Impaired fibrinolysis in hypertension and obesity due to high plasminogen activator inhibitor-1 level in plasma.

In order to elucidate the influence of the risk factors of coronary heart disease on the fibrinolytic activity, relationships between blood pressure, body mass index (BMI), plasma lipoprotein (a) (Lp(a)) level and the plasma levels of tissue plasminogen activator (tPA) and plasminogen activator inhibitor-1 (PAI-1) were analyzed in the subjects with mild hypertension. Systolic blood pressure showed a positive correlation with total PAI-1 and free PAI-1. Diastolic blood pressure showed no correlation with these proteins involved in the fibrinolytic system. BMI had a positive correlation with total PAI-1, free PAI-1 and euglobulin clot lysis time (ECLT). Plasma Lp(a) level showed correlation with neither blood pressure nor fibrinolytic parameters, but it showed weak negative correlation with body mass index (BMI). These results suggest that high blood pressure and obesity tend to increase free PAI-1 which reduces fibrinolytic activity. Lp(a), however, seems not to influence directly the fibrinolytic system but may work to decrease fibrinolytic activity only in conjunction with other risk factors. The effects of daily drinking of alcohol and smoking on the fibrinolytic system were also investigated in the present study and we obtained the results that habitual drinking increased plasma levels of both tPA and PAI-1 whereas smoking did not affect fibrinolytic activity. These results suggest that risk factors for coronary heart disease such as hypertension and obesity are closely related to the impaired fibrinolysis.