are preferred for liquid fat applications. Research is needed to evaluate the effects of STA on emerging CVD risk markers such as fibrinogen and to understand the responses in different populations.

Postprandial factor VII metabolism: the effect of the R353Q and 10 bp polymorphisms

Elevated levels of coagulation factor VII activity (FVIIc) are associated with increased risk of CHD. FVIIc is strongly determined by two polymorphisms (R353Q and 0/10 base pairs (bp)) and plasma triacylglycerol (TAG) concentrations. The Q and 10 bp polymorphisms show strong linkage disequilibrium and have been associated with lower levels of fasting FVII, but there has been little investigation of the effect of these genotypes on the postprandial FVII metabolism. The present study demonstrated that fasting activated factor VII (FVIIa) and factor VII antigen (FVIIag) levels were significantly lower in the heterozygotes carrying the Q and 10 bp alleles (n12), than in the R/0 bp homozygotes (n12) (43·0 (SE 4·8)v. 23·9 (SE 6·5) mU/ml and 85·7 (SE 5·4)v. 71·6 (SE 7·5) % respectively). During postprandial lipaemia there was a significant increase in FVIIa in R/0 bp homozygotes but not in the heterozygotes carrying the Q and 10 bp alleles. The proportion of FVIIa (FVIIa : FVIIag) increased in the homozygotes but not in the heterozygotes (2·04 (SE 0·35)v. 1·20 (SE 0·26) respectively). Therefore possession of the relatively common Q and 10 bp alleles is not associated with postprandial activation of FVII, which may in turn have a protective effect against CHD.

Dietary stearic acid and risk of cardiovascular disease: Intake, sources, digestion, and absorption

Individual FA have diverse biological effects, some of which affect the risk of cardiovascular disease (CVD). In the context of food-based dietary guidance designed to reduce CVD risk, fat and FA recommendations focus on reducing saturated FA (SFA) and trans FA (TFA), and ensuring an adequate intake of unsaturated FA. Because stearic acid shares many physical properties with the other long-chain SFA but has different physiological effects, it is being evaluated as a substitute for TFA in food manufacturing. For stearic acid to become the primary replacement for TFA, it is essential that its physical properties and biological effects be well understood.

Influence of stearic acid on hemostatic risk factors in humans

Stearic acid has been claimed to be prothrombotic. Elevated plasma factor VII coagulant activity (FVIIc) may raise the risk of coronary thrombosis in the event of plaque rupture. Fibrinogen, an acute-phase protein, is necessary for normal blood clotting; however, elevated levels of fibrinogen increase the risk of coronary heart disease (CHD). Here I report the results of three controlled, human dietary intervention studies, which used a randomized crossover design to investigate the hemostatic effects of stearic acid-rich test diets in healthy young men. A diet high in stearic acid (shea butter) resulted in a 13% lower fasting plasma FVIIc than a high palmitic acid diet, and was 18% lower than a diet high in myristic and lauric acids (P = 0.001) after 3 wk of intervention. The stearic acid-rich test fat increased plasma fibrinogen concentrations slightly compared with the myristic-lauric acid diet (P < 0.01). When investigating the acute effects of fatty meals, those high in stearic acid (synthesized test fat) resulted in a smaller postprandial increase in FVII than those high in trans and oleic FA, indicating a smaller increase in activated FVII after ingesting stearic acid compared with fats high in monounsaturated FA, probably caused by lower postprandial lipemia. Thus, the present investigations did not find dietary stearic acid to be more thrombogenic, in either fasting effects compared with other long-chain FA, or in acute effects compared with dietary unsaturated FA, including trans monounsaturated FA. The slightly increased effect on fasting plasma fibrinogen may be biologically insignificant, but it should be investigated further.

Dietary fatty acids and the haemostatic system

Studies of the effects of dietary fatty acids on the haemostatic system, and their potential relevance for the thrombotic component of coronary heart disease (CHD), have a pedigree as long as those linking dietary fat, plasma lipoprotein metabolism and atheroma. Achievements have not been as impressive, however, partly owing to the relatively slow evolution of our understanding of the complicated physiology, biochemistry and pathology of haemostasis and fibrinolysis, which remains incomplete. Progress was also retarded up to 1980 by a general reluctance to acknowledge the pathogenic importance of thrombosis for myocardial infarction. Interest in dietary fat and the haemostatic mechanism re-emerged with reports of associations of haemostatic variables with plasma triacylglycerol levels and risk of CHD. This review summarises the history, focuses on evidence for dietary C18-unsaturated fatty acids as important determinants of factor VII (FVII) activation and plasminogen activator inhibitor type 1 (PAI-1) levels, and discusses possible underlying mechanisms involving ATP binding cassette (ABC) transporters and peroxisome proliferator-activated receptors. The potential relevance of these effects for CHD is discussed. In the presence of unstable atheromatous plaques, increased levels of activated FVII and PAI-1 induced by diets rich in mixtures of saturated and unsaturated fats may raise the risk of occlusive thrombosis in the event of plaque rupture.

