Changes in plasma copeptin, the c-terminal portion of arginine vasopressin during water deprivation and excess in healthy subjects

J Clin Endocrinol Metab. 2007 Oct;92(10):3973-8. doi: 10.1210/jc.2007-0232. Epub 2007 Jul 17.


Context: The measurement of arginine vasopressin (AVP) is often cumbersome because it is unstable with a short half-life time. AVP is derived from a larger precursor peptide along with the more stable peptide copeptin. Copeptin is the C-terminal part of provasopressin and has been shown to be a useful tool to indicate AVP concentration in critically ill patients.

Objective: The objective of the study was to evaluate the clinical usefulness of copeptin as a new marker in disordered states of blood volume and plasma osmolality.

Design and setting: This was a prospective observational study in a university hospital.

Participants and main outcome measures: Three techniques with respective control studies were used in 24 healthy adults to produce changes in plasma osmolality and/or volume: 1) a 28-h water deprivation, 2) a 17-h hypertonic saline infusion combined with thirsting, and 3) a hypotonic saline infusion with iv desmopressin administration during free water intake.

Results: Water deprivation produced a weight loss of 1.7 kg, an increase in plasma osmolality to 294.8 +/- 4.3 mosmol/kg, and an increase of copeptin from 4.6 +/- 1.7 pmol/liter to 9.2 +/- 5.2 pmol/liter (P < 0.0001). During hypertonic saline infusion and thirsting with a raise of plasma osmolality to 296.1 +/- 3.4 mosmol/kg, copeptin increased from 4.9 +/- 3.0 pmol/liter to 19.9 +/- 4.8 pmol/liter (P < 0.0001). Conversely, during hypotonic saline infusion, plasma osmolality decreased to 271.3 +/- 4.1 mosmol/kg, and copeptin decreased from 6.2 +/- 2.4 pmol/liter to 2.4 +/- 2.1 pmol/liter (P < 0.01).

Conclusion: Copeptin shows identical changes during disordered water states as previously shown for AVP. It might be a reliable marker of AVP secretion and substitute for the measurement of circulating AVP levels in clinical routine.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Arginine Vasopressin / blood
  • Arginine Vasopressin / chemistry
  • Biomarkers / blood*
  • Blood Volume / physiology
  • Chemistry, Clinical / methods*
  • Chemistry, Clinical / standards
  • Drinking / physiology*
  • Female
  • Glycopeptides / blood*
  • Humans
  • Hypovolemia / blood
  • Male
  • Osmolar Concentration
  • Protein Structure, Tertiary
  • Reproducibility of Results
  • Sodium / blood
  • Water Deprivation / physiology*


  • Biomarkers
  • Glycopeptides
  • copeptins
  • Arginine Vasopressin
  • Sodium