Persistent response to acute psychosocial stress

1. بسم الله الرحمن الرحیم Persistent response to acute psychosocial stress AlirezaMohammadi(1), Maryam AlemAref(1), AsgarEmamgoli(1), Zahra Boorboor(1) , BoshraHatef(*) 1- Neuroscience research center, Baqiyatallah university of medical science ,Tehran, Iran. Electronic Poster Code: For e.g.: A-10-353-1 Mahsa Asadi- Department of Medical Education, School of Medicine- Aia University of Medical Sciences, Tehran, Iran

2. Introduction Repetitive stress occurs every day. Therefore, the biological modifiers should have enough time to restore the normal state of hemostasis, otherwise chronic stress would be anticipated. Stress activates two axes concurrently, hypothalamus-pituitary-adrenal (HPA) and sympathetic-adrenal medullary (SAM). The activation of HPA leads to the increase of cortisol in body fluids and the activation of SAM increases the heart rate (1). Acute psychosocial stress is a valid method of stress induction in human, which is followed by the assessment of the psychological, biochemistry and electrophysiological indices (2). The Triet Social Stress Test (TSST) as a model of Psychological acute stress is a real condition that happens several times in lifespan. The aim of the present study was to examine the persistence of stress based on subjective emotion, salivary cortisol and linear and non-linear features of heart rate variation (HRV) in both genders Mahsa Asadi- Department of Medical Education, School of Medicine- Aia University of Medical Sciences, Tehran, Iran

3. Method Participants Young participants (23 men, 10 women) Aged 18-30 years Variables Salivary Cortisol Emotive visual analogue scale Heart Rate Variation (heart rate-relative power of frequency- complexity) Mahsa Asadi- Department of Medical Education, School of Medicine- Aia University of Medical Sciences, Tehran, Iran

4. Result Frequency power EVAS Cortisol Complexity Heart Rate Mahsa Asadi- Department of Medical Education, School of Medicine- Aia University of Medical Sciences, Tehran, Iran

5. The persistence of biological changes due to stress is critical because the overload of stress is dangerous for hemostasis and returning to the normal state. Recovery time after TSST was evaluated to reach the required interval time between stressful status to prevent allostatic load and overload (29). Previous studies showed that the increase of cortisol continued until 15-20 minutes and returned to baseline 40 - 60 minutes after TSST (6, 11). The dynamic shifts in the brain networks to comprehensively reallocate its neural resources according to cognitive demands against stressful condition was reverse to pre-stress about 60 minutes (12). But some other markers such as salivary alpha amylase enzyme or heart rate and RR mean of HRV immediately returned to baseline after TSST (30). The findings of the current study regarding HRV showed that the heart rate and mean of RR interval returned to baseline immediately after stress, as the previous studies confirmed it (2, 6, 8, 17). There are many studies showing that the power of frequency or non-linear features of HRV changed during acute stress as the sign of the increased sympathetic tone activity in both genders (10, 31). In addition, it has been proven that the LF and LF/HF mostly increased and the complexity of HRV decreased based on SD of RR and Poincare plot, sample and spectral entropy and alpha 1 of DFA during stress, which are also the signs of sympathovagal shift to sympathetic tone (7, 31, 32). Discussion Mahsa Asadi- Department of Medical Education, School of Medicine- Aia University of Medical Sciences, Tehran, Iran

6. Conclusion The base of cortisol played a critical role in modifying the physiological response to stress. In addition, after recovery, no stressful emotion remained, while the non-linear features of HRV did not return to baseline. Mahsa Asadi- Department of Medical Education, School of Medicine- Aia University of Medical Sciences, Tehran, Iran

7. References • YaribeygiH, Panahi Y, Sahraei H, Johnston TP, Sahebkar A. THE IMPACT OF STRESS ON BODY FUNCTION: A REVIEW. EXCLI JOURNAL. 2017;16:1057-72. • Kirschbaum C, Pirke K-M, Hellhammer DH. The ‘Trier Social Stress Test’–a tool for investigating psychobiological stress responses in a laboratory setting. Neuropsychobiology. 1993;28(1-2):76-81. • Castaldo R, Melillo P, Bracale U, Caserta M, Triassi M, Pecchia L. Acute mental stress assessment via short term HRV analysis in healthy adults: A systematic review with meta-analysis. Mahsa Asadi- Department of Medical Education, School of Medicine- Aia University of Medical Sciences, Tehran, Iran

8. Final Questions • What is already known about the subject? • Acute stress has immediately physiological effect such as increased of cortisol and heart rate • What could be added to the current knowledge by this study? • the acute stress has long-time physiological effect that not consciousness such as the increase of cortisol and decrease of heart rate variation. • The response of cortisol to stress related to baseline level of cortisol not gender different Mahsa Asadi- Department of Medical Education, School of Medicine- Aia University of Medical Sciences, Tehran, Iran