The link between high-fat meals and postprandial activation of blood coagulation factor VII possibly involves kallikrein

Contrary to low-fat meals, high-fat meals are known to cause postprandial f actor VII (FVII) activation, but the mechanism is unknown. To study the pos tprandial FVII activation in detail, 18 young men consumed in randomized or der high-fat or low-fat test meals. Fasting and non-fasting blood samples w ere collected. The high-fat test was associated with an increase in plasma triglyceride and kallikrein concentrations and postprandial FVII activation (p<0.001). Plasma kallikrein was strongly associated with triglycerides in fasting and nonfasting samples (r(2)=0.74-0.87, p<0.0001), suggesting that triglyceride-rich lipoproteins may activate prokallikrein. Neither plasma triglycerides nor kallikrein and activated FVII were statistically associat ed. This may suggest that additional factors are involved in the postprandi al FVII activation. No clear evidence for a role of tissue factor expressio n by monocytes, factor XII or insulin in postprandial FVII activation was o bserved. Tissue factor pathway inhibitor and prothrombin fragment 1+2, a ma rker of thrombin generation, were not affected postprandially after either the high-fat or the low-fat meals. Our findings indicate that triglyceride- rich lipoproteins activate prokallikrein postprandially, which might form a n important initial event in FVII activation after consumption of high-fat meals.