Nights Of Sleep Restriction Research Articles

Sleep Restriction Increases the Risk of Developing Cardiovascular Diseases by Augmenting Proinflammatory Responses through IL-17 and CRP

BackgroundSleep restriction, leading to deprivation of sleep, is common in modern 24-h societies and is associated with the development of health problems including cardiovascular diseases. Our objective was to investigate the immunological effects of prolonged sleep restriction and subsequent recovery sleep, by simulating a working week and following recovery weekend in a laboratory environment.Methods and FindingsAfter 2 baseline nights of 8 hours time in bed (TIB), 13 healthy young men had only 4 hours TIB per night for 5 nights, followed by 2 recovery nights with 8 hours TIB. 6 control subjects had 8 hours TIB per night throughout the experiment. Heart rate, blood pressure, salivary cortisol and serum C-reactive protein (CRP) were measured after the baseline (BL), sleep restriction (SR) and recovery (REC) period. Peripheral blood mononuclear cells (PBMC) were collected at these time points, counted and stimulated with PHA. Cell proliferation was analyzed by thymidine incorporation and cytokine production by ELISA and RT-PCR. CRP was increased after SR (145% of BL; p<0.05), and continued to increase after REC (231% of BL; p<0.05). Heart rate was increased after REC (108% of BL; p<0.05). The amount of circulating NK-cells decreased (65% of BL; p<0.005) and the amount of B-cells increased (121% of BL; p<0.005) after SR, but these cell numbers recovered almost completely during REC. Proliferation of stimulated PBMC increased after SR (233% of BL; p<0.05), accompanied by increased production of IL-1β (137% of BL; p<0.05), IL-6 (163% of BL; p<0.05) and IL-17 (138% of BL; p<0.05) at mRNA level. After REC, IL-17 was still increased at the protein level (119% of BL; p<0.05).Conclusions5 nights of sleep restriction increased lymphocyte activation and the production of proinflammatory cytokines including IL-1β IL-6 and IL-17; they remained elevated after 2 nights of recovery sleep, accompanied by increased heart rate and serum CRP, 2 important risk factors for cardiovascular diseases. Therefore, long-term sleep restriction may lead to persistent changes in the immune system and the increased production of IL-17 together with CRP may increase the risk of developing cardiovascular diseases.

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

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. 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. A significant increase in white blood cells (WBC) (5.79 +/- 1.05 vs. 6.89 +/- 1.31 10(3) cell/microl, p = 0.03), and neutrophils (3.17 +/- 0.69 vs 4.24 +/- 0.97 10(3) cell/microl, 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. 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.

A single night of sleep deprivation increases ghrelin levels and feelings of hunger in normal‐weight healthy men

Sleep loss is currently proposed to disturb endocrine regulation of energy homeostasis leading to weight gain and obesity. Supporting this view, a reduction of sleep duration to 4 h for two consecutive nights has recently been shown to decrease circulating leptin levels and to increase ghrelin levels, as well as self-reported hunger. We hypothesized that similar endocrine alterations occur even after a single night of sleep restriction. In a balanced order, nine healthy normal-weight men spent three nights in our sleep laboratory separated by at least 2 weeks: one night with a total sleep time of 7 h, one night with a total sleep time of 4.5 h and one night with total sleep deprivation (SD). On a standard symptom-rating scale, subjects rated markedly stronger feelings of hunger after total SD than after 7 h sleep (3.9 +/- 0.7 versus 1.7 +/- 0.3; P = 0.020) or 4.5 h sleep (2.2 +/- 0.5; P = 0.041). Plasma ghrelin levels were 22 +/- 10% higher after total SD than after 7 h sleep (0.85 +/- 0.06 versus 0.72 +/- 0.04 ng mL(-1); P = 0.048) with intermediate levels of the hormone after 4.5 h sleep (0.77 +/- 0.04 ng mL(-1)). Serum leptin levels did not differ between conditions. Feelings of hunger as well as plasma ghrelin levels are already elevated after one night of SD, whereas morning serum leptin concentrations remain unaffected. Thus, our results provide further evidence for a disturbing influence of sleep loss on endocrine regulation of energy homeostasis, which on the long run may result in weight gain and obesity.

Slow wave sleep enhancement with gaboxadol reduces daytime sleepiness during sleep restriction.

