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. 2023 Jun 30:15:491-498.
doi: 10.2147/NSS.S399644. eCollection 2023.

The Relationship Between Cognitive Impairments and Sleep Quality Measures in Persistent Insomnia Disorder

Erika C S Künstler  1   2 , Peter Bublak  1 , Kathrin Finke  1 , Nicolas Koranyi  1 , Marie Meinhard  1 , Matthias Schwab  1   2 , Sven Rupprecht  1   2
Affiliations

The Relationship Between Cognitive Impairments and Sleep Quality Measures in Persistent Insomnia Disorder

Erika C S Künstler et al. Nat Sci Sleep. .

Abstract

Study objectives: Persistent insomnia disorder (pID) is linked to neurocognitive decline and increased risk of Alzheimer's Disease (AD) in later life. However, research in this field often utilizes self-reported sleep quality data - which may be biased by sleep misperception - or uses extensive neurocognitive test batteries - which are often not feasible in clinical settings. This study therefore aims to assess whether a simple screening tool could uncover a specific pattern of cognitive changes in pID patients, and whether these relate to objective aspect(s) of sleep quality.

Methods: Neurocognitive performance (Montreal Cognitive Assessment; MoCA), anxiety/depression severity, and subjective sleep quality (Pittsburgh Sleep Quality Index: PSQI; Insomnia Severity Index: ISI) data were collected from 22 middle-aged pID patients and 22 good-sleepers. Patients underwent overnight polysomnography.

Results: Compared to good-sleepers, patients had lower overall cognitive performance (average: 24.6 versus 26.3 points, Mann-Whitney U = 136.5, p = <0.006), with deficits in clock drawing and verbal abstraction. In patients, poorer overall cognitive performance correlated with reduced subjective sleep quality (PSQI: r(42) = -0.47, p = 0.001; and ISI: r(42) = -0.43, p = 0.004), reduced objective sleep quality (lower sleep efficiency: r(20) = 0.59, p = 0.004 and less REM-sleep: r(20) = 0.52, p = 0.013; and increased sleep latency: r(20) = -0.57, p = 0.005 and time awake: r(20) = -0.59, p = 0.004). Cognitive performance was not related to anxiety/depression scores.

Conclusion: Using a simple neurocognitive screening tool, we found that pID patients showed cognitive deficiencies that related to both subjective/self-reported and objective/polysomnographic measures of sleep quality. Furthermore, these cognitive changes resembled those seen in preclinical non-amnestic AD, and thus could indicate incumbent neurodegenerative processes in pID. Interestingly, increased REM-sleep was correlated with better cognitive performance. However, whether REM-sleep is protective against neurodegeneration requires further investigation.

Keywords: Alzheimer’s disease; cognitive screening; insomnia; neurodegeneration; polysomnography; sleep.

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Conflict of interest statement

The authors report no conflicts of interest in this work.

Figures

Figure 1
Figure 1
Correlation between overall MoCA score and sleep latency (A); wake after sleep onset (B); REM sleep (C); and sleep efficiency (D) in patients with pID.
Figure 2
Figure 2
Distribution of overall MoCA scores relative to scores on subjective, self-reported sleep quality measures. (A) PSQI: Pittsburgh Sleep Quality Inventory; (B) ISI: Insomnia Severity Index. Note that due to overlapping scores, some points in the scatterplot represent multiple data points.
See this image and copyright information in PMC

References

    1. Yaffe K, Falvey CM, Hoang T. Connections between sleep and cognition in older adults. Lancet Neurol. 2014;13(10):1017–1028. doi: 10.1016/S1474-4422(14)70172-3 - DOI - PubMed
    1. Iranzo A, Santamaria J. Sleep in neurodegenerative diseases. In: Chokroverty S, Billiard M, editors. Sleep Med. New York, NY: Springer; 2015:271–283.
    1. Shamim SA, Warriach ZI, Tariq MA, et al. Insomnia: risk factor for neurodegenerative diseases. Cureus. 2019;11(10):e6004. doi: 10.7759/cureus.6004 - DOI - PMC - PubMed
    1. Minakawa EN, Wada K, Nagai Y. Sleep disturbance as a potential modifiable risk factor for Alzheimer’s disease. Int J Mol Sci. 2019;20(4):803. doi: 10.3390/ijms20040803 - DOI - PMC - PubMed
    1. Roth T. Insomnia: definition, prevalence, etiology, and consequences. J Clin Sleep Med. 2007;3(5):S7–S10. doi: 10.5664/jcsm.26929 - DOI - PMC - PubMed