No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Effects of Window Opening on the Bedroom Environment and resulting Sleep Quality
Abstract
The effects of two window states (closed or open) on the bedroom environment and on sleep quality were investigated. Twenty-seven subjects (14 males and 13 females, 20-33 years old) without sleep disorders and chronic diseases participated. The subjects slept for two consecutive nights with windows open and two consecutive nights with windows closed in four dormitory rooms adapted for the purpose of this study, one person at a time. The order of exposure was balanced among participants. Bed temperature, room temperature, relative humidity (RH), carbon dioxide (CO2), particles (PM2.5), and noise were monitored during sleep. Sleep quality was measured using subjective ratings, a wrist-worn sleep tracker, and (for one group of 14 subjects only) polysomnography (PSG) for home use; snoring in this sub-group and awakenings were also registered. Higher PM2.5 and noise levels were found with windows open, while higher room temperature, RH, and CO2 levels were measured with windows closed. There were no differences between conditions in terms of objectively measured sleep stages but the subjects with the PSG attached snored significantly less and woke up significantly less often when sleeping with windows open. Start sleep time, end sleep time, total sleep time (TST) and time in bed (TIB) measured with the sleep tracker were confirmed by the measurements made using PSG, light sleep (N1 + N2) and sleep latency were in moderate agreement but there was no significant agreement for REM and deep sleep (N3). When sleeping with windows open, the subjects rated the air as fresher but reported higher noise levels, feeling less rested, a worse mental state and well-being, and their replies on the Groningen sleep quality scale indicated poorer sleep quality. There was no clear association between the performance test score and sleep quality. These results suggest that sleeping with windows open can provide some benefits by increasing ventilation with outdoor air, reducing CO2 concentrations, improving air quality as indicated by the subjectively rated air freshness and some of the parameters defining sleep quality, but it may also result in some discomfort if there are episodic loud noise events outdoors. Further studies are required to clarify the role of open windows in achieving good sleep quality.
... Liao et al. [36] found that sleeping with the window open improved the bedroom IAQ and provided benefits for sleep quality. Moreover, several studies have shown the positive effect of door opening on the concentration of CO 2 [5,41,42]. Two Danish studies by Fan et al. also showed that door opening alone tended to reduce the level of TVOC, but this effect was smaller than the effect of an open window [1,2,37]. One of these studies indicated that open window and closed door resulted in the best IAQ. ...
... In the absence of an agreed metric for IAQ [15], CO 2 concentration is commonly used as an indicator of ventilation adequacy but is not itself regarded as a hazardous component. CO 2 has been used in many previous studies to characterize bedroom ventilation [1,41,44,[63][64][65]. A CO 2 concentration of 1000 ppm is often used as a threshold value, see e.g., Ref. [66]. ...
... The bedroom H2B1 with lowest CO 2 concentration had extensive window opening. • In line with previous studies [5,41,42], keeping the bedroom door open seemed to give a considerable reduction for the CO 2 concentrations when the window is closed, see Fig. 7(b). For example, bedrooms H8B1 and H11B2 have a good IAQ with little window opening and extensive door opening. ...
... The findings from laboratory experiments require validation in actual bedrooms because they are usually based on measurements performed in environments that are not normally used for sleeping and often based on the measurements performed over one night only. Field studies have therefore been carried out to examine the relationship between bedroom ventilation and sleep quality Liao et al., 2022Liao et al., , 2021bMishra et al., 2018;Strøm-Tejsen et al., 2016;Xiong et al., 2020;Xu et al., 2021;Yan et al., 2022a;Zhang et al., 2021). Many of these studies were cross-sectional (Liao et al., 2022;Xiong et al., 2020;Xu et al., 2021;Yan et al., 2022a;Zhang et al., 2021). ...
... In these studies, sleep quality and bedroom environmental quality were monitored and subsequently their correlations were examined using statistical modelling, taking into account that sleeping conditions were changing randomly from night to night and these changes could affect sleep quality. To better explore the effects of bedroom ventilation in actual settings, some field studies used an intervention approach where bedroom ventilation was changed from week to week in a systematic fashion Mishra et al., 2018;Strøm-Tejsen et al., 2016) except for one study in which each condition was measured on only two consecutive nights (Liao et al., 2021b). In most of these studies, bedroom ventilation was varied by either opening or closing the windows or doors in actual bedrooms. ...
... In a study to address this gap that showed positive effects of increased ventilation on sleep quality (Strøm-Tejsen et al., 2016), ventilation was changed by operating or idling inaudible fans supplying outdoor air to bedrooms; the study was performed with students in a dormitory building. In this study and in many other studies to date students were recruited to sleep in chambers or measurements were made in student dormitory buildings and not in conventional dwellings (Fan et al., 2022b;Liao et al., 2021b;Mishra et al., 2018;Strøm-Tejsen et al., 2016;Xu et al., 2020). This may limit the application of the findings and their extrapolation to other population groups and settings. ...
A four-week-long field intervention experiment was conducted in twenty-nine bedrooms with extract ventilation systems and air inlet vents. During the first week no interventions took place. In the three weeks that followed, each participant slept for one week under a low, medium, and high ventilation rate condition in a balanced order. These conditions were established by covertly altering the fan speed of the exhaust ventilation system without changing other settings. Participants were not informed when or even whether the changes to bedroom ventilation would be executed. The bedroom environmental quality was monitored continuously and sleep quality was monitored using wrist-worn trackers. Tests of cognitive performance were conducted in the evening and morning. In twelve bedrooms where clear differences between the three ventilation conditions occurred, as indicated by the measured CO2 concentrations, participants had significantly less deep sleep, more light sleep and more awakenings at lower ventilation rate conditions. In twenty-three bedrooms where a clear difference in ventilation rate between the high and low ventilation conditions was observed, as confirmed by the measured CO2 concentrations, the duration of deep sleep was significantly shorter in the low ventilation rate condition. No differences in cognitive performance between conditions were observed. At lower ventilation rate conditions, the concentrations of CO2 increased, as did the relative humidity, while bedroom temperatures remained unchanged. The present results, which were obtained in actual bedrooms, confirm the findings in previous studies of a positive effect of increased ventilation on sleep quality. Further studies with larger populations and better control of bedroom conditions, particularly ventilation, are required.
... Only a few field intervention studies have been conducted to investigate the effects of window and door opening on bedroom ventilation, IAQ, and sleep quality [5,30,[34][35][36]. Canha et al. [30] explored the effects on IAQ during sleep of four different window and door configurations in one naturally ventilated bedroom. ...
... The measured CO 2 concentration was also reduced. Liao et al. [35] found in a study with 27 subjects that window opening reduced snoring and the number of awakenings at night. Mishra et al. [34] observed that window or door opening in 17 bedrooms resulted in deeper sleep as reported by the participants; lower CO 2 concentrations were found, and the objectively measured number of awakenings at night decreased, sleep efficiency increased. ...
... The studies mentioned above either did not monitor sleep quality, were cross-sectional or generally carried out in dormitories with students [5,30,[34][35][36]. Not all of them focused on the effects of window and door opening on the levels of different pollutants in bedrooms and sleep quality. ...
Indoor Air Quality (IAQ) and sleep quality measurements over a period of two weeks were performed all night in 40 bedrooms in Denmark during the heating season. In the first week, the bedroom conditions were typical of what participants would normally experience during sleep. In the second week, the participants were asked to open the doors or windows if they had been closed or the opposite. A change in the 95th percentile of the measured CO2 concentration by more than 200 ppm in the expected direction on the same weekdays of the two-week measurement period was taken to indicate that an effective intervention had taken place. The measurements in the 29 bedrooms that met this criterion were grouped depending on how the windows or doors had been manipulated. Objectively measured and subjectively rated bedroom IAQ improved when the windows were open except that the NO2 concentration was slightly higher. Sleep was longer under this condition and sleep quality was subjectively assessed to be better. Similar effects were not observed when the doors were open although the 95th percentile of CO2 concentration decreased by as much as when the windows were open. No effects were seen in the 11 bedrooms in which the change to the bedroom conditions made by the participants did not change the CO2 concentration by at least 200 ppm, as would be expected. The present study provides evidence that sufficient dilution and/or removal of pollutants is necessary to ensure good bedroom IAQ and good sleep quality.
... Sleep quality can be affected by numerous factors, including the indoor environmental quality of the bedroom, which includes four main aspects, namely thermal, acoustic, visual, and air quality [8]. Previous studies have investigated the effects of thermal, acoustic, and visual environments on sleep quality, while only a few have investigated the effects of bedroom air quality [9][10][11][12][13][14]. In the absence of an agreed metric for indoor air quality (IAQ) [15], ventilation rate is used to characterize IAQ [16]. ...
... It is generally agreed that higher ventilation rates lead to better IAQ [17]. Carbon dioxide (CO 2 ) is normally used as a marker of ventilation adequacy [18]; it was used in previous studies characterizing bedroom ventilation [9][10][11][12][13][14]. reviewed how bedroom ventilation affects IAQ and sleep quality based on the available ten studies [19]. ...
... They have been reported to be in good agreement with polysomnography in measuring time asleep (total sleep time) and sleep efficiency, and they provide gross estimates of sleep stages, although they have been reported to underestimate sleep latency [39]. Fitbits and other similar actigraphy monitors have been used in many previous studies of sleep quality [10][11][12][13]. ...
