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- Cedernaes, Jonathan, et al.
(författare)
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A single night of partial sleep loss impairs fasting insulin sensitivity but does not affect cephalic phase insulin release in young men
- 2016
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Ingår i: Journal of Sleep Research. - : Wiley. - 0962-1105 .- 1365-2869. ; 25:1, s. 5-10
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Tidskriftsartikel (refereegranskat)abstract
- The present study sought to investigate whether a single night of partial sleep deprivation (PSD) would alter fasting insulin sensitivity and cephalic phase insulin release (CPIR) in humans. A rise in circulating insulin in response to food-related sensory stimulation may prepare tissues to break down ingested glucose, e.g. by stimulating rate-limiting glycolytic enzymes. In addition, given insulin's anorexigenic properties once it reaches the brain, the CPIR may serve as an early peripheral satiety signal. Against this background, in the present study 16 men participated in two separate sessions: one night of PSD (4.25 h sleep) versus one night of full sleep (8.5 h sleep). In the morning following each sleep condition, subjects' oral cavities were rinsed with a 1-molar sucrose solution for 45 s, preceded and followed by blood sampling for repeated determination of plasma glucose and serum insulin concentrations (-3, +3, +5, +7, +10 and +20 min). Our main result was that PSD, compared with full sleep, was associated with significantly higher peripheral insulin resistance, as indicated by a higher fasting homeostasis model assessment of insulin resistance index (+16%, P = 0.025). In contrast, no CPIR was observed in any of the two sleep conditions. Our findings indicate that a single night of PSD is already sufficient to impair fasting insulin sensitivity in healthy men. In contrast, brief oral cavity rinsing with sucrose solution did not change serum insulin concentrations, suggesting that a blunted CPIR is an unlikely mechanism through which acute sleep loss causes metabolic perturbations during morning hours in humans.
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| 2. |
- Cedernaes, Jonathan, et al.
(författare)
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Learning and sleep-dependent consolidation of spatial and procedural memories are unaltered in young men under a fixed short sleep schedule
- 2016
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Ingår i: Neurobiology of Learning and Memory. - : Elsevier BV. - 1074-7427 .- 1095-9564. ; 131, s. 87-94
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To investigate if a fixed short sleep schedule impairs one of the main functions of sleep, which is to consolidate newly learned memories. Methods: Sixteen young men participated in two experimental conditions, each of which lasted for 3 consecutive days and nights in our laboratory: a short sleep schedule (4.25-h sleep opportunity per night) versus a normal sleep schedule (8.5 h per night). In the evening after two experimental nights, participants learned locations of 15 card pairs (spatial memory task) and a procedural finger tapping sequence task. Post-sleep retrieval of both memory tasks was tested the next morning. Results: The short sleep schedule, compared with the normal sleep schedule, considerably altered sleep characteristics, e.g. the proportion of time in slow-wave sleep increased across the three experimental nights. In contrast, neither learning in the evening of day 2, nor subsequent overnight memory consolidation (i.e. concerning the change in memory performance between pre-sleep learning on day 2 and post sleep retrieval on day 3) differed between the normal and short sleep schedule conditions. Conclusions: Our findings suggest that learning in the evening and subsequent sleep-dependent consolidation of procedural and spatial memories are unaltered in young men living under a fixed short sleep schedule. Future studies are warranted to validate our findings in other groups (e.g. adolescents and older subjects) and after more prolonged chronic sleep loss paradigms.
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| 3. |
- Cedernaes, Jonathan, et al.
(författare)
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Short Sleep Makes Declarative Memories Vulnerable to Stress in Humans
- 2015
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Ingår i: Sleep. - : Oxford University Press (OUP). - 0161-8105 .- 1550-9109. ; 38:12, s. 1861-1868
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Tidskriftsartikel (refereegranskat)abstract
- Study Objective: This study sought to investigate the role of nocturnal sleep duration for the retrieval of oversleep consolidated memories, both prior to and after being cognitively stressed for similar to 30 minutes the next morning. Design: Participants learned object locations (declarative memory task comprising 15 card pairs) and a finger tapping sequence (procedural memory task comprising 5 digits) in the evening. After learning, participants either had a sleep opportunity of 8 hours (between similar to 23:00 and similar to 07:00, full sleep condition) or they could sleep between similar to 03:00 and similar to 07:00 (short sleep condition). Retrieval of both memory tasks was tested in the morning after each sleep condition, both before (similar to 08:30) and after being stressed (similar to 09:50). Setting: Sleep laboratory. Participants: 15 healthy young men. Results: The analyses demonstrated that oversleep memory changes did not differ between sleep conditions. However, in their short sleep condition, following stress hallmarked by increased subjective stress feelings, the men were unable to maintain their pre-stress performance on the declarative memory task, whereas their performance on the procedural memory task remained unchanged. While men felt comparably subjectively stressed by the stress intervention, overall no differences between pre- and post-stress recalls were observed following a full night of sleep. Conclusions: The findings suggest that 8-h sleep duration, within the range recommended by the US National Sleep Foundation, may not only help consolidate newly learned procedural and declarative memories, but also ensure full access to both during periods of subjective stress.
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| 5. |
- Johansson, Åsa, et al.
(författare)
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NLRC4 Inflammasome Is an Important Regulator of Interleukin-18 Levels in Patients With Acute Coronary Syndromes Genome-Wide Association Study in the PLATelet inhibition and patient Outcomes Trial (PLATO)
- 2015
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Ingår i: Circulation. - 1942-325X .- 1942-3268. ; 8:3, s. 498-506
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Tidskriftsartikel (refereegranskat)abstract
- Background Interleukin 18 (IL-18) promotes atherosclerotic plaque formation and is increased in patients with acute coronary syndromes. However the relative contribution of genetic variants to the IL-18 levels has not been fully determined. Methods and Results Baseline plasma IL-18 levels were measured in 16633 patients with acute coronary syndrome, of whom 9340 had genetic data that passed genotype quality control. A 2-stage genome-wide association study was performed, followed by combined analyses using >10 million genotyped or imputed genetic markers. Single nucleotide polymorphisms at 3 loci (IL18, NLRC4, and MROH6) were identified (P<3.15x10(-8)) in the discovery cohort (n=3777) and replicated in the remaining patients (n=5563). In the pooled data (discovery+replication cohort), 7 independent associations, in 5 chromosomal regions, were associated with IL-18 levels (minimum P=6.99x10(-72)). Six single nucleotide polymorphisms are located in predicted promoter regions of which one disrupts a transcription factor binding site. One single nucleotide polymorphism in NLRC4 is a rare missense variant, predicted to be deleterious to the protein. Altogether, the identified genetic variants explained 8% of the total variation in IL-18 levels in the cohort. Conclusions Our results show that genetic variants play an important role in determining IL-18 levels in patients with acute coronary syndrome and we have identified genetic variants located in the IL-18 gene (IL18) or close to genes that are involved in procaspase-1 activation (NLRC4 and CARD16, CARD17, and CARD18). These associations also highlight the importance of the NLRC4 inflammasome for IL-18 production in acute coronary syndrome patients.
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