The effect of oral presentation on salivary 3-methoxy-4-hydroxy-phenylglycol (MHPG) and cortisol concentrations in training doctors: a preliminary study

Excerpt

Exposure to a stress task activates the sympathetic nervous system. Salivary 3-methoxy-4-hydroxy-phenylglycol (MHPG; the major metabolite of norepinephrine) concentrations closely reflect the plasma MHPG levels and are used as indices of noradrenergic activity. On the contrary, exposure to a stress task also activates the hypothalamic–pituitary–adrenal (HPA) axis resulting in the secretion of cortisol from the adrenal cortex. The level of salivary cortisol elevates in response to a stress task including oral presentations. We examined concentrations of salivary MHPG (sMHPG) and cortisol levels in a sample of doctors in training (6 males: mean age = 29.6 ± 3.0 years; 6 females: 26.8 ± 0.2 years) exposed to oral presentations. All the participants gave written informed consent, and this study was approved by the ethic committee of the Faculty of Medicine, Saga University. Each subject gave an oral presentation in a training course. In brief, each participant gave an oral presentation about the same theme: “How to treat patients who suffered from diabetes mellitus” to the audience who were invited. All the presentations were started in the afternoon at 2 p.m. and lasted for 1 h. After the presentation, the performance of each trainee was evaluated by the audience. Salivary sample was collected three times (just before the beginning of the presentation, immediately, and at 10 min after the presentation) for each participant. The concentration of sMHPG was measured by the gas chromatography-mass spectrometry. Salivary cortisol was measured using a commercially available enzyme immunoassay kit [1, 2]. …