title: Higher morning serum cortisol level predicts increased fibrinogen but not shortened APTT.
abstract: BACKGROUND
  There is emerging evidence that serum cortisol might be independently associated with prothrombotic activity, suggesting that increased cortisol levels might finally contribute to the pathogenesis of atherosclerotic disorders. Since hypercoagulability is principally sustained by either defective naturally occurring anticoagulant mechanisms or to heightened coagulation factors, most of which are cumulatively explored by the activated partial thromboplastin time (APTT), the present investigation was designed to asses the potential relationship between morning serum cortisol, APTT and fibrinogen in a general population of healthy outpatients.
  
  
  METHODS
  We performed a retrospective analysis on the database of our Laboratory Information System to retrieve results of morning serum cortisol, APTT and fibrinogen, which were performed on consecutive outpatients referred by general practitioners for routine blood testing over the previous 2 years.
  
  
  RESULTS
  Cumulative results for morning serum cortisol, APTT and fibrinogen were retrieved for 302 adults >35 years old (M/F = 61/90; age 49 +/- 13 years; range 35-79). A statistically significant increased concentration of fibrinogen was observed in subject with morning serum cortisol values above the upper limit of the reference range (P < 0.001), whereas the concentration of APTT was not significantly different between the two subgroups of subjects with normal and increased morning serum cortisol (P = 0.432). This difference remained statistically significant even after adjusting for age and sex. In multivariable linear regression analysis, the concentration of fibrinogen, but not the value of the APTT, was significantly associated with morning serum cortisol.
  
  
  CONCLUSIONS
  The results of this retrospective investigation confirm that baseline cortisol levels might predict higher fibrinogen in the general population. This potential biological interrelationship deserves further scrutiny for the potential implications on prediction and prevention of the cardiovascular risk.
authors.affiliation: Sezione di Chimica Clinica, Dipartimento di Scienze Morfologico-Biomediche, Università di Verona, Ospedale Policlinico G.B. Rossi, Piazzale Scuro, 10, Verona, 37134, Italy. ulippi@tin.it
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Lippi
authors.forename: Massimo
authors.initials: M
authors.lastname: Franchini
authors.forename: Gian Luca
authors.initials: GL
authors.lastname: Salvagno
authors.forename: Martina
authors.initials: M
authors.lastname: Montagnana
authors.forename: Gian Cesare
authors.initials: GC
authors.lastname: Guidi
mesh_terms: D000328:Adult; D000368:Aged; D001777:Blood Coagulation; D002940:Circadian Rhythm; D005260:Female; D005340:Fibrinogen / Q000032:analysis*; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D008297:Male; D008875:Middle Aged; D010314:Partial Thromboplastin Time; D012189:Retrospective Studies; D015854:Up-Regulation
chemical_list: D005340:Fibrinogen; D006854:Hydrocortisone