Chronic Moderate Sleep Restriction in Older Long and Older Average Sleepers

描述（由申请人提供）：流行病学研究一致表明，自我报告的睡眠时间<7小时和< 8小时与死亡率和发病率增加有关。与睡眠不足相关的风险与大量实验文献一致，这些文献表明深度睡眠限制会产生有害影响。然而，关于慢性中度睡眠限制的研究很少，而慢性中度睡眠限制更为常见，因此从公共健康的角度来看更为重要。虽然流行病学数据表明，睡眠限制可能会促进长睡眠者的健康/长寿，但与长睡眠有关的风险几乎没有实验研究过。老年人可能比年轻人更容易受到进一步睡眠障碍的负面影响，尤其是通过炎症机制。如果像许多人假设的那样，长时间睡眠反映了潜在的发病率，那么长时间睡眠者的负面影响可能至少和普通睡眠者一样明显。另一方面，老年人可能会忍受（或受益于）适度的睡眠限制。老年人往往倾向于花过多的时间在床上（TIB），特别是长睡眠者，而额外的TIB可能会导致与年龄相关的睡眠碎片和发病率，这可以通过适度的TIB限制来改善。在HL71560中，年龄较大的长睡眠者（b> 8.5小时/夜）在8周90分钟TIB限制中没有出现不良反应。HL71560扩展的目的是：(1)检查老年长睡眠者和老年平均睡眠者遵守60分钟TIB限制的能力；(2)对比12周60分钟TIB限制对老年人长睡眠者和平均睡眠者健康相关指标的影响。这项研究还应该提供这些群体关于睡眠习惯/信念的基因分型和定性信息。100名报告每晚睡眠8-9小时的老年人（60-80岁）和100名报告每晚睡眠6-7.25小时的相同年龄段的成年人将在5年的时间里在4个实验地点进行研究。在2周的基线后，参与者将被随机分配到两个12周治疗组中的一个。(1)一个睡眠限制组（n=60名长睡眠者和n=60名普通睡眠者）将被分配到一个固定的睡眠-觉醒时间表，在这个时间表中，每个参与者的卧床时间精确地减少到比基线TIB低60分钟。(2)对照组（n=40名长睡眠者和n=40名平均睡眠者）不受睡眠限制，但也有固定的睡眠时间表。睡眠将通过活动记录仪和每日日记进行持续评估。调查问卷将通过一个研究网站回答。测量将包括体重、葡萄糖耐量、嗜睡、抑郁、生活质量、精神运动警惕性、汽车事故发生率、疾病发生率和多种炎症标志物。在干预的第2周和第6周进行体检，并由一名研究监察员进一步监测潜在的不良影响。后续评估将进行12个月。拟议的临床试验将提供有史以来对慢性中度TIB限制的风险和益处进行的最全面的1期评估。

DESCRIPTION (provided by applicant): Epidemiologic studies have consistently shown that self-reported sleep durations of <7 hr and >8 hr are associated with increased mortality and morbidity. The risks associated with short sleep are consistent with a vast experimental literature indicating detrimental effects of profound sleep restriction. However, there has been little study of chronic moderate sleep restriction, which is far more common, and thus more important from a public health standpoint. The risks associated with long sleep have scarcely been experimentally examined, though epidemiologic data suggest sleep restriction might promote health/longevity in long sleepers. Older adults might be more vulnerable than young adults to negative effects of further sleep impairment, perhaps particularly via inflammatory mechanisms. Negative effects might be at least as evident in long sleepers as in average sleepers if long sleep reflects underlying morbidity, as many have posited. On the other hand, older adults might tolerate (or benefit) from moderate sleep restriction. Older adults often tend to spend excessive time in bed (TIB), particularly long sleepers, and extra TIB could contribute to age-related sleep fragmentation and morbidity, which could be ameliorated with modest TIB restriction. In HL71560, older long sleepers (> 8.5 hr/night) experienced no adverse effects of 8 wk of 90-min TIB restriction. The aims of this expansion of HL71560 are: (1) to examine the ability of older long sleepers and older average sleepers to adhere to 60 min TIB restriction; and (2) to contrast effects of 12 weeks of 60 min TIB restriction on health-related measures in older long vs. average sleepers. The study should also provide genotyping and qualitative information about habits/beliefs about sleep in these groups. One hundred older adults (ages 60-80 yr) who report sleeping 8-9 hr per night and 100 adults of the same age range who report sleeping 6-7.25 hr per night will be examined at 4 experimental sites over 5 years. Following a 2-week baseline, participants will be randomly assigned to one of two 12-week treatment groups. (1) A sleep restriction group (n=60 long sleepers and n=60 average sleepers) will be assigned to a fixed sleep- wake schedule, in which time in bed is reduced precisely 60 min below each participant's baseline TIB. (2) A control group (n=40 long sleepers and n=40 average sleepers) will have no sleep restriction, but will also follow a fixed sleep schedule. Sleep will be assessed continuously with actigraphy and a daily diary. Questionnaires will be answered via a study web site. Measures will include body weight, glucose tolerance, sleepiness, depression, quality of life, psychomotor vigilance, incidence of automobile accidents, incidence of illness, and multiple markers of inflammation. Physical exams during weeks 2 and 6 of the intervention and a study ombudsman will further monitor potential adverse effects. Follow-up assessments will be conducted for 12 months. The proposed clinical trial will provide the most comprehensive Phase 1 assessment of risks and benefits of chronic moderate TIB restriction ever conducted.