INTERRELATIONSHIPS BETWEEN HEMOSTATIC TESTS AND THE EFFECTS OF SOME DIETARY DETERMINANTS IN THE CAERPHILLY COHORT OF OLDER MEN

Inter-relationships between fibrinogen, platelets and other haemostati c factors were examined in 1030 men aged 55-99 years. Fasting blood wa s taken and used for cell counts, platelet counts and platelet paramet ers, aggregation of platelets to ADP by a whole blood method and a fil ter test of platelet activation. Plasma fibrinogen, von Willebrand fac tor, factor VII and plasma viscosity were measured by standard methods . A stressed bleeding time was conducted on the forearm of the arm not used for venepuncture. Variability within the laboratory and short-te rm intra-subject variation were examined and found to be acceptably sm all. The effect of age on the tests was modest, except for von Willebr and factor which increased by about 50% of a SD for every 10 years of age. Cholesterol and triglyceride levels had small effects on the plat elet tests and a large effect on factor VII. A number of dietary and l ife-style determinants were examined: smokers had increased levels of fibrinogen, viscosity and white cell count and reduced bleeding times. Alcohol drinkers showed reduced platelet activity and have lower leve ls of fibrinogen, von Willebrand factor and white cell count. Men who took fish oil capsules had substantially increased bleeding times and lower levels of von Willebrand factor and men who took capsules contai ning an extract of garlic showed reduced platelet retention in the fil ter test.