Parameters describing the bedroom environment and sleep quality were measured overnight for one week in 84 randomly selected actual bedrooms in Denmark from September to December 2020. The median age of participants was 26 years (interquartile range (IQR) (Laverge et al., 2015; Fan et al., 2021; Berglund et al., 1999; Zhang et al., 2016; Bjorvatn et al., 2017; Verbruggen et al., 2021; Liao et al., 2021; Xiong et al., 2020; Deng et al., 2021) [24-32] years); 41 were males. Carbon dioxide (CO2), temperature, and relative humidity were measured continuously. Sleep quality was assessed by the Groningen Sleep Quality Scale (GSQS) on two mornings and was assessed using wrist-worn sleep trackers. Skin temperature was monitored continuously. Bedroom indoor air quality (IAQ) was rated by participants on two occasions just before sleep in the evening and upon waking up in the morning. Measurements from 75 bedrooms were complete. The median [IQR] of mean CO2, air temperature and relative humidity measured during sleep were 1,120 [741–4,804] ppm, 23.4 [22.3–24.4]°C, and 48.6 [44.7–55.4]%. The median [IQR] of GSQS was 4.0 [1.0–6.0] suggesting medium to poor subjectively rated sleep quality; the objectively measured sleep efficiency, and percentage of light, deep and REM sleep were in normal ranges: 88.1 [86.1–89.5]%, 59.4 [54.9–64.5]%, 18.3 [15.0–21.7]%, and 23.0 [18.4–26.4]%. The subjectively-assessed sleep quality decreased when perceived IAQ was reduced. Opening the bedroom door or window, which is a proxy for enhanced ventilation, also improved subjectively-assessed sleep quality and IAQ. The cross-sectional nature of the study prompts the validation of the present results with protocols that include measurements of other pollutants besides CO2 as well as the examination of underlying mechanisms. Nevertheless, they strongly suggest that keeping high bedroom IAQ is essential.
... Sleep quality, which has a significant effect on daily activities, is highly dependent on environmental factors and physical and mental functions of people. A high-quality sleep environment in terms of noise, room temperature, and relative humidity is necessary for good sleep quality [1,2]. CO2 concentration is considered as an indicator of the ventilation efficiency of the environment and thus the indoor air quality. ...
... CO2 concentration is considered as an indicator of the ventilation efficiency of the environment and thus the indoor air quality. Higher ventilation rates and so lower CO2 concentrations provide a reduction in the number of awakenings [2][3][4] and higher sleep quality [4][5][6]. ...
Sleep quality, which significantly affects daily life, is also affected by indoor air quality as well as comfort aspects such as noise, temperature, and relative humidity in the sleeping environment. Carbon dioxide concentration is commonly considered as an indicator of indoor air quality, and it has been observed that increasing concentrations increase the number of awakenings resulting in lower sleep quality. In this study, ventilation flow rate is investigated specifically for bedroom and dormitory room dimensions as recommended by different countries to ensure that the carbon dioxide concentration in sleeping spaces is below an upper limit value (1000 ppm). The ventilation flow rate is evaluated by comparison to the methods recommended in ASHRAE standards (Ventilation Rate Procedure–VRP, Indoor Air Quality Procedure–IAQP and Natural Ventilation Procedure–NVP). Although VRP is widely used because a constant flow rate is recommended, which is an advantage due to design simplicity, it has been found to be insufficient for smaller sleeping space volumes and it gives higher values for larger volumes compared to the needed ventilation flow rates recommended by IAQP. Moreover, the fact that the flow rates calculated with VRP and IAQP overlap in a very narrow area shows that the use of VRP values for effective designs is limited. Consequently, we suggest that the system design should be operated with the IAQP and with demand-controlled ventilation, and an approach is offered to designers for direct use in practice.
... concentration and sleep quality [111,112]. In addition, Perl et al. and Zanobetti et al. paid attention to the effect of odors and PM 10 [113,114]. ...
... Roeder et al. concluded that subjects who wore PSG might sleep more in the supine position than normally [254], changes in respiratory airflow affected the quality of sleep and perception of air quality. In the research conducted by Liao et al. [112], participants with PSG snored more (p < 0.02) and woke up more often (p < 0.02), and annoyance caused by the PSG was second to thermal environment, even greater than that caused by noise. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 P R O O F A common form of ACT is a bracelet or watch worn on a part of the body, with less contact with the human body; besides, the non-contact mattress sleep monitoring system had been successfully developed and used [162], thus it is unlikely that ACT substantially influence normal sleep. A traditional ECG monitoring method involves placing electrode patches on chest, which can cause discomfort, but great strides have been made in the development of noncontact ECG monitoring methods [255,256]. ...
To date, although many studies had focused on the impact of environmental factors on sleep, how to choose the proper assessment method for objective sleep quality was often ignored, especially for healthy subjects in bedroom environment. In order to provide methodological guidance for future research, this paper reviewed the assessments of objective sleep quality applied in environmental researches, compared them from the perspective of accuracy and interference, and statistically analyzed the impact of experimental type and subjects’ information on method selection. The review results showed that, in contrast to polysomnography (PSG), the accuracy of actigraphy (ACT), respiratory monitoring-oxygen saturation monitoring (RM-OSM), and electrocardiograph (ECG) could reach up to 97, 80.38, and 79.95%, respectively. In terms of sleep staging, PSG and ECG performed the best, ACT the second, and RM-OSM the worst; as compared to single methods, mix methods were more accurate and better at sleep staging. PSG interfered with sleep a great deal, while ECG and ACT could be non-contact, and thus the least interference with sleep was present. The type of experiment significantly influenced the choice of assessment method (p < 0.001), 85.3% of researchers chose PSG in laboratory study while 82.5% ACT in field study; moreover, PSG was often used in a relatively small number of young subjects, while ACT had a wide applicable population. In general, researchers need to pay more attention at selection of assessments in future studies and this review can be used as a reliable reference for experimental design.
... The conclusion was that sleep quality was not affected when the average CO 2 level resulted by ventilation in bedrooms had been below 750 ppm (e.g., Refs. [10,22]), while average levels above 1,150 ppm were consistently found to cause disruption to sleep (e.g., Refs. [11,13,23]). ...
... Other studies found that by opening the window, opening the door to the hallway or increasing ventilation, CO 2 , temperature, and humidity in the bedroom decrease while PM 2.5 and noise levels increase. 11,55,57,[61][62][63] While it is difficult to establish causality from these data, they do suggest that there is a trade-off with positive effects on some and negative effects on other bedroom environmental variables. ...
Objective:
Climate change and urbanization increasingly cause extreme conditions hazardous to health. The bedroom environment plays a key role for high-quality sleep. Studies objectively assessing multiple descriptors of the bedroom environment as well as sleep are scarce.
Methods:
Particulate matter with a particle size <2.5 µm (PM2.5), temperature, humidity, carbon dioxide (CO2), barometric pressure, and noise levels were continuously measured for 14 consecutive days in the bedroom of 62 participants (62.9% female, mean ± SD age: 47.7 ± 13.2 years) who wore a wrist actigraph and completed daily morning surveys and sleep logs.
Results:
In a hierarchical mixed effect model that included all environmental variables and adjusted for elapsed sleep time and multiple demographic and behavioral variables, sleep efficiency calculated for consecutive 1-hour periods decreased in a dose-dependent manner with increasing levels of PM2.5, temperature, CO2, and noise. Sleep efficiency in the highest exposure quintiles was 3.2% (PM2.5, p < .05), 3.4% (temperature, p < .05), 4.0% (CO2, p < .01), and 4.7% (noise, p < .0001) lower compared to the lowest exposure quintiles (all p-values adjusted for multiple testing). Barometric pressure and humidity were not associated with sleep efficiency. Bedroom humidity was associated with subjectively assessed sleepiness and poor sleep quality (both p < .05), but otherwise environmental variables were not statistically significantly associated with actigraphically assessed total sleep time and wake after sleep onset or with subjectively assessed sleep onset latency, sleep quality, and sleepiness. Assessments of bedroom comfort suggest subjective habituation irrespective of exposure levels.
Conclusions:
These findings add to a growing body of evidence highlighting the importance of the bedroom environment-beyond the mattress-for high-quality sleep.
... Mishra et al. (2018) reported that subjectively rated depth of sleep improved with windows open. Liao et al. (2021) found that open windows reduced snoring during sleep, while Laverge and Janssens (2011) observed a small effect of ventilation achieved by opening windows on the objectively measured sleep pattern. ...
We performed a survey of the types of bedroom ventilation in Danish dwellings (January–February 2020) and the associated subjective sleep quality. Five hundred and seventeen people responded. Their median age was 33 years old and 55.4% of them were males. We used an online questionnaire and collected information on the type of bedroom ventilation, bedroom airing behaviour by the respondents, the bedroom environment, building surroundings and location, and sleep disturbance caused by stuffy air, noise, and the thermal environment. Subjective sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI); its median among respondents was >5 indicating reduced sleep quality. 35.4% of the bedrooms had mechanical, 24.6% exhaust, and 40.0% natural ventilation. Sleeping in a bedroom with mechanical ventilation tended to reduce sleep disturbance. The absence of mechanical ventilation and the presence of carpet in the bedroom were all associated with stuffy air causing sleep disturbance, which was the second most sleep disturbing factor. PSQI increased significantly with increased sleep disturbance. People who reported that their sleep was disturbed by stuffy air or “too warm” conditions opened windows frequently during the day or night, but no association was found between PSQI and bedroom airing behaviours. Our results are valid for the heating season and the survey would have to be repeated in the non-heating season to permit generalization of the findings. The results present associations and are qualitative, so field measurements are necessary to validate the present observations and provide further explanations.
Aim
The present study was conducted to determine the effect of the superficial heat–cold application on the sleep quality of patients with restless leg syndrome.
Design
This study was a systematic review and meta‐analysis.
Methods
In the present study, the electronic databases Scopus, ProQuest, Web of Science, PubMed, SID and Google Scholar were searched from their inception to September 2023. The quality of included studies was evaluated through the Cochrane Collaboration's Risk of Bias Tool, and finally, a meta‐analysis was conducted by calculating standardised mean differences (SMDs).
Results
The meta‐analysis results revealed that superficial heat–cold application improved sleep quality in patients with RLS (SMD = 0.685, 95% CI: 0.421–0.950). The meta‐regression results showed that as the temperature increased, the intervention was more effective in improving sleep quality (β = 0.0182, 95% CI: 0.0096–0.0268, p < 0.05). Moreover, the effectiveness of the intervention in improving the sleep quality of patients with RLS reduced significantly as the duration of intervention in each session (β = −0.031, 95% CI: −0.059 to −0.001, p < 0.05) as well as participants' age increased (β = −0.013, 95% CI: −0.024 to −0.001, p = 0.0259).
Patient or Public Contribution
This research showed that superficial heat–cold application had the capability to improve the sleep quality of patients with restless leg syndrome. In addition, in this study, settings were suggested according to which the maximum effectiveness of the intervention could be achieved.
