Effect of strenuous exercise on fibrinogen and fibrinolysis in healthy elderly men and women

The elevated incidence of thrombotic disease in elderly people may be associated with an increase in PAI-1 and fibrinogen with ageing. Cross-sectional studies report an inverse relation of PAI-1 and fibrinogen with physical activity, but training studies show inconsistent results. In a controlled intervention study among elderly subjects (aged 60-80 years) we observed a moderate decrease in PAI-1 antigen (4%, -2.1 +/- 2.4 ng/ml), a significant increase in t-PA activity (11%, 0.07 +/- 0.04 IU/ml) and an unexpected significant increase in fibrinogen (6%, 0.18 +/- 0.07 g/l) in subjects following a 6-month intensive training program as compared to controls. Reduction in PAI-1 antigen was significantly associated with a decrease in triglycerides (beta = 10.3 ng/ml per 1 mM, p <0.01) and insulin (beta = 2.37 ng/ml per 1 mU/l, p = 0.07). Increase in fibrinogen coincided with a rise in C-reactive protein (p <0.001). These data suggest that regular intensive activity may increase fibrinolytic activity in a moderate way, but also may cause chronically elevated plasma levels of acute phase proteins in elderly persons.