The effects of controlled acute psychological stress on serum cortisol and plasma metanephrine concentrations in healthy subjects.

Background: As cortisol and metanephrine are involved in the stress response, it is often recommended that individuals are relaxed at the time of venepuncture, however, evidence behind these recommendations is lacking. We investigated the effects of acute psychological stress on serum cortisol and plasma metanephrine concentrations in healthy individuals exposed to varying levels of psychological stress and compared these results to self-reported measures of stress.

Methods: Ten medical students completed two medical in-person simulations (one low-complexity, one high-complexity) in a random order. At four times, participants completed the State-Trait Anxiety Inventory (STAI) and serum cortisol and plasma metanephrine/normetanephrine were tested.

Results: Median (interquartile range) STAI prior to the low-complexity simulation was 44 (18) versus 33 (13) afterwards (P = 0.050). STAI prior to the high-complexity simulation was 33 (10) versus 48 (17) afterwards (P = 0.007). Cortisol prior to the low-complexity simulation was 272 nmol/L (115) versus 247 (115) afterwards (P = 0.333). Prior to the high-complexity simulation, cortisol was 246 (70) versus 261 (137) afterwards (P = 0.859). Metanephrine prior to the low-complexity simulation was 242 pmol/L (79) versus 247 (93) afterwards (P = 0.515). Metanephrine prior to the high-complexity simulation was 220 (81) versus 251 pmol/L (120) afterwards (P = 0.074). Normetanephrine prior to the low-complexity simulation was 593 pmol/L (247) versus 682 (281) afterwards (P = 0.047 for the difference). Normetanephrine prior to the high-complexity simulation was 696 (123) versus 705 pmol/L (224) afterwards (P = 0.169).

Conclusions: The trend in cortisol levels largely reflected changes in STAI. We outline some implications of these findings for current practice and future research.