To evaluate the quality of available evidence on the effects of environmental noise exposure on sleep a systematic review was conducted. The databases PSYCINFO, PubMed, Science Direct, Scopus, Web of ...Science and the TNO Repository were searched for non-laboratory studies on the effects of environmental noise on sleep with measured or predicted noise levels and published in or after the year 2000. The quality of the evidence was assessed using GRADE criteria. Seventy four studies predominately conducted between 2000 and 2015 were included in the review. A meta-analysis of surveys linking road, rail, and aircraft noise exposure to self-reports of sleep disturbance was conducted. The odds ratio for the percent highly sleep disturbed for a 10 dB increase in L
was significant for aircraft (1.94; 95% CI 1.61-2.3), road (2.13; 95% CI 1.82-2.48), and rail (3.06; 95% CI 2.38-3.93) noise when the question referred to noise, but non-significant for aircraft (1.17; 95% CI 0.54-2.53), road (1.09; 95% CI 0.94-1.27), and rail (1.27; 95% CI 0.89-1.81) noise when the question did not refer to noise. A pooled analysis of polysomnographic studies on the acute effects of transportation noise on sleep was also conducted and the unadjusted odds ratio for the probability of awakening for a 10 dBA increase in the indoor L
was significant for aircraft (1.35; 95% CI 1.22-1.50), road (1.36; 95% CI 1.19-1.55), and rail (1.35; 95% CI 1.21-1.52) noise. Due to a limited number of studies and the use of different outcome measures, a narrative review only was conducted for motility, cardiac and blood pressure outcomes, and for children's sleep. The effect of wind turbine and hospital noise on sleep was also assessed. Based on the available evidence, transportation noise affects objectively measured sleep physiology and subjectively assessed sleep disturbance in adults. For other outcome measures and noise sources the examined evidence was conflicting or only emerging. According to GRADE criteria, the quality of the evidence was moderate for cortical awakenings and self-reported sleep disturbance (for questions that referred to noise) induced by traffic noise, low for motility measures of traffic noise induced sleep disturbance, and very low for all other noise sources and investigated sleep outcomes.
Summary Noise is pervasive in everyday life and can cause both auditory and non-auditory health effects. Noise-induced hearing loss remains highly prevalent in occupational settings, and is ...increasingly caused by social noise exposure (eg, through personal music players). Our understanding of molecular mechanisms involved in noise-induced hair-cell and nerve damage has substantially increased, and preventive and therapeutic drugs will probably become available within 10 years. Evidence of the non-auditory effects of environmental noise exposure on public health is growing. Observational and experimental studies have shown that noise exposure leads to annoyance, disturbs sleep and causes daytime sleepiness, affects patient outcomes and staff performance in hospitals, increases the occurrence of hypertension and cardiovascular disease, and impairs cognitive performance in schoolchildren. In this Review, we stress the importance of adequate noise prevention and mitigation strategies for public health.
The psychomotor vigilance test (PVT) is among the most widely used measures of behavioral alertness, but there is large variation among published studies in PVT performance outcomes and test ...durations. To promote standardization of the PVT and increase its sensitivity and specificity to sleep loss, we determined PVT metrics and task durations that optimally discriminated sleep deprived subjects from alert subjects.
Repeated-measures experiments involving 10-min PVT assessments every 2 h across both acute total sleep deprivation (TSD) and 5 days of chronic partial sleep deprivation (PSD).
Controlled laboratory environment.
74 healthy subjects (34 female), aged 22-45 years.
TSD experiment involving 33 h awake (N = 31 subjects) and a PSD experiment involving 5 nights of 4 h time in bed (N = 43 subjects).
In a paired t-test paradigm and for both TSD and PSD, effect sizes of 10 different PVT performance outcomes were calculated. Effect sizes were high for both TSD (1.59-1.94) and PSD (0.88-1.21) for PVT metrics related to lapses and to measures of psychomotor speed, i.e., mean 1/RT (response time) and mean slowest 10% 1/RT. In contrast, PVT mean and median RT outcomes scored low to moderate effect sizes influenced by extreme values. Analyses facilitating only portions of the full 10-min PVT indicated that for some outcomes, high effect sizes could be achieved with PVT durations considerably shorter than 10 min, although metrics involving lapses seemed to profit from longer test durations in TSD.
