Summary
Blood coagulation activation might be one mechanism linking acute mental stress with
coronary events. We investigated the natural habituation of coagulation responses
and recovery to short-term mental stress.Three times with one-week intervals, 24 men
(mean age 47 ± 7 years) underwent the same 13-min stressor (preparation, job interview,
mental arithmetic). During each visit venous blood was obtained four times (baseline,
immediately post-stress, 45 min of recovery, 105 min of recovery). Eight blood coagulation
parameters were measured at weeks one and three. Acute stress provoked increases in
von Willebrand factor antigen, fibrinogen, clotting factor FVII activity (FVII:C),
FVIII:C, FXII:C (p’s ≤0.019), and D-dimer (N.S.). All coagulation parameters experienced
full recovery except FVIII:C (p = 0.022). Stress did not significantly affect activated
partial thromboplastin time and prothrombin time. At all time points FVIII:C and FXII:C
levels were significantly higher at week one compared to week three (p’s ≤0.041).
Before catheter insertion, systolic blood pressure (p = 0.001) and heart rate (p =
0.026) were relatively higher at week one. Unlike the magnitude of systolic blood
pressure response to stress (p = 0.007) and of cortisol recovery from stress (p =
0.002), the magnitude of all coagulation responses to stress and the recovery from
stress were similar in week one and week three. Sympathetic activation with anticipatory
stress best explained increased baseline activity in FVIII and FXII at week one. An
incapacity of the coagulation system to adapt to stress repeats is perhaps a consequence
of evolution, but might also contribute to increased coronary risk in some individuals,
particularly in those with cardiovascular diseases.
Keywords
Blood coagulation - cardiovascular disease - psychological stress - recovery - habituation