title: Copeptin, a stable peptide derived from the vasopressin precursor, correlates with the individual stress level.
abstract: BACKGROUND
  During stress, vasopressin is a potent synergistic factor of CRH as a hypothalamic stimulator of the HPA axis. The measurements of CRH and vasopressin levels are cumbersome because of their instability and short half-life. Copeptin is a more stable peptide stoichiometrically released from the same precursor molecule. The aim of our study was to compare copeptin and cortisol levels in different stress situations.
  
  
  METHODS
  Three groups of patients with increasing stress levels were investigated: a) healthy controls without apparent stress (n=20), b) hospitalized medical patients with moderate stress (n=25) and c) surgical patients 30 minutes after extubation, with maximal stress (n=29). In all patients we assessed cortisol and copeptin levels. Copeptin levels were measured with a new sandwich immunoassay.
  
  
  RESULTS
  Cortisol levels in controls were (median, IQ range, 486 [397-588] nmol/L), not significantly different as compared to medical patients (438 [371-612] nmol/L, p=0.69). Cortisol levels in surgical patients after extubation were higher (744 [645-1062] nmol/L p<0.01 vs controls and medical patients). Copeptin levels in controls were 4.3 [3.2-5.5] pmol/L, which was lower as compared to medical patients (17.5 [6.4-24.1], p<0.001) and surgical patients after extubation (67.5 [37.8-110.0] pmol/L, p<0.001). The correlation between copeptin levels and cortisol was r=0.46, p<0.001.
  
  
  CONCLUSIONS
  Copeptin is a novel marker of the individual stress level. It more subtly mirrors moderate stress as compared to cortisol values.
authors.affiliation: Department of Endocrinology, Diabetology and Clinical Nutrition, University Hospital Basel, Basel, Switzerland. katanm@uhbs.ch
authors.forename: Mira
authors.initials: M
authors.lastname: Katan
authors.forename: Nils
authors.initials: N
authors.lastname: Morgenthaler
authors.forename: Isabelle
authors.initials: I
authors.lastname: Widmer
authors.forename: Jardena J
authors.initials: JJ
authors.lastname: Puder
authors.forename: Caroline
authors.initials: C
authors.lastname: König
authors.forename: Beat
authors.initials: B
authors.lastname: Müller
authors.forename: Mirjam
authors.initials: M
authors.lastname: Christ-Crain
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000097:blood; D000328:Adult; D015415:Biomarkers; D015992:Body Mass Index; D015331:Cohort Studies; D005260:Female; D006020:Glycopeptides / Q000032:analysis / Q000378:metabolism*; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007031:Hypothalamus / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D012727:Sex Characteristics; D013315:Stress, Psychological / Q000378:metabolism*; D014667:Vasopressins / Q000032:analysis / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D006020:Glycopeptides; C048197:copeptins; D014667:Vasopressins; D000324:Adrenocorticotropic Hormone; D006854:Hydrocortisone