Core body temperature (CBT) rhythm and sleep process are closely intertwined, yet there is a lack of quantitative methods to link them. To accomplish the research link of “sleeping thermal environment - body temperature - sleep quality” and also to establish a new sleep staging methodology, sleep staging models based on random forest algorithm were constructed. These models fulfilled the requirement of distinguishing four sleep stages (Waking stage, REM stage, Light sleep and Deep sleep) based on the CBT rhythm. The database utilized for model construction emanated from a winter sleep experiment, wherein seven male and seven female participants underwent a consecutive three-night testing protocol within laboratory settings. Data analysis results confirmed that (1) For the separately constructed sleep staging models for males and females, their accuracies stood at 0.70 and 0.77, respectively. The overall performance of the female model marginally surpassed that of the male model; (2) The predominant error in existing models arisen from misjudgments of adjacent sleep stages, such as misclassifying REM stage and deep sleep as light sleep, and this phenomenon may arise from the individual difference in CBT distribution; (3) Personalized sleep staging models have promising prospects, with their peak accuracy reaching an impressive 95% - nearly approaching the performance of gold standard polysomnography (PSG). In summary, this study elucidates the inherent quantitative connection between CBT rhythm and sleep stages, and the proposed sleep staging model has practical value.
People are exposed to myriad of airborne pollutants in their homes. Owing to diverse potential sources of air pollution and human activity patterns, accurate assessment of residential exposures is complex. In this study, we explored the relationship between personal and stationary air pollutant measurements in residences of 37 participants working from home during the heating season. Stationary environmental monitors (SEMs) were located in the bedroom, living room or home office and personal exposure monitors (PEMs) were worn by the participants. SEMs and PEMs included both real-time sensors and passive samplers. During three consecutive weekdays, continuous data were obtained for particle number concentration (size range 0.3-10 μm), carbon dioxide (CO2), and total volatile organic compounds (TVOC), while passive samplers collected integrated measures of 36 volatile organic compounds (VOCs) and semi volatile organic compounds (SVOCs). The personal cloud effect was detected in >80% of the participants for CO2 and >50% participants for PM10. Multiple linear regression analysis showed that a single CO2 monitor placed in the bedroom efficiently represented personal exposure to CO2 (R2 = 0.90) and moderately so for PM10 (R2 = 0.55). Adding a second or third sensor in a residence did not lead to improved exposure estimates for CO2, with only 6-9% improvement for particles. Selecting data from SEMs when participants were in the same room improved personal exposure estimates by 33% for CO2 and 5% for particles. Out of 36 detected VOCs and SVOCs, 13 had at least 50% higher concentrations in personal versus stationary samples. Findings from this study aid improved understanding of the complex dynamics of gaseous and particle pollutants and their sources in residences, and could support the development of refined procedures for residential air quality monitoring and inhalation exposure assessment.
Bu kitap, iç çevre kalitesi (ses, ışık, ısıl konfor ve iç hava kalitesi) bileşenlerinin, uyku kalitesi ve ertesi gün sağlık ve zihinsel performansı üzerine günümüze kadar yapılan araştırmaların derlemesini ve değerlendirmesini içeren özgün çalışmalardan oluşmaktadır. Çalışmaların amacı, iç çevre parametrelerinin etkileri üzerine okuyucuya veyaşam alanı tasarımcılarına günümüz itibariyle bir çerçeve çizmek, ilgili araştırma alanlarını akademisyenlere tanıtmaktır.
Kitap şu bölümlerden oluşmaktadır: Bölüm 1: İÇ HAVA KALİTESİNİN UYKU KALİTESİNE VE ERTESİ GÜN SAĞLIK VE PERFORMANSINA ETKİSİ -
Macit Toksoy, Berrin Tuğrul, Sait Cemil Sofuoğlu
Bölüm 2: AKUSTİK KONFOR VE UYKU - Çağrı Şahin, Sait Cemil Sofuoğlu, Macit Toksoy
Bölüm 3: IŞIK VE UYKU - Begüm Can-Terzi, Sait Cemil Sofuoğlu, Macit Toksoy
Bölüm 4: ISIL KONFOR VE UYKU KALİTESİ - Sezgi Koçak Soylu, İbrahim Atmaca
Bölüm 5: UYKU ORTAMINDA İÇ ÇEVRE KALİTESİNİN HAD ANALİZİ İLE İNCELENMESİ ÜZERİNE BİR DERLEME - Nur Çobanoğlu, Ziya Haktan Karadeniz
Bölüm 6: KALİTELİ BİR UYKU İÇİN HAVALANDIRMANIN ÖNEMİ ve TASARIMI - Nur Çobanoğlu, Ziya Haktan Karadeniz, Sait Cemil Sofuoğlu, Macit Toksoy
Background:
Sleep affects psychiatric health and perceived stress during adolescence.
Objective:
The first aim of this study was to investigate the prevalence of poor sleep in a sample of Swedish adolescents aged 15 to 19 years. The second aim was to investigate correlations between: a) sleep and psychiatric symptoms and; b) sleep and perceived stress. The third aim was to examine possible sex differences in sleep.
Method:
In 2011, a total of 185 Swedish adolescents (aged 15 to 19 years) from two upper secondary schools participated in this cross-sectional study. We used three different psychometric scales: Pittsburgh Sleep Quality Index (PSQI), Symptoms Checklist (SCL-90), and Perceived Stress Scale (PSS) to measure sleep, general psychiatric health and perceived stress.
Results:
In total, 76% of the female students and 71% of the male students had poor overall sleep quality. A large majority, 93%, reported daytime dysfunction and 60% reported problems staying awake during daily activities. The correlation between sleep and general psychiatric health was 0.44 and the correlation between sleep quality and perceived stress was 0.48. Female students reported significantly more sleep disturbances than male students do.
Conclusions:
Three out of four of the upper secondary school students presented with poor overall sleep that associated with psychiatric symptoms and perceived stress. These findings add to results from earlier studies and imply that interventions to improve sleep in adolescents, individually as well as on a societal level, should be considered as one way of trying to impact the observed rising numbers of psychiatric complaints. Such interventions may improve mental and somatic health in adolescents and prevent the development of psychiatric and stress-related symptoms. Further studies of possible methods, and their implementation, for improving sleep in adolescents should be of high priority.
In southern Europe, the present stock of social housing is ventilated naturally, with practice varying in the different seasons of the year. In winter, windows are kept closed most of the day with the exception of short periods for ventilation, whereas the rest of the year the windows are almost permanently open. In cold weather, air changes depend primarily on the air infiltrating across the envelope and when the temperature is warm, on the air flowing in through open windows. CO2, PM2.5, and TVOC concentration patterns were gathered over a year’s time in three social housing developments in southern Europe with different airtightness conditions and analyzed to determine possible relationships between environmental parameters and occupants’ use profiles. Correlations were found between TVOC and CO2 concentrations, for human activity was identified as the primary source of indoor contaminants: peak TVOC concentrations were related to specific household activities such as cooking or leisure. Indoor and outdoor PM2.5 concentrations were likewise observed to be correlated, although not linearly due to the presence of indoor sources. Ventilation as presently practiced in winter appears to be insufficient to dilute indoor contaminants in all three buildings, nor does summertime behavior guarantee air quality.
Background
Wearable sleep monitors are of high interest to consumers and researchers because of their ability to provide estimation of sleep patterns in free-living conditions in a cost-efficient way.
Objective
We conducted a systematic review of publications reporting on the performance of wristband Fitbit models in assessing sleep parameters and stages.
Methods
In adherence with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement, we comprehensively searched the Cumulative Index to Nursing and Allied Health Literature (CINAHL), Cochrane, Embase, MEDLINE, PubMed, PsycINFO, and Web of Science databases using the keyword Fitbit to identify relevant publications meeting predefined inclusion and exclusion criteria.
ResultsThe search yielded 3085 candidate articles. After eliminating duplicates and in compliance with inclusion and exclusion criteria, 22 articles qualified for systematic review, with 8 providing quantitative data for meta-analysis. In reference to polysomnography (PSG), nonsleep-staging Fitbit models tended to overestimate total sleep time (TST; range from approximately 7 to 67 mins; effect size=-0.51, P
Study Objectives:
There is limited knowledge regarding the effects of air pollution on sleep disorders, particularly in children. The aim of this study is to investigate this association in Chinese children.
Methods:
During 2012–2013, 59754 children aged 2–17 years were randomly selected from 27 districts in seven northeastern Chinese cities. All participants’ sleep was evaluated with the Sleep Disturbance Scale for Children. Four year average concentrations of pollutants were calculated for particles with an aerodynamic diameter of ≤1 µm (PM1), ≤2.5 µm (PM2.5) from a spatial statistical model, and ≤10 µm (PM10), sulfur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3), and carbon monoxide (CO) from monitoring stations. To examine the effects, two-level regression analysis was used, controlling for covariates.
Results:
We observed that sleep disorder was generally associated with all air pollutants, with the highest odds among PM1 exposure for male (odds ratio [OR] 1.55; 95% confidence interval [95% CI] 1.36–1.76) and female (OR 1.50; 95% CI 1.30–1.72) children. The overall strongest association with sleep disorder symptom was exposure to PM1 and Disorders of Excessive Somnolence (OR 1.43; 95% CI 1.30–1.58). PM1 and PM2.5 were strongly associated with all sleep disorder symptoms in females (ORs ranged for PM1 from 1.19 to 1.49; and PM2.5 1.18 to 1.44). The association between air pollutants and total sleep score was generally greater in female than in male children.
Conclusions:
Our findings suggest that exposure to air pollutants increases the odds of sleep disorder in children and point to the need to make reducing exposure to air pollutants a public health priority.
Study Objectives:
There is limited knowledge regarding the effects of air pollution on sleep disorders, particularly in children. The aim of this study is to investigate this association in Chinese children.
Methods:
During 2012–2013, 59754 children aged 2–17 years were randomly selected from 27 districts in seven northeastern Chinese cities. All participants’ sleep was evaluated with the Sleep Disturbance Scale for Children. Four year average concentrations of pollutants were calculated for particles with an aerodynamic diameter of ≤1 µm (PM1), ≤2.5 µm (PM2.5) from a spatial statistical model, and ≤10 µm (PM10), sulfur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3), and carbon monoxide (CO) from monitoring stations. To examine the effects, two-level regression analysis was used, controlling for covariates.
