One hundred and forty-five normal subjects (61 men, 82 women) of age between 19 and 77 years were grouped into groups of young (<30 years); middle aged (31–50 years), and older (>51 years), according to their gender and body mass index (BMI). A new in vitro test [Gorog Thrombosis Test (GTT)] was used to measure in sequence both platelet reactivity [occlusion time (OT)] and spontaneous thrombolysis [lysis time (LT)] from one non-anticoagulated blood sample.
OT in all women was 315±9.2 s (mean±S.E.M.), in all men OT was 300±10.6 s. The mean LT in all women was 2557±201.5 s, and in all men LT was 2493±198.6 s. Advanced age did not enhance platelet reactivity (OT), but increased BMI did (P=0.039). Spontaneous thrombolysis (LT) was impaired in older men but not in women (difference between young vs. middle age: P=0.019; young vs. older: P=0.0002).
Our findings suggest that in men, spontaneous thrombolytic activity is reduced with age, and this may explain the increased frequency and severity of thromboembolic events. Interestingly, in women, spontaneous thrombolytic activity did not change after menopause.