Peking University Sixth Hospital, Peking University Institute of Mental Health, Key Laboratory of Mental Health, Ministry of Health (Peking University), National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Beijing, China.
National Institute on Drug Dependence and Beijing Key laboratory of Drug Dependence Research, Peking University, Beijing, China.
Sleep. 2019 Jan 1;42(1). doi: 10.1093/sleep/zsy192.
Objective sleep duration has been linked to insomnia severity. However, cognitive functions of people with insomnia with different sleep durations have been seldom addressed. Brain-derived neurotrophic factor (BDNF) has an important role in cognitive function and has been linked to clinical insomnia recently. The present study aimed to evaluate the comprehensive cognitive functions in people with primary insomnia with different objective sleep durations, and further examine the involvement of peripheral BDNF.
Fifty-seven people with insomnia were subdivided into short sleep duration (SSD, sleep time < 6 hr) group and normal sleep duration (NSD, sleep time ≥ 6 hr) group based on polysomnography data. Twenty-nine healthy controls (HC) were matched on age, gender, and education. Cognitive function was assessed using a comprehensive and sensitive neuropsychological test battery. Both objective and subjective insomnia statuses were estimated. Serum BDNF level was measured using enzyme-linked immune sorbent assay.
Compared with HC, the SSD group showed impaired neuropsychological performances in spatial span, brief visuospatial memory test, fluency, managing emotions, and continuous performance tests. In contrast, NSD had bad performance only in brief visuospatial memory test and continuous performance tests, and relatively better than SSD group in the latter test. People with SSD insomnia but not NSD had decreased BDNF levels compared with HC, and neuropsychological performance was positively correlated with BDNF levels only in SSD group.
Primary insomnia was associated with impaired neuropsychological performance, and the impairment might be related to decreased objective sleep duration. In addition, decreased peripheral BDNF might mediate the impaired cognitive functions of people with insomnia with SSD.
客观睡眠时间与失眠严重程度有关。然而，不同睡眠时间的失眠患者的认知功能却很少被提及。脑源性神经营养因子（BDNF）在认知功能中具有重要作用，最近与临床失眠有关。本研究旨在评估不同客观睡眠时间原发性失眠患者的综合认知功能，并进一步探讨外周 BDNF 的参与情况。
根据多导睡眠图数据，将 57 例失眠患者分为短睡眠组（SSD，睡眠时间<6 小时）和正常睡眠组（NSD，睡眠时间≥6 小时）。29 名健康对照（HC）按年龄、性别和教育程度匹配。采用综合敏感的神经心理测试量表评估认知功能。同时评估客观和主观的失眠状况。采用酶联免疫吸附试验（ELISA）法测定血清 BDNF 水平。
与 HC 相比，SSD 组在空间跨度、简短视空间记忆测试、流畅性、情绪管理和连续性能测试方面表现出较差的神经心理表现。相比之下，NSD 仅在简短视空间记忆测试和连续性能测试中表现不佳，且在后者测试中相对优于 SSD 组。与 HC 相比，SSD 失眠患者的 BDNF 水平降低，且神经心理表现仅与 SSD 组的 BDNF 水平呈正相关。
原发性失眠与神经心理表现受损有关，这种损害可能与客观睡眠时间减少有关。此外，外周 BDNF 的减少可能介导 SSD 失眠患者认知功能的损害。