Due to their superior conceptual and statistical properties and high sensitivity to sleep deprivation, metrics involving response speed and lapses should be considered primary outcomes for the 10-min PVT. In contrast, PVT mean and median metrics, which are among the most widely used outcomes, should be avoided as primary measures of alertness. Our analyses also suggest that some shorter-duration PVT versions may be sensitive to sleep loss, depending on the outcome variable selected, although this will need to be confirmed in comparative analyses of separate duration versions of the PVT. Using both sensitive PVT metrics and optimal test durations maximizes the sensitivity of the PVT to sleep loss and therefore potentially decreases the sample size needed to detect the same neurobehavioral deficit. We propose criteria to better standardize the 10-min PVT and facilitate between-study comparisons and meta-analyses.
Abstract
Study Objectives
The high prevalence of chronic insufficient sleep in the population has been a concern due to the associated health and safety risks. We evaluated secular trends in sleep ...duration over the most recent 14-year period.
Methods
The American Time Use Survey, representative of US residents ≥15 years, was used to investigate trends in self-reported sleep duration and waking activities for the period 2003–2016 (N = 181335 respondents).
Results
Sleep duration increased across survey years both on weekdays (+1.40 min/year) and weekends (+0.83 min/year, both p < .0001, adjusted models). This trend was observed in students, employed respondents, and retirees, but not in those unemployed or not in the labor force. On workdays, the prevalence of short (≤7 hr), average (>7–9 hr), and long (>9 hr) sleep changed by −0.44% per year (p < .0001), −0.03% per year (p = .5515), and +0.48% per year (p < .0001), respectively. The change in sleep duration was predominantly explained by respondents retiring earlier in the evening. The percentage of respondents who watched TV or read before bed—two prominent waking activities competing with sleep—decreased over the same time period, suggesting that portions of the population are increasingly willing to trade time in leisure activities for more sleep. The results also suggest that increasing online opportunities to work, learn, bank, shop, and perform administrative tasks from home freed up time that likely contributed to increased sleep duration.
Conclusions
The findings indicate first successes in the fight against sleep deficiency. Public health consequences of the observed increase in the prevalence of long sleep remain unclear and warrant further investigation.
Attention is a cognitive domain that can be severely affected by sleep deprivation. Previous neuroimaging studies have used different attention paradigms and reported both increased and reduced brain ...activation after sleep deprivation. However, due to large variability in sleep deprivation protocols, task paradigms, experimental designs, characteristics of subject populations, and imaging techniques, there is no consensus regarding the effects of sleep loss on the attending brain. The aim of this meta-analysis was to identify brain activations that are commonly altered by acute total sleep deprivation across different attention tasks.
Coordinate-based meta-analysis of neuroimaging studies of performance on attention tasks during experimental sleep deprivation.
The current version of the activation likelihood estimation (ALE) approach was used for meta-analysis. The authors searched published articles and identified 11 sleep deprivation neuroimaging studies using different attention tasks with a total of 185 participants, equaling 81 foci for ALE analysis.
The meta-analysis revealed significantly reduced brain activation in multiple regions following sleep deprivation compared to rested wakefulness, including bilateral intraparietal sulcus, bilateral insula, right prefrontal cortex, medial frontal cortex, and right parahippocampal gyrus. Increased activation was found only in bilateral thalamus after sleep deprivation compared to rested wakefulness.
Acute total sleep deprivation decreases brain activation in the fronto-parietal attention network (prefrontal cortex and intraparietal sulcus) and in the salience network (insula and medial frontal cortex). Increased thalamic activation after sleep deprivation may reflect a complex interaction between the de-arousing effects of sleep loss and the arousing effects of task performance on thalamic activity.
Traffic noise disturbs sleep and may impair recuperation. There is limited information on single and combined effects of air, road, and rail traffic noise on sleep and recuperation.
Repeated ...measures.
Polysomnographic laboratory study.
72 healthy subjects, mean ± standard deviation 40 ± 13 years, range 18-71 years, 32 male.
Exposure to 40, 80, or 120 rail, road, and/or air traffic noise events.