Results:
We observed that sleep disorder was generally associated with all air pollutants, with the highest odds among PM1 exposure for male (odds ratio [OR] 1.55; 95% confidence interval [95% CI] 1.36–1.76) and female (OR 1.50; 95% CI 1.30–1.72) children. The overall strongest association with sleep disorder symptom was exposure to PM1 and Disorders of Excessive Somnolence (OR 1.43; 95% CI 1.30–1.58). PM1 and PM2.5 were strongly associated with all sleep disorder symptoms in females (ORs ranged for PM1 from 1.19 to 1.49; and PM2.5 1.18 to 1.44). The association between air pollutants and total sleep score was generally greater in female than in male children.
Conclusions:
Our findings suggest that exposure to air pollutants increases the odds of sleep disorder in children and point to the need to make reducing exposure to air pollutants a public health priority.
Objective:
The apnea-hypopnea index (AHI) does not provide information about the apnea depth and length. We aimed to evaluate the correlation of the oxygen desaturation index (ODI) with AHI and the subjective symptoms because it is known that hypoxia plays an important role in morbidity and complications of obstructive sleep apnea syndrome (OSAS).
Methods:
We reviewed the data of patients who applied to our clinic between 2010 and 2014 and underwent polysomnography (PSG) with a diagnosis of suspected sleep apnea. The demographic and anthropometric data of the patients were recorded. Epworth sleepiness scale (ESS) and values of AHI and ODI were analyzed in PSG.
Results:
A total of 321 patients were divided into four groups, according to AHI as follows: 82 (25.5%) common snoring, 77 (24%) mild obstructive sleep apnea (OSA), 71 (22.1%) moderate OSA, and 91 (28.3%) severe OSA. A strong correlation was detected between AHI and ODI (p<0.005 and r=0.904) in all patient groups. There was a positive correlation between AHI and ESS (p<0.05 and r=0.435), but the correlation of ESS with ODI was stronger than that with AHI (p<0.05 and r=0.504).
Conclusion:
The subjective symptoms of sleep apnea syndrome seem to be closely related to oxygen desaturations. Hypoxia during apnea periods of OSA is important; therefore, we suggest that ODI is as valuable as AHI in diagnosing and grading the OSAS.
Located within the ascending reticular activating system are nuclei which release neurotransmitters such as acetylcholine, serotonin, dopamine, and norepinephrine. These nuclei have widespread projections that extend into the limbic system and throughout cortex. Activation of these neurotransmitters during awake states leads to arousal, while inhibition leads to the loss of consciousness experienced during slow-wave sleep. Previously, we proposed a mechanism in which cardiorespiratory synchronization may underlie the widespread hyperpolarization that occurs throughout the brain during slow-wave sleep. We further propose that a similar homeostatic mechanism may be involved in sleep-wake transitions and maintaining various arousal states including rapid eye movement sleep, waking, and anxiety. Widespread depolarization associated with more rapid, shallow breathing and desynchronized cardiorespiratory oscillatory activity may underlie waking, anxiety, and rapid eye movement sleep states. The exact voltage values of these widespread membrane potential changes remain unknown and possibly highly variable between different neural areas and cell types. Here, we place these consciousness states on a spectrum of approximated widespread membrane potential values with anxiety states being the most depolarized, followed by waking states, and rapid eye movement sleep. We propose that although these widespread membrane potential changes are minor, they may underlie transitions between and maintenance of varying levels of arousal. Further research on these mechanisms could provide insights into how the brain functions. This homeodynamic arousal mechanism involves the established feed-forward and feedback signaling between the ascending reticular activating system and the hypothalamus, as well as the modulation by cardiorespiratory oscillatory feedback from the body. Understanding the basic mechanisms responsible for the states of sleep, waking, and anxiety could lead to better treatment options in health and disease.
A re-analysis of two independent laboratory studies was made in which a total of 60 female subjects had been
exposed for several hours to 6 different air quality conditions in groups of 6 people at a time. The subjects
performed typical office tasks at their own pace during exposures. Measured carbon dioxide (CO2) concentrations
and outdoor air supply rates were used to calculate CO2 produced by subjects at each air quality level. The
re-analysis showed that CO2 produced by subjects was affected by air quality (P<0.015). It decreased by ca. 13%
when the percentage dissatisfied with the perceived air quality increased from 8% to 40%, indicating a
dose-response relationship. A change in breathing pattern (shallow breathing) or a slow down of work rate in
polluted air would both reduce metabolic rate and thus the CO2 production rate.
Fatigue is a non-specific symptom that is common in chronic diseases and represents one of the most disabling symptoms in Parkinson's disease. PD patients often experience cognitive deficits related above all to executive functions. The relationship between cognitive changes and fatigue in PD patients has not been explored in depth. The Attention Network Test (ANT) is a rapid, widely used test to measure the efficiency of three attentional networks, i.e., alerting, orienting, and executive, by evaluating reaction times (RTs) in response to visual stimuli. To assess the association between fatigue and the efficiency of the attentional networks, according to the Posnerian view, ANT was administered to 15 parkinsonian patients with fatigue (PFS-16 > 2.95), 17 parkinsonian patients without fatigue, and 37 age- and sex-matched healthy controls. Anxiety, depression, quality of sleep, and quality of life were also assessed. Parkinsonian patients displayed significantly longer RTs and lower executive network efficiency than controls. Patients with fatigue displayed significantly lower executive network efficiency than patients without fatigue. Moreover, patients with fatigue exhibited a lower accuracy than either patients without fatigue or controls. Finally, patients without fatigue displayed a more efficient alerting network than either patients with fatigue or controls. Although the pathogenesis of fatigue is multifactorial, our results indicate that fatigue may be closely related to an alteration of the striato-thalamo-cortical loop connecting the neostriatum to the prefrontal cortex, which is also responsible for the executive dysfunction that is typical of Parkinson's disease.
Agreement and correlation are widely-used concepts that assess the association between variables. Although similar and related, they represent completely different notions of association. Assessing agreement between variables assumes that the variables measure the same construct, while correlation of variables can be assessed for variables that measure completely different constructs. This conceptual difference requires the use of different statistical methods, and when assessing agreement or correlation, the statistical method may vary depending on the distribution of the data and the interest of the investigator. For example, the Pearson correlation, a popular measure of correlation between continuous variables, is only informative when applied to variables that have linear relationships; it may be non-informative or even misleading when applied to variables that are not linearly related. Likewise, the intraclass correlation, a popular measure of agreement between continuous variables, may not provide sufficient information for investigators if the nature of poor agreement is of interest. This report reviews the concepts of agreement and correlation and discusses differences in the application of several commonly used measures. Copyright © 2016 by Editorial Department of the Shanghai Archives of Psychiatry.
The effects of bedroom air quality on sleep and next-day performance were examined in two field intervention experiments in single-occupancy student dormitory rooms. The occupants, half of them women, could adjust an electric heater to maintain thermal comfort but they experienced two bedroom ventilation conditions, each maintained for one week, in balanced order. In the initial pilot experiment (N=14) bedroom ventilation was changed by opening a window (the resulting average CO2 level was 2585 or 660 ppm). In the second experiment (N=16) an inaudible fan in the air intake vent was either disabled or operated whenever CO2 levels exceeded 900 ppm (the resulting average CO2 level was 2395 or 835 ppm). Bedroom air temperatures varied over a wide range but did not differ between ventilation conditions. Sleep was assessed from movement data recorded on wristwatch-type actigraphs and subjects reported their perceptions and their well-being each morning using online questionnaires. Two tests of next-day mental performance were applied. Objectively measured sleep quality and the perceived freshness of bedroom air improved significantly when the CO2 level was lower, as did next-day reported sleepiness and ability to concentrate and the subjects' performance of a test of logical thinking. This article is protected by copyright. All rights reserved.
In this paper, the results from a field study on the influence of ventilation rate on the sleep pattern are presented. The testgroup was asked to sleep in their normal sleeping environment (student dorms) in order to cause as little disruption in the normal pattern as possible. For the same reason, actigraphy was used to measure sleep patterns since this is one of the least disturbing measurement techniques available. The student dorms were selected as a location because all rooms are identical and basic conditions are therefore very similar for all the participants in the study. The participants were also asked to fill out a number of questionnaires to determine their general attitude towards sleep and to get an idea of their subjective appreciation of the sleep quality experienced over the test period. The results show only a very small effect of the ventilation rate on the sleep pattern. IMPLICATIONS The results presented are among the very few data available for the assessment of bedroom air quality and its effect on the occupants. In conjunction with other and future data, they will allow to develop ventilation criteria and standards that are specific to the residential situation instead of the office work based criteria that dominate the current standards.
Current thermal comfort theories and standards are mainly concerned with people in waking state. The effects of air temperature on sleep quality and thermal comfort of sleeping people were investigated in this study by experimenting on human subjects. Sleep quality was evaluated by subjective questionnaires performed in the morning as well as electroencephalogram (EEG) signals, which were continuously recorded during the all-night sleep period. Subjective assessments on thermal comfort were performed both before and after sleep. Analysis on EEG signals indicated that the subjects took longer time to fall asleep and experienced shorter period of slow wave sleep (SWS) when the room temperatures moderately deviated from neutral. Consistently, they reported poorer subjective sleep quality in such conditions. The returned subjective questionnaires on thermal comfort from subjects reflected that the thermal comfort temperature was higher in sleep compared with that in waking state. Their skin temperatures were increased with air temperature and fluctuated during the sleeping period. In view of the distinctive requirements from waking people, it makes sense to study the thermal comfort of sleeping people. The results also have practical implications on energy savings in bedrooms.
Sleep bruxism (SB) is reported to vary in frequency over time. The aim of this study was to assess the first night effect on SB.
A retrospective polysomnographic (PSG) analysis was performed of data from a sample of SB patients (12 females, 4 males; age range: 17-39 years) recorded in a sleep laboratory over 2 consecutive nights. Sleep parameters and jaw muscle activity variables (i.e., rhythmic masticatory muscle activity [RMMA]) for SB were quantified and compared between the 2 nights. Subjects were classified into groups according to severity of RMMA frequency, such as low frequency (2-4 episodes/h and/or < 25 bursts/h) and moderate-high frequency (≥ 4 episodes/h and ≥ 25 bursts/h).
