Factor VIIa Response to a Fat-Rich Meal Does Not Depend on Fatty Acid Composition

A fat-rich meal increases activated factor VII (FVIIa), but it is not clear whether this increase depends on the fatty acid composition of the meal. Therefore, we studied the FVIIa response to fat-rich meals with different fatty acid composition in a randomized controlled crossover trial and investigated whether this response is mediated by an increase in serum triglycerides. Elderly women (> 60 years, n=91) received on separate days four different fat-rich breakfasts (50 energy percent [en%] of fat) and a control breakfast (1.5 en% fat; crossover). The fat-rich breakfasts differed in fatty acid composition: one rich in palmitic acid (21.7 g), one in stearic acid (18.6 g), and the other two in linoleic and linolenic acid-one with a ratio 3:1 (12.5/3.9 g) and the other with a ratio of 15:1 (18.8/1.2 g). At 8 AM before the breakfast (fasting) and at 1 and 3 PM, blood samples were taken, in which FVIIa and serum triglycerides were measured. FVIIa response to the fat-rich meals ranged from 11.6 mU/mL (95% confidence interval: 8.3,14.9) on the stearic meal to 15.9 mU/mL (12.0,19.8) on the linoleic/linolenic 15:1 meal at 1 PM and from 14.9 mU/mL (10.6,19.2) to 21.1 mU/mL (16.6,25.6) for the same meals at 3 PM. The responses did not differ between the fat-rich meals. After the control breakfast, FVIIa decreased, with 6.3 mU/mL (3.9,8.7) at 1 PM and 8.7 mU/mL (6.3,11.1) at 3 PM. The triglyceride response was lower after both linoleic/linolenic rich breakfasts compared with the palmitic and stearic breakfast (P<.05) and was not associated with the FVIIa response at any of the blood sampling occasions. The results of this study show that the response of FVIIa to a fat-rich meal is independent of its fatty acid composition and is not mediated by serum triglycerides.