Sleep restriction increases white blood cells, mainly neutrophil count, in young healthy men: A pilot study

SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Temporal Dissociation between Myeloperoxidase (MPO)-Modified LDL and MPO Elevations during Chronic Sleep Restriction and Recovery in Healthy Young Men

OBJECTIVES: Many studies have evaluated the ways in which sleep disturbances may influence inflammation and the possible links of this effect to cardiovascular risk. Our objective was to investigate the effects of chronic sleep restriction and recovery on several blood cardiovascular biomarkers. METHODS AND RESULTS: Nine healthy male non-smokers, aged 22-29 years, were admitted to the Sleep Laboratory for 11 days and nights under continuous electroencephalogram polysomnography. The study consisted of three baseline nights of 8 hours sleep (from 11 pm to 7 am), five sleep-restricted nights, during which sleep was allowed only between 1 am and 6 am, and three recovery nights of 8 hours sleep (11 pm to 7 am). Myeloperoxidase-modified low-density lipoprotein levels increased during the sleep-restricted period indicating an oxidative stress. A significant increase in the quantity of slow-wave sleep was measured during the first recovery night. After this first recovery night, insulin-like growth factor-1 levels increased and myeloperoxidase concentration peaked. CONCLUSIONS: We observed for the first time that sleep restriction and the recovery process are associated with differential changes in blood biomarkers of cardiovascular disease

Age modulates the effects of sleep restriction in women

Study Objectives: To investigate how age influences the effects of 3 nights of sleep restriction in healthy women. Design: After a baseline night, sleep was restricted to 4 hours during 3 consecutive nights. One recovery night followed the sleep restriction. Setting: The sleep-restriction experiments were conducted under standardized conditions with continuous electroencephalographic ambulatory recordings. Before entering the study, the subjects underwent a polysomnographic recording for exclusion of sleep disorder and adaptation to the laboratory environment. Participants: Eleven young women (aged 20-30 years) and 10 older women (aged 55-65 years) were included in the study. Intervention: The subjects were admitted to the sleep laboratory for 5 consecutive nights and days. After 1 baseline night, 3 nights of sleep restriction to 4 hours were performed and were followed by 1 recovery night of 8 hours. Continuous ambulatory electroencephalographic recordings were performed, as well as the Maintenance of Wakefulness Test (8:30 AM and 1:30 PM), the Stanford Sleepiness Scale, and the Psychomotor Vigilance Test. Results: Young women were more affected by sleep restriction than were the older women. This was evidenced by more sleep onsets during the Maintenance of Wakefulness Test sessions in the young subjects, who also rated themselves more sleepy than the older women. Conclusions: Age influences the impact of sleep restriction on vigilance in women.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Cancelling ECG artifacts in EEG using a modified independent component analysis approach

We introduce a new automatic method to eliminate electrocardiogram (ECG) noise in an electroencephalogram (EEG) or electrooculogram (EOG). It is based on a modification of the independent component analysis (ICA) algorithm which gives promising results while using only a single-channel electroencephalogram (or electrooculogram) and the ECG. To check the effectiveness of our approach, we compared it with other methods, that is, ensemble average subtraction (EAS) and adaptive filtering (AF). Tests were carried out on simulated data obtained by addition of a filtered ECG on a visually clean original EEG and on real data made up of 10 excerpts of polysomnographic (PSG) sleep recordings containing ECG artifacts and other typical artifacts (e.g. movement, sweat, respiration, etc.). We found that our modified ICA algorithm had the most promising performance on simulated data since it presented the minimal root mean-squared error. Furthermore, using real data, we noted that this algorithm was the most robust to various waveforms of cardiac interference and to the presence of other artifacts, with a correction rate of 91.0%, against 83.5% for EAS and 83.1% for AF.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Sleep restriction increases blood neutrophils, total cholesterol and low density lipoprotein cholesterol in postmenopausal women: A preliminary study.