Overall, no first night effects were found for most sleep variables. However, total sleep time, sleep efficiency, and stage transitions showed significant time and group interactions (repeated measures ANOVAs, p ≤ 0.05). The RMMA episode index did not differ between the 2 nights, whereas the second night showed significantly higher burst index, bruxism time index, and mean burst duration (repeated measure ANOVAs, p ≤ 0.05). Five patients of 8 in the low frequency group were classified into the moderate-high frequency group on the second night, whereas only one patient in the moderate-high frequency group moved to the low frequency group.
The results showed no overall first night effect on severity of RMMA frequency in young and healthy patients with SB. In clinical practice, one-night sleep recording may be sufficient for moderate-high frequency SB patients. However, low RMMA frequency in the first night could be confirmed by a second night based on the patient's medical and dental history.
Hasegawa Y; Lavigne G; Rompré P; Kato T; Urade M; Huynh N. Is there a first night effect on sleep bruxism? A sleep laboratory study. J Clin Sleep Med 2013;9(11):1139-1145.
In sleep efficiency monitoring system, actigraphy is the simplest and most commonly used device. However, low specificity to wakefulness of actigraphy was revealed in previous studies. In this study, we assumed that sleep/wake estimation using actigraphy and electromyography (EMG) signals would show different patterns. Furthermore, each EMG pattern in two states (sleep, wake during sleep) was analysed. Finally, we proposed two types of method for the estimation of sleep/wake patterns using only EMG signals from anterior tibialis muscles and the results were compared with PSG data.
Seven healthy subjects and five patients (2 obstructive sleep apnea, 3 periodic limb movement disorder) participated in this study. Night time polysomnography (PSG) recordings were conducted, and electrooculogram, EMG, electroencephalogram, electrocardiogram, and respiration data were collected. Time domain analysis and frequency domain analysis were applied to estimate the sleep/wake patterns. Each method was based on changes in amplitude or spectrum (total power) of anterior tibialis electromyography signals during the transition from the sleep state to the wake state. To obtain the results, leave-one-out-cross-validation technique was adopted.
Total sleep time of the each group was about 8 hours. For healthy subjects, the mean epoch-by-epoch results between time domain analysis and PSG data were 99%, 71%, 80% and 0.64 (sensitivity, specificity, accuracy and kappa value), respectively. For frequency domain analysis, the corresponding values were 99%, 73%, 81% and 0.67, respectively. Absolute and relative differences between sleep efficiency index from PSG and our methods were 0.8 and 0.8% (for frequency domain analysis). In patients with sleep-related disorder, our proposed methods revealed the substantial agreement (kappa > 0.61) for OSA patients and moderate or fair agreement for PLMD patients.
The results of our proposed methods were comparable to those of PSG. The time and frequency domain analyses showed the similar sleep/wake estimation performance.
This study investigated perceived sleep quality among 11-, 13- and 15-year-old Finnish adolescents (n = 4187). Additionally, associations of selected behavioural, social and psychological factors with subjective sleep quality were examined among 15-year-olds. This study is part of an international, WHO-co-ordinated survey of school children's health and lifestyle (the HBSC Study). In Finland, research data represented the whole country. The data were collected during March-May 1994. Pupils responded anonymously to a standardized questionnaire during a class period. About every 10th adolescent felt that their sleep quality was at most satisfactory, about 30% of pupils had had difficulties in falling asleep and almost every fifth adolescent reported nocturnal awakenings every week. Thus, a large proportion of pupils in every classroom has a weakened ability to concentrate on school work or other activities. Among 15-year-old boys, a good home atmosphere was the most important contributing factor to good perceived sleep quality. A health-promotive lifestyle (good sleep hygiene and infrequent use of addictive substances) and good self-perception also had significant correlation with good perceived sleep quality. In 15-year-old girls, a good home atmosphere, good self-perception and health-promotive habits played an equally important role in associations with subjective sleep quality. Physical activity in leisure time had minor but significant correlation with perceived sleep quality among girls. In both sexes, perceived home atmosphere had a significant association with all the factors that had correlated significantly with subjective sleep quality. Results indicate that a good home atmosphere, a health-promotive lifestyle and good self-perception are important constituents of good sleep among 15-year-olds. Good and refreshing sleep is one of the constituents for general well-being among adolescents. That is why these issues provide a challenge for health promotion and health education.
To examine the impact of using American Academy of Sleep Medicine (AASM) recommended EEG derivations (F4/M1, C4/M1, O2/M1) vs. a single derivation (C4/M1) in polysomnography (PSG) on the measurement of sleep and cortical arousals, including inter- and intra-observer variability.
Prospective, non-blinded, randomized comparison.
Three Australian tertiary-care hospital clinical sleep laboratories.
30 PSGs from consecutive patients investigated for obstructive sleep apnea (OSA) during December 2007 and January 2008.
N/A.
To examine the impact of EEG derivations on PSG summary statistics, 3 scorers from different Australian clinical sleep laboratories each scored separate sets of 10 PSGs twice, once using 3 EEG derivations and once using 1 EEG derivation. To examine the impact on inter- and intra-scorer reliability, all 3 scorers scored a subset of 10 PSGs 4 times, twice using each method. All PSGs were de-identified and scored in random order according to the 2007 AASM Manual for the Scoring of Sleep and Associated Events. Using 3 referential EEG derivations during PSG, as recommended in the AASM manual, instead of a single central EEG derivation, as originally suggested by Rechtschaffen and Kales (1968), resulted in a mean ± SE decrease in N1 sleep of 9.6 ± 3.9 min (P = 0.018) and an increase in N3 sleep of 10.6 ± 2.8 min (P = 0.001). No significant differences were observed for any other sleep or arousal scoring summary statistics; nor were any differences observed in inter-scorer or intra-scorer reliability for scoring sleep or cortical arousals.
This study provides information for those changing practice to comply with the 2007 AASM recommendations for EEG placement in PSG, for those using portable devices that are unable to comply with the recommendations due to limited channel options, and for the development of future standards for PSG scoring and recording. As the use of multiple EEG derivations only led to small changes in the distribution of derived sleep stages and no significant differences in scoring reliability, this study calls into question the need to use multiple EEG derivations in clinical PSG as suggested in the AASM manual.
Environmental stimulus, especially noise and light, is thought to disrupt sleep in patients in the intensive care unit (ICU). This study aimed to determine the physiological and psychological effects of ICU noise and light, and of earplugs and eye masks, used in these conditions in healthy subjects.
Fourteen subjects underwent polysomnography under four conditions: adaptation, baseline, exposure to recorded ICU noise and light (NL), and NL plus use of earplugs and eye masks (NLEE). Urine was analyzed for melatonin and cortisol levels. Subjects rated their perceived sleep quality, anxiety levels and perception of environmental stimuli.
Subjects had poorer perceived sleep quality, more light sleep, longer rapid eye movement (REM) latency, less REM sleep when exposed to simulated ICU noise and light (P < 0.05). Nocturnal melatonin (P = 0.007) and cortisol secretion levels (P = 0.004) differed significantly by condition but anxiety levels did not (P = 0.06). Use of earplugs and eye masks resulted in more REM time, shorter REM latency, less arousal (P < 0.05) and elevated melatonin levels (P = 0.002).
Earplugs and eye masks promote sleep and hormone balance in healthy subjects exposed to simulated ICU noise and light, making their promotion in ICU patients reasonable.
: The concept of attention as central to human performance extends back to the start of experimental psychology, yet even a few years ago, it would not have been possible to outline in even a preliminary form a functional anatomy of the human attentional system. New developments in neuroscience have opened the study of higher cognition to physiological analysis, and have revealed a system of anatomical areas that appear to be basic to the selection of information for focal (conscious) processing. The importance of attention is its unique role in connecting the mental level of description of processes used in cognitive science with the anatomical level common in neuroscience. Sperry describes the central role that mental concepts play in understanding brain function. As is the case for sensory and motor systems of the brain, our knowledge of the anatomy of attention is incomplete. Nevertheless, we can now begin to identify some principles of organization that allow attention to function as a unified system for the control of mental processing. Although many of our points are still speculative and controversial, we believe they constitute a basis for more detailed studies of attention from a cognitive-neuroscience viewpoint. Perhaps even more important for furthering future studies, multiple methods of mental chronometry, brain lesions, electrophysiology, and several types of neuro-imaging have converged on common findings.
In recent years, three attentional networks have been defined in anatomical and functional terms. These functions involve alerting, orienting, and executive attention. Reaction time measures can be used to quantify the processing efficiency within each of these three networks. The Attention Network Test (ANT) is designed to evaluate alerting, orienting, and executive attention within a single 30-min testing session that can be easily performed by children, patients, and monkeys. A study with 40 normal adult subjects indicates that the ANT produces reliable single subject estimates of alerting, orienting, and executive function, and further suggests that the efficiencies of these three networks are uncorrelated. There are, however, some interactions in which alerting and orienting can modulate the degree of interference from flankers. This procedure may prove to be convenient and useful in evaluating attentional abnormalities associated with cases of brain injury, stroke, schizophrenia, and attention-deficit disorder. The ANT may also serve as an activation task for neuroimaging studies and as a phenotype for the study of the influence of genes on attentional networks.
Long-term sleep deprivation is common in today's society. Recent experiments have demonstrated that short-term sleep deprivation in healthy subjects results in adverse physiologic changes, including a decreased glucose tolerance and an increased blood pressure. However, the long-term health consequences of long-term sleep deprivation are unclear. The objective of this study was to determine whether decreased sleep duration (from self-reports) is associated with an increased risk of coronary events.
We studied a cohort of 71 617 US female health professionals (aged 45-65 years), without reported coronary heart disease (CHD) at baseline, who were enrolled in the Nurses' Health Study. Subjects were mailed a questionnaire in 1986 asking about daily sleep duration. Subjects were followed up until June 30, 1996, for the occurrence of CHD-related events. We assessed the relationship between self-reported sleep duration and incident CHD.
