School of Nursing and Health Professions, University of San Francisco, San Francisco, CA.
School of Social Development and Public Policy, Beijing Normal University, Beijing, China.
Int J Geriatr Psychiatry. 2021 Jan;36(1):96-105. doi: 10.1002/gps.5401. Epub 2020 Sep 1.
The relationships between sleep problems, cognitive impairments, and depression have been established in the aging population. However, less is known about the role of late-life onset insomnia and sex involved in these dyad or tripartite relationships. This study aimed to consider onset age of insomnia and sex in the relationship between sleep parameters, cognition and depression among older adults with current insomnia complaints.
A multistep sampling method was adopted to recruit participants with current insomnia complaints in China in 2018. Sleep measures include onset age of insomnia (64 years old or before vs during/after 65), three factors from insomnia severity index (ISI; nighttime, daytime, and perception), excessive daytime sleepiness, and sleep duration. Outcome measures were mini-mental state examination (MMSE) and center for epidemiologic studies depression scale (CESD).
The average age of older adults was 75 (SD = 7.1). Among them, 62% participants are female. In general, older aged, female, late-life onset insomnia as well as interaction of sex * onset age of insomnia were significantly associated with poorer cognition. Yet, age, sex, and onset age of insomnia were not significant indicators for depression. For female participants, later onset of insomnia, nighttime symptoms of insomnia, excessive daytime sleepiness and depression were risk factors for cognitive decline. Nevertheless, only daytime sleepiness, together with depression, were found positively associated with male participants' cognitive decline.
There were robust associations between daytime sleepiness, depressive symptoms, and poor cognitive performance. More importantly, late-life onset insomnia was particularly indicative for poor cognitive performance among female older adults. Future study should emphasize the specific mechanism involved in changes of sleep patterns in the development of cognitive impairment among older adults. Sex differences in the relationship between onset age of insomnia and cognition also require further attention.
睡眠问题、认知障碍和抑郁之间的关系在老年人群中已经得到证实。然而，对于晚年发作的失眠症以及其在这些双元或三元关系中的性别作用知之甚少。本研究旨在考虑老年失眠症患者的失眠症发病年龄和性别在睡眠参数、认知和抑郁之间的关系。
采用多步骤抽样方法于 2018 年在中国招募有当前失眠症抱怨的老年人。睡眠测量包括失眠症发病年龄（64 岁或之前与 65 岁及之后）、失眠严重程度指数（ISI；夜间、白天和感知）的三个因素、日间嗜睡和睡眠时间。结果测量包括简易精神状态检查（MMSE）和流行病学研究中心抑郁量表（CESD）。
老年人的平均年龄为 75（SD=7.1）岁。其中，62%的参与者为女性。一般来说，年龄较大、女性、晚年发作的失眠症以及性别*失眠症发病年龄的相互作用与认知功能较差显著相关。然而，年龄、性别和失眠症发病年龄并不是抑郁的显著指标。对于女性参与者，失眠症发病较晚、失眠症夜间症状、日间嗜睡和抑郁是认知能力下降的危险因素。然而，只有日间嗜睡以及抑郁与男性参与者的认知能力下降呈正相关。
日间嗜睡、抑郁症状与认知表现差之间存在显著关联。更重要的是，晚年发作的失眠症尤其预示着女性老年人群认知能力下降。未来的研究应强调睡眠模式变化与老年人认知障碍发展之间的具体机制。失眠症发病年龄与认知之间的性别差异也需要进一步关注。
