Slow-wave sleep

About: Slow-wave sleep is a research topic. Over the lifetime, 6543 publications have been published within this topic receiving 320663 citations. The topic is also known as: deep sleep.

In quest of identifying vulnerability markers for psychiatric disorders by all-night polysomnography.

Abstract: Background: The persistence of a depressionlike sleep pattern in fully remitted depressed patients suggests that the pattern is a trait characteristic of sleep measurements. However, in the past, subjects have undergone investigation only after the onset of the disorder, and, therefore, the altered sleep pattern may merely represent a biological scar. Methods: We polysomnographically investigated 54 healthy subjects who had no lifetime or current diagnosis of a psychiatric disorder but had at least one first-degree relative with major depression or a bipolar disorder and at least one further close relative with major depression, a bipolar disorder, or a schizophrenic disorder. Twenty unrelated control probands without a personal and family history of psychiatric disorders and 18 unrelated inpatients with major depression served as reference groups. Prior to investigation, all healthy subjects had been free of any prescription and nonprescription drug for at least 3 months. The depressed patients were free of drugs for at least 1 week. All subjects slept for 2 nights in the sleep research unit. The sleep of the second night was recorded and visually scored. Results: Analysis of the individual sleep cycles in these subjects revealed both a reduced amount of slow wave sleep and increased rapid eye movement density in the first sleep cycle. Discriminant analysis showed that 10 subjects (18%) had sleep patterns similar to those of depressed patients. Conclusions: According to our observations, one fifth of the healthy subjects with a high genetic load for psychiatric disorders showed a conspicuous (depression-like) sleep pattern. The follow-up will determine whether this sleep pattern indeed represents a trait marker indicating vulnerability.

Sleep-disordered breathing in stable methadone programme patients: a pilot study.

Abstract: Aims. To explore the possibility that stable MMP patients have sleep-disordered breathing (SDB) and abnormal sleep architecture defined by nocturnal sleep stages and sleep efficiency. Design. Observational. Setting. Regional Methadone Service and sleep disorders laboratory in a university affiliated hospital. Participants and measurements. Ten stable MMP patients and nine normal subjects were assessed clinically and with overnight polysomnography. Findings. There were no differences in age, sex and body mass index between the groups. The methadone dose ranged between 50 and 120 mg/day. Six patients had central apnoea index (CAI) greater than 5, four had a CAI greater than 10 and three of these exhibited periodic breathing. No normal subject had central sleep apnoea. The patients had lower sleep efficiency ( p < 0.05), less slow wave sleep ( p < 0.01), less rapid eye movement sleep ( p < 0.05) and more Stage 2 sleep ( p < 0.05) than controls. Conclusions. Stable MMP patients have more sleep architecture abnormalities than controls and a higher prevalence of central sleep apnoea. Further studies are needed to confirm these findings, to delineate the mechanisms for the abnormalities and to assess whether the SDB is related to sudden death in stable MMP patients. We recommend that MMP patients have awake and sleep respiration assessed to identify those potentially at risk.

Effects of sleep fragmentation on appetite and related hormone concentrations over 24 h in healthy men.

Abstract: In addition to short sleep duration, reduced sleep quality is also associated with appetite control. The present study examined the effect of sleep fragmentation, independent of sleep duration, on appetite profiles and 24Â h profiles of hormones involved in energy balance regulation. A total of twelve healthy male subjects (age 23 (sd 4) years, BMI 24·4 (sd 1·9)Â kg/m2) completed a 24Â h randomised crossover study in which sleep (23.30-07.30 hours) was either fragmented or non-fragmented. Polysomnography was used to determine rapid-eye movement (REM) sleep, slow-wave sleep (SWS) and total sleep time (TST). Blood samples were taken at baseline and continued hourly for the 24Â h period to measure glucose, insulin, ghrelin, leptin, glucagon-like peptide 1 (GLP-1) and melatonin concentrations. In addition, salivary cortisol levels were measured. Visual analogue scales were used to score appetite-related feelings. Sleep fragmentation resulted in reduced REM sleep (69·4Â min compared with 83·5Â min; P<Â 0·05) and preservation of SWS without changes in TST. In fragmented v. non-fragmented sleep, glucose concentrations did not change, while insulin secretion was decreased in the morning, and increased in the afternoon (P<Â 0·05), and GLP-1 concentrations and fullness scores were lower (P<Â 0·05). After dinner, desire-to-eat ratings were higher after fragmented sleep (P<Â 0·05). A single night of fragmented sleep, resulting in reduced REM sleep, induced a shift in insulin concentrations, from being lower in the morning and higher in the afternoon, while GLP-1 concentrations and fullness scores were decreased. These results may lead to increased food intake and snacking, thus contributing to a positive energy balance.