[Plasma fibrinogen as a cardiovascular risk factor].

Recent prospective epidemiological studies have shown that plasma fibrinogen is a powerful, independent risk factor of arteriosclerotic diseases such as ischemic heart disease, stroke and peripheral vascular disease. Cross-sectional studies have shown correlation of fibrinogen with various factors, including age, gender, race and smoking. Plasma fibrinogen strongly affects blood coagulation, blood rheology and platelet aggregation. In addition, fibrinogen, fibrin and their degradation products have direct effects on the vascular wall. The migration of vascular smooth muscle cells from the media into the intima and their proliferation play an important role in the pathogenesis of atherosclerosis and in the organization of thrombi. Smooth muscle cells adhere to substrate-bound fibrinogen/fibrin. The cells migrate to a gradient of soluble fibrinogen (chemotaxis). The cells also migrate in a dose-dependent manner to a gradient of substrate-bound fibrinogen and fibrin (haptotaxis). The relation among hyperfibrinogenemia, atherosclerosis and thrombosis is highly complicated. There is no prospective study on fibrinogen and cardiovascular disorders among Japanese. Studying plasma fibrinogen to predict cardiovascular disorders may provide some new insight into their pathophysiological mechanisms.