BACKGROUND given the complex relationship between sleep and neurodegenerative processes, it is important to examine whether changes in sleep patterns occur prior or close to dementia onset. OBJECTIVE to examine the relationship between sleep parameters and dementia incidence and, to characterize trajectories of sleep patterns before dementia diagnosis. DESIGN a 14-year longitudinal study including a nested case-control study. SETTING the French Three-City Study. SUBJECTS overall, 1,749 cognitively healthy participants (≥65 years) for the longitudinal study and, 182 incident dementia cases and 719 controls matched by sex, age and educational level for the case-control study. METHODS dementia cases were assessed at each visit and self-reported sleep parameters at baseline, 2, 8, 10, 12 and 14 years. Cox models were used to estimate the risk of dementia associated with baseline sleep parameters (sleep duration, time in bed (TIB), sleep timing, sleepiness and insomnia). Latent-process mixed models were performed to compare sleep trajectories according to the case-control status. RESULTS long baseline nighttime and 24-h sleep durations (≥9 h) as well as being persistent or becoming long sleepers during follow-up were associated with dementia incidence. Trajectories of sleep durations and TIB showed faster increases in cases compared with controls up to 12 years before dementia. The mean differences [95%CI] for 24-h sleep duration between cases and controls were: 0.27 h [0.01;0.52], 0.34 [0.09;0.58] and 0.67 [0.44;0.90] at -12, -8 and -2 years, respectively. Bedtime trajectories showed an earlier bedtime in cases up to -8 years. CONCLUSION long sleep duration and earlier bedtime may impact dementia incidence.

中文翻译：

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痴呆前睡眠持续时间和时间的轨迹：一项为期 14 年的随访研究。

背景 鉴于睡眠与神经退行性过程之间的复杂关系，检查睡眠模式的变化是否发生在痴呆症发作之前或附近是很重要的。目的检查睡眠参数与痴呆症发病率之间的关系，并在痴呆症诊断之前表征睡眠模式的轨迹。设计一项为期 14 年的纵向研究，包括一项巢式病例对照研究。设置法国三城市研究。受试者总体而言，1,749 名认知健康的参与者（≥65 岁）用于纵向研究，182 名痴呆症患者和 719 名按性别、年龄和教育水平匹配的对照者用于病例对照研究。方法 痴呆病例在每次就诊时进行评估，并在基线、2、8、10、12 和 14 岁时自我报告睡眠参数。Cox 模型用于估计与基线睡眠参数（睡眠持续时间、卧床时间 (TIB)、睡眠时间、嗜睡和失眠）相关的痴呆症风险。执行潜过程混合模型以根据病例对照状态比较睡眠轨迹。结果 长基线夜间和 24 小时睡眠时间（≥9 小时）以及在随访期间持续或成为长睡眠者与痴呆发病率相关。睡眠持续时间和 TIB 的轨迹显示，与痴呆前 12 年的对照组相比，病例增加更快。病例和对照组之间 24 小时睡眠时间的平均差异 [95%CI] 为：在 -12、-8 和 -2 时分别为 0.27 小时 [0.01;0.52]、0.34 [0.09;0.58] 和 0.67 [0.44;0.90]年，分别。就寝时间轨迹显示，在长达 -8 岁的病例中，就寝时间较早。