Effects of orthostasis on endocrine responses to psychosocial stress
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- 作者：Urs M. Nater ; Beate Ditzen ; Jana Strahler ; Ulrike Ehlert
- 关键词：HPA axis ; SAM system ; Psychosocial stress ; Catecholamines ; Cortisol ; Orthostasis
- 刊名：International Journal of Psychophysiology
- 出版年：December, 2013
- 年：2013
- 卷：90
- 期：3
- 页码：341-346
- 全文大小：380 K
文摘
Standardized psychological procedures have been designed to induce physiological stress responses. However, the impact of standing (orthostasis) on the physiological reaction after psychological stress remains unclear. The purpose of the current analysis was to examine and quantify the relative contribution of orthostasis to the physiological stress response by comparing a 鈥渟tanding with stress鈥?to a 鈥渟tanding without stress鈥?condition. We investigated the effect of standing with and without stress on responses of the sympathetic-adrenomedullary (SAM) system and the hypothalamic-pituitary-adrenal (HPA) axis using a standardized psychosocial stress protocol (Trier Social Stress Test) and a non-stress condition in a repeated measures design. Subjects (m>N m> = 30) were exposed to both conditions in randomized order and had to maintain a standing, upright position for 10 minutes. In the 鈥渟tanding with stress鈥?condition, significant increases in repeatedly assessed plasma norepinephrine (NE) and epinephrine (EP), as well as in saliva cortisol were found, while in the 鈥渟tanding without stress鈥?condition, no significant changes in plasma epinephrine and saliva cortisol were observed. Calculations of the relative contribution of orthostasis to physiological stress responses revealed that 25.61% of the NE increase, 82.94% of the EP increase, and 68.91% of the cortisol increase, could be attributed to psychosocial stress adjusted for the effects of orthostasis and basal endocrine output. Although these results are indicative for a marked endocrine reaction that is caused by psychosocial stress alone, our findings show that the contribution of orthostasis must be taken into account when interpreting endocrine data collected in a psychosocial stress test.