Copeptin concentrations during psychological stress: the PsyCo study.

OBJECTIVE

The prognostic/diagnostic biomarker copeptin, an arginine vasopressin surrogate, reflects physical stress. Whether copeptin concentration increases upon psychological stress is unknown. We investigated psychological stress effects on copeptin secretion in healthy volunteers and patients with central diabetes insipidus (DI).

DESIGN

A prospective observational study was conducted to study the relation between copeptin concentration and psychological stress.

METHODS

A total of 20 healthy adults (ten female) and eight patients with central DI (four female) underwent the Trier Social Stress Test including, in order, 30-min waiting period, 10-min anticipation period, 10-min test period and 40-min recovery. Serum copeptin and cortisol concentrations and self-rated stress component feelings were determined in the pre-/post-anticipation period, post-test period and twice post-recovery.

RESULTS

In healthy volunteers, the median (25th-75th percentile) copeptin concentration peaked immediately during the post-test period at 5.1 (3.2-7.0) pmol/l, vs 3.7 (2.6-5.4) pmol/l at baseline. Over the measurement course, copeptin concentration significantly elevated (coefficient; 95% CI) (0.14; 0.06-0.23, P=0.002). The important predictors of increase in copeptin concentration were feelings of tension (0.06; 0.04-0.08, P<0.001) and avoidance (0.07; 0.04-0.10; P<0.001). Copeptin and cortisol levels were associated (0.43; 0.13-0.72, P<0.005). Patients with DI had lower baseline concentrations (1.55 (1.2-3.1) pmol/l) when compared with healthy volunteers, P=0.006. Patients with DI showed no increase upon psychological stress (peak 2.15 pmol/l (1.5-2.28), P=0.79). By contrast, cortisol values were similar in patients and volunteers.

CONCLUSIONS

In healthy volunteers, copeptin levels significantly increased after psychological stress testing; this response was blunted in patients with DI.