This study examines the effects of sleep restricted to 4h for three consecutive nights on blood parameters known to be associated with cardiovascular risk in healthy postmenopausal women.Clinical TrialJournal ArticleResearch Support, Non-U.S. Gov'tSCOPUS: ar.jinfo:eu-repo/semantics/publishe

Sleep restriction increases white blood cells, mainly neutrophil count, in young healthy men: A pilot study

Karim Zouaoui Boudjeltia2, Brice Faraut1,2, Patricia Stenuit1, Maria José Esposito1,2, Michal Dyzma1,2, Dany Brohée2, Jean Ducobu2, Michel Vanhaeverbeek2, Myriam Kerkhofs1,21Sleep Laboratory; 2Laboratory of Experimental Medicine (ULB 222 Unit), CHU de Charleroi Vésale Hospital, Université Libre de Bruxelles, Montigny-le-Tilleul, BelgiumObjectives: This study examines the effects of sleep restricted to four hours for three consecutive nights on blood parameters, known to be associated with cardiovascular risk, in young healthy men.Material and methods: Eight young healthy men (age 24.5 ± 3.3 years) were studied in the sleep restricted group. Nine young healthy men (age 24 ± 2 years) were included in the control group and spent the days and nights in the sleep lab, while sleeping eight hours/night. One baseline night was followed by three nights of sleep restriction to four hours and by one recovery night of eight hours. Blood samplings were performed after the baseline night and after the third night of sleep restriction or without restriction for the control group.Results: A significant increase in white blood cells (WBC) (5.79 ± 1.05 vs. 6.89 ± 1.31 103 cell/µl, p = 0.03), and neutrophils (3.17 ± 0.69 vs 4.24 ± 0.97 103 cell/µl, p = 0.01) was observed after the third night of sleep restriction. Other blood parameters were not affected. No significant variation was observed in the control group.Conclusion: Sleep restriction affected WBC count, mainly neutrophils, considered as risk factor for cardiovascular disease. Stress induced by the short term sleep restriction could be involved in this observation.Keywords: sleep restriction, men, cardiovascular risk, cholesterol, neutrophil

Automatic sleep spindle detection in patients with sleep disorders

In this paper, we present a new automatic method for sleep spindle detection. It consist of a generalisation of the Schimicek's method [12] that takes more types of artefacts into account and uses variable thresholds regarding the statistical properties of the signal. Validity of our process is examined on the basis of visual spindle scoring performed by an expert. Results obtained are compared to those obtained by Schimicek's method. For a specificity of 90%, we obtain a sensitivity of 76.9% while Schimicek's method has a sensitivity of 70.4%. Moreover an increase of the area under the ROC curve is observed and confirms that the detection process is improved. © 2006 IEEE.SCOPUS: cp.pinfo:eu-repo/semantics/publishe

Benefits of napping and an extended duration of recovery sleep on alertness and immune cells after acute sleep restriction.

Understanding the interactions between sleep and the immune system may offer insight into why short sleep duration has been linked to negative health outcomes. We, therefore, investigated the effects of napping and extended recovery sleep after sleep restriction on the immune and inflammatory systems and sleepiness. After a baseline night, healthy young men slept for a 2-h night followed by either a standard 8-h recovery night (n=12), a 30-min nap (at 1p.m.) in addition to an 8-h recovery night (n=10), or a 10-h extended recovery night (n=9). A control group slept 3 consecutive 8-h nights (n=9). Subjects underwent continuous electroencephalogram polysomnography and blood was sampled every day at 7a.m. Leukocytes, inflammatory and atherogenesis biomarkers (high-sensitivity C-reactive protein, interleukin-8, myeloperoxidase, fibrinogen and apolipoproteins ApoB/ApoA), sleep patterns and sleepiness were investigated. All parameters remained unchanged in the control group. After sleep restriction, leukocyte and - among leukocyte subsets - neutrophil counts were increased, an effect that persisted after the 8-h recovery sleep, but, in subjects who had a nap or a 10-h recovery sleep, these values returned nearly to baseline. Inflammatory and atherogenesis biomarkers were unchanged except for higher myeloperoxidase levels after sleep restriction. The increased sleepiness after sleep restriction was reversed better in the nap and extended sleep recovery conditions. Saliva cortisol decreased immediately after the nap. Our results indicate that additional recovery sleep after sleep restriction provided by a midday nap prior to recovery sleep or a sleep extended night can improve alertness and return leukocyte counts to baseline values.JOURNAL ARTICLESCOPUS: ar.jinfo:eu-repo/semantics/publishe