Postprandial activation of hemostatic factors: role of dietary fatty acids

Intake of dietary fat is an important determinant of the plasma concentration of triacylglycerol-rich lipoproteins, and the degree of alimentary lipemia is reported to have effects on hemostatic status including platelet function. Although association between the amount of dietary fat intake, lipemic response and certain cardiovascular disease (CVD) risk factors (VIIa and PAI-1) has been reported, the significance of the fatty acid composition of ingested fat for the postprandial lipid concentrations and the hemostatic factors is still unclear. Accumulating evidence suggests a relationship between dietary fatty acids and emerging hemostatic CVD risk factors, although much of this evidence is incomplete or conflicting. In order to improve our knowledge in this area, sufficient sample size in future studies are required to take into account of the genetic variation (gene polymorphisms for VII, PAI-1), sex, physical activity, stage of life factors, and sufficient duration to account for adaptation for definitive conclusions.

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.

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.

Chylomicron particle size and number, factor VII activation and dietary monounsaturated fatty acids

This study evaluated the effects of substituting dietary saturated fatty acids (SFAs) with monounsaturated fatty acids (MUFAs) on postprandial chylomicron (triacylglycerol (TAG), apolipoprotein B-48 (apo B-48) and retinyl ester (RE)), chylomicron particle size and factor VII (FVII) response when subjects were given a standard meal. In a controlled sequential design, 51 healthy young subjects followed an SFA-rich diet (Reference diet) for 8 weeks after which half of the subjects followed a moderate MUFA diet (n=25) and half followed a high MUFA diet (n=26) for 16 weeks. Fasting lipoprotein and lipid measurements were evaluated at baseline and at 8-week intervals during the Reference and MUFA diets. In 25 of the subjects (n=12 moderate MUFA, n=13 high MUFA), postprandial responses to a standard test meal containing RE and 13C-tripalmitin were investigated at the end of the Reference and the MUFA diet periods. Although there were no differences in the postprandial lipid markers (TAG, RE, 13C-TAG) on the two diets, the postprandial apo B-48 response (incremental area under the curve (IAUC)) was reduced by 21% on the moderate MUFA diet (NS) and by 54% on the high MUFA diet (P<0.01). The postprandial peak concentrations of apo B-48 were reduced by 33% on the moderate MUFA diet (P<0.01) and 48% on the high MUFA diet (P<0.001). Fasting values for factor VII activity (FVIIc), activated factor VII (FVIIa) or factor VII antigen (FVIIag) did not differ significantly when subjects were transferred from Reference to MUFA diets. However, the postprandial increases in coagulation FVII activity (FVIIc) were 18% lower and of activated FVII (FVIIa) were 17% lower on the moderate MUFA diet (NS). Postprandial increases in FVIIc and FVIIa were 50% (P<0.05) and 29% (P<0.07) lower on the high MUFA diet and the area under the postprandial FVIIc response curve (AUC) was also lower on the high MUFA diet (P<0.05). Significantly higher ratios of RE:apo B-48 (P<0.001) and 13C-palmitic acid:apo B-48 (P<0.01) during both MUFA diets suggest that the CMs formed carry larger amounts of dietary lipids per particle, reflecting an adaptation to form larger lipid droplets in the enterocyte when increased amounts of dietary MUFAs are fed. Smaller numbers of larger chylomicrons may explain attenuated activation of factor VII during the postprandial state when the background diet is rich in MUFA.

Protective effect of dietary monounsaturated fat on arteriosclerosis: beyond cholesterol

The consumption of diets enriched in monounsaturated fat has been related to a lower rate of coronary heart disease. It is well known that this dietary model decreases LDL-cholesterol plasma levels when replacing a saturated fat enriched diet. For this reason, a high monounsaturated fat diet is now being advocated to prevent cardiovascular disease, especially in Mediterranean countries. However, some expert panels-the Joint Task Force of European and other Societies on Coronary Prevention and the International Task Force for Prevention of Coronary Heart Disease-recommend replacing dietary saturated fat by complex carbohydrates, limiting the intake of total fat to <30% of the energy and monounsaturated fat to no more than 10-15% of total calories, reaching a similar effect on LDL-cholesterol plasma levels to a high monounsaturated fat diet. The most appropriate nutritional model to prevent arteriosclerosis should be supported by research into other biological effects of both diets. Therefore, it is interesting to review the non-lipid effect of monounsaturated fat, starting with its influence on other cardiovascular risk factors, such as carbohydrate metabolism and blood pressure. Moreover, substantial evidence of the effect of dietary monounsaturated fat on a wide range of healthy benefits beyond cholesterol, which have been investigated in recent years, such as lipoprotein oxidation, coagulation, fibrinolysis and endothelium, will be discussed. Furthermore, many observational epidemiological studies suggest that a high intake of monounsaturated fat is associated with reduced coronary risk and this will be analyzed in accordance with the clinical evidence to discuss the best dietary model to prevent coronary artery disease.

