Relationships Between Questionnaire Ratings of Sleep Quality and Polysomnography in Healthy Adults

Enhancing construction safety: predicting worker sleep deprivation using machine learning algorithms

Sleep deprivation is a critical issue that affects workers in numerous industries, including construction. It adversely affects workers and can lead to significant concerns regarding their health, safety, and overall job performance. Several studies have investigated the effects of sleep deprivation on safety and productivity. Although the impact of sleep deprivation on safety and productivity through cognitive impairment has been investigated, research on the association of sleep deprivation and contributing factors that lead to workplace hazards and injuries remains limited. To fill this gap in the literature, this study utilized machine learning algorithms to predict hazardous situations. Furthermore, this study demonstrates the applicability of machine learning algorithms, including support vector machine and random forest, by predicting sleep deprivation in construction workers based on responses from 240 construction workers, identifying seven primary indices as predictive factors. The findings indicate that the support vector machine algorithm produced superior sleep deprivation prediction outcomes during the validation process. The study findings offer significant benefits to stakeholders in the construction industry, particularly project and safety managers. By enabling the implementation of targeted interventions, these insights can help reduce accidents and improve workplace safety through the timely and accurate prediction of sleep deprivation.

The effects of exercise programs on sleep architecture in obstructive sleep apnea: a meta-analysis of randomized controlled trials

OBJECTIVES

Exercise is an effective intervention for obstructive sleep apnea (OSA). However, the effects of exercise on objective sleep architecture in patients with OSA remain unknown. This meta-analysis aimed to collect data from randomized controlled trials of exercise interventions in patients with OSA, with a specific focus on objective sleep parameters derived from polysomnography.

METHODS

Randomized control trials that targeted patients with OSA aged >18 years, measured sleep using polysomnography after exercise programs, and reported the proportion of sleep stages were included for meta-analysis. Bias was assessed using the revised Cochrane risk-of-bias tool and funnel plots. The random effects model was applied.

RESULTS

Six studies with a total of 236 patients were included in the meta-analysis. There were no significant differences in the total sleep time (TST), sleep efficiency, sleep onset latency, stage N1 sleep, or rapid eye movement sleep between the exercise and control groups. Participation in an exercise program lasting >12 weeks significantly decreased stage N2 and increased stage N3 sleep as observed in the subgroup analysis. Although this tendency did not reach statistical significance in the total-group analysis, it was significant after excluding the possible confounding effects of heart disease.

CONCLUSIONS

The exercise program decreased N2 and increased N3 proportions over the TST among patients with OSA, which may correspond to subjective sleep quality. The beneficial effects were significant when the program lasted >12 weeks and after excluding the confounding effects of heart disease. Exercise program duration should be considered when providing clinical advice.

The effectiveness of exercise interventions targeting sleep in older adults with cognitive impairment or Alzheimer's disease and related dementias (AD/ADRD): A systematic review and meta-analysis

Sleep loss is associated with reduced health and quality of life, and increased risk of Alzheimer's disease and related dementias. Up to 66% of persons with Alzheimer's disease and related dementias experience poor sleep, which can predict or accelerate the progression of cognitive decline. Exercise is a widely accessible intervention for poor sleep that can protect against functional and cognitive decline. No previous systematic reviews have investigated the effectiveness of exercise for sleep in older adults with mild cognitive impairment or Alzheimer's disease and related dementias. We systematically reviewed controlled interventional studies of exercise targeting subjectively or objectively (polysomnography/actigraphy) assessed sleep in persons with mild cognitive impairment or Alzheimer's disease and related dementias. We conducted searches in PubMed, Embase, Scopus and Cochrane-Library (n = 6745). Nineteen randomised and one non-randomised controlled interventional trials were included, representing the experiences of 3278 persons with mild cognitive impairment or Alzheimer's disease and related dementias. Ten had low-risk, nine moderate-risk, and one high-risk of bias. Six studies with subjective and eight with objective sleep outcomes were meta-analysed (random-effects model). We found moderate- to high-quality evidence for the beneficial effects of exercise on self-reported and objectively-measured sleep outcomes in persons with mild cognitive impairment or Alzheimer's disease and related dementias. However, no studies examined key potential moderators of these effects, such as sex, napping or medication use. Our results have important implications for clinical practice. Sleep may be one of the most important modifiable risk factors for a range of health conditions, including cognitive decline and the progression of Alzheimer's disease and related dementias. Given our findings, clinicians may consider adding exercise as an effective intervention or adjuvant strategy for improving sleep in older persons with mild cognitive impairment or Alzheimer's disease and related dementias.

A Soft Bioelectronic Patch for Simultaneous Respiratory and Cardiovascular Monitoring

Sleep is critical to maintaining physical and mental health. Measuring physiological parameters to quantify sleep quality without uncomfortable user experience remains highly desired but a challenge. Here, this work develops a soft bioelectronic patch to perform simultaneous respiration and cardiovascular monitoring during sleep in a wearable and non-invasive manner. The soft bioelectronic patch system is mainly composed of a pressure sensor, a flexible printed circuit for signal processing, and a soft thermoplastic urethane mold for assembling different functional modules. The soft bioelectronic patch holds a sensitivity of >0.12 V kPa-1 and a remarkable low-frequency response from 0.5 to 15 Hz. It is demonstrated to continuously monitor respiration and heartbeat during the whole night, which could be harnessed for sleep monitoring and obstructive sleep apnea-hypopnea syndrome diagnosis. The reported soft bioelectronic patch represents a simple and convenient platform technology for sleep study.

Challenges in measuring sleep quality among women with endometriosis: A comparison of two questionnaires

OBJECTIVE

This study aimed to underscore the issues associated with the dichotomization of categories in sleep questionnaires among women diagnosed with endometriosis and sleep disturbances, as well as their potential impact on the validity of the research findings.

BACKGROUND

A range of questionnaires is employed across settings from primary care to research to classify sleep disturbances. Insomnia Severity Index (ISI) and the Pittsburgh Sleep Quality Index (PSQI) are two frequently utilized instruments for evaluating sleep. Nonetheless, these tools may produce divergent outcomes when applied to the same population.

METHODS

To evaluate the sleep quality of patients with deep endometriosis (DE), two self-administered questionnaires were utilized: ISI and PSQI. Patients rated their average pelvic pain over the preceding four weeks on a numeric rating scale (NRS) ranging from 0 to 10. Patients with an ISI score >14 or PSQI >5 were classified as poor sleepers, while the others as good sleepers.

RESULTS

Among the 161 patients who completed both sleep questionnaires, 129 (80 %) rated their subjective sleep quality as good. However, when the scores from the sleep questionnaires were analyzed, only 17 (11 %) patients were classified as good sleepers by the PSQI, whereas the ISI classified 83 (52 %) patients as good sleepers. When comparing the standardized scores, moderate to good reliability was found (intraclass correlation coefficient, 0.76; 95 % confidence interval, 0.69-0.82).

CONCLUSION

Both questionnaires yield consistent scores that seem comparable in women with DE; however, the cutoff values seem inadequate for this population. Therefore, we can probably rely on both questionnaire scores, yet their recommended cutoff values should be approached with caution.

Nigerian prisoners' experience: prison circumstances, family support and sleep quality

PURPOSE

This study aims to determine the association between prison circumstances, perceived family support and sleep quality among male inmates at the Ibara prison, Ogun State.

