• Tamara Hew-Butler, Martin D Hoffman, Kristin J Stuempfle, Ian R Rogers, Nils G Morgenthaler, and Joseph G Verbalis.
• Exercise Science Program, School of Health Sciences, Oakland University, Rochester, Michigan. USA. hew@oakland.edu
• Clin J Sport Med. 2011 May 1;21(3):211-7.

ObjectiveTo evaluate changes in both the N-terminal (arginine vasopressin; AVP) and C-terminal (copeptin) fragments of the vasopressin prohormone before, during, and after an ultramarathon race and to assess vasopressin and copeptin concentrations in runners with and without hyponatremia.DesignObservational study.SettingThree trials (2 sodium balance and 1 hyponatremia treatment) in 2 separate approximately 160-km footraces [Western States Endurance Run (WSER) and Javelina Jundred (JJ100)].ParticipantsSix hyponatremic and 20 normonatremic runners; 19 finishers with 7 completing 100 km.Main Outcome MeasuresPlasma AVP ([AVP]p), copeptin ([copeptin]p), sodium ([Na]p), and protein (%plasma volume change; %PV) concentrations.ResultsIn the WSER Sodium Trial, a 3-fold prerace to postrace increase in both [AVP]p (0.7 ± 0.4 to 2.7 ± 1.9 pg/mL; P < 0.05) and [copeptin]p (10.3 ± 12.5 to 28.2 ± 16.3 pmol/L; nonsignificant) occurred, despite a 2 mEq/L decrease in [Na]p (138.7 ± 2.3 to 136.7 ± 1.6 mEq/L; NS). A significant correlation was noted between [AVP]p and [copeptin]p postrace (r = 0.82; P < 0.05). In the WSER Treatment Trial, despite the presence of hyponatremia pretreatment versus posttreatment ([Na]p = 130.3 vs 133.5 mEq/L, respectively), both [AVP]p (3.2 vs 2.1 pg/mL) and [copeptin]p (22.5 vs 24.9 pmol/L) were well above the detectable levels. A significant correlation was noted between [AVP]p and [copeptin]p 60 minutes after treatment (r = 0.94; P < 0.05). In the JJ100 Sodium Trial, significant correlations were found between [copeptin]p change and %PV change (r = -0.34; P < 0.05) and between [AVP]p change and [Na]p change (r = 0.39; P < 0.05) but not vice-versa.Conclusions[Copeptin]p seems to be a reliable surrogate of stimulated [AVP]p during exercise. Nonosmotic vasopressin stimulation occurs during ultradistance running. [Copeptin]p may better reflect chronic (%PV) vasopressin secretion under conditions of endurance exercise.

26 keywords...

hide…