A total of 934 coronary events were documented (271 fatal and 663 nonfatal) during the 10 years of follow up. Age-adjusted relative risks (95% confidence intervals) of CHD (with 8 hours of daily sleep being considered the reference group) for individuals reporting 5 or fewer, 6, and 7 hours of sleep were 1.82 (1.34-2.41), 1.30 (1.08-1.57), and 1.06 (0.89-1.26), respectively. The relative risk (95% confidence interval) for 9 or more hours of sleep was 1.57 (1.18-2.11). After adjusting for various potential confounders, including snoring, body mass index, and smoking, the relative risks of CHD (95% confidence intervals) for individuals reporting 5 or fewer, 6, and 7 hours of sleep were 1.45 (1.10-1.92), 1.18 (0.98-1.42), and 1.09 (0.91-1.30), respectively. The relative risk (95% confidence interval) for 9 or more hours of sleep was 1.38 (1.03-1.86).
Short and long self-reported sleep durations are independently associated with a modestly increased risk of coronary events.
Sleep is essential for our health and well-being. Some research suggests that air quality influences sleep quality in bedrooms, but the evidence is limited. Research, until now, has focused on how indoor air quality affects health, comfort, and cognitive performance during waking hours. Less information is available on the levels of indoor air quality and ventilation in bedrooms, as well as on their consequences for sleep quality and the next-day performance. This paper addresses the former by reviewing research published in peer-reviewed journals in this millennium. The bedroom ventilation has been chosen as a specific focus of this review paper, which also includes a review of selected international standards for bedroom ventilation. Arising out of this review based on a framework of comparison of field data with CO2 and ventilation benchmarks from widely adopted international standards, an attempt is made to generalize the level of bedroom ventilation that exists in practice in residential dwellings and apartments across different seasons and different parts of the world. Besides, based on a limited number of studies dealing with the impact of bedroom ventilation on sleep quality, an attempt is also made to associate the measured field data with a potential impact on sleep quality.
Introduction
Pediatric sleep-disordered breathing (SDB) describes a spectrum of disease ranging from snoring to upper airway resistance syndrome and obstructive sleep apnea (OSA). Anatomical features assessed during orthodontic exams are often associated with symptoms of SDB in children. Hence, we need to determine the prevalence of positive risk for SDB in the pediatric orthodontic population compared with a general pediatric population and understand comorbidities associated with SDB risk among orthodontic patients.
Methods
Responses from Pediatric Sleep Questionnaires were collected from 390 patients between the ages of 5 and 16 years, seeking orthodontic treatment. Prevalence of overall SDB risk, habitual snoring, and sleepiness were determined in the orthodontic population and compared with those previously reported by identical methods in the general pediatric population. Additional health history information was used to assess comorbidities associated with SDB risk in 130 of the patients.
Results
At 10.8%, the prevalence of positive SDB risk was found to be significantly higher in the general pediatric orthodontic population than in a healthy pediatric population (5%). The prevalence of snoring and sleepiness in the orthodontic population was 13.3% and 17.9%, respectively. Among the comorbidities, nocturnal enuresis (13.6%), overweight (18.2%), and attention deficit hyperactivity disorder (31.8%) had a higher prevalence in orthodontic patients with higher SDB risk (P < 0.05).
Conclusions
There is a higher pediatric SDB risk prevalence in the orthodontic population compared with a healthy pediatric population. Orthodontic practitioners should make SDB screening a routine part of their clinical practice.
Contaminants of biological origin, such as fungi and bacteria, are ubiquitous inside the residences and especially in bedroom microenvironments. Epidemiological studies have shown that fungal exposure is associated with respiratory and allergic symptoms. Infants and young children comprise a susceptible population to study, since they spend most of their day inside their rooms. A study was undertaken to investigate environmental factors (temperature and relative humidity), indoor pollutants (PM2.5, CO2), building characteristics and occupant activities in relation to the spectrum and levels of settled fungi in 25 Greek young’s children bedrooms, and to evaluate the fungal qualitative and quantitative composition of houses with and without asthmatic/allergic children. In this context, on-site house inspections to study the Indoor Air Quality (IAQ) in bedrooms of young children below three years of age were conducted in Athens, Greece. Sampling campaigns were conducted over one-week period using Electrostatic Dust Collectors (EDCs) to quantify fungal and bacterial exposure in settled dust and real-time monitoring techniques for environmental parameters (T, RH, CO2, PM2.5). The present investigation revealed that the predominant dustborne genus was Cladosporium followed by Alternaria and Aspergillus, and that living in a suburban area, the presence of an attached garage and the presence of a carpet in the bedroom were significant predictors of fungal concentrations. Furthermore, although the difference was not statistically significant, higher fungal concentrations were recorded in the houses with asthmatic or atopic children.
We examined sleep behaviors in allied health students (N = 77) with the following questionnaires: Caffeine Consumption, Pittsburgh Sleep Quality Index (PSQI), Profile of Mood States, and Mental and Physical State and Trait Energy and Fatigue Scales. Students averaged 6.56 hr of sleep per night. More than half of the students received borderline or poor sleep quality scores on the PSQI. Students with poor sleep quality had a significantly higher proportion of mood disturbances than students with optimal sleep quality. These results highlight the need for educational programs to emphasize the sleep hygiene practices of their students.
Indoor environment, in addition to many other factors, such as emotion and body condition, can disturb an individual's sleep. This paper aimed to determine the relationship between indoor environment and sleep quality based on subjective questionnaires and objective measurements. First, a massive online investigation was conducted in China to collect basic information, the Pittsburgh Sleep Quality Index (PSQI) questionnaire, and information on sleep environment control method from respondents. The main qualitative conclusion from this investigation was that individuals have differing perceptions of the effects of environment on sleep quality. Sleep quality varies based on age and personal salary. Gender differences were also discussed in the online investigation. Men tended to have poorer sleep quality than women. To quantitatively explore the effects of indoor environment on sleep quality, a field study was conducted in university dormitories. The field study involved the measurement of various environmental and physiological parameters, and used subjective questionnaires before and after sleep. Preference for different environmental parameters relating to sleep quality were discussed. The most satisfactory operative temperature was found to be 24.2 °C, and subjects have a lower neutral temperature and a broader accepted temperature range during sleep. A multivariate analysis indicated that several environmental factors thought to disturb sleep are interrelated and therefore require more transactional analysis and research.
Objectives:
Poor air quality has become a national public health concern in China. This study examines the impact of ambient fine particulate matter (PM2.5) air pollution on health behaviors among college students in Beijing, China.
Study design:
Prospective cohort study.
Methods:
Health surveys were repeatedly administered among 12,000 newly admitted students at Tsinghua University during 2012-2015 over their freshman year. Linear individual fixed-effect regressions were performed to estimate the impacts of ambient PM2.5concentration on health behaviors among survey participants, adjusting for various time-variant individual characteristics and environmental measures.
Results:
Ambient PM2.5concentration was found to be negatively associated with time spent on walking, vigorous physical activity and sedentary behavior in the last week, but positively associated with time spent on nighttime/daytime sleep among survey participants. An increase in the ambient PM2.5concentration by one standard deviation (36.5 μg/m³) was associated with a reduction in weekly total minutes of walking by 7.3 (95% confidence interval [CI] = 5.3-9.4), a reduction in weekly total minutes of vigorous physical activity by 10.1 (95% CI = 8.5-11.7), a reduction in daily average hours of sedentary behavior by 0.06 (95% CI = 0.02-0.10) but an increase in daily average hours of nighttime/daytime sleep by 1.07 (95% CI = 1.04-1.11).
Conclusions:
Ambient PM2.5air pollution was inversely associated with physical activity level but positively associated with sleep duration among college students. Future studies are warranted to replicate study findings in other Chinese cities and universities, and policy interventions are urgently called to reduce air pollution level in China's urban areas.
We evaluated the performance of a consumer multi-sensory wristband (Fitbit Charge 2™), against polysomnography (PSG) in measuring sleep/wake state and sleep stage composition in healthy adults.
In-lab PSG and Fitbit Charge 2™ data were obtained from a single overnight recording at the SRI Human Sleep Research Laboratory in 44 adults (19—61 years; 26 women; 25 Caucasian). Participants were screened to be free from mental and medical conditions. Presence of sleep disorders was evaluated with clinical PSG. PSG findings indicated periodic limb movement of sleep (PLMS, > 15/h) in nine participants, who were analyzed separately from the main group (n = 35). PSG and Fitbit Charge 2™ sleep data were compared using paired t-tests, Bland–Altman plots, and epoch-by-epoch (EBE) analysis.
In the main group, Fitbit Charge 2™ showed 0.96 sensitivity (accuracy to detect sleep), 0.61 specificity (accuracy to detect wake), 0.81 accuracy in detecting N1+N2 sleep (“light sleep”), 0.49 accuracy in detecting N3 sleep (“deep sleep”), and 0.74 accuracy in detecting rapid-eye-movement (REM) sleep. Fitbit Charge 2™ significantly (p < 0.05) overestimated PSG TST by 9 min, N1+N2 sleep by 34 min, and underestimated PSG SOL by 4 min and N3 sleep by 24 min. PSG and Fitbit Charge 2™ outcomes did not differ for WASO and time spent in REM sleep. No more than two participants fell outside the Bland–Altman agreement limits for all sleep measures. Fitbit Charge 2™ correctly identified 82% of PSG-defined non-REM–REM sleep cycles across the night. Similar outcomes were found for the PLMS group.
Fitbit Charge 2™ shows promise in detecting sleep-wake states and sleep stage composition relative to gold standard PSG, particularly in the estimation of REM sleep, but with limitations in N3 detection. Fitbit Charge 2™ accuracy and reliability need to be further investigated in different settings (at-home, multiple nights) and in different populations in which sleep composition is known to vary (adolescents, elderly, patients with sleep disorders).
Sleep disturbance is commonly reported by participants with post-traumatic stress disorder, but objective evidence of poor sleep is often absent. Here we compared self-report and actigraphic evaluations of sleep between veterans with post-traumatic stress disorder and controls. Participants reported their sleep retrospectively for the month before the recording night and on the recording night. On the recording night, they wore an Actiwatch-64 and were instructed to press the marker button upon getting into bed, each time they awoke, and at their final awakening. The post-traumatic stress disorder group reported much worse sleep than controls on the Pittsburgh Sleep Quality Index for the previous month and somewhat poorer sleep on the recording night. However, on the recording night, neither diary nor actigraphic measures of number of awakenings, total time in bed, nor time lying awake after sleep onset differed between participants with and without post-traumatic stress disorder. Diary-reported number of awakenings was fewer than actigraphically captured awakenings. These results suggest a memory bias towards remembering worse sleep on the nights before the recording night.
