ACTIVATION OF COAGULATION-FACTOR-VII DURING ALIMENTARY LIPEMIA

Dietary studies have established a connection between plasma lipoprote ins and coagulation factor VII. The present study was undertaken to sp ecifically examine whether factor VII is activated during alimentary l ipemia and to investigate the relations of factor VII mass and activit y state with fasting and postprandial lipoproteins and free fatty acid s (FFAs). Factor VII levels were therefore determined in plasma sample s taken before and after intake of a standardized, oral fat load of a mixed-meal type in 33 men (mean age+/-SD, 48.8+/-3.2 years) with a pre vious myocardial infarction at a young age and 10 healthy, age-matched control subjects. A panel of methods for factor VII determination was used to ensure that changes in all potentially existing forms of the factor during alimentary lipemia would be included. Substantial activa tion of factor VII was found to occur during alimentary lipemia, where as the number of factor VII molecules remained constant or even appear ed to decrease after the test meal. Activation of factor VII was more pronounced in factor VII molecules was higher in control subjects. Int erestingly, factor VII activation, which correlated quantitatively wit h the degree of postprandial triglyceridemia, seemed to be related to FFA production during lipolysis of triglyceride-rich lipoproteins that were generated in response to fat intake. Postheparin plasma lipoprot ein lipase activity was lower in patients, which could offer one expla nation why factor VII activity was lower during alimentary lipemia in these subjects despite their exaggerated postprandial triglyceridemia. Thus, activation of coagulation factor VII during alimentary lipemia may result in a procoagulant state that is likely to promote the forma tion of a coronary thrombus in individuals with established coronary a rtery disease.