Department of Psychology, University of Bath, Claverton Down, Bath, BA2 7AY, UK.
Stress. 2010 Jul;13(4):292-300. doi: 10.3109/10253890903524785.
Chronic pain is often equated with chronic stress yet the relationship between chronic pain and hypothalamic-pituitary-adrenal (HPA) axis activity is poorly understood. The objective of this study was to examine diurnal functioning of the HPA axis in patients with clinically defined non-inflammatory chronic pain syndrome (CPS) compared to controls. The sample consisted of 37 adults with CPS and 47 healthy controls. All participants provided saliva samples at awakening, 12:00, 18:00 and 21:00 h on two consecutive days, as well as completing self-report questionnaires relating to anxiety and depression. The CPS group had a significantly lower overall mean diurnal salivary cortisol concentration compared to the control group (p < 0.01) but no significant differences were found between the two groups for repeated cortisol sampling across the day. However, a three-way interaction of time of day by patient status by sex was found (p < 0.032), with lower cortisol concentration in male patients compared to female patients in the afternoon period. No significant group effect was found for the rate of decline in the circadian rise in cortisol concentration. These data demonstrate that CPS is associated with a degree of hypocortisolemia, particularly in male patients. The altered dynamics of cortisol secretion in CPS in relation to the onset and duration of pain in patients remains to be determined.
慢性疼痛常与慢性应激相提并论，但慢性疼痛与下丘脑-垂体-肾上腺（HPA）轴活动之间的关系尚不清楚。本研究的目的是比较临床定义的非炎症性慢性疼痛综合征（CPS）患者与对照组之间 HPA 轴的昼夜功能。样本包括 37 名 CPS 成年患者和 47 名健康对照者。所有参与者在连续两天的早晨、12:00、18:00 和 21:00 点提供唾液样本，并完成与焦虑和抑郁相关的自我报告问卷。CPS 组的总体日间唾液皮质醇浓度明显低于对照组（p < 0.01），但两组之间全天重复的皮质醇采样无显著差异。然而，发现了时间、患者状态和性别之间的三向交互作用（p < 0.032），下午男性患者的皮质醇浓度低于女性患者。在皮质醇浓度昼夜升高的下降率方面，未发现组间有显著差异。这些数据表明，CPS 与一定程度的皮质醇减少症有关，尤其是在男性患者中。CPS 中皮质醇分泌动力学的改变与患者疼痛的发作和持续时间有关，仍有待确定。
