Examination stress results in altered cardiovascular responses to acute challenge and lower cortisol

The present study examined how cardiovascular and salivary cortisol responses varied in response to an acute challenge in medical students under exam stress versus those not under exam stress. One hundred and twenty-nine medical students were randomly assigned to undertake a CO2 inhalation test either prior to an examination period (exam group) or during a regular academic period (non-exam group). Heart rate (HR) and blood pressure (BP) were measured for 5 min before and 5 min after the task, and salivary cortisol samples were collected 1 min before and 10 and 30 min after the CO2 inhalation test. Participants also completed a questionnaire measuring self-reported perceived stress. The exam group exhibited significantly higher HR reactivity following the CO2 inhalation test and slower systolic blood pressure (SBP) recovery compared with the non-exam group. The exam group also reported higher perceived stress and higher stress scores were related to higher HR reactivity following CO2 inhalation. Female students across both groups exhibited significantly lower SBP reactivity compared with male students. Salivary cortisol levels were consistently lower in the exam group. These findings indicate that ongoing natural stress alters cortisol secretion and cardiovascular responses in the face of an acute stress challenge.