Department of Psychology, University of Michigan, Ann Arbor, MI 48109, USA.
Sleep Disorders Center and Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA.
Sleep. 2023 Mar 9;46(3). doi: 10.1093/sleep/zsac262.
Insomnia may be a modifiable risk factor for later-life cognitive impairment. We investigated: (1) which insomnia symptoms are associated with subsequent cognitive functioning across domains; (2) whether insomnia-cognition associations are mediated by mental and physical health; and (3) whether these associations are modified by gender.
Participants included 2595 adults ages 51-88 at baseline (Mage=64.00 ± 6.66, 64.5% women) in the Health and Retirement Study. The frequency of insomnia symptoms (difficulty initiating sleep, night time awakenings, early awakenings, and feeling unrested upon awakening) at baseline (2002) were quantified using a modified Jenkins Sleep Questionnaire. Cognition was assessed in 2016 via the Harmonized Cognitive Assessment Protocol and operationalized with factor scores corresponding to five domains. Depressive symptoms and vascular conditions in 2014 were assessed via self-report. Structural equation models estimated total, indirect, and direct effects of insomnia symptoms on subsequent cognition through depressive symptoms and vascular diseases, controlling for baseline sociodemographic and global cognition.
Frequent difficulty initiating sleep was associated with poorer episodic memory, executive function, language, visuoconstruction, and processing speed 14 years later (-0.06 ≤ β ≤ -0.04; equivalent to 2.2-3.4 years of aging). Depressive symptoms explained 12.3%-19.5% of these associations and vascular disease explained 6.3%-14.6% of non-memory associations. No other insomnia symptoms were associated with cognition, and no associations were modified by gender.
Difficulty initiating sleep in later life may predict future cognitive impairment through multiple pathways. Future research with longitudinal assessments of insomnia, insomnia treatments, and cognition is needed to evaluate insomnia as a potential intervention target to optimize cognitive aging.
失眠可能是导致晚年认知障碍的可改变风险因素。我们调查了：（1）哪些失眠症状与随后的认知功能有关；（2）失眠与认知的关联是否通过心理健康和身体健康来介导；（3）这些关联是否受到性别影响。
参与者包括健康与退休研究中的 2595 名年龄在 51-88 岁的成年人（基线时平均年龄=64.00±6.66，64.5%为女性）。基线（2002 年）使用改良的 Jenkins 睡眠问卷量化了失眠症状（入睡困难、夜间觉醒、早醒和醒来时感到不安）的频率。认知功能在 2016 年通过协调的认知评估方案进行评估，并用对应于五个领域的因子得分来表示。2014 年通过自我报告评估抑郁症状和血管疾病。结构方程模型估计了失眠症状通过抑郁症状和血管疾病对随后认知的总、间接和直接影响，同时控制了基线社会人口统计学和整体认知。
频繁出现入睡困难与 14 年后的情景记忆、执行功能、语言、视觉构建和处理速度较差相关（β=-0.06 至-0.04；相当于衰老 2.2-3.4 年）。抑郁症状解释了这些关联的 12.3%-19.5%，血管疾病解释了非记忆关联的 6.3%-14.6%。其他失眠症状与认知无关，且性别对任何关联均无影响。
晚年入睡困难可能通过多种途径预测未来的认知障碍。需要进行前瞻性研究，评估失眠、失眠治疗和认知，以评估失眠作为优化认知老化的潜在干预靶点的可能性。
