Dockray Samantha, Bhattacharyya Mimi R, Molloy Gerard J, Steptoe Andrew
Psychobiology Group, Department of Epidemiology and Public Health, University College London, 1-19 Torrington Place, London WC1E 6BT, UK.
Psychoneuroendocrinology. 2008 Jan;33(1):77-82. doi: 10.1016/j.psyneuen.2007.10.001. Epub 2007 Nov 8.
Studies of the salivary cortisol awakening response (CAR) may be confounded by delays between waking in the morning and obtaining the 'waking' salivary sample. We used wrist actigraphy to provide objective information about waking time, and studied the influence of delays in taking the waking sample on the CAR. Eighty-three men and women (mean age 61.30 years) who were referred to hospital with suspected coronary artery disease were studied. Saliva samples were obtained on waking and 15 and 30 min later. The mean interval between waking defined by actigraphy and reported waking time was 6.12+/-(S.D.) 14.8 min, with 55.4% having no delay. The waking saliva sample was obtained an average 5.78+/-15.0 min after self-reported waking, and 12.24+/-20.3 min after objective waking. The waking cortisol value was significantly higher in participants who had a delay between waking and sampling >15 min (mean 14.46+/-6.34 nmol/l) than in those with zero (mean 10.45+/-6.41 nmol/l) or 1-15 min delays (mean 11.51+/-5.99 nmol/l, p=0.043). Cortisol did not increase between 15 and 30 min after waking in those who delayed >15 min. There were no differences in CAR between participants with zero and 1-15 min delays from objectively defined waking to reported sample times. A small proportion (14.7%) of participants who did not delay saliva sampling showed no increase in cortisol over the 30 min after waking. These CAR nonresponders did not differ from the remainder on sleep patterns, waking time, clinical or medication characteristics, but were more likely to be of higher socioeconomic status (p=0.009). We conclude that long delays between waking and obtaining 'waking' cortisol samples will lead to misleading CAR results, but that delays up to 15 min may not be problematic. A small minority of individuals do not show a positive CAR despite not delaying saliva sampling after waking.
对唾液皮质醇觉醒反应（CAR）的研究可能会因早晨醒来与获取“觉醒时”唾液样本之间的延迟而受到干扰。我们使用手腕活动记录仪来提供关于醒来时间的客观信息，并研究了获取觉醒样本的延迟对CAR的影响。对83名因疑似冠状动脉疾病而被转诊至医院的男性和女性（平均年龄61.30岁）进行了研究。在醒来时以及15分钟和30分钟后采集唾液样本。通过活动记录仪定义的醒来时间与报告的醒来时间之间的平均间隔为6.12±（标准差）14.8分钟，55.4%的人没有延迟。自我报告醒来后平均5.78±15.0分钟采集觉醒唾液样本，客观醒来后12.24±20.3分钟采集。醒来与采样之间延迟超过15分钟的参与者的觉醒皮质醇值（平均14.46±6.34纳摩尔/升）显著高于延迟为零（平均10.45±6.41纳摩尔/升）或1至15分钟（平均11.51±5.99纳摩尔/升，p = 0.043）的参与者。延迟超过15分钟的人在醒来后15至30分钟内皮质醇没有增加。从客观定义的醒来时间到报告的采样时间，延迟为零和1至15分钟的参与者之间的CAR没有差异。一小部分（14.7%）没有延迟唾液采样的参与者在醒来后的30分钟内皮质醇没有增加。这些CAR无反应者在睡眠模式、醒来时间、临床或用药特征方面与其余参与者没有差异，但更有可能具有较高的社会经济地位（p = 0.009）。我们得出结论，醒来与获取“觉醒时”皮质醇样本之间的长时间延迟会导致误导性的CAR结果，但延迟长达15分钟可能没有问题。一小部分个体尽管醒来后没有延迟唾液采样，但并未表现出阳性CAR。
