Department of Big Data in Health Science, Zhejiang University School of Public Health and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China.
The Key Laboratory of Intelligent Preventive Medicine of Zhejiang Province, Hangzhou, China.
Age Ageing. 2023 Sep 1;52(9). doi: 10.1093/ageing/afad163.
Given the importance of sleep in maintaining neurocognitive health, both sleep duration and quality might be component causes of dementia. However, the possible role of insomnia symptoms as risk factors for dementia remain uncertain.
We prospectively studied 22,078 participants in the Swedish National March Cohort who were free from dementia and stroke at baseline. Occurrence of dementia was documented by national registers during a median follow-up period of 19.2 years. Insomnia symptoms and sleep duration were ascertained by Karolinska Sleep Questionnaire. Multivariable Cox proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI).
Compared to participants without insomnia at baseline, those who reported any insomnia symptom experienced a greater incidence of dementia during follow-up (HR 1.08, 95% CI: 1.03, 1.35). Difficulty initiating sleep versus non-insomnia (HR 1.24, 95% CI: 1.02, 1.52), but not difficulty maintaining sleep or early morning awakening was associated with an increased risk of dementia. Short sleep duration was associated with increased risk of dementia (6 h vs. 8 h, HR 1.29, 95% CI: 1.11-1.51; 5 h vs. 8 h, HR 1.26, 95% CI: 1.00-1.57). Stratified analyses suggested that insomnia symptoms increased the risk of dementia only amongst participants with ≥7 h sleep (vs. non-insomnia HR 1.24, 95% CI: 1.00-1.54, P = 0.05), but not amongst short sleepers (<7 h). Short sleep duration also did not further inflate the risk of dementia amongst insomniacs.
Insomnia and short sleep duration increase the risk of dementia amongst middle-aged to older adults.
鉴于睡眠在维持神经认知健康方面的重要性，睡眠时长和质量都可能是痴呆症的致病因素。然而，失眠症状作为痴呆症风险因素的作用仍不确定。
我们前瞻性地研究了 22078 名瑞典国家三月队列研究的参与者，这些参与者在基线时无痴呆和中风。通过国家登记册在中位随访期 19.2 年内记录痴呆的发生情况。通过 Karolinska 睡眠问卷确定失眠症状和睡眠时长。使用多变量 Cox 比例风险模型估计风险比（HR）和 95%置信区间（CI）。
与基线时无失眠症状的参与者相比，报告有任何失眠症状的参与者在随访期间发生痴呆的发生率更高（HR 1.08，95%CI：1.03，1.35）。入睡困难与非失眠（HR 1.24，95%CI：1.02，1.52）相关，而维持睡眠困难或早醒与痴呆风险增加无关。睡眠时长较短与痴呆风险增加相关（6 小时 vs. 8 小时，HR 1.29，95%CI：1.11-1.51；5 小时 vs. 8 小时，HR 1.26，95%CI：1.00-1.57）。分层分析表明，失眠症状仅在睡眠时间≥7 小时的参与者中增加痴呆风险（与非失眠相比，HR 1.24，95%CI：1.00-1.54，P=0.05），而在睡眠时间较短的参与者中则没有（<7 小时）。睡眠时间较短也不会进一步增加失眠患者的痴呆风险。
失眠和睡眠时长较短会增加中年及以上人群发生痴呆的风险。
