PLASMA-FIBRINOGEN - ARE THERE AGE-DEPENDENT CHANGES

Fibrinogen, proposed as risk factor for cardio- and cerebrovascular disease in several prospective studies, was examined in 129 clinically healthy persons (23-90 years). Fibrinogen rose by 17-29 mg/dl/decade, depending on the determination method employed. Comparing six different assays based upon immunological, functional and physical properties, no decline of the ''specific'' coagulation activity was found. However, the comparability of the methods employed showed to be extremely poor. The susceptibility of plasma fibrinogen to heat precipitation was similar for all ages. Only N-acetylneuraminic (NANA)/mg fibrin rose slightly, confirming possible age-dependent posttranslational changes, the consequences of which still have to be clarified. In conclusion, an increase of plasma fibrinogen concentration occurred with advancing age which may contribute to the risk of vascular diseases in the elderly. No changes of the coagulation activity were observed.