关键词: 儿童版特里尔社会应激测试, 应激反应, 皮质醇, 唾液α-淀粉酶, 情绪

Abstract: There is substantial evidence indicating that repeated exposures to psychosocial stress in childhood might alter function of hypothalamic-pituitary-adrenal (HPA) axis and sympathetic nervous system (SNS), in turn, increase the risk of various diseases in adulthood. Studying physiological responses to psychosocial stressors, especially in childhood, may help to understand the underlying mechanisms that are involved in diseases pathogenesis and to intervene early in life. Trier Social Stress Test for Children (TSST-C) is a protocol for induction of moderate to intense psychosocial stress in a laboratory setting. It comprises a 10-min anticipatory period, a 5-min public speaking task (children receive the beginning of a story and finish telling the story as exciting as possible) and a 5-min mental arithmetic task (children are required to subtract 7 serially from 758 as quickly and accurately as possible, and children have to restart at 758 when a mistake is made) facing two evaluative and non-responsive audience members. The TSST-C is the most widely used psychosocial stress protocol in stress research of human subjects and reliably elicits physiological stress responses, including salivary cortisol and salivary α-amylase responses, which have been recognized as reliable biomarkers for the HPA axis and SNS function, respectively. However, the applicability of TSST-C in inducing cortisol and salivary α-amylase responses among healthy Chinese children remains largely unknown. With this background, our study examined both cortisol and salivary α-amylase responses to the TSST-C in a sample of healthy children (N=150, 76 boys, 11.15 ± .86 years) in Beijing, China. Following recent stress response research (Yim et al., 2010), children completed an adapted version of the TSST-C using a different public speaking task (introducing oneself to a hypothetical new classroom of students), which is likely to induce comparable physiological responses in individuals somewhat wider age ranges than what has been examined in the past. All laboratory sessions were scheduled during the afternoon (between 14:00 and 17:30) to control for the diurnal variations of cortisol secretion. Participants were asked to refrain from any food or drink for at least 30 min before laboratory sessions. A total of six segments of salivary samples and subjective stress measures were obtained throughout the session: baseline (-20 min), after preparation (-3 min), after TSST-C task (+1 min), first recovery (+10 min), second recovery (+25 min) and third recovery (+50 min). The salivary samples were collected for analyzing cortisol and salivary α-amylase. And the subjective stress measures were used for assessing children’s psychological response. The results showed that: (1) Children exhibited significant increases in cortisol and salivary α-amylase levels, and reported higher levels of negative affect, such as anxiety and nervousness, following the TSST-C. (2) The associations among cortisol response, salivary α-amylase response, and subjective emotional response failed to reach significance. In conclusion, the findings indicate that TSST-C induces both physiological and psychological responses of sufficient magnitude in Chinese children. TSST-C is a protocol with good applicability in healthy Chinese children and could be used for stress research to explore the associations among psychosocial stressors, stress responses of HPA axis and SNS, and physical health in Chinese children.

Key words: Trier Social Stress Test for Children, stress response, cortisol, salivary α-amylase, emotion