DESIGN/METHODOLOGY/APPROACH

It was a cross-sectional study of 300 male inmates interviewed with socio-demographic proforma and Pittsburgh sleep quality index.

FINDINGS

While all respondents described the prison as being overcrowded, half of them used inappropriate sleeping materials daily and 41.4% decried a very noisy environment at night. Twenty-seven percent of the respondents described poor family support while 47.3% experienced poor sleep quality. Though nature of sleeping material and self-awareness of sleep problem were associated with poor sleep quality, no predictor of the latter was identified.

RESEARCH LIMITATIONS/IMPLICATIONS

The study was conducted among males only because of the relative dominance of the male gender in the prison population. This makes analysis of gender difference impossible. Furthermore, sleep studies may be preferred over reports by some sleep experts.

PRACTICAL IMPLICATIONS

Findings from this study may culminate in taking steps to improve the Nigerian prison conditions as well as the prisoner's welfare.

SOCIAL IMPLICATIONS

Developing support group for relatives of inmates may be a focus of social intervention for these inmates. Also, inmates with good sleep quality are likely to partake effectively in the prison reformation programmes and may not self-medicate with sedatives.

ORIGINALITY/VALUE

This study provides a scholarly documentation of the state of Nigerian prisons; inmates' perception of family support; prevalence and correlates of poor sleep quality among a group of male inmates.

Subjective sleep assessments are correlated with EEG-related sleep measurements of the first sleep cycle in healthy young adults

This study examined whether subjective and objective sleep parameters (sleep stage, electroencephalography [EEG] power, heart rate variability) are related to the progression of sleep cycles using differences in the variables between two nights. We hypothesized that the association between night-to-night differences between subjective and objective sleep variables reflect the difference in objective sleep variables in the first sleep cycle. Seventy-seven healthy adults (23.8 ± 2.2 years; 41 females) participated in polysomnographic recordings on two consecutive nights. To extract the variables that represent the difference between the nights, the sleep parameters of Night 1 were subtracted from those of Night 2. Spearman's rho was used to assess correlations between subjective sleep assessments and objective sleep parameters, with false discovery rate correction for multiple comparisons. Subjective sleep assessments were significantly correlated with whole-night sleep architecture and quantitative EEG activity, but not with heart rate variability during the night. Among sleep cycles, subjective sleep parameters were correlated with the objective sleep parameters in the first sleep cycle ("Ease of falling asleep" vs. waking after sleep onset [r = - 0.382], "Depth of sleep" vs. EEG theta power [r = 0.404], "Quality of sleep" vs. the percentage of stage N3 [r = 0.412] and EEG delta power [r = 0.458], all p < 0.05). These results suggest the importance of taking the difference among the nights into account when assessing subjective sleep quality. This study clarified that sleep in the first sleep cycle has a dominant influence on subjective sleep assessments.

Supplementary Information

The online version contains supplementary material available at 10.1007/s41105-022-00437-x.

Poor quality sleep is associated with greater carotid intima media thickness among otherwise healthy resident doctors

Background

Sleep is important for maintaining the metabolic processes in the body, and hence, disruption in sleep leads to metabolic derangement and accelerated atherosclerosis. The effect of sleep duration on subclinical atherosclerosis has been examined in several studies; however, data regarding sleep quality is lacking. The study aimed to assess the association between sleep quality and carotid intima-media thickness among healthy young doctors.

Materials and Methods

This was an observational cross-sectional study among 110 healthy young resident doctors. Anthropometric data were recorded and morning fasting venous blood samples were collected to assess fasting blood sugar, lipid profile and glycosylated haemoglobin (HbA1c). Pittsburgh Sleep Quality Index and Berlin questionnaire assessed subjective sleep quality and risk for obstructive sleep apnea, respectively. Carotid ultrasonography was done to detect the intima-media thickness.

Results

Average age of the participants was 26.45 (±1.43) years, and 51.8% were male. Self-reported poor sleep quality was found in 54.5%. Carotid intima-media thickness (CIMT) was increased among 44.5% of participants. In the multivariate analysis, only poor sleep quality appeared to be associated with higher CIMT (P < 0.001, OR = 7.4; 95% CI = 2.70-20.32). When different components of sleep quality was analyzed through multivariate logistic regression, subjective sleep onset latency (>30 min), sleep efficiency (<85%) and sleep disturbance was found to be associated with the increased CIMT.

Conclusion

Poor sleep quality, especially prolonged sleep onset latency, poor sleep efficiency, and sleep disturbance are associated with increased carotid intima-media thickness among healthy young adults.

Sleep Continuity, Stability and Cyclic Organization Are Impaired in Insomniacs: A Case-Control Study

The possibility of distinguishing insomniacs from good sleepers based on polysomnography (PSG) remains an open question. While these groups show modest differences in traditional PSG parameters, some studies suggest that finer measures may be more useful. Here we assess differences between good sleepers (GS), poor sleepers (PS) and insomniacs (IN) in classical PSG measures as well as in sleep continuity, stability and cyclic organization. PSG-monitored sleep (two nights) of 17 IN (diagnosed through a standard clinical interview; Pittsburgh Sleep Quality Index (PSQI) ≥ 5, Insomnia Severity Index (ISI) > 14) was compared to that of 33 GS (PSQI < 5) and 20 PS (PSQI ≥ 5, ISI ≤ 14). Compared to GS, IN were impaired in sleep macrostructure (sleep latency, sleep efficiency, WASO%) and in continuity, stability and organization, whereas PS only showed disrupted continuity and stability. Spindle parameters were comparable between IN and GS, but the former displayed enhanced power in fast frequency bands. Our findings support the hypothesis of a continuum between individuals with self-reported poor sleep and insomniacs. Further, they add to extant data on impaired sleep continuity, stability and organization in poor sleepers and elderly individuals, underlining the utility of including these measures in standard sleep assessments.

Sleep Quality Evaluation Based on Single-Lead Wearable Cardiac Cycle Acquisition Device

In clinical conditions, polysomnography (PSG) is regarded as the "golden standard" for detecting sleep disease and offering a reference of objective sleep quality. For healthy adults, scores from sleep questionnaires are more reliable than other methods in obtaining knowledge of subjective sleep quality. In practice, the need to simplify PSG to obtain subjective sleep quality by recording a few channels of physiological signals such as single-lead electrocardiogram (ECG) or photoplethysmography (PPG) signal is still very urgent. This study provided a two-step method to differentiate sleep quality into "good sleep" and "poor sleep" based on the single-lead wearable cardiac cycle data, with the comparison of the subjective sleep questionnaire score. First, heart rate variability (HRV) features and ECG-derived respiration features were extracted to construct a sleep staging model (wakefulness (W), rapid eye movement (REM), light sleep (N1&N2) and deep sleep (N3)) using the multi-classifier fusion method. Then, features extracted from the sleep staging results were used to construct a sleep quality evaluation model, i.e., classifying the sleep quality as good and poor. The accuracy of the sleep staging model, tested on the international public database, was 0.661 and 0.659 in Cardiology Challenge 2018 training database and Sleep Heart Health Study Visit 1 database, respectively. The accuracy of the sleep quality evaluation model was 0.786 for our recording subjects, with an average F1-score of 0.771. The proposed sleep staging model and sleep quality evaluation model only requires one channel of wearable cardiac cycle signal. It is very easy to transplant to portable devices, which facilitates daily sleep health monitoring.

