Age, sex and racial differences in fibrin formation and fibrinolysis within the healthy population

Increased fibrin generation and reduced fibrinolytic potential have been detected using global coagulation assays in several hypercoagulable states including cardiovascular disease and venous thromboembolism. We aimed in this study to define the impact of age, sex and race on fibrin generation and lysis using the Overall Haemostatic Potential (OHP) assay in a group of stringently defined healthy adults. Healthy adult patients not receiving anticoagulation and without a history of thrombotic disease were prospectively recruited. Iindividuals with cardiovascular risk factors (e.g. hypertension, diabetes, smoking), receiving hormonal therapy, antiplatelet agents or with abnormal routine blood tests were also excluded. Platelet-poor plasma was obtained and the OHP assay, which evaluates fibrin formation with and without tissue plasminogen activator, was performed on all plasma samples. 144 healthy subjects (34.7% male) with median age 42 years (interquartile range 20, 77) were recruited. After multivariate analysis, age at least 50 years and female sex were associated with significantly increased fibrin generation parameters (overall coagulation potential, OHP, maximum optical density, fibrin) as well as reduced markers of fibrinolysis (overall fibrinolytic potential and time-to-50% lysis). There were no significant differences in OHP parameters between whites, East Asians and South Asians after accounting for age and sex. This study defines age, sex and racial differences of fibrin generation and fibrinolysis as measured by the OHP assay in a sample of healthy subjects. Further studies are warranted in diseased populations, where there is growing awareness of the role of global coagulation assay in defining prothrombotic and hypofibrinolytic states.