Cortisol, β-endorphin and oxidative stress markers in healthy medical students in response to examination stress

Background: The psychosomatic connection pertaining to the relationship between perceived stress and the milieu interieur that must be evident during a naturalistic stressor event is not well explored. Objective: This study therefore examines the interrelationship between perceived stress scores, endocrine levels and oxidant-antioxidant activities under the duress of examination stress, an appropriate example of a naturalistic stressor. Materials and Methods: Apparently healthy year one medical students participated. Results: Examination stress induced significant increases in perceived stress scores (p<0.001), serum cortisol (p<0.05) and plasma β-endorphin (p<0.05) levels, and erythrocyte lipid peroxidation (p<0.001), but a significant (p<0.001) decrease in the antioxidant superoxide dismutase activity. In addition, during the examination, the perceived stress scores were found to be correlated positively with lipid peroxidation (r2=0.23; p<0.01) but negatively with β-endorphin (r2=0.14; p<0.05). After the examination, the perceived stress scores correlated positively only with cortisol (r2=0.09; p<0.05). Conclusion: Sitting for an examination increases cortisol secretion, as well as, β-endorphin levels and induces oxidative stress. The high levels of β- endorphin appear to have an ameliorating effect on cortisol and the perception of stress. This finding awaits further investigation.