This work examined window/door opening as means of bedroom ventilation and the consequent effect upon occupants’ sleep, using data from 17 healthy volunteers. Bedroom CO2 level, temperature, and relative humidity were measured over 5 days, for two cases: open window or door (internal, bedroom door), and closed window and door. Participant filled questionnaires and sleep diary provided subjective measure of sleep quality. Actigraphy objectively monitored the participants during sleep. Additionally, a FlexSensor, placed under pillows of participants, detected movement during sleep. Average CO2 level for the Open conditions was 717 ppm (SD = 197 ppm) and for Closed conditions was 1150 ppm (SD = 463 ppm). Absolute humidity levels were similar for both conditions, while Open conditions were slightly cooler (mean = 19.7°C, SD = 1.8°C) than Closed (mean = 20.1°C, SD = 1.5°C). Results showed significant correlations (P < .001) between actigraphy data and questionnaire responses for: sleep latency (r = .45), sleep length (r = .87), and number of awakenings (r = .28). Of all analyzed sleep parameters, questionnaire-based depth of sleep (P = .002) and actigraphy-based sleep phase (P = .003) were significantly different between Open and Closed conditions.
Recent studies suggest that exposure to air pollution might be associated with severity of sleep-disordered breathing (SDB). However, the association between air pollution exposure, especially particulate matter with aerodynamic diameters <= 2.5 μm (PM2.5), and SDB is still unclear. We collected 4312 participants' data from the Taipei Medical University Hospital's Sleep Center and air pollution data from the Taiwan Environmental Protection Administration. Associations of particulate matter with aerodynamic diameters <=10 μm (PM10), PM2.5, nitrogen dioxide (NO2), ozone (O3) and sulfur dioxide (SO2) with apnea-hypopnea index (AHI) and oxygen desaturation index (ODI) were investigated by generalized additive models. We found that an interquartile range (IQR) increase in 1-year mean PM2.5 (3.4 μg/m(3)) and NO2 (2.7 ppb) was associated with a 4.7% and 3.6% increase in AHI, respectively. We also observed the association of an IQR increase in 1-year mean PM2.5 with a 2.5% increase in ODI. The similar pattern was found in the association of daily mean PM2.5 exposure with increased AHI. Moreover, participants showed significant AHI and ODI responses to air pollution levels in spring and winter. We concluded that exposure to PM2.5 was associated with SDB. Effects of air pollution on AHI and ODI were significant in spring and winter.
Sleep disorders may pose a risk to workers in the workplace. We aimed to investigate the associations between metal fume fine particulate matter (PM2.5) and sleep quality in workers. We assessed the effects of personal exposure to metal fume PM2.5 on lung functions, urinary biomarkers, and sleep quality in shipyard welding workers. In total, 96 welding workers and 54 office workers were recruited in the present study; office workers were exposed to 82.1 ± 94.1 μg/m(3) PM2.5 and welding workers were exposed to 2166.5 ± 3149.1 μg/m(3). Welding workers had significantly lower levels of FEV25-75 than office workers (p < 0.05). An increase in 1 μg/m(3) PM2.5 was associated with a decrease of 0.003 ng/mL in urinary serotonin (95% CI = -0.007-0.000, p < 0.05) in all workers and with a decrease of 0.001 ng/mL in serotonin (95% CI = -0.004-0.002, p < 0.05) in welding workers, but these were not observed in office workers. There was no significant association of PM2.5 with urinary cortisol observed in any workers. Urinary serotonin was associated with urinary Cu, Mn, Co, Ni, Cd, and Pb. Urinary cortisol was associated with Cu, Mn, Co, Ni, Cd, and Pb. Sixteen subjects were randomly selected from each of the office and welding workers for personal monitoring of sleep quality using a wearable device. We observed that welding workers had greater awake times than did office workers (p < 0.05). Our study observed that exposure to heavy metals in metal fume PM2.5 may disrupt sleep quality in welding workers.
The objective of this study was to confirm the effect of humid heat exposure on sleep stages and body temperature. Seven healthy male volunteers with a mean age of 22.7±1.63, served as the subjects. The experiments were carried out under four different conditions of room temperature and relative humidity: 29°C RH 50% (29/50), 29°C RH 75% (29/75), 35°C RH 50% (35/50), and 35°C RH 75% (35/75). The subjects wearing only shorts slept from 23:00 to 7:00 on a bed, which was covered with a 100% cotton sheet. EEG, EOG, and mental EMG were recorded through the night. Rectal temperature (Tr) and skin temperature were measured continuously. The 35/75 condition caused more wake and a lower sleep efficiency index (SEI) and stage S3+S4 than 29/50 and 29/75. Stage REM and stage 3 were significantly decreased at 35/75 than at 29/50 and 35/50. Tr was maintained at a higher level at 35/75 than under the other conditions. Mean skin temperature was higher at 35/50 and 35/75 than at 29/50 and 29/75. These results suggest that humid heat exposure during night sleep increases the thermal load to supress the sleep-evoked Tr decrease, stage 3, SWS, and REM, and increase wakefulness.
Objectives: To provide evidence-based recommendations and guidance to the public regarding indicators of
good sleep quality across the life-span.
Methods: The National Sleep Foundation assembled a panel of experts from the sleep community and
representatives appointed by stakeholder organizations (Sleep Quality Consensus Panel). A systematic
literature review identified 277 studies meeting inclusion criteria. Abstracts and full-text articles
were provided to the panelists for review and discussion. A modified Delphi RAND/UCLA Appropriateness
Method with 3 rounds of voting was used to determine agreement.
Results: Foremost of the sleep continuity variables (sleep latency, number of awakenings N5 minutes, wake
after sleep onset, and sleep efficiency), the panel members agreed that these measures were appropriate
indicators of good sleep quality across the life-span. However, overall, there was less or no consensus regarding sleep architecture or nap-related variables as elements of good sleep quality.
Conclusions: There is consensus among experts regarding some indicators of sleep quality among otherwise
healthy individuals. Education and public health initiatives regarding good sleep quality will require sustained and collaborative efforts from multiple stakeholders. Future research should explore how sleep
architecture and naps relate to sleep quality. Implications and limitations of the consensus recommendations
are discussed.
Objective:
Intraclass correlation coefficient (ICC) is a widely used reliability index in test-retest, intrarater, and interrater reliability analyses. This article introduces the basic concept of ICC in the content of reliability analysis.
Discussion for researchers:
There are 10 forms of ICCs. Because each form involves distinct assumptions in their calculation and will lead to different interpretations, researchers should explicitly specify the ICC form they used in their calculation. A thorough review of the research design is needed in selecting the appropriate form of ICC to evaluate reliability. The best practice of reporting ICC should include software information, "model," "type," and "definition" selections.
Discussion for readers:
When coming across an article that includes ICC, readers should first check whether information about the ICC form has been reported and if an appropriate ICC form was used. Based on the 95% confident interval of the ICC estimate, values less than 0.5, between 0.5 and 0.75, between 0.75 and 0.9, and greater than 0.90 are indicative of poor, moderate, good, and excellent reliability, respectively.
Conclusion:
This article provides a practical guideline for clinical researchers to choose the correct form of ICC and suggests the best practice of reporting ICC parameters in scientific publications. This article also gives readers an appreciation for what to look for when coming across ICC while reading an article.
This comprehensive atlas of tracings of polysomnographic studies covers the technical aspects of conducting studies, and includes the features of the various adult and pediatric sleep disorders. Comprehensive and contemporary atlas Discusses the significance of findings and their correlation with the clinical presentation of the patient Authoritative and well-organized With 61 contributors.
Twenty-five subjects were exposed to different levels of carbon dioxide (CO2 ) and bioeffluents. The ventilation rate was set high enough to create a reference condition of 500 ppm CO2 with subjects present; additional CO2 was then added to supply air to reach levels of 1,000 or 3,000 ppm, or the ventilation rate was reduced to allow metabolically-generated CO2 to reach the same two levels (bioeffluents increased as well). Heart rate, blood pressure, End-Tidal CO2 (ETCO2 ), oxygen saturation of blood (SPO2 ), respiration rate, nasal peak flow and forced expiration were monitored and the levels of salivary α-amylase and cortisol were analyzed. The subjects performed a number of mental tasks during exposures and assessed their levels of comfort and the intensity of their acute health symptoms. During exposure to CO2 at 3,000 ppm, when CO2 was added or ventilation was restricted, ETCO2 increased more and heart rate decreased less than the changes that occurred in the reference condition. Exposure to bioeffluents, when metabolically-generated CO2 was at 3,000 ppm, significantly increased diastolic blood pressure and salivary α-amylase level compared with pre-exposure levels, and reduced the performance of a cue-utilisation test: these effects may suggest higher arousal/stress. A model is proposed describing how mental performance is affected by exposure to bioeffluents. This article is protected by copyright. All rights reserved.
The objective of this study was to compare to each other the methods currently recommended by the American Academy of Sleep Medicine (AASM) to measure snoring: an acoustic sensor, a piezoelectric sensor and a nasal pressure transducer (cannula). Ten subjects reporting habitual snoring were included in the study, performed at Landspitali-University Hospital, Iceland. Snoring was assessed by listening to the air medium microphone located on a patient's chest, compared to listening to two overhead air medium microphones (stereo) and manual scoring of a piezoelectric sensor and nasal cannula vibrations. The chest audio picked up the highest number of snore events of the different snore sensors. The sensitivity and positive predictive value of scoring snore events from the different sensors was compared to the chest audio: overhead audio (0.78, 0.98), cannula (0.55, 0.67) and piezoelectric sensor (0.78, 0.92), respectively. The chest audio was capable of detecting snore events with lower volume and higher fundamental frequency than the other sensors. The 200 Hz sampling rate of the cannula and piezoelectric sensor was one of their limitations for detecting snore events. The different snore sensors do not measure snore events in the same manner. This lack of consistency will affect future research on the clinical significance of snoring. Standardization of objective snore measurements is therefore needed. Based on this paper, snore measurements should be audio-based and the use of the cannula as a snore sensor be discontinued, but the piezoelectric sensor could possibly be modified for improvement.
