Age-related reduction in daytime sleep propensity and nocturnal slow wave sleep

Dijk, Derk-Jan; Groeger, John A; Stanley, Neil; Deacon, Stephen

Abstract

Objective:To investigate whether age-related and experimental reductions in SWS and sleep continuity are associated with increased daytime sleep propensity.Methods:Assessment of daytime sleep propensity under baseline conditions and following experimental disruption of SWS. Healthy young (20-30 y, n = 44), middle-aged (40-55 y, n = 35) and older (66-83 y, n = 31) men and women, completed a 2-way parallel group study. After an 8-h baseline sleep episode, subjects were randomized to 2 nights with selective SWS disruption by acoustic stimuli, or without disruption, followed by 1 recovery night. Objective and subjective sleep propensity were assessed using the Multiple Sleep Latency Test (MSLT) and the Karolinska Sleepiness Scale (KSS).Findings:During baseline sleep, SWS decreased (P < 0.001) and the number of awakenings increased (P < 0.001) across the 3 age groups. During the baseline day, MSLT values increased across the three age groups (P < 0.0001) with mean values of 8.7min (SD: 4.5), 11.7 (5.1) and 14.2 (4.1) in the young, middle-aged, and older adults, respectively. KSS values were 3.7 (1.0), 3.2 (0.9), and 3.4 (0.6) (age-group: P = 0.031). Two nights of SWS disruption led to a reduction in MSLT and increase in KSS in all 3 age groups (SWS disruption vs. control: P < 0.05 in all cases).Conclusions: Healthy aging is associated with a reduction in daytime sleep propensity, sleep continuity, and SWS. In contrast, experimental disruption of SWS leads to an increase in daytime sleep propensity. The age-related decline in SWS and reduction in daytime sleep propensity may reflect a lessening in homeostatic sleep requirement. Healthy older adults without sleep disorders can expect to be less sleepy during the daytime than young adults.

Citation

Dijk, D.-J., Groeger, J. A., Stanley, N., & Deacon, S. (2010). Age-related reduction in daytime sleep propensity and nocturnal slow wave sleep. SLEEP, 33(2), 211-223

• Journal Article Type: Article
• Acceptance Date: Oct 1, 2009
• Publication Date: 2010-02
• Deposit Date: Nov 13, 2014
• Journal: Sleep
• Print ISSN: 0161-8105
• Publisher: Oxford University Press
• Peer Reviewed: Peer Reviewed
• Volume: 33
• Issue: 2
• Pages: 211-223
• Keywords: Aging; Insomnia; Slow wave sleep; Sleepiness; Alertness
• Public URL: https://hull-repository.worktribe.com/output/467184
• Publisher URL: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2817908/
• Additional Information: http://www.journalsleep.org/OpenAccess.aspx states open access is through PubMed Central. No mention of repositories.