Cross-Sectional and Longitudinal Associations between Subjective Sleep Difficulties and Self-Perceptions of Aging

BACKGROUND

Only one study has explored the associations of subjective sleep difficulties with self-perceptions of aging. It focused on a global indicator of self-perceptions of aging (subjective age) despite individuals reporting different experiences of aging in relation to different life domains. The concept of awareness of negative age-related change, capturing perceived losses across five domains (e.g., physical health, cognition), may be more appropriate when relating subjective sleep difficulties to self-perceptions of aging. We examined whether nine different indicators of subjective sleep difficulties predict levels of awareness of negative age-related change and subjective age, measured concurrently and one year later, while controlling for covariates (mood and daily function).

PARTICIPANTS/METHODS

We used data from the PROTECT cohort study; 4,482 UK residents (mean age = 66.1; SD = 6.9) completed measures of awareness of age-related change, subjective age, mood, daily function, and subjective sleep difficulties.

RESULTS

Based on linear regression analyses, poorer quality of sleep, lower alertness after awakening, satisfaction with sleep, depth of sleep, more frequent early awakening, difficulty falling asleep, more times awake during a night, fewer hours of sleep during the night and more hours of sleep during the day predicted higher awareness of negative age-related change at baseline and follow-up (p< .001). Associations were small in size. Associations between subjective sleep difficulties and subjective age were either negligible or statistically non-significant.

CONCLUSIONS

Although subjective sleep difficulties are one of the many factors associated with awareness of negative age-related change, addressing sleep difficulties, alongside negative mood, and poor daily functioning, may promote a small additional increase in positive self-perceptions of aging.

Sleep Quality Among Burn Survivors And The Importance Of Intervention: A Systematic Review And Meta-Analysis

Burn survivors undergo a plethora of physiologic disturbances which can greatly affect quality of life (QOL) and healing processes. This review aimed to systematically examine sleep quality among individuals with burns and to explore the effectiveness of interventions using a meta-analytic approach. A systematic review of the literature was conducted by searching for articles using various databases. Titles and abstracts were screened and full texts of retained articles were assessed based on eligibility criteria. Methodological quality was ascertained in all articles using various scales. Overall, 5,323 articles were screened according to titles and abstracts and 25 articles were retained following full-text screening. Of the twenty-five articles, 17 were assessed qualitatively while 8 were included in the meta-analysis. Based on the qualitative analysis, sleep was found to be negatively affected in burn patients. The subsample of 8 articles included in the meta-analysis showed an overall weighted mean effect size (Hedges's g) of 1.04 (SE = 0.4, 95% CI, z = 3.0; p < 0.01), indicating a large, positive effect of intervention on sleep quality for burn patients. This review was able to demonstrate the detrimental effects of burn injury on sleep quality. Several interventions have been examined throughout the literature and have shown to be beneficial for sleep quality. However, there is great heterogeneity between existing interventions. The results from this review suggest that further research is needed before recommendations can be made as to which intervention is most effective at improving sleep in patients suffering from burn injuries.

Investigating the relationship between objective measures of sleep and self-report sleep quality in healthy adults: a review

STUDY OBJECTIVES

Sleep is one of the most common factors related to health, yet a standard definition of sleep quality has not been identified. Polysomnography provides important information about objective sleep variables. However, the relationship between objective sleep variables and perception of sleep quality remains unclear. The purpose of this review was to (1) summarize the current methods of measuring objective sleep macrostructure and microstructure, including electroencephalography arousals, spectral frequency, cyclic alternating pattern, and self-report sleep quality, and (2) investigate the relationship between objective measures of sleep physiology and self-report sleep quality in healthy adults.

METHODS

A literature search was conducted using Medline, PubMed, and PsycInfo databases and cited reference searches. Eligible studies included a comparison between self-report sleep quality and polysomnography sleep measures in healthy adults.

RESULTS

Thirteen studies were identified. Measurement of self-report sleep quality varied widely across studies. Total sleep time and sleep efficiency were most consistently related to sleep quality, while other objective sleep variables, including electroencephalography spectral analysis, were not reliably predictive of self-report sleep quality in healthy adults. There is preliminary support that microstructural sleep analysis with cyclic alternating pattern may be related to self-reported sleep quality.

CONCLUSIONS

Further research is needed to define and standardize self-report measures of sleep quality and investigate the microstructure of sleep. Objective measures of sleep and experiences of "quality" sleep are not as closely related as one may expect in healthy individuals, and understanding this relationship further is necessary to improve the clinical utility of sleep physiology.

CITATION

Cudney LE, Frey BN, McCabe RE, Green SM. Investigating the relationship between objective measures of sleep and self-report sleep quality in healthy adults: a review. J Clin Sleep Med. 2022;18(3):927-936.

Objective underpinnings of self-reported sleep quality in middle-aged and older adults: the importance of N2 and wakefulness

STUDY OBJECTIVES

The measurable aspects of brain function (polysomnography, PSG) that are correlated with sleep satisfaction are poorly understood. Using recent developments in automated sleep scoring, which remove the within- and between-rater error associated with human scoring, we examine whether PSG measures are associated with sleep satisfaction.

DESIGN AND SETTING

A single night of PSG data was compared to contemporaneously collected measures of sleep satisfaction with Random Forest regressions. Whole and partial night PSG data were scored using a novel machine learning algorithm.

PARTICIPANTS

Community-dwelling adults (N = 3165) who participated in the Sleep Heart Health Study.

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

Models explained 30% of sleep depth and 27% of sleep restfulness, with a similar top four predictors: minutes of N2 sleep, sleep efficiency, age, and minutes of wake after sleep onset (WASO). With increasing self-reported sleep quality, there was a progressive increase in N2 and decrease in WASO of similar magnitude, without systematic changes in N1, N3 or REM sleep. In comparing those with the best and worst self-reported sleep satisfaction, there was a range of approximately 30 min more N2, 30 min less WASO, an improvement of sleep efficiency of 7-8%, and an age span of 3-5 years. Examination of sleep most proximal to morning awakening revealed no greater explanatory power than the whole-night data set.

CONCLUSIONS

Higher N2 and concomitant lower wake is associated with improved sleep satisfaction. Interventions that specifically target these may be suitable for improving the self-reported sleep experience.

REM Sleep: An Unknown Indicator of Sleep Quality

Standard polysomnographic analysis of sleep has not provided evidence of an objective measure of sleep quality; however, factors such as sleep duration and sleep efficiency are those more consistently associated with the subjective perception of sleep quality. Sleep reduction as currently occurs in our 24/7 society has had a profound impact on sleep quality; the habitual sleep period should fit within what is a limited nighttime window and may not be sufficient to satisfy the whole sleep process; moreover, the use of artificial light during the evening and early night hours can delay and disturb the circadian rhythms, especially affecting REM sleep. The correct phase relationship of the sleep period with the circadian pacemaker is an important factor to guarantee adequate restorative sleep duration and sleep continuity, thus providing the necessary background for a good night's sleep. Due to the fact that REM sleep is controlled by the circadian clock, it can provide a window-like mechanism that defines the termination of the sleep period when there is still the necessity to complete the sleep process (not only wake-related homeostasis) and to meet the circadian end of sleep timing. An adequate amount of REM sleep appears necessary to guarantee sleep continuity, while periodically activating the brain and preparing it for the return to consciousness.

