Postprandial variations in fibrinolytic activity in middle-aged men are modulated by plasminogen activator inhibitor I 4G-675/5G genotype but not by the fat content of a meal.
BACKGROUND
Decreased fibrinolytic activity is associated with an increased risk of ischemic heart disease and elevated plasma triacylglycerol concentrations.


OBJECTIVE
The goal was to determine whether plasminogen activator inhibitor 1 (PAI-1) and fibrinolytic activities are influenced by 1) dietary fat intake from a test meal and 2) the PAI-1 4G allele.


METHODS
A parallel randomized controlled trial was used to compare the effect on fibrinolytic activity, measured as dilute clot lysis time, of high-oleate or high-palmitate test meals (both containing 50 g fat; both n = 18) with that of a low-fat test meal (15 g fat; n = 15) in men aged > 52 y. In a second study, postprandial changes in PAI-1 activity were measured in 32 men in response to a high-oleate meal containing 50 g fat. The results from both studies were analyzed according to PAI-1 4G-675/5G genotype.


RESULTS
Fasting dilute clot lysis time was positively associated with body mass index (r = 0.326, P = 0.02) and was shortened postprandially (P < 0.00001) independent of the fat content of the meal. Fasting PAI-1 activity was higher in those carrying the 4G allele and was correlated with fasting plasma triacylglycerol concentrations (r = 0.48, P = 0.008) and factor VII coagulant activity (r = 0.46, P = 0.012) after adjustments for age, body mass index, and genotype. Plasma PAI-1 activity decreased significantly after a meal but was not associated with postprandial changes in plasma triacylglycerols after a high-fat meal. The postprandial increase in plasma triacylglycerols was higher in subjects carrying the 4G allele.


CONCLUSIONS
Fibrinolytic activity is not lower after meals rich in palmitate or oleate than after a low-fat meal.
Sanders
Thomas A B
TA
Nutrition Food and Health Research Centre, King's College London, United Kingdom. tom.sanders@kcl.ac.uk
de Grassi
Tamara
T
Acharya
Jayshree
J
Miller
George J
GJ
Humphries
Steve E
SE
D002784:Cholesterol / Q000097:blood; D004041:Dietary Fats / Q000008:administration & dosage / Q000494:pharmacology*; D005215:Fasting / Q000378:metabolism; D005342:Fibrinolysis / Q000187:drug effects*; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D019301:Oleic Acid / Q000008:administration & dosage / Q000494:pharmacology; D019308:Palmitic Acid / Q000008:administration & dosage / Q000494:pharmacology; D017395:Plasminogen Activator Inhibitor 1 / Q000235:genetics* / Q000378:metabolism; D019518:Postprandial Period
D004041:Dietary Fats; D017395:Plasminogen Activator Inhibitor 1; D019301:Oleic Acid; D019308:Palmitic Acid; D002784:Cholesterol