title: Relationship between hemoconcentration and blood coagulation responses to acute mental stress.
abstract: BACKGROUND
  Acute mental stress elicits reliable changes in blood coagulation factors. We studied whether stress-related changes in coagulation measures are associated with concomitant hemoconcentration.
  
  
  METHODS
  Twenty-two men (mean age 47+/-8 years) underwent the Trier Social Stress Test (TSST) combining 13 min of task preparation, job interview, and mental arithmetic. Venous blood was obtained immediately before the preparation phase and immediately after stress to determine seven measures of coagulation and three measures of hemoconcentration.
  
  
  RESULTS
  Clotting factor VII activity (FVII:C; 99.5+/-21.9 vs. 104.5+/-23.7 IU; p=0.016), FVIII:C (96.3+/-18.1 vs. 105.1+/-25.7 IU; p=0.008), FXII:C (95.8+/-26.7 vs. 102.6+/-26.4 IU; p=0.002), and von Willebrand factor antigen (vWF; 103.3+/-36.3 vs. 110.1+/-43.3 IU; p=0.009) all increased from baseline to poststress, with a similar statistical trend observed for d-dimer (177.6+/-85.5 vs. 180.5+/-83.9 ng/ml; p=0.058). The absolute increases in fibrinogen and in soluble tissue factor were not significant. Hematocrit (40.8+/-2.5 vs. 42.7+/-2.8; p<0.001) and hemoglobin (14.5+/-0.81 vs. 15.2+/-0.97; p<0.001) increased, and plasma volume (59.2%+/-2.5 vs. 54.6+/-4.2%; p<0.001) decreased from baseline to poststress. Unlike with heart rate (HR) and blood pressure (BP) reactivity, there emerged no significant relationship between change scores in any hemoconcentration and coagulation measure (all r values<0.4, all p values>0.05).
  
  
  CONCLUSIONS
  We corroborated significant changes in coagulation measures in response to acute mental stress compatible, with the notion that stress may elicit a hypercoagulable state. However, stress hemoconcentration appears not to explain a substantial proportion in coagulation changes elicited by acute mental stress.
authors.affiliation: Institute for Behavioral Sciences, Federal Institute of Technology, Zurich, Switzerland.
authors.forename: Lilian
authors.initials: L
authors.lastname: Zgraggen
authors.forename: Joachim E
authors.initials: JE
authors.lastname: Fischer
authors.forename: Katharina
authors.initials: K
authors.lastname: Mischler
authors.forename: Daniel
authors.initials: D
authors.lastname: Preckel
authors.forename: Brigitte M
authors.initials: BM
authors.lastname: Kudielka
authors.forename: Roland
authors.initials: R
authors.lastname: von Känel
mesh_terms: D000328:Adult; D001777:Blood Coagulation; D001779:Blood Coagulation Factors / Q000378:metabolism; D001794:Blood Pressure; D006304:Health Status; D006339:Heart Rate; D006400:Hematocrit; D006439:Hemodynamics; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D007407:Interviews as Topic; D008297:Male; D008875:Middle Aged; D013315:Stress, Psychological / Q000097:blood*
chemical_list: D001779:Blood Coagulation Factors; D006454:Hemoglobins