No evidence for intra-individual correlations between sleep-mediated declarative memory consolidation and slow-wave sleep

STUDY OBJECTIVES

Memory consolidation benefits from a retention period filled with sleep. Several theoretical accounts assume that slow-wave sleep (SWS) contributes functionally to processes underlying the stabilization of declarative memories during sleep. However, reports on correlations between memory retention and the amount of SWS are mixed and typically rely on between-subject correlations and small sample sizes. Here we tested for the first time whether the amount of SWS during sleep predicts the effect of sleep on memory consolidation on an intra-individual level in a large sample.

METHODS

One hundred and fifty-nine healthy participants came to the lab twice and took a 90 min nap in both sessions. Sleep-mediated memory benefits were tested using the paired associates word-learning task in both sessions.

RESULTS

In contrast to the theoretical prediction, intra-individual differences in sleep-mediated memory benefits did not significantly correlate with differences in SWS or SWA between the two naps. Also between subjects, the amount of SWS did not correlate with memory retention across the nap. However, subjective ratings of sleep quality were significantly associated with the amount of SWS.

CONCLUSION

Our results question the notion that the amount of SWS per se is functionally related to processes of memory consolidation during sleep. While our results do not exclude an important role of SWS for memory, they suggest that "more SWS" does not necessarily imply better memory consolidation.

Sleep quality and architecture in COPD: the relationship with lung function abnormalities

OBJECTIVE

Impaired respiratory mechanics and gas exchange may contribute to sleep disturbance in patients with COPD. We aimed to assess putative associations of different domains of lung function (airflow limitation, lung volumes, and gas exchange efficiency) with polysomnography (PSG)-derived parameters of sleep quality and architecture in COPD.

METHODS

We retrospectively assessed data from COPD 181 patients ≥ 40 years of age who underwent spirometry, plethysmography, and overnight PSG. Univariate and multivariate linear regression models predicted sleep efficiency (total sleep time/total recording time) and other PSG-derived parameters that reflect sleep quality.

RESULTS

The severity of COPD was widely distributed in the sample (post-bronchodilator FEV1 ranging from 25% to 128% of predicted): mild COPD (40.3%), moderate COPD (43.1%), and severe-very severe COPD (16.6%). PSG unveiled a high proportion of obstructive sleep apnea (64.1%) and significant nocturnal desaturation (mean pulse oximetry nadir = 82.2% ± 6.9%). After controlling for age, sex, BMI, apnea-hypopnea index, nocturnal desaturation, comorbidities, and psychotropic drug prescription, FEV1/FVC was associated with sleep efficiency (β = 25.366; R2 = 14%; p < 0.001), whereas DLCO predicted sleep onset latency (β = -0.314; R2 = 13%; p < 0.001) and rapid eye movement sleep time/total sleep time in % (β = 0.085; R2 = 15%; p = 0.001).

CONCLUSIONS

Pulmonary function variables reflecting severity of airflow and gas exchange impairment, adjusted for some potential confounders, were weakly related to PSG outcomes in COPD patients. The direct contribution of the pathophysiological hallmarks of COPD to objectively measured parameters of sleep quality seems to be less important than it was previously assumed.

Are Reallocations between Sedentary Behaviour and Physical Activity Associated with Better Sleep in Adults Aged 55+ Years? An Isotemporal Substitution Analysis

Physical activity has been proposed as an effective alternative treatment option for the increasing occurrence of sleep problems in older adults. Although higher physical activity levels are associated with better sleep, the association between specific physical activity intensities and sedentary behaviour (SB) with sleep remains unclear. This study examines the associations of statistically modelled time reallocations between sedentary time and different physical activity intensities with sleep outcomes using isotemporal substitution analysis. Device-measured physical activity data and both objective and subjective sleep data were collected from 439 adults aged 55+ years. Replacing 30 min of SB with moderate to vigorous intensity physical activity (MVPA) was significantly associated with an increased number of awakenings. Moreover, a reallocation of 30 min between light physical activity (LPA) and MVPA was significantly associated with increased sleep efficiency. Furthermore, reallocating 30 min of SB to LPA showed a significant association with decreased sleep efficiency. There were no significant associations of time reallocations for wake time after sleep onset, length of awakenings, and sleep quality. These results improve our understanding of the interrelationships between different intensities of movement behaviours and several aspects of sleep in older adults.

Prevalence and Determinants of Bad Sleep Perception among Italian Children and Adolescents

Although sleep problems at young ages are well investigated, the prevalence of bad sleepers and the determinants of sleep quality perception remain unexplored in these populations. For this purpose, we addressed these issues in a sample of children (n = 307), preadolescents (n = 717), and adolescents (n = 406) who completed the School Sleep Habits Survey, addressing sleep quality perception, sleep habits, sleep features, daytime behavior and sleep disturbances, circadian preference, and dreaming. The sample was split in “good sleepers” and “bad sleepers”, based on the answer to the question item assessing overall subjective sleep quality. Being a bad sleeper was reported by 11.7% of the sample, with significant between-groups differences (children: 8.3%; preadolescents: 11.3%; adolescents: 15.3%; p = 0.01). At all ages, relative to good sleepers, bad sleepers showed higher eveningness, sleepiness, and depression, longer sleep latency, more frequent insufficient sleep, nocturnal awakenings, sleep–wake behavioral problems, and unpleasant dreams (all p’s ≤ 0.01). Sleep quality perception was predicted: in children, by depressed mood, eveningness, and unpleasant dreams (all p’s ≤ 0.01); in preadolescents, by sleep latency, awakening frequency, depressed mood, sufficiency of sleep, and unpleasant dreams (all p’s < 0.01); in adolescents, by awakening frequency, depressed mood, and sufficiency of sleep (all p’s < 0.001). In children, bad subjective sleep quality appears to be mainly determined by daytime psychological features, for example, depressed mood, whereas at later ages, sleep characteristics, such as frequent awakenings, add to the former determinants. This could depend on (a) the appearance, with increasing age, of objective sleep modifications and (b) a greater attention paid by adolescents to their sleep characteristics.

A quantitative analysis of the effect of bilateral subthalamic nucleus-deep brain stimulation on subjective and objective sleep parameters in Parkinson's disease

OBJECTIVE

To explore how subjective and objective sleep parameters respond to bilateral subthalamic nucleus-deep brain stimulation (STN-DBS) in patients with Parkinson's disease (PD).

METHODS

Thirty DBS sleep studies were included by searching PubMed, Embase, and the Cochrane Library, and only 21 prospectively designed studies, including 541 patients, were eligible for the main analysis. We evaluated sleep disturbance using 1 objective measurement, polysomnography (PSG), and 4 subjective scales, including PD Sleep Scale (PDSS), Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), and restless legs syndrome (RLS). We pooled data using the standard mean difference (SMD). The primary outcome was a change in sleep parameters 6 months postoperatively. Outcomes from <12 months to ≥12 months follow-up were compared in the subgroup analysis. Meta-regression was further conducted.

