Center for Circadian and Sleep Medicine, Department of Neurology, Northwestern University, Feinberg School of Medicine, Chicago, IL, USA.
Biostatistics Division, Department of Preventive Medicine, Northwestern University, Feinberg School of Medicine, Chicago, IL, USA.
Sleep. 2021 Jun 11;44(6). doi: 10.1093/sleep/zsaa274.
Insomnia is common in older adults, and is associated with poor health, including cognitive impairment and cardio-metabolic disease. Although the mechanisms linking insomnia with these comorbidities remain unclear, age-related changes in sleep and autonomic nervous system (ANS) regulation might represent a shared mechanistic pathway. In this study, we assessed the relationship between ANS activity with indices of objective and subjective sleep quality in older adults with insomnia.
Forty-three adults with chronic insomnia and 16 age-matched healthy sleeper controls were studied. Subjective sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI), objective sleep quality by electroencephalogram spectral components derived from polysomnography, and ANS activity by measuring 24-h plasma cortisol and norepinephrine (NE).
Sleep cycle analysis displayed lower slow oscillatory (SO: 0.5-1.25 Hz) activity in the first cycle in insomnia compared to controls. In insomnia, 24-h cortisol levels were higher and 24-h NE levels were lower than controls. In controls, but not in insomnia, there was a significant interaction between NE level during wake and SO activity levels across the sleep cycles, such that in controls but not in insomnia, NE level during wake was positively associated with the amount of SO activity in the first cycle. In insomnia, lower 24-h NE level and SO activity in the first sleep cycle were associated with poorer subjective sleep quality.
Dysregulation of autonomic activity may be an underlying mechanism that links objective and subjective measures of sleep quality in older adults with insomnia, and potentially contribute to adverse health outcomes.
老年人中失眠很常见，且与健康状况不佳有关，包括认知障碍和心血管代谢疾病。尽管将失眠与这些合并症联系起来的机制尚不清楚，但与年龄相关的睡眠和自主神经系统（ANS）调节变化可能代表一个共同的机制途径。在这项研究中，我们评估了自主神经活动与失眠老年人客观和主观睡眠质量指标之间的关系。
研究了 43 名患有慢性失眠的成年人和 16 名年龄匹配的健康睡眠者对照。使用匹兹堡睡眠质量指数（PSQI）评估主观睡眠质量，通过多导睡眠图得出的脑电图频谱成分评估客观睡眠质量，并通过测量 24 小时血浆皮质醇和去甲肾上腺素（NE）评估自主神经活动。
睡眠周期分析显示，与对照组相比，失眠患者的第一个周期中的慢振荡（SO：0.5-1.25 Hz）活动较低。在失眠患者中，24 小时皮质醇水平高于对照组，24 小时去甲肾上腺素水平低于对照组。在对照组中，但不在失眠患者中，在整个睡眠周期中，清醒期间的去甲肾上腺素水平与 SO 活动水平之间存在显著的相互作用，即只有在对照组中，而不是在失眠患者中，清醒期间的去甲肾上腺素水平与第一个周期中的 SO 活动量呈正相关。在失眠患者中，较低的 24 小时去甲肾上腺素水平和第一个睡眠周期中的 SO 活动与较差的主观睡眠质量相关。
自主神经活动的失调可能是将失眠老年人的客观和主观睡眠质量指标联系起来的一个潜在机制，并可能对不良健康结果产生影响。
