PLASMA-FIBRINOGEN AND PHYSIOLOGICAL AGING

Results of prospective studies indicate that increased fibrinogen conc entration is significantly associated with the risk of arterioscleroti c vessel disease. As the fibrinogen concentration is considered to ris e with aging, determination of its physiological values with various m ethods in strictly healthy adult and aged individuals is a prerequisit e to evaluating the relative contribution of fibrinogen to cardiovascu lar diseases. Fibrinogen concentration was determined in 209 healthy s ubjects, aged 19 to 96 years. Persons over the age of 60 were recruite d according to the stringent criteria of the Senieur protocol establis hed for human immunogerontological studies. Fibrinogen concentrations, obtained by heating precipitation and by thrombin clotting time with both electromagnetic water-bath and semiautomatic coagulometer, ranged from 1.55 to 3.70 g/L. A rise in plasma concentration was observed wi th aging. Independently of age, females exhibited higher concentration s than males. Significantly higher values were observed in subjects ov er 60 years of age, in both sexes, in comparison with the younger grou ps.