RESULTS

STN-DBS significantly improved all 4 subjective sleep scales in the 6-month follow-up: ESS (SMD = 0.234), PDSS (SMD = 0.724), PSQI (SMD = 1.374) and RLS (SMD = 1.086), while most PSG parameters remained unchanged, except for shortened rapid eye movement sleep latency (RSL) (SMD = 0.520). In the over-12-month follow-up, improvement persisted in PDSS but not in ESS. Dopamine drug reduction (p = 0.009) and motor improvement (p = 0.036) were correlated with ESS improvement and PDSS improvement, respectively.

CONCLUSIONS

Bilateral STN-DBS continuously improved subjective nocturnal sleep, while its effect on ESS lasted for only 1 year. Medication reduction and motor improvement may contribute to improved daytime sleepiness and better subjective nocturnal sleep, respectively. Except for a shortened RSL, STN-DBS did not change PSG parameters, including sleep efficiency and sleep architecture.

REGISTRATION

Open Science Framework: DOI 10.17605/OSF.IO/3EGRC.

Associations of short sleep duration with appetite-regulating hormones and adipokines: A systematic review and meta-analysis

In the current study, a systematic review and meta-analysis were conducted to summarize and assess whether short sleep duration is associated with appetite-regulating hormones and adipokine levels. Reference databases were searched for studies related to sleep and appetite-regulating hormones and adipokines. Qualitative and quantitative syntheses were conducted to evaluate the relationship between sleep duration and the level of appetite-regulating hormones and adipokines, including leptin, ghrelin, adiponectin, resistin, and orexin. Twenty-one of 3536 studies, covering a total of 2250 participants, met the inclusion criteria. Leptin, ghrelin, and adiponectin were included in the meta-analysis. Ghrelin levels were higher in the short sleep group (standard mean difference [SMD] = 0.14, 95% CI [0.03, 0.25], p = 0.01). Significant differences between the short sleep group and recommended sleep group were also noted in leptin level experimental subgroup studies (SMD = 0.19, 95% CI [0.03, 0.35], p = 0.02) and ghrelin level cross-sectional subgroup studies (SMD = 0.14, 95% CI [0.02, 0.27], p = 0.03). A rise in leptin and ghrelin levels were also observed in sleep deprivation groups (SMD = 0.24, 95% CI [0.10, 0.39], p = 0.001 and SMD = 0.18, 95% CI [0.04, 0.33], p = 0.01, respectively). In conclusion, short sleep duration is associated with an increased ghrelin level, while sleep deprivation had a significant effect on the levels of both leptin and ghrelin.

Impact of sleep on female and male reproductive functions: a systematic review

OBJECTIVE

To evaluate the association of sleep parameters on female and male reproductive functions.

DESIGN

Systematic review.

SETTING

Not applicable.

PATIENT(S)

Female and male individuals, either healthy or infertile.

INTERVENTION(S)

Relevant articles were identified according to the The Preferred Reporting Items for Systematic Reviews and Meta-analyses recommendations in the PubMed and EMBASE databases from January 1, 2000 to June 8, 2020.

MAIN OUTCOME MEASURE(S)

The association between sleep and ovary function, spermatic function, natural fertility, and in vitro fertilization (IVF) outcomes was assessed.

RESULT(S)

A total of 33 studies that looked at the association between sleep and either ovary function (n = 10), spermatic function (n = 12), natural fertility (n = 5), or IVF outcomes (n = 6) were included. Overall, female and male fertility, as well as IVF outcomes may be affected by short sleep duration, evening chronotype, or shift/night work schedules. However, the results were hardly comparable due to the heterogeneous study methodologies used.

CONCLUSION(S)

Sleep may be an original and innovative parameter to consider in the reproduction field. Further investigation is needed to elucidate how sleep and fertility are interrelated and how sleep might constitute a useful modifiable target in infertility management.

Current Status and Future Challenges of Sleep Monitoring Systems: Systematic Review

Background

Sleep is essential for human health. Considerable effort has been put into academic and industrial research and in the development of wireless body area networks for sleep monitoring in terms of nonintrusiveness, portability, and autonomy. With the help of rapid advances in smart sensing and communication technologies, various sleep monitoring systems (hereafter, sleep monitoring systems) have been developed with advantages such as being low cost, accessible, discreet, contactless, unmanned, and suitable for long-term monitoring.

Objective

This paper aims to review current research in sleep monitoring to serve as a reference for researchers and to provide insights for future work. Specific selection criteria were chosen to include articles in which sleep monitoring systems or devices are covered.

Methods

This review investigates the use of various common sensors in the hardware implementation of current sleep monitoring systems as well as the types of parameters collected, their position in the body, the possible description of sleep phases, and the advantages and drawbacks. In addition, the data processing algorithms and software used in different studies on sleep monitoring systems and their results are presented. This review was not only limited to the study of laboratory research but also investigated the various popular commercial products available for sleep monitoring, presenting their characteristics, advantages, and disadvantages. In particular, we categorized existing research on sleep monitoring systems based on how the sensor is used, including the number and type of sensors, and the preferred position in the body. In addition to focusing on a specific system, issues concerning sleep monitoring systems such as privacy, economic, and social impact are also included. Finally, we presented an original sleep monitoring system solution developed in our laboratory.

Results

By retrieving a large number of articles and abstracts, we found that hotspot techniques such as big data, machine learning, artificial intelligence, and data mining have not been widely applied to the sleep monitoring research area. Accelerometers are the most commonly used sensor in sleep monitoring systems. Most commercial sleep monitoring products cannot provide performance evaluation based on gold standard polysomnography.

Conclusions

Combining hotspot techniques such as big data, machine learning, artificial intelligence, and data mining with sleep monitoring may be a promising research approach and will attract more researchers in the future. Balancing user acceptance and monitoring performance is the biggest challenge in sleep monitoring system research.

Single-layered ultra-soft washable smart textiles for all-around ballistocardiograph, respiration, and posture monitoring during sleep

Good sleep is considered to be the cornerstone for maintaining both physical and mental health. However, nearly one billion people worldwide suffer from various sleep disorders. To date, polysomnography (PSG) is the most commonly used sleep-monitoring technology,however, it is complex, intrusive, expensive and uncomfortable. Unfortunately, present noninvasive monitoring technologies cannot simultaneously achieve high sensitivity, multi-parameter monitoring and comfort. Here, we present a single-layered, ultra-soft, smart textile for all-around physiological parameters monitoring and healthcare during sleep. With a high-pressure sensitivity of 10.79 mV/Pa, a wide working frequency bandwidth from 0 Hz to 40 Hz, good stability, and decent washability, the single-layered ultra-soft smart textile is simultaneously capable of real-time detection and tracking of dynamic changes in sleep posture, and subtle respiration and ballistocardiograph (BCG) monitoring. Using the set of patient generated health data, an obstructive sleep apnea-hypopnea syndrome (OSAHS) monitoring and intervention system was also developed to improve the sleep quality and prevent sudden death during sleep. This work is expected to pave a new and practical pathway for physiological monitoring during sleep.

Sleep continuity, stability and organization in good and bad sleepers

The relationship between objective and subjective sleep quality is still debated. Here, we investigate differences in objective sleep parameters in habitual subjective good sleepers and bad sleepers with the aim of evaluating sleep continuity, stability and organization as possible determinants of subjective sleep quality. In total, 38 subjects (good sleepers, N = 18; bad sleepers, N = 20) underwent two nights of sleep recording. Traditional sleep parameters displayed no between-groups differences. Conversely, bad sleepers showed lower sleep continuity (awakenings frequency), stability (e.g. arousals and state transitions frequency) and organization (e.g. number of sleep cycles and time spent in cycles). Our findings point to the involvement of these measures in determining habitual sleep quality perception and suggest the possibility to include them in standard sleep assessments.

