The Peter Harrison Centre for Disability Sport, School of Sport, Exercise, and Health Sciences, Loughborough University, Loughborough, LE11 3TU, UK.
Eur J Appl Physiol. 2018 Jun;118(6):1179-1187. doi: 10.1007/s00421-018-3847-6. Epub 2018 Apr 7.
Salivary secretory immunoglobulin A (sIgA), saliva flow rate and plasma cortisol concentrations have been shown to be influenced by exercise, particularly the intensity exercise is performed at, and circadian variation. The autonomic nervous system partly regulates salivary secretion, but it is not yet known whether cortisol also explains some variation in salivary parameters.
Twelve moderately trained male individuals ([Formula: see text]: 46.2 ± 6.8 mL·kg·min) performed three 45-min constant load exercise trials in the morning: arm cranking exercise at 60%[Formula: see text]; moderate cycling at 60%[Formula: see text]; and easy cycling at 60%[Formula: see text]. Timed saliva samples and blood samples for plasma cortisol concentration determination were obtained before, post, 2 h post, and 4 h post-exercise. Saliva was collected in an additional resting trial at the same time points.
At each time point for each exercise trial, negative correlations between cortisol and saliva flow rate (explaining 25 ± 17% of the variance, R = 0.002-0.46) and positive correlations between cortisol and sIgA concentration (explaining 8 ± 8% of the variance R = 0.002-0.24) were found. Saliva flow rate increased over time, whereas sIgA concentration and cortisol decreased over time for all trials (P < 0.05), there was no effect of time for sIgA secretion rate (P = 0.16).
These results show a relationship between cortisol and saliva flow rate, which directly impacts on the concentration of salivary analytes. This study further confirms circadian variations in salivary parameters which must be acknowledged when standardising salivary data collection.
唾液分泌免疫球蛋白 A（sIgA）、唾液流速和血浆皮质醇浓度已被证明受到运动的影响，特别是运动的强度和昼夜变化。自主神经系统部分调节唾液分泌，但目前尚不清楚皮质醇是否也能解释唾液参数的一些变化。
12 名中等训练水平的男性个体（年龄：46.2±6.8 岁；体重：83.4±13.6 kg；体脂率：11.4±4.2%）在上午进行了三次 45 分钟的恒负荷运动试验：手臂曲柄运动，强度为 60%最大摄氧量；中等强度自行车运动，强度为 60%最大摄氧量；轻松自行车运动，强度为 60%最大摄氧量。在运动前、运动后 2 小时和 4 小时以及运动后即刻，采集时间唾液样本和血液样本以测定血浆皮质醇浓度。在同一时间点还进行了一次额外的休息试验以采集唾液。
在每个运动试验的每个时间点，均发现皮质醇与唾液流速（解释 25±17%的变异，R=0.002-0.46）呈负相关，皮质醇与 sIgA 浓度（解释 8±8%的变异，R=0.002-0.24）呈正相关。所有试验中，唾液流速随时间增加，而 sIgA 浓度和皮质醇随时间降低（P<0.05），但 sIgA 分泌率无时间效应（P=0.16）。
这些结果表明皮质醇与唾液流速之间存在关系，这直接影响唾液分析物的浓度。本研究进一步证实了唾液参数的昼夜变化，在标准化唾液数据采集时必须予以考虑。
