CONACyT Chairs, National Council of Science and Technology, Mexico.
National Institute of Psychiatry Ramón de la Fuente Muñiz, Mexico.
J Alzheimers Dis. 2023;95(2):477-491. doi: 10.3233/JAD-230101.
Sleep disruption in elderly has been associated with an increased risk of cognitive impairment and its transition into Alzheimer's disease (AD). High arousal indices (AIs) during sleep may serve as an early-stage biomarker of cognitive impairment non-dementia (CIND).
Using full-night polysomnography (PSG), we investigated whether CIND is related to different AIs between NREM and REM sleep stages.
Fourteen older adults voluntarily participated in this population-based study that included Mini-Mental State Examination, Neuropsi battery, Katz Index of Independence in Activities of Daily Living, and single-night PSG. Subjects were divided into two groups (n = 7 each) according to their results in Neuropsi memory and attention subtests: cognitively unimpaired (CU), with normal results; and CIND, with -2.5 standard deviations in memory and/or attention subtests. AIs per hour of sleep during N1, N2, N3, and REM stages were obtained and correlated with Neuropsi total score (NTS).
AI (REM) was significantly higher in CU group than in CIND group. For the total sample, a positive correlation between AI (REM) and NTS was found (r = 0.68, p = 0.006), which remained significant when controlling for the effect of age and education. In CIND group, the AI (N2) was significantly higher than the AI (REM) .
In CIND older adults, this attenuation of normal arousal mechanisms in REM sleep are dissociated from the relative excess of arousals observed in stage N2. We propose as probable etiology an early hypoactivity at the locus coeruleus noradrenergic system, associated to its early pathological damage, present in the AD continuum.
老年人的睡眠中断与认知障碍及其向阿尔茨海默病（AD）的转变风险增加有关。睡眠期间高唤醒指数（AIs）可能是认知障碍非痴呆（CIND）的早期生物标志物。
使用全夜多导睡眠图（PSG），我们研究了 CIND 是否与 NREM 和 REM 睡眠阶段之间不同的 AIs 有关。
14 名老年人自愿参加了这项基于人群的研究，该研究包括简易精神状态检查、神经心理学测试、Katz 日常生活活动独立性指数和单夜 PSG。根据神经心理学测试记忆和注意力子测试的结果，将受试者分为两组（每组 n = 7）：认知正常（CU），结果正常；和 CIND，记忆和/或注意力子测试低于 -2.5 个标准差。获得每个睡眠阶段（N1、N2、N3 和 REM）每小时的 AI，并与神经心理学测试总分（NTS）相关。
CU 组的 REM 期 AI 明显高于 CIND 组。对于总样本，发现 REM 期 AI 与 NTS 呈正相关（r = 0.68，p = 0.006），当控制年龄和教育的影响时，该相关性仍然显著。在 CIND 组中，N2 期的 AI 明显高于 REM 期的 AI。
在 CIND 老年患者中，REM 睡眠中正常唤醒机制的这种减弱与在 N2 期观察到的唤醒增加相对过剩是分离的。我们提出一种可能的病因学，即蓝斑去甲肾上腺素能系统的早期低活性与其在 AD 连续体中的早期病理损伤有关。