Effects of physical activity programs on sleep outcomes in older adults: a systematic review

BACKGROUND

One in two older adults report sleep problems, which not only cause fatigue, but also negatively affect general functioning, activities of daily living, and physical and mental health. Although it is known that physical activity is positively associated with sleep in older adults, the effects of physical activity programs on sleep in older adults has not been reviewed. The aim of this systematic review was to systematically review the effects of physical activity programs on sleep in generally healthy older adults aged 60+ years.

METHODS

Searches were performed in PubMed, Embase, Web of Science, SPORTDiscus, PEDro and CINAHL. The methodological quality of the included studies was rated using the 'Quality Assessment Tool for Quantitative Studies'. Only studies of moderate and strong quality were included. This review was registered in PROSPERO (CRD42018094007).

RESULTS

Fourteen studies met the inclusion criteria (six randomised controlled trials and eight pretest-posttest studies). Of these studies, five were moderate and nine were strong quality studies. Mean age of study samples ranged from 64 to 76 years. Exercise programs included various activities aimed at improving mobility, endurance and strength. Intervention duration ranged from 2 weeks to 12 months. Eleven studies used subjective measures of sleep, two used objective measures and one used both. Sixteen different sleep outcomes were reported. All but one study, found at least one significant improvement on sleep outcomes. No significantly detrimental effects were reported. Effect sizes, calculated in ten studies, ranged from 0,34-1,55 and were substantial (≥0,8) in four studies.

CONCLUSIONS

This systematic review suggests that exercise programs positively affect various aspects of sleep in generally healthy older adults. More specifically, moderate intensity exercise programs, with a frequency of three times per week and a duration of 12 weeks up to 6 months, showed the highest number of significant improvements in different sleep outcomes in older adults. Furthermore, programs that offered single exercise types, such as Baduanjin, Tai chi and the silver yoga program, or a combination of exercises showed the highest proportion of significant versus reported effects on sleep outcomes.

HYPNOTIC SUGGESTIONS GIVEN BEFORE NIGHTTIME SLEEP EXTEND SLOW-WAVE SLEEP AS COMPARED TO A CONTROL TEXT IN HIGHLY HYPNOTIZABLE SUBJECTS

While slow-wave sleep (SWS) is fundamental for maintaining health and well-being, it is typically reduced with stress or age. The authors have previously reported that hypnotic suggestions before sleep increased SWS duration and slow-wave activity (SWA) during a midday nap in hypnotizable younger and older women. To test generalizability, they investigated this effect across 8 hours nighttime sleep in 43 healthy young French-speaking subjects (19 males) of high and low hypnotizability. In accordance with their previous results, listening to hypnotic suggestions before sleep was followed by higher amounts of SWS in highly hypnotizable subjects and higher SWA power compared to a control condition. The effects were most pronounced at the beginning of the night. Further studies are needed to examine whether hypnotic suggestions can deepen sleep also above non-intervention nights. The findings provide a basis for the examination and potential application of hypnosis to improve sleep in clinical populations.

Determinants of perceived sleep quality in normal sleepers

Objective: This study aimed to establish the determinants of perceived sleep quality over a longer period of time, taking into account the separate contributions of actigraphy-based sleep measures and self-reported sleep indices. Methods: Fifty participants (52 ± 6.6 years; 27 females) completed two consecutive weeks of home monitoring, during which they kept a sleep-wake diary while their sleep was monitored using a wrist-worn actigraph. The diary included questions on perceived sleep quality, sleep-wake information, and additional factors such as well-being and stress. The data were analyzed using multilevel models to compare a model that included only actigraphy-based sleep measures (model Acti) to a model that included only self-reported sleep measures to explain perceived sleep quality (model Self). In addition, a model based on the self-reported sleep measures and extended with nonsleep-related factors was analyzed to find the most significant determinants of perceived sleep quality (model Extended). Results: Self-reported sleep measures (model Self) explained 61% of the total variance, while actigraphy-based sleep measures (model Acti) only accounted for 41% of the perceived sleep quality. The main predictors in the self-reported model were number of awakenings during the night, sleep onset latency, and wake time after sleep onset. In the extended model, the number of awakenings during the night and total sleep time of the previous night were the strongest determinants of perceived sleep quality, with 64% of the variance explained. Conclusion: In our cohort, perceived sleep quality was mainly determined by self-reported sleep measures and less by actigraphy-based sleep indices. These data further stress the importance of taking multiple nights into account when trying to understand perceived sleep quality.

(Re)Conceptualizing Sleep Among Children with Anxiety Disorders: Where to Next?

Children with anxiety disorders (AD) characteristically complain of sleep problems and the extent to which cognitive behavioral treatments (CBT) for childhood anxiety produce sleep-based improvements is a topic of increasing interest. The current paper reviews available evidence for subjective sleep complaints and objective sleep alterations in children and adolescents with AD, including investigations of potential changes in sleep following anxiety-focused CBT. Despite pervasive complaints of poor sleep, the empirical literature provides minimal evidence for actual sleep-wake alterations in this population of youth and evidence for sleep-based changes following treatment for anxiety is minimal. In line with calls for more comprehensive models of the role of sleep in developmental psychopathology, several fundamental gaps in understanding are described and highlighted as essential avenues for clarifying the nature and consequences of poor quality sleep among youth with clinical levels of anxiety. In a second section of the paper, an emerging body of novel, translational research investigating more intricate sleep-anxiety relationships is introduced with potential implications for both etiological models and treatment design and delivery.

Unravelling the Prospective Associations Between Mixed Anxiety-Depression and Insomnia During the Course of Cognitive Behavioral Therapy

OBJECTIVE

Previous studies have suggested that there is a reciprocal relationship between anxiety/depression and insomnia. However, little is known about the prospective relationships between these constructs across the course of cognitive behavioral therapy (CBT). The aim of the study was to examine these relationships in clients who received short-term CBT in a primary care setting.

METHODS

A total of 653 clients (mean [SD] age = 37.8 [12.9], 26.4% men) with mild to moderate levels of anxiety and depression and a treatment duration of at least 7 weeks were included for analyses. The clients completed questionnaires measuring mixed anxiety-depression (MAD - Patient Health Questionnaire Anxiety and Depression Scale) and insomnia (3 items derived from the Karolinska Sleep Questionnaire representing core DSM-V criteria) on a session-to-session basis. The data were analyzed using latent growth curve models and random intercept cross-lagged panel models.

RESULTS

The results of the latent growth curve models showed that there was a significant decrease in both MAD (cubic slope; B = .002, p < .001, quadratic slope; B = .036, p < .001, linear slope; B = -.205, p < .001) and insomnia (linear slope; B = -.080, p < .001) across treatment. A strong correlation (r = .838, p < .001) between the linear slopes indicated co-occurring change processes. The cross-lagged panel model showed that insomnia significantly predicted MAD at the subsequent measurements (B = .190, p < .001), but not vice versa (B = .252, p = .343).

