Determinants of plasma D-dimer levels in a traveling population

BACKGROUND: Plasma D-dimer measurement is a widely used diagnostic test for assessing individuals with suspected venous thromboembolism (VTE). Whilst a negative test is helpful in ruling out thrombosis, the significance and determinants of an elevated plasma D-dimer level in otherwise healthy subjects are poorly understood. OBJECTIVES: To determine the association between recognized risk factors for VTE and plasma D-dimer levels in an adult population. Subjects and methods: Blood samples for measurement of plasma D-dimer levels were obtained from 1000 adults aged <70 years who were participating in a study investigating the incidence of VTE in long distance air travellers. The relationship between D-dimer levels and selected risks factors for VTE including thrombophilia status was investigated. RESULTS: The median (Inter-quartile range) D-dimer level was 243 ng mL(-1) (175-345). Multivariate analysis showed that plasma D-dimer levels were positively associated with increasing age, larger body mass index, female gender, the use of hormone therapy, thrombophilia state, and the presence of co-morbid conditions. CONCLUSION: Plasma D-dimer levels vary markedly between individuals and are associated with known risk factors for VTE, including the presence of thrombophilia conditions. The potential role for the measurement of plasma D-dimer as a marker for thrombosis risk requires further investigation.