Journal of sleep research
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Journal of sleep research · Feb 2015
Clinical TrialSubjective-objective sleep discrepancy among older adults: associations with insomnia diagnosis and insomnia treatment.
Discrepancy between subjective and objective measures of sleep is associated with insomnia and increasing age. Cognitive behavioural therapy for insomnia improves sleep quality and decreases subjective-objective sleep discrepancy. This study describes differences between older adults with insomnia and controls in sleep discrepancy, and tests the hypothesis that reduced sleep discrepancy following cognitive behavioural therapy for insomnia correlates with the magnitude of symptom improvement reported by older adults with insomnia. ⋯ Sleep discrepancy was significantly greater and more variable across nights in older adults with insomnia than controls, P ≤ 0.001 for all. Treatment with cognitive behavioural therapy for insomnia was associated with significant reduction in the Insomnia Severity Index score that correlated with changes in mean level and night-to-night variability in wake after sleep onset discrepancy, P < 0.001 for all. Study of sleep discrepancy patterns may guide more targeted treatments for late-life insomnia.
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Journal of sleep research · Feb 2015
Effects of sleep/wake history and circadian phase on proposed pilot fatigue safety performance indicators.
The Karolinska Sleepiness Scale and Samn-Perelli fatigue ratings, and psychomotor vigilance task performance are proposed as measures for monitoring commercial pilot fatigue. In laboratory studies, they are sensitive to sleep/wake history and circadian phase. The present analyses examined whether they reliably reflect sleep/wake history and circadian phase during transmeridian flight operations. ⋯ Subjective ratings showed expected associations with sleep/wake history and circadian phase. The response speed showed expected circadian variation but was not associated with sleep/wake history at the top of the descent. This may reflect moderate levels of fatigue at this time and/or atypically fast responses among pilots.
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Journal of sleep research · Dec 2014
Obstructive sleep apnea is associated with increased arterial stiffness in severe obesity.
Obstructive sleep apnea is associated with obesity and metabolic syndrome, leading to greater cardiovascular risk. Severely obese patients with obstructive sleep apnea may still be at risk of adverse health outcomes, even without previous cardiovascular disease. Pulse wave analysis non-invasively measures peripheral pulse waveforms and derives measures of haemodynamic status, including arterial stiffness, augmentation pressure and subendocardial viability ratio. ⋯ Arterial stiffness correlated with mean arterial blood pressure (P = 0.003) and obstructive sleep apnea severity (apnea-hypopnea index; P < 0.001). apnea-hypopnea index significantly predicted arterial stiffness in multiple regression analysis, but components of the metabolic syndrome did not. Thus, patients with obstructive sleep apnea with severe obesity have increased arterial stiffness that may potentially influence cardiovascular risk independently of metabolic abnormalities. The presence of obstructive sleep apnea in severe obesity identifies a group at high cardiovascular risk; clinicians should ensure that risk factors are managed appropriately in this group whether or not treatment of obstructive sleep apnea is offered or accepted by patients.
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Journal of sleep research · Aug 2014
Comparative Study Clinical TrialComparison of a novel non-contact biomotion sensor with wrist actigraphy in estimating sleep quality in patients with obstructive sleep apnoea.
Ambulatory monitoring is of major clinical interest in the diagnosis of obstructive sleep apnoea syndrome. We compared a novel non-contact biomotion sensor, which provides an estimate of both sleep time and sleep-disordered breathing, with wrist actigraphy in the assessment of total sleep time in adult humans suspected of obstructive sleep apnoea syndrome. Both systems were simultaneously evaluated against polysomnography in 103 patients undergoing assessment for obstructive sleep apnoea syndrome in a hospital-based sleep laboratory (84 male, aged 55 ± 14 years and apnoea-hypopnoea index 21 ± 23). ⋯ Here, the number of misclassifications of obstructive sleep apnoea severity compared with full polysomnography was reduced from 10/103 (for total respiratory recording time alone) to 7/103 and 4/103 (for actigraphy and biomotion sensor total sleep time estimate, respectively). We conclude that the biomotion sensor provides a viable alternative to actigraphy for sleep estimation in the assessment of obstructive sleep apnoea syndrome. As a non-contact device, it is suited to longitudinal assessment of sleep, which could also be combined with polygraphy in ambulatory studies.
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Journal of sleep research · Aug 2014
Memory sources of dreams: the incorporation of autobiographical rather than episodic experiences.
The present study aimed to explore autobiographical memories (long-lasting memories about the self) and episodic memories (memories about discrete episodes or events) within dream content. We adapted earlier episodic memory study paradigms and reinvestigated the incorporation of episodic memory sources into dreams, operationalizing episodic memory as featuring autonoetic consciousness, which is the feeling of truly re-experiencing or reliving a past event. Participants (n = 32) recorded daily diaries and dream diaries, and reported on wake-dream relations for 2 weeks. ⋯ However, the majority of dreams (>80%) were found to contain low to moderate incorporations of autobiographical memory features. These findings demonstrate the inactivity of intact episodic memories, and emphasize the activity of autobiographical memory and processing within dreams. Taken together, this suggests that memories for personal experiences are experienced fragmentarily and selectively during dreaming, perhaps in order to assimilate these memories into the autobiographical memory schema.