Boyce W T, Chesterman E
Department of Pediatrics, University of California, San Francisco 94143.
J Dev Behav Pediatr. 1990 Jun;11(3):105-11.
Physiologic responses to environmental stress show striking interindividual differences, beginning early in life. Whereas cardiovascular reactivity (CVR) to stress has been linked to short- and long-term changes in health, little previous work has addressed reactivity in children, and no past studies have investigated the relationship of reactivity to psychosocial factors, such as stressful life events (LE) and social support (SS). We therefore studied cardiovascular response to psychologically and physically stressful laboratory tasks in 25 adolescent boys. The degree of individual CVR was examined cross-sectionally in relationship to LE, SS, and "sense of permanence" (SP), a construct reflecting the stability or continuity in the child's life experience. Heart rate reactivity (HRR) and mean arterial pressure reactivity (BPR) were bimodally distributed, with a subpopulation of approximately 20% of subjects demonstrating an exaggerated cardiovascular response. SP was related to BPR at a borderline level of significance (R = 0.33, p less than 0.10), whereas SS was unrelated to either reactivity variable. Unexpectedly, LE was strongly and inversely related to both HRR and BPR (R = -0.40 and -0.47, respectively, p less than 0.05). Subjects reporting low numbers of previous stressful life events had the highest level of cardiovascular reactivity. Possible explanations for this finding included (1) the development of a hyperdynamic response as a consequence of avoiding or denying stressful experience, (2) an effect of exaggerated CVR on cognition and the reporting of stressful events, or, most plausibly, (3) an 'inoculation effect,' in which previous LE facilitate the development of effective coping strategies, thereby diminishing responses to stressful laboratory tasks.
对环境压力的生理反应在生命早期就表现出显著的个体差异。虽然压力引起的心血管反应性（CVR）与健康的短期和长期变化有关，但之前很少有研究涉及儿童的反应性，也没有过去的研究调查过反应性与心理社会因素的关系，如应激性生活事件（LE）和社会支持（SS）。因此，我们研究了25名青春期男孩在心理和身体应激实验室任务中的心血管反应。我们横断面地研究了个体CVR程度与LE、SS以及“永久感”（SP）的关系，“永久感”是一个反映儿童生活经历稳定性或连续性的概念。心率反应性（HRR）和平均动脉压反应性（BPR）呈双峰分布，约20%的受试者表现出夸张的心血管反应。SP与BPR在临界显著水平相关（R = 0.33，p < 0.10），而SS与任何一个反应性变量均无关。出乎意料的是，LE与HRR和BPR均呈强烈的负相关（分别为R = -0.40和-0.47，p < 0.05）。报告先前应激性生活事件数量较少的受试者心血管反应性水平最高。这一发现的可能解释包括：（1）由于避免或否认应激经历而产生的高动力反应；（2）夸张的CVR对认知和应激事件报告的影响；或者最有可能的是，（3）一种“接种效应”，即先前的LE促进了有效应对策略的发展，从而减少了对应激实验室任务的反应。