To evaluate the impact of enhanced slow wave sleep (SWS) on behavioral, psychological, and physiological changes resulting from sleep restriction. A double-blind, parallel group, placebo-controlled design was used to compare gaboxadol (GBX) 15 mg, a SWS-enhancing drug, to placebo during 4 nights of sleep restriction (5 h/night). Behavioral, psychological, and physiological measures of the impact of sleep restriction were assessed in both groups at baseline, during sleep restriction and following recovery sleep. Sleep research laboratory. Forty-one healthy adults; 9 males and 12 females (mean age: 32.0 +/- 9.9 y) in the placebo group and 10 males and 10 females (mean age: 31.9 +/- 10.2 y) in the GBX group. Both experimental groups underwent 4 nights of sleep restriction. Each group received either GBX 15 mg or placebo on all sleep restriction nights, and both groups received placebo on baseline and recovery nights. Polysomnography documented a SWS-enhancing effect of GBX with no group difference in total sleep time during sleep restriction. The placebo group displayed the predicted deficits due to sleep restriction on the multiple sleep latency test (MSLT) and on introspective measures of sleepiness and fatigue. Compared to placebo, the GBX group showed significantly less physiological sleepiness on the MSLT and lower levels of introspective sleepiness and fatigue during sleep restriction. There were no differences between groups on the psychomotor vigilance task (PVT) and a cognitive test battery, but these measures were minimally affected by sleep restriction in this study. The correlation between change from baseline in MSLT on Day 6 and change from baseline in SWS on Night 6 was significant in the GBX group and in both group combined. The results of this study are consistent with the hypothesis that enhanced SWS, in this study produced by GBX, reduces physiological sleep tendency and introspective sleepiness and fatigue which typically result from sleep restriction.

Effects of sleep restriction on cognition in women

The aim of the present study was to investigate how three nights of sleep restriction affected cognitive functions in young and aged healthy women. Ten young (20–30 years) and ten aged (55–65 years) women participated to the study. After one baseline night (11pm–07am), their sleep was restricted to 4 h per night (01–05am) during three nights. A recovery night of 8 h (11 pm–07 am) followed the sleep restriction. The neurobehavioural assessment included evaluation of Attention (Stroop, Trail Making test, Tests of Attentional Performance), Memory (Buschke, Logical Memory, PASAT, Brown Peterson), Addition of numbers and Abstraction (Wisconsin). Sleep restriction decreased significantly the speed of execution, particularly in the young women, without affecting the accuracy of the answers. This effect was the most significant on reaction times in simple tests. The more complex tasks (PASAT, Brown Peterson, Logical Memory, Addition of numbers, Wisconsin) were not affected. However, the inhibition of an automatic activity (Stroop test) and the formation of a memory trace (Buschke memory test) were disturbed in both young and older women.

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

Objectives This study examines the effects of sleep restricted to 4 h for three consecutive nights on blood parameters known to be associated with cardiovascular risk in healthy postmenopausal women. Material and methods Ten healthy postmenopausal women aged 55–65 years treated with hormonal replacement therapy (HT) were included in the study. After one baseline night, three nights of sleep restricted to 4 h were performed and were followed by one recovery night of 8 h. Blood samplings were performed after the baseline night and after the third night of sleep restriction. Results A significant increase in white blood cells (WBC), monocytes, neutrophils, total cholesterol, and low density lipoprotein cholesterol (LDL-c) was observed after the third night of sleep restriction. Conclusion Sleep restriction to 4 h of sleep for three consecutive nights affected two factors associated with cardiovascular risk in healthy postmenopausal women treated with HT.

Age Modulates the Effects of Sleep Restriction in Women

To investigate how age influences the effects of 3 nights of sleep restriction in healthy women. After a baseline night, sleep was restricted to 4 hours during 3 consecutive nights. One recovery night followed the sleep restriction. 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. Eleven young women (aged 20-30 years) and 10 older women (aged 55-65 years) were included in the study. 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. 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. Age influences the impact of sleep restriction on vigilance in women.

Daytime Vigilance after Morning Bright Light Exposure in Volunteers Subjected to Sleep Restriction

This study was designed to test the hypothesis that bright light (BL) can have a stimulating effect on vigilance even in the absence of suppression of melatonin secretion and that this effect can be detected when measured in subjects with low vigilance levels. Seven normal subjects were exposed to bright-white light (BL group) and seven to dim-red light (DL group) on 2 consecutive days, each following a night of 4-h sleep restriction. The light treatment was administered in the late morning, between 0900 and 1330 hours. Salivary melatonin measurements indicated that BL did not suppress melatonin secretion or induce circadian phase shifts. The effects of the two treatments were compared on validated measures of daytime vigilance: immediate effects were evaluated on subjective alertness during the light treatment, whereas short-term (0.5–10.5 h) and long-term (20.5–34.5 h) carryover effects were measured on subjective alertness, daytime sleep latencies (DSL), and psychomotor performance. After two nights of sleep restriction, subjective alertness and daytime sleep latencies decreased significantly, but there was no effect of the light treatment. BL treatment did not affect global performance, but there was an effect on the strategy used by the subjects, as shown by faster reaction times and increased percentage of errors in the BL group. It was concluded that daytime BL exposure did not have a stimulating effect on our measures of vigilance even in sleep-deprived subjects but that it may increase physiological arousal and affect the subjects’ behavior in some specific performance tasks.