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.

Dietary treatment of thrombogenic disorders related to the metabolic syndrome

The increased risk of coronary heart disease associated with the metabolic syndrome may be partially explained by prothrombotic deviations of the haemostatic system. Individuals with insulin resistance, dyslipidaemia and obesity are characterized by elevated plasma fibrinogen and factor VII coagulant activity levels and raised concentrations of plasminogen-activator inhibitor, the main inhibitor of endogenous fibrinolysis. These haemostatic abnormalities may be corrected with dietary treatment of the underlying clinical disorder. Dietary trials of diseased and healthy volunteers suggest that the optimal antithrombotic diet is a low-fat diet with a high content of foods rich in complex carbohydrates and dietary fibre. The dietary fatty acid composition has a profound effect on blood lipids, but seems of minor importance for the haemostatic system.

Postprandial response of activated factor VII in elderly women depends on the R353Q polymorphism

BACKGROUND

Activated factor VII (FVIIa) is a very potent coagulant and may be a key determinant of the outcome of a cardiovascular event. The main determinants of FVIIa are the R353Q polymorphism and dietary fat intake, which may have an interactive effect.

OBJECTIVE

The objective was to investigate whether the response of FVIIa to a fat-rich breakfast varies across genotypes of the R353Q polymorphism.

DESIGN

Ninety-one apparently healthy elderly women (>60 y of age), 56 with the RR genotype and 35 with the RQ or QQ genotype, participated in a randomized, controlled crossover study. Subjects received 5 breakfasts, each on a separate day: 1 low-fat control breakfast and 4 high-fat test breakfasts. Blood samples were taken for measurement of FVIIa at 0800 before each breakfast (fasting) and at 1300 and 1500.

RESULTS

The mean (+/-SD) fasting FVIIa concentration was 93.3 +/- 26.7 U/L in women with the RR genotype, 49.3 +/- 19.1 U/L in those with the RQ genotype and 39.5 +/- 17.2 U/L in those with the QQ genotype. The mean absolute response to all 4 test breakfasts was 37.0 U/L in those with the RR genotype and 16. 1 U/L in those carrying the Q allele (P < 0.001 for difference). Likewise, the FVIIa response relative to fasting FVIIa was significantly higher in women homozygous for the R allele.

CONCLUSION

This observation may indicate a considerable difference in cardiovascular risk between genotype groups as a result of an increase in FVIIa after a fat-rich diet.

Dietary oleic and palmitic acids and postprandial factor VII in middle-aged men heterozygous and homozygous for factor VII R353Q polymorphism

BACKGROUND

The R353Q genotype is a major determinant of factor VII coagulant (FVIIc) activity, which is associated with an increased risk of ischemic heart disease (IHD) and elevated plasma triacylglycerol concentrations.

OBJECTIVE

The objectives were to 1) compare the effects of meals rich in palmitate or oleate with those of a meal low in fat on FVIIc in subjects with moderately elevated plasma nonfasting triacylglycerol concentrations and 2) determine whether the postprandial increase in FVIIc induced by dietary oleate differs in carriers of the Q allele.

DESIGN

Fifty-two men aged >52 y with nonfasting plasma triacylglycerol concentrations between 2 and 5.5 mmol/L were randomly assigned to receive isoenergetic (5.1 MJ) meals providing 50 g high-oleate or high-palmitate oils or a low-fat meal providing 15 g high-oleate oil. In a second study, 17 men aged >52 y who were heterozygous for factor VII R353Q polymorphism were age-matched with subjects homozygous for the R allele and their responses to a 50-g, high-oleate meal were measured.

RESULTS

FVIIc decreased by 11% after the low-fat meal. FVIIc increased by 9% and FVIIa (the activated form of FVII) increased by 55% after the high-oleate meal, whereas FVIIc did not change but FVIIa increased by 25% after the high-palmitate meal. Fasting FVIIc and FVIIa concentrations were 24% and 48% lower, respectively, in men with the RQ genotype than in men with the RR genotype but increased postprandially in both groups with no evidence of a genotype interaction.

CONCLUSIONS

A high-fat meal rich in oleate increases FVIIa, whereas a low-fat meal does not, in men at high risk of IHD, independent of R353Q genotype.