Influence of aging on the activity of the hemostatic system: prothrombin fragment 1+2, thrombin-antithrombin III complexes and D-dimers in 80 healthy subjects with age ranging from 20 to 94 years.

To determine the influence of aging on the activity of the hemostatic system, we measured the plasma concentration of prothrombin fragments 1+2 (F 1+2), thrombin-antithrombin III complexes (TAT) and fibrin degradation fragments D-dimers (D-D) in 80 healthy subjects with age ranging between 20 and 94 years. All subjects were free of acute or chronic diseases. The three markers (semi-log scale) were positively correlated with age (r greater than 0.7, p less than 0.01). Mean plasma levels of F 1+2, TAT and D-D were two- to five-fold higher in subjects with age greater than or equal to 60 as compared to those less than 60 years (n = 40 in both groups). In these two groups, normal values for F 1+2, TAT and D-D ranged from 0.3-1.2 vs 0.7-2.4 nmol/l, 1.4-2.6 vs 1.9-6.4 micrograms/l and 33-433 vs 312-1180 micrograms/l, respectively. Sex did not influence the results. We conclude that the activity of the hemostatic system is markedly age-dependent, and that elderly subjects display a biological picture of "prethrombotic" state. In addition, for a right clinical use of these three markers, age should be taken into account when normal range is to be established.