Investigations on the changes of the blood coagulation-fibrinolysis system as a risk factor for coronary heart disease. I. Prevalence of the changes in the blood coagulation-fibrinolysis system in a middle aged male population.
Platelet count and adhesivity, availability of platelet factor 3, fibrinogen concentration and plasma antiplasmin activity were studied in 2,000 men aged 40 to 60 years. The results were estimated in comparison with the data obtained in 100 young apparently healthy subjects. Platelet count was within normal limits in 90% of the cases but with an increased prevalence of upper normal values. Platelet adhesivity to glass, expressed as adhesivity index, varied widely in both directions : a low index was found in 20.23% of the cases ; the high adhesivity index varied with age from 12.27% in subjects aged 40, to 26.5% in aged 56-60. Availability of platelet factor 3 was clearly increased in a large number of middle-aged men. Fibrinogen concentration correlated with age. Antiplasmin activity was significantly higher in the elderly subjects than in the young controls.