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

Surrey Sleep Research Centre, Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK.
Sleep (Impact Factor: 5.06). 02/2010; 33(2):211-23.
Source: PubMed

ABSTRACT To investigate whether age-related and experimental reductions in SWS and sleep continuity are associated with increased daytime sleep propensity.
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).
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 8.7 min (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).
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.


Available from: Steve Deacon, Apr 20, 2015
  • [Show abstract] [Hide abstract]
    ABSTRACT: Determine the effects of high versus moderate workload on sleep physiology and neurobehavioral measures, during sleep restriction (SR) and no sleep restriction (NSR) conditions.
    Sleep 10/2014; DOI:10.5665/sleep.4164 · 5.06 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: This editorial of the topic issue of the World Journal of Urology provides a state of the art on nocturia which includes descriptions of the terminology, epidemiology, health-related quality of life, medical and financial consequences, pathophysiology, assessment tools and treatment strategies of nocturia. This summary also includes a flowchart on the pathophysiology of nocturia with illustration of the various causes of reduced bladder capacity, increased fluid intake or increased diuresis; a flowchart with the key findings of frequency-volume charts to determine the underlying pathophysiology; and a flowchart on the treatment of the various causes of nocturia. The editorial critically discusses current assessment and treatment strategies in patients with lower urinary tract symptoms suggestive of benign prostatic hyperplasia (LUTS/BPH) and nocturia. The outcome of nocturia remains hidden in drug trials of patients with LUTS/BPH because nocturia-specific measures were not included. The authors recommend using frequency-volume charts, measurement of the hours of undisturbed sleep, and nocturia-specific quality of life questionnaires (e.g., ICIQ-N or N-Qol) in all future studies in patients with LUTS/BPH and nocturia.
    World Journal of Urology 09/2014; 32(5). DOI:10.1007/s00345-014-1396-0 · 3.42 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: This study aimed to examine the association between polysomnographic sleep and subjective habitual sleep quality and restoration from sleep. Thirty-one normal sleepers completed the Karolinska Sleep Questionnaire and multiple home polysomnography recordings (n = 2-5). Using linear regression, sleep quality and restoration were separately analyzed as functions of standard polysomnography parameters: sleep efficiency, total sleep time, sleep latency, stage 1 and 2 sleep, slow-wave sleep, rapid eye movement sleep, wake time after sleep onset, and awakenings (n), averaged across recordings. Stage 2 and slow-wave sleep predicted worse and better sleep quality, respectively. Also, slow-wave sleep predicted less subjective restoration, although adjustment for age attenuated this relation. Our findings lend some physiological validity to ratings of habitual sleep quality in normal sleepers. Data were less supportive of a physiological correlate of ratings of restoration from sleep.
    Behavioral Sleep Medicine 11/2014; DOI:10.1080/15402002.2014.974181 · 1.56 Impact Factor