Thosar Saurabh S, Radvany Ella, Brito Leandro C, Bowles Nicole P, McHill Andrew W, Butler Matthew P, Shea Steven A
Oregon Institute of Occupational Health Sciences, Oregon Health & Science University, Portland, OR, USA; School of Nursing, Oregon Health & Science University, Portland, OR, USA; OHSU-PSU School of Public Health Oregon Health & Science University, Portland, OR, USA; Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR, USA.
Oregon Institute of Occupational Health Sciences, Oregon Health & Science University, Portland, OR, USA; Lewis & Clark College, Portland, OR, USA.
Sleep Med. 2025 Aug;132:106568. doi: 10.1016/j.sleep.2025.106568. Epub 2025 May 12.
Adverse cardiovascular (CV) events occur most frequently in the morning. People who wake up later in the morning appear to have an increased risk of these events, but the mechanisms causing this effect are unknown. Vascular endothelial function (VEF) is a prognostic marker for these adverse events. Thus, we hypothesized that later wake times are associated with impaired morning VEF. Moreover, since sex differences exist in sleep timing and cardiovascular physiology, we also explored sex differences in any such relationship between wake times and morning VEF. Twenty-four healthy volunteers self-selected a sleep schedule of 8 h in bed for at least one week and were provided with an equivalent 8 h sleep opportunity in the laboratory. We measured dim-light melatonin onset (DLMO) as a circadian phase marker from salivary samples and quantified sleep using polysomnography. After the 8-h sleep opportunity, we measured VEF via flow-mediated dilation. We tested correlations between self-selected sleep-wake timing and VEF. Results: In the group as a whole, there was no significant relationship between waketimes and VEF (r = -0.36, p = 0.16). However, in females, later wake time was significantly associated with attenuated VEF (r = -0.76, p = 0.03), and this was the complete opposite in males (r = 0.69, p = 0.04). Furthermore, in females, later DLMO (r = -0.77, p = 0.025) was also associated with attenuated VEF, but this relationship was not present in males. These initial data suggest that the time of awakening is associated with VEF during the vulnerable morning hours, but this relationship is the opposite between males and females.
不良心血管（CV）事件最常发生在早晨。早晨起床较晚的人似乎发生这些事件的风险增加，但导致这种影响的机制尚不清楚。血管内皮功能（VEF）是这些不良事件的一个预后标志物。因此，我们假设起床时间较晚与早晨VEF受损有关。此外，由于睡眠时间和心血管生理存在性别差异，我们还探讨了起床时间与早晨VEF之间这种关系中的性别差异。24名健康志愿者自行选择在床上睡8小时的睡眠时间表，持续至少一周，并在实验室获得同等的8小时睡眠机会。我们从唾液样本中测量暗光褪黑素起始时间（DLMO）作为昼夜节律相位标志物，并使用多导睡眠图对睡眠进行量化。在8小时睡眠机会后，我们通过血流介导的血管舒张来测量VEF。我们测试了自行选择的睡眠-觉醒时间与VEF之间的相关性。结果：在整个组中，起床时间与VEF之间没有显著关系（r = -0.36，p = 0.16）。然而，在女性中，起床时间较晚与VEF减弱显著相关（r = -0.76，p = 0.03），而在男性中则完全相反（r = 0.69，p = 0.04）。此外，在女性中，较晚的DLMO（r = -0.77，p = 0.025）也与VEF减弱有关，但这种关系在男性中不存在。这些初步数据表明，在易发生不良事件的早晨时段，觉醒时间与VEF有关，但这种关系在男性和女性中相反。
