بررسی مقدار آلفا آمیلاز بزاقی تحت استرس روانشناختی و ارتباط آن با نشخوار فکری و پنج ویژگی شخصیتی

Background and purpose: Salivary alpha amylase (SAA) is used as a noninvasive biomarker to assess the activity of the sympathetic-adrenal-medullary system. The aim of this study was to evaluate the salivary alpha-amylase level under psychological stress and its relationship with rumination and the five personality traits. Materials and methods: In a cross-sectional study, 45 medical students who wanted to take final exams were selected using simple random sampling. NEO Personality Inventory-Short Form and emotional control questionnaire (ECQ) were completed two months before the exam. Saliva samples were taken from the students in non-stressful (control) and stressful conditions. SSA level was measured by photometry and data was analyzed using paired samples t-test, Pearson correlation analysis and stepwise regression. Results: Results: A significant difference was found between the mean of SAA level in the rest and under exam stress. Also, we found a significant correlation between SAA level with neuroticism (P<0.01), agreeableness (P<0.05) and rumination (P<0.01), explaining 49% of the variance of salivary alpha-amylase under stress exam. Conclusion: According to this study, the SAA level may increase in individuals with traits of neuroticism, agreeableness and ruminative thoughts in response to psychological stressors (e.g. exam). Also, measuring SAA levels could be used in assessing physiological responses to stress, as a non-invasive method.