Prothrombin concentrations in middle-aged men and women – stability over time and correlations with cardiovascular risk factors

Prothrombin is a vitamin K-dependent glycoprotein synthesized in the liver and circulating in blood as an inactive zymogen. The corresponding activated thrombin enzyme is a central player in hemostasis and thrombosis. Still, little is known about the individual variation over time of the prothrombin concentration in plasma in the general population. This study aimed to establish the prothrombin plasma level and its correlation with cardiovascular risk factors in the general population. A novel aptamer-based electrochemical biosensor, which in a single, direct incubation step and within five minutes quantifies the prothrombin concentration in molar amounts, was used for analysis of plasma samples from 141 non-anticoagulated individuals in the Swedish cardiopulmonary bioimage study (SCAPIS). Plasma samples from baseline and from re-examination after one year of follow-up were tested. The study population consisted of 141 individuals with a mean age of 57.3 (standard deviation 3.79) years, and 66 (47%) were females. The mean (±standard deviation) prothrombin concentrations in plasma were 1565 nM (±249) and 1526 nM (±319) at baseline and one-year follow-up, respectively. There was a strong correlation between the individual prothrombin concentration at baseline and one year later, r=0.658, p