Strahler Jana, Fuchs Reinhard, Nater Urs M, Klaperski Sandra
Clinical Biopsychology, Dept. of Psychology, University of Marburg, Germany.
Institute of Sport and Sport Science, University of Freiburg, Freiburg, Germany.
Psychoneuroendocrinology. 2016 Jun;68:14-9. doi: 10.1016/j.psyneuen.2016.02.022. Epub 2016 Feb 26.
Salivary cortisol (sCort) and alpha-amylase (sAA) are popular measurement tools for investigating hypothalamic-pituitary-adrenal and autonomic functioning, respectively. Despite their widespread use, only little is known about whether lifestyle factors such as regular exercise and physical fitness impact these two salivary stress markers. The lack of an objectively assessed fitness status is a major drawback of nearly all previous studies in this area. Our main objective was therefore to examine the impact of fitness status on sCort and sAA responses to a validated stressor.
Sedentary to low-active men (N=115, 45.7±10.1 years, 26.7±3.4kg/m(2)) were exposed to the Trier Social Stress Test for Groups and provided saliva samples before and repeatedly after the stressor. An ergometer lactate exercise test provided information on physical fitness, that is, power achieved at the individual anaerobic threshold relative to body weight. From age-specific percentiles, a 2- (n=65 low fitness, n=50 high fitness) and a 3-group (n=37 low fitness, n=49 moderate fitness, n=29 high fitness) solution were calculated to elucidate the impact of different fitness levels.
Prior to stress testing, sCort and sAA levels were similar in all groups. While both markers increased significantly due to stress exposure, fitness effects appeared rather small. When applying the 3-group solution, we observed attenuated sCort slopes in high- and moderate-fit men. Although sAA response slopes were pronounced in high-fit men, they failed to reach statistical significance. Mean stress reactivity (area under the curve with respect to ground, baseline, and response maximum) did not differ between groups and no association with fitness level was found.
Our findings suggest only a weak effect of objectively assessed physical fitness on biological stress responses with attenuated hypothalamic-pituitary-adrenal but (non-significantly) higher autonomic responses in fitter men. Physical fitness is a factor that should not be neglected in future studies employing salivary stress markers, especially in studies interested in acute stress responses.
唾液皮质醇（sCort）和α-淀粉酶（sAA）分别是用于研究下丘脑-垂体-肾上腺功能和自主神经功能的常用测量工具。尽管它们被广泛使用，但关于规律运动和身体素质等生活方式因素是否会影响这两种唾液应激标志物，人们所知甚少。几乎所有此前该领域研究的一个主要缺陷是缺乏对健康状况的客观评估。因此，我们的主要目标是研究健康状况对sCort和sAA对经过验证的应激源反应的影响。
久坐至低活动水平的男性（N = 115，45.7±10.1岁，26.7±3.4kg/m²）接受了团体版的特里尔社会应激测试，并在应激源之前和之后多次提供唾液样本。进行了功率计乳酸运动测试以获取身体素质信息，即相对于体重在个体无氧阈值时达到的功率。根据年龄特异性百分位数，计算出两组（n = 65低身体素质组，n = 50高身体素质组）和三组（n = 37低身体素质组，n = 49中等身体素质组，n = 29高身体素质组）的分组，以阐明不同健康水平的影响。
在应激测试之前，所有组的sCort和sAA水平相似。虽然由于应激暴露，这两种标志物均显著升高，但健康状况的影响似乎较小。采用三组分组时，我们观察到高身体素质和中等身体素质男性的sCort斜率减弱。虽然高身体素质男性的sAA反应斜率明显，但未达到统计学显著性。各组之间的平均应激反应性（相对于基线和反应最大值的曲线下面积）没有差异，且未发现与健康水平相关。
我们的研究结果表明，客观评估的身体素质对生物应激反应的影响较弱，下丘脑-垂体-肾上腺反应减弱，但（未显著）健康状况较好的男性自主神经反应较高。在未来使用唾液应激标志物的研究中，尤其是对急性应激反应感兴趣的研究中，身体素质是一个不应被忽视的因素。
