ADVERTISEMENT
CURRENT ISSUE
SEPTEMBER 2014
KINDLE EDITION



SEARCH JOURNAL ARCHIVES


SEARCH PUBMED


MANUSCRIPT SUBMISSIONS


SUBSCRIBE TO SLEEP

CONTINUING MEDICAL EDUCATION


ADVERTISE WITH US


ABOUT SLEEP

ABSTRACT SUPPLEMENTS


ACCEPTED PAPERS
Bookmark and Share         RSS Feed

VOLUME 33, ISSUE 02

AGE-RELATED REDUCTION IN SLEEPINESS AND SWS
Age-Related Reduction in Daytime Sleep Propensity and Nocturnal Slow Wave Sleep

Derk-Jan Dijk, PhD1; John A. Groeger, PhD1,2; Neil Stanley, PhD1; Stephen Deacon, PhD3

1Surrey Sleep Research Centre, Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK; 2Department of Psychology, University of Surrey, Guildford, UK; 3H. Lundbeck A/S, Denmark and Lundbeck Ltd, UK



  Expand  Table of Contents    
Text size:  

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.
Keywords: Aging, insomnia, slow wave sleep, sleepiness, alertness

Expand  Table of Contents
ADVERTISEMENT
Classifieds View SLEEP 2011 Poster Presentations Online