CONCLUSIONS

Changes in MAD and insomnia are co-occurring processes during the course of CBT. Changes in insomnia predicted prospectively changes in MAD, but not vice versa. Targeting insomnia in the context of brief CBT in clients with mild to moderate anxiety and depression may therefore further reduce not only symptoms of insomnia but also symptoms of anxiety and depression.

App-technology to improve lifestyle behaviors among working adults - the Health Integrator study, a randomized controlled trial

BACKGROUND

Mobile health, mHealth is recognized as a strategy to improve lifestyle behaviors. Research targeting specific lifestyle behaviors has shown that interventions using smartphones can be effective. However, few studies have evaluated solutions with multicomponent interventions, tailoring the intervention to the specific needs of the participant using a combination of mHealth and conventional treatment. To accomplish this, we developed Health Integrator, an mHealth platform with services and offers in the areas of diet, physical activity, sleeping habits, stress, alcohol and tobacco use. In the system, the user selects an area of intervention together with a health coach and set weekly goals. This study protocol presents the design and methodology of the Health Integrator Study, a randomized controlled trial to promote improved lifestyle behaviors.

METHODS

A three-arm parallel randomized controlled trial (1:1:1) is conducted in the Stockholm County, Sweden. In total, 209 employees at a four different companies representing both white and blue collar workers, have been recruited. Participants are randomized to either a control group or to one of two intervention groups receiving a 3-month lifestyle behavior change program including either 1) use of Health Integrator and monthly health coaching sessions or 2) only Health Integrator. At baseline and follow-up after 3- and 6-months, all participants answer questionnaires assessing lifestyle behaviors and quality of life. At baseline and the 3-month follow-up (end of intervention period), weight, height, waist circumference and blood pressure are measured, and all participants wear an Actigraph accelerometer for 7 days to assess physical activity. Blood lipid profile and HbA1c are measured among all participants at baseline. If baseline measures fall outside the normal range, a second measurement is done after 3 months.

DISCUSSION

The Health Integrator Intervention Study will evaluate if a personalized intervention combining mHealth and conventional programs for lifestyle change, with or without additional health coach sessions, can improve lifestyle behaviors and quality of life. Based on the results from this trial, Health Integrator can easily be implemented within a broad public.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03579342 . Retrospectively registered, first submitted May 8, 2018.

Time Perspective Biases Are Associated With Poor Sleep Quality, Daytime Sleepiness, and Lower Levels of Subjective Well-Being Among Older Adults

This study examined the extent to which individual differences in time perspective, i.e., habitual way of relating to the personal past, present, and future, are associated with sleep quality and daytime sleepiness in a sample of older adults. The participants (N = 437, 60–90 years) completed the Karolinska Sleep Questionnaire (KSQ), a the Swedish version of the Zimbardo Time Perspective Inventory (S-ZTPI), and two ratings of subjective well-being (SWB) (life satisfaction, happiness). Based on established relationships between dimension of time perspective and other variables (e.g., depression) and relations between negative retrospection (rumination) and negative prospection (worry) in prior studies, we expected higher scores on Past Negative and Future Negative to be linked to poor sleep quality and (indirectly) increased daytime sleepiness. Moreover, we examined the possibility that variations in perceived sleep and sleepiness during the day mediates the expected association between an aggregate measure of deviations from a so called balanced time perspective (DBTP) and SWB. In regression analyses controlling for demographic factors (age, sex, and work status), higher scores on Past Negative and Future Negative predicted poorer sleep quality and higher levels of daytime sleepiness. Additionally, most of the association between time perspective and daytime sleepiness was accounted for by individual differences in sleep quality. Finally, structural equation modeling yielded results consistent with the hypothesis that variations in sleep mediate part of the negative relationship between DBTP and SWB. Given that good sleep is essential to multiple aspects of health, future studies evaluating relationships between time perspective and adverse health outcomes should consider sleep quality as a potentially contributing factor.

Women with both sleep problems and snoring show objective impairment of sleep

OBJECTIVE

Combined insomnia and obstructive sleep apnea has been the focus of considerable research with respect to its health effects. A related issue is whether sleep disturbances in combination with snoring might exert effects on objective sleep variables in the non-clinical general population. The purpose of the present study was to investigate the polysomnographical characteristics of individuals who had sought medical help for both disturbed sleep and for snoring. No previous work of this type has been carried out.

METHOD

For this study we used a representative set of data of 384 women with one night of in-home PSG. We identified those individuals who had sought medical help for sleep problems (SL), individuals that had sought help for snoring (SN), as well as those that had sought help for either both (Combined), or for neither (Control).

RESULTS

Our results yielded an N of 46, 16, 21, and 301 individuals, respectively. A one-factor analysis of variance showed significant main effects on N1% (F = 10.2, p < 0.001), N3% (F = 2.7, p < 0.05), AHI/h (F = 5.5, p < 0.001), and a delta power measure (F = 3.8, p < 0.05). The combined group showed significantly higher levels than the other groups for N1% (29% vs < 21%), AHI/h (19/h vs < 10/h) and lower levels for N3%, and a measure of delta power. Reported sleep quality measures did not show the same pattern, since the highest/lowest value were found for either the group presenting snoring alone or sleep problems alone.

CONCLUSION

We concluded that individuals who had sought help for both insomnia and snoring showed impaired sleep in terms of PSG and that this was not reflected in ratings of sleep or health. This suggests that simultaneous sleep disturbances and snoring may potentiate each other to cause impaired sleep, yet the mechanism still needs to be elucidated.

Conceptions of sleep experience: a layman perspective

OBJECTIVE

To date, there is little information on how lay people understand and discuss sleep in the context of daily life. Efforts to conceptualize sleep quality have been largely driven by clinical considerations of sleep disorders. As such, they are not necessarily of how normal sleepers without clinical expertise conceptualize sleep quality. A phenomenological approach was taken to understand the essence of the sleep experience and the concepts held by lay people without sleep disorders. A sentence completion questionnaire was developed and administered to a quota sample of 64 respondents who were selected aiming for sufficient representation of different gender, ages, and education levels.

RESULTS

Significant sentences and meaningful units were derived inductively, resulting in a classification of nine categories. The major facets of sleep experience of lay people were 'daytime functioning', 'interruptions during the night' and 'before bed state'. This implies that the experienced sleep quality is not only depending on the progress of the night. These results can guide future research to provide suitable psychometric measures for normal sleepers, as well as the design of sleep data visualization applications in the context of health self-monitoring.

Impacts of artificial light at night on sleep: A review and prospectus

Natural cycles of light and darkness govern the timing of most aspects of animal behavior and physiology. Artificial light at night (ALAN)-a recent and pervasive form of pollution-can mask natural photoperiodic cues and interfere with biological rhythms. One such rhythm vulnerable to perturbation is the sleep-wake cycle. ALAN may greatly influence sleep in humans and wildlife, particularly in animals that sleep predominantly at night. There has been some recent evidence for impacts of ALAN on sleep, but critical questions remain. Some of these can be addressed by adopting approaches already entrenched in sleep research. In this paper, we review the current evidence for impacts of ALAN on sleep, highlight gaps in our understanding, and suggest opportunities for future research.