This scale [1] measures the subjective level of sleepiness at a particular time during the day. On this scale subjects indicate which level best reflects the psycho-physical sate experienced in the last 10 min. The KSS is a measure of situational sleepiness. It is sensitive to fluctuations.
Objective:
The objective was to conduct a scientifically rigorous update to the National Sleep Foundation's sleep duration recommendations.
Methods:
The National Sleep Foundation convened an 18-member multidisciplinary expert panel, representing 12 stakeholder organizations, to evaluate scientific literature concerning sleep duration recommendations. We determined expert recommendations for sufficient sleep durations across the lifespan using the RAND/UCLA Appropriateness Method.
Results:
The panel agreed that, for healthy individuals with normal sleep, the appropriate sleep duration for newborns is between 14 and 17 hours, infants between 12 and 15 hours, toddlers between 11 and 14 hours, preschoolers between 10 and 13 hours, and school-aged children between 9 and 11 hours. For teenagers, 8 to 10 hours was considered appropriate, 7 to 9 hours for young adults and adults, and 7 to 8 hours of sleep for older adults.
Conclusions:
Sufficient sleep duration requirements vary across the lifespan and from person to person. The recommendations reported here represent guidelines for healthy individuals and those not suffering from a sleep disorder. Sleep durations outside the recommended range may be appropriate, but deviating far from the normal range is rare. Individuals who habitually sleep outside the normal range may be exhibiting signs or symptoms of serious health problems or, if done volitionally, may be compromising their health and well-being.
The purpose of this investigation was to determine whether there is gender difference in sleep comfort of healthy individuals at various temperatures. During winter, sleep quality was examined under different indoor temperatures (17, 20 and 23°C) using questionnaires and electroencephalogram (EEG). To explore the mechanism responsible for gender differences in comfortable sleeping temperatures, mean skin temperature, finger temperature and finger blood flow were measured. The results showed that females would prefer a higher ambient temperature during sleep than the men. The mean skin temperature for females was higher than that of males, whereas finger skin temperature and finger blood flow were significantly lower in females than in males. Furthermore, skin temperature and finger blood flow were more sensitive to ambient temperature with females than in males. The gender differences in preferred sleeping temperature could therefore be related to these physiological characteristics. Both subjective evaluations and EEG found better sleep quality in males under the same temperatures compared to females. Skin temperature changes over the course of the night also demonstrated longer periods of deep sleep in males compared to females.
Information processing difficulties are common in patients with chronic fatigue syndrome (CFS). It has been shown that the time it takes to process a complex cognitive task, rather than error rate, may be the critical variable underlying CFS patients' cognitive complaints. The Attention Network Task (ANT) developed by Fan and colleagues may be of clinical utility to assess cognitive function in CFS, because it allows for simultaneous assessment of mental response speed, also called information processing speed, and error rate under three conditions challenging the attention system. Comparison of data from two groups of CFS patients (those with and without comorbid major depressive disorder; n = 19 and 22, respectively) to controls (n = 29) consistently showed that error rates did not differ among groups across conditions, but speed of information processing did. Processing time was prolonged in both CFS groups and most significantly affected in response to the most complex task conditions. For simpler tasks, processing time was only prolonged in CFS participants with depression. The data suggest that the ANT may be a task that could be used clinically to assess information processing deficits in individuals with CFS.
The effects of day-sleep on the quality ofsleep are not restricted to the night-work period itself. Effects can be measured during night-sleep in the period following night-work. A study on these after-effects, using a self-report instrument to measure sleep quality, is described. A total of N=7O operators wcrc observed over five consecutive undisturbed nights after a working period of seven morning shifts (N= 35) and after a working period of seven night-shifts (N= 35). The quality of sleep during the third night after the night-shift period was still significantly worse than the third night after the rnorning-shift period. No differential (after-)effects were observed with respect to differences in sleep duration.
The characteristics of thermal comfort and indoor air quality (IAQ) in bedrooms, occupants’ perceptions and their impact on sleep quality are not often studied. It becomes even more interesting if climatic conditions allow Naturally/Mechanically Ventilated (NMV) concepts as opposed to Air-conditioning (AC) and this becomes very significant from an energy perspective. This paper reports our findings from such a study conducted in a hot and humid climate. Objective measurements of thermal comfort and IAQ were carried out during sleeping period in 12 NMV and 12 AC bedrooms over a period of 2 months. Questionnaire responses were sought from each subject at the end of the objective measurements to assess their perceptions on thermal comfort and indoor air quality of the bedrooms during sleep and their sleeping conditions. Although the “Historical” and “Immediate” responses for the NMV and AC bedrooms indicate that there was a good level of acceptability for both Thermal Comfort and Perceived Air Quality (PAQ), it was found that NMV bedroom was a better sleeping environment. The subjects’ immediate perception of PAQ and thermal comfort were reasonably correlated with their historical perceptions. The subjects’ perception of PAQ was fairly closely correlated to their perception of Thermal Comfort. There was a considerable increase in the carbon dioxide level in an AC bedroom relative to a NMV bedroom. However, there was no clear evidence to substantiate that sleeping duration decreased with increasing level of carbon dioxide, but the findings do suggest that high level of carbon dioxide may hinder the duration of sleep.
The ongoing “Indoor Environment and Children’s Health” (IECH) study investigates the environmental risk factors in homes and their association with asthma and allergy among children aged 1–5 years. As part of the study, the homes of 500 children between 3 and 5 years of age were inspected. The selected children included 200 symptomatic children (cases) and 300 randomly selected children (bases). As part of the inspection, the concentration of carbon dioxide in the bedrooms of the children was continuously measured over an average of 2.5 days. The ventilation rates in the rooms during the nights when the children were sleeping in the room were calculated using a single-zone mass balance for the occupant-generated CO2. The calculated air change rates were log-normally distributed (R2 > 0.98). The geometric mean of the air change rates in both the case and the base group was 0.46 air changes per hour (h−1; geom. SD = 2.08 and 2.13, respectively). Approximately 57% of both cases and bases slept at a lower ventilation rate than the minimum required ventilation rate of 0.5 h−1 in new Danish dwellings. Only 32% of the bedrooms had an average CO2 concentration below 1000 ppm during the measured nights. Twenty-three percent of the rooms experienced at least a 20-minute period during the night when the CO2 concentration was above 2000 ppm and 6% of the rooms experienced concentrations above 3000 ppm. The average air change rate was higher with more people sleeping in the room. The air change rate did not change with the increasing outdoor temperature over the 10-week experimental period. The calculation method provides an estimate of the total airflow into the bedroom, including airflows both from outdoors and from adjacent spaces. To study the accuracy of the calculated air change rates and their deviation from the true outside air change rates, we calculated CO2 concentrations at different given air change rates using an indoor air quality and ventilation model (Contam). Subsequently we applied our calculation procedure to the obtained data. The air change rate calculated from the generated CO2 concentrations was found to be between 0% and 51% lower than the total air change rate defined in the input variables for the model. It was, however, higher than the true outside air change rate. The relative error depended on the position of the room in relation to the adjacent rooms, occupancy in the adjacent room, the nominal air change rate and room-to-room airflows.
Six male subjects slept nude except for shorts on a bed made from nylon webbing at 5 different ambient temperatures (TaS): 21, 24, 29 (thermoneutrality), 34 and 37 degrees C. Standard electrophysiological recordings were obtained and analyzed for sleep stages. Temperature displayed a significant quadratic trends for nearly every sleep variable, such that TaS above or below thermoneutrality had similar effects on sleep patterns. Multiple comparisons showed that 21 degrees C was the most disruptive condition, and that cold TaS were generally more disruptive to sleep than warm TaS. There were marked individual differences in sensitivity of sleep to cold. Decreases in REM sleep in humans produced by heat or cold probably result from a general disruption of sleep processes rather than being specifically related to the status of the thermoregulatory system during REM sleep.
Attention and arousal are multi-dimensional psychological processes, which interact closely with one another. The neural substrates of attention, as well as the interaction between arousal and attention, are discussed in this review. After a brief discussion of psychological and neuropsychological theories of attention, event-related potential correlates of attention are discussed. Essentially, attention acts to modulate stimulus-induced electrical potentials (N100/P100, P300, N400), rather than generating any unique potentials of its own. Functional neuroimaging studies of attentional orienting, selective attention, divided attention and sustained attention (and its inter-dependence on underlying levels of arousal) are then reviewed. A distinction is drawn between the brain areas which are crucially involved in the top-down modulation of attention (the 'sources' of attention) and those sensory-association areas whose activity is modulated by attention (the 'sites' of attentional expression). Frontal and parietal (usually right-lateralised) cortices and thalamus are most often associated with the source of attentional modulation. Also, the use of functional neuroimaging to test explicit hypotheses about psychological theories of attention is emphasised. These experimental paradigms form the basis for a 'new generation' of functional imaging studies which exploit the dynamic aspect of imaging and demonstrate how it can be used as more than just a 'brain mapping' device. Finally, a review of psychopharmacological studies in healthy human volunteers outlines the contributions of the noradrenergic, cholinergic and dopaminergic neurotransmitter systems to the neurochemical modulation of human attention and arousal. While, noradrenergic and cholinergic systems are involved in 'low-level' aspects of attention (e.g. attentional orienting), the dopaminergic system is associated with more 'executive' aspects of attention such as attentional set-shifting or working memory.
This study describes the relationship of time in bed and quality of sleep with concentration and functioning at school. Neurotic and psychosomatic symptoms have been used as control variables. The sample consisted of 449 Dutch children in the seventh and eighth grades of elementary school. The age of the children varied between 9 y 5 mo and 14 y 5 mo. Seven schools participated in the research, with a total of 18 classes. The results indicated that 43% of the children had difficulty getting up in the morning. Furthermore, 15% of the children reported sleep problems and 25% did not feel rested at school. Time in bed and sleep quality show no relationship with concentration. Sleep quality, feeling rested at school and less distinct bedtimes were clearly related to school functioning. Another result was that children who had no difficulty getting up displayed more achievement motivation. Being open to the teacher's influence and achievement motivation depended mainly on sleep characteristics. Not getting bored at school, self-image as a pupil and control over aggressive behaviour were also influenced by gender, age, neuroticism and neurosomaticism.