Department of Psychiatry, University Hospital of Heraklion, Crete, Greece.
Sleep Research and Treatment Center, Department of Psychiatry, Penn State University, Hershey, PA, USA.
J Alzheimers Dis. 2021;79(2):763-771. doi: 10.3233/JAD-200958.
Apolipoprotein E gene (APOE) ɛ4 allele increases the risk for Alzheimer's disease (AD). Furthermore, among patients with cognitive impairment, longer sleep duration is associated with worse cognitive performance. To date, literature examining the associations between APOE ɛ4 allele and objective sleep duration is limited.
Our aim was to assess the association between APOE ɛ4 and objective sleep duration, among patients with mild cognitive impairment (MCI) and AD. A sub-sample of 89 patients with AD (n = 49) and MCI (n = 40) were recruited from a large, population-based cohort of 3,140 elders (>60 years) residing on Crete, Greece.
All participants underwent medical history/physical examination, extensive neuropsychiatric and neuropsychological evaluation, 3-day 24 h actigraphy and APOE ɛ4 allele genotyping. Comparisons of sleep duration variables between APOE ɛ4 allele carriers and non-carriers were assessed using ANCOVA, controlling for confounders.
The sample included 18 APOE ɛ4 carriers and 71 non-carriers, aged 78.6±6.6 and 78.2±6.5 years, respectively. Comparisons between the APOE ɛ4 carriers and non-carriers revealed no significant differences in terms of demographic and clinical variables. In terms of objective sleep duration across the two groups, APOE ɛ4 carriers compared to non-carriers had significantly longer nighttime Total Sleep Time (nTST) (7.7±1.4 versus 7.2±1.3 h, respectively, p = 0.011), as well as 24 h TST (8.5±1.6 versus 7.8±1.5 h, respectively, p = 0.012).
Among patients with MCI and AD, APOE ɛ4 carriers have longer objective nighttime and 24 h sleep duration compared to non-carriers. These findings further support that objective long sleep duration is a genetically-driven pre-clinical marker associated with worse prognosis in elderly with cognitive impairment.
载脂蛋白 E 基因（APOE）ɛ4 等位基因增加了患阿尔茨海默病（AD）的风险。此外，在认知障碍患者中，较长的睡眠时间与较差的认知表现相关。迄今为止，研究 APOE ɛ4 等位基因与客观睡眠时间之间关联的文献有限。
我们旨在评估轻度认知障碍（MCI）和 AD 患者中 APOE ɛ4 与客观睡眠时间之间的关联。从居住在希腊克里特岛的 3140 名老年人（>60 岁）的大型人群队列中招募了 89 名 AD 患者（n=49）和 MCI 患者（n=40）的亚样本。
所有参与者均接受了病史/体检、广泛的神经精神和神经心理学评估、3 天 24 小时活动记录仪和 APOE ɛ4 等位基因基因分型。使用协方差分析（ANCOVA）评估睡眠时间变量在 APOE ɛ4 等位基因携带者和非携带者之间的差异，同时控制混杂因素。
该样本包括 18 名 APOE ɛ4 携带者和 71 名非携带者，年龄分别为 78.6±6.6 和 78.2±6.5 岁。APOE ɛ4 携带者和非携带者在人口统计学和临床变量方面无显著差异。在两组的客观睡眠时间方面，与非携带者相比，APOE ɛ4 携带者的夜间总睡眠时间（nTST）明显更长（分别为 7.7±1.4 小时和 7.2±1.3 小时，p=0.011），24 小时 TST 也更长（分别为 8.5±1.6 小时和 7.8±1.5 小时，p=0.012）。
在 MCI 和 AD 患者中，与非携带者相比，APOE ɛ4 携带者的客观夜间和 24 小时睡眠时间更长。这些发现进一步支持客观长睡眠时间是一种与认知障碍老年人预后较差相关的遗传驱动的临床前标志物。