Athletes underestimate sleep quantity during daytime nap opportunities

This study examined the difference between athletes' self-reported and objective sleep durations during two nap opportunities. Twelve well-trained male soccer players' sleep durations were assessed using polysomnography and a self-report question during a 60- and 120-min nap opportunity. Participants underestimated sleep compared to objective sleep assessments for both the 60-min nap opportunity (p = 0.004) and 120-min nap opportunity (p = 0.001). Soccer players underestimated their sleep duration by approximately 10 min per hour of nap opportunity. It is yet to be determined if athletes are likely to underestimate sleep duration during their main nighttime sleep period.

What Sways People's Judgment of Sleep Quality? A Quantitative Choice-Making Study With Good and Poor Sleepers

Study objectives:

We conceptualized sleep quality judgment as a decision-making process and examined the relative importance of 17 parameters of sleep quality using a choice-based conjoint analysis.

Methods:

One hundred participants (50 good sleepers; 50 poor sleepers) were asked to choose between 2 written scenarios to answer 1 of 2 questions: “Which describes a better (or worse) night of sleep?”. Each scenario described a self-reported experience of sleep, stringing together 17 possible determinants of sleep quality that occur at different times of the day (day before, pre-sleep, during sleep, upon waking, day after). Each participant answered 48 questions. Logistic regression models were fit to their choice data.

Results:

Eleven of the 17 sleep quality parameters had a significant impact on the participants’ choices. The top 3 determinants of sleep quality were: Total sleep time, feeling refreshed (upon waking), and mood (day after). Sleep quality judgments were most influenced by factors that occur during sleep, followed by feelings and activities upon waking and the day after. There was a significant interaction between wake after sleep onset and feeling refreshed (upon waking) and between feeling refreshed (upon waking) and question type (better or worse night of sleep). Type of sleeper (good vs poor sleepers) did not significantly influence the judgments.

Conclusions:

Sleep quality judgments appear to be determined by not only what happened during sleep, but also what happened after the sleep period. Interventions that improve mood and functioning during the day may inadvertently also improve people’s self-reported evaluation of sleep quality.

Optimal Questions for Sleep in Epidemiological Studies: Comparisons of Subjective and Objective Measures in Laboratory and Field Studies

Epidemiological studies on sleep often use questionnaires, and measurement of validity provides necessary guidance in selection of valid single sleep questions. Twenty-five items assessing different aspects of sleep, including overall sleep quality, specific sleep parameters, nocturnal restoration, and exposure-related questions, were tested. This involved coherence with objective polysomnographic (PSG) laboratory measurements of sleep in 47 participants and application of selected items under field conditions in over 3,000 participants. Items on overall sleep quality correlated significantly with PSG data. For specific sleep parameter questions, tiredness in the morning, time to fall asleep, difficulties to sleep and estimated number of awakenings were correlated to PSG data. Questions asking specifically about the effect of potential sleep disturbances correlated poorly with PSG data, but showed highest effects between environmental exposure (noise and vibration) and control nights in the laboratory and highest correlation with the dose of exposure in the field. In conclusion, healthy participants seem to be able to access their sleep reliably; and sleep questions asking about specific sleep parameters can be recommended for the assessment of sleep.

The critical influence of nocturnal breathing complaints on the quality of sleep after stroke: the Pittsburgh Sleep Quality Index and STOP-BANG

ABSTRACT In stroke patients particularly, many factors, such as sleep-related respiratory disturbances, can impair sleep. Cheap and easy-to-use tools have been created to identify sleep quality and sleep disturbances in patients after stroke. This study described the scores of the sleep apnea screening questionnaire - STOP-BANG - in patients after a stroke, and correlated the findings with sleep quality measured by the Pittsburgh Sleep Quality Index (PSQI). The scores of the STOP-BANG and PSQI were 4.3 ± 1.8 and 76 ± 3.9, respectively. The STOP-BANG scores were higher in poor sleepers (4.5 ± 1.6 versus 3.5 ± 1.9; p = 0.032). Logistic regression analysis was used to identify predictors of subjective sleep quality (PSQI) and the STOP-BANG as a predictor of poor quality sleep, with a relative risk of 1.6, controlled for age and sex. This study indicated that sleep quality was largely influenced by sleep breathing problems, which were well identified by the STOP-BANG, especially in younger stroke patients.

Do Older Adults Need Sleep? A Review of Neuroimaging, Sleep, and Aging Studies

PURPOSE OF REVIEW

Sleep habits, sleep physiology, and sleep disorders change with increasing age. However, there is a longstanding debate regarding whether older adults need sleep to maintain health and daily functioning (reduced-sleep-need view). An alternative possibility is that all older adults need sleep, but that many older adults have lost the ability to obtain restorative sleep (reduced-sleep-ability view). Prior research using behavioral and polysomnography outcomes has not definitively disentangled the reduced-sleep-need and reduced-sleep-ability views. Therefore, this review examines the neuroimaging literature to determine whether age-related changes in sleep cause-or are caused by-age-related changes in brain structure, function, and pathology.

RECENT FINDINGS

In middle-aged and older adults, poorer sleep quality, greater nighttime hypoxia, and shorter sleep duration related to cortical thinning in frontal regions implicated in slow wave generation, in frontoparietal networks implicated in cognitive control, and in hippocampal regions implicated in memory consolidation. Furthermore, poor sleep quality was associated with higher amyloid burden and decreased connectivity in the default mode network, a network that is disrupted in the pathway to Alzheimer's disease.

SUMMARY

All adults need sleep, but cortical thinning and amyloidal deposition with advancing age may weaken the brain's ability to produce restorative sleep. Therefore, sleep in older adults may not always support identical functions for physical, mental, and cognitive health as in young adults.

When a gold standard isn't so golden: Lack of prediction of subjective sleep quality from sleep polysomnography

BACKGROUND

Reports of subjective sleep quality are frequently collected in research and clinical practice. It is unclear, however, how well polysomnographic measures of sleep correlate with subjective reports of prior-night sleep quality in elderly men and women. Furthermore, the relative importance of various polysomnographic, demographic and clinical characteristics in predicting subjective sleep quality is not known. We sought to determine the correlates of subjective sleep quality in older adults using more recently developed machine learning algorithms that are suitable for selecting and ranking important variables.

METHODS

Community-dwelling older men (n=1024) and women (n=459), a subset of those participating in the Osteoporotic Fractures in Men study and the Study of Osteoporotic Fractures study, respectively, completed a single night of at-home polysomnographic recording of sleep followed by a set of morning questions concerning the prior night's sleep quality. Questionnaires concerning demographics and psychological characteristics were also collected prior to the overnight recording and entered into multivariable models. Two machine learning algorithms, lasso penalized regression and random forests, determined variable selection and the ordering of variable importance separately for men and women.

RESULTS

Thirty-eight sleep, demographic and clinical correlates of sleep quality were considered. Together, these multivariable models explained only 11-17% of the variance in predicting subjective sleep quality. Objective sleep efficiency emerged as the strongest correlate of subjective sleep quality across all models, and across both sexes. Greater total sleep time and sleep stage transitions were also significant objective correlates of subjective sleep quality. The amount of slow wave sleep obtained was not determined to be important.

CONCLUSIONS

Overall, the commonly obtained measures of polysomnographically-defined sleep contributed little to subjective ratings of prior-night sleep quality. Though they explained relatively little of the variance, sleep efficiency, total sleep time and sleep stage transitions were among the most important objective correlates.