Information on the relationships between the previous night's sleep and the next-day diurnal cortisol rhythm is inconsistent due to confounding factors such as sleep measurements (trait/state sleep and objective/subjective sleep) and cortisol sampling schemes. Therefore, this study aimed to investigate these relationships, considering the confounding factors. College students (n = 79) wore actigraphy for 3 days to undergo an evaluation of previous night-time sleep objectively and reported their subjective sleep parameters in a sleep diary. In addition, participants provided six salivary cortisol samples daily. Furthermore, six cortisol sampling schemes were created to reflect diurnal cortisol rhythms, and two different methods were used to calculate the index of diurnal cortisol slope (DCS). A multilevel model was created to examine the impact of both trait and state sleep on next-day diurnal cortisol rhythm. The results revealed that higher objective state sleep efficiency and longer objective state total sleep time were associated with a higher cortisol awakening response (CAR). Moreover, higher objective trait sleep efficiency and longer objective trait total sleep time were associated with higher waking cortisol levels and steeper DCS. In addition, a minimum of four saliva samples were required at different time points, including upon waking, 30 min after waking, 1 h after waking, and at bedtime, to explore the relationship of sleep efficiency/total sleep time with waking cortisol, CAR, and DCS. Furthermore, the index of the peak-to-bed slope was appropriately employed to examine the relationship between sleep efficiency and DCS, whereas the wake-to-bed slope was effective for examining the relationship between total sleep time and DCS. In summary, this study clarified the relationship between sleep and next-day diurnal cortisol rhythm and suggested a cost-effective cortisol sampling schedule and calculation methods.

由于睡眠测量（特质/状态睡眠和客观/主观睡眠）和皮质醇采样方案等混杂因素，有关前一晚睡眠与第二天皮质醇节律之间关系的信息不一致。因此，本研究旨在研究这些关系，考虑混杂因素。大学生（n = 79）佩戴体动记录仪三天，对之前的夜间睡眠进行客观评估，并在睡眠日记中报告他们的主观睡眠参数。此外，参与者每天提供六个唾液皮质醇样本。此外，创建了六种皮质醇采样方案来反映昼间皮质醇节律，并使用两种不同的方法来计算昼间皮质醇斜率（DCS）指数。创建了一个多级模型来检查特质和状态睡眠对第二天皮质醇昼夜节律的影响。结果显示，较高的客观状态睡眠效率和较长的客观状态总睡眠时间与较高的皮质醇觉醒反应（CAR）相关。此外，较高的客观特征睡眠效率和较长的客观特征总睡眠时间与较高的清醒皮质醇水平和较陡的 DCS 相关。此外，在不同时间点，包括醒来时、醒来后30分钟、醒来后1小时和就寝时，至少需要四个唾液样本，以探讨睡眠效率/总睡眠时间与清醒皮质醇、CAR的关系。和 DCS。此外，峰-床斜率指数可适当地用于检验睡眠效率与 DCS 之间的关系，而唤醒-床斜率指数可有效检验总睡眠时间与 DCS 之间的关系。总之，本研究阐明了睡眠与次日皮质醇节律之间的关系，并提出了一种具有成本效益的皮质醇采样时间表和计算方法。