Subjects were investigated for 11 consecutive nights, which included 8 noise exposure nights and one noise-free control night. Noise effects on sleep structure and continuity were subtle, even in nights with combined exposure, most likely because of habituation and an increase in arousal thresholds both within and across nights. However, cardiac arousals did not habituate across nights. Noise exposure significantly affected subjective assessments of sleep quality and recuperation, whereas objective performance was unaffected, except for a small increase in mean PVT reaction time (+4 ms, adjusted P < 0.05). Road traffic noise led to the strongest changes in sleep structure and continuity, whereas subjective assessments of sleep were worse after nights with air and rail traffic noise exposure. In contrast to daytime annoyance, cortical arousal probabilities and cardiac responses were significantly lower for air than for road and rail traffic noise (all P < 0.0001). These differences were explained by sound pressure level rise time and high frequency (> 3 kHz) noise event components.
Road, rail, and air traffic noise differentially affect objective and subjective assessments of sleep. Differences in the degree of noise-induced sleep fragmentation between traffic modes were explained by the specific spectral and temporal composition of noise events, indicating potential targets for active and passive noise control. Field studies are needed to validate our findings in a setting with higher ecologic validity.
Much of the current science on, and mathematical modeling of, dynamic changes in human performance within and between days is dominated by the two-process model of sleep-wake regulation, which posits ...a neurobiological drive for sleep that varies homeostatically (increasing as a saturating exponential during wakefulness and decreasing in a like manner during sleep), and a circadian process that neurobiologically modulates both the homeostatic drive for sleep and waking alertness and performance. Endogenous circadian rhythms in neurobehavioral functions, including physiological alertness and cognitive performance, have been demonstrated using special laboratory protocols that reveal the interaction of the biological clock with the sleep homeostatic drive. Individual differences in circadian rhythms and genetic and other components underlying such differences also influence waking neurobehavioral functions. Both acute total sleep deprivation and chronic sleep restriction increase homeostatic sleep drive and degrade waking neurobehavioral functions as reflected in sleepiness, attention, cognitive speed, and memory. Recent evidence indicating a high degree of stability in neurobehavioral responses to sleep loss suggests that these trait-like individual differences are phenotypic and likely involve genetic components, including circadian genes. Recent experiments have revealed both sleep homeostatic and circadian effects on brain metabolism and neural activation. Investigation of the neural and genetic mechanisms underlying the dynamically complex interaction between sleep homeostasis and circadian systems is beginning. A key goal of this work is to identify biomarkers that accurately predict human performance in situations in which the circadian and sleep homeostatic systems are perturbed.
To understand the health impact of long-duration spaceflight, one identical twin astronaut was monitored before, during, and after a 1-year mission onboard the International Space Station; his twin ...served as a genetically matched ground control. Longitudinal assessments identified spaceflight-specific changes, including decreased body mass, telomere elongation, genome instability, carotid artery distension and increased intima-media thickness, altered ocular structure, transcriptional and metabolic changes, DNA methylation changes in immune and oxidative stress-related pathways, gastrointestinal microbiota alterations, and some cognitive decline postflight. Although average telomere length, global gene expression, and microbiome changes returned to near preflight levels within 6 months after return to Earth, increased numbers of short telomeres were observed and expression of some genes was still disrupted. These multiomic, molecular, physiological, and behavioral datasets provide a valuable roadmap of the putative health risks for future human spaceflight.
Questionnaires are valuable data collection instruments in public health research, and can serve to pre-screen respondents for suitability in future studies. Survey non-response leads to reduced ...effective sample sizes and can decrease representativeness of the study population, so high response rates are needed to minimize the risk of bias. Here we present results on the success of different postal questionnaire strategies at effecting response, and the effectiveness of these strategies at recruiting participants for a field study on the effects of aircraft noise on sleep.
In total, we mailed 17 rounds of 240 questionnaires (total n = 4080) to randomly selected households around Atlanta International Airport. Different mailing rounds were varied in the length of the questionnaire (11, 26 or 55 questions), survey incentive (gift card or $2 cash), number of follow-up waves (0, 2 or 3), incentive for participating in a 5-night in-home sleep study ($100, $150 or $200), and address personalization.
We received completed questionnaires from 407 respondents (response rate 11.4%). Personalizing the address, enclosing a $2 cash incentive with the initial questionnaire mailing and repeated follow-up mailings were effective at increasing response rate. Despite the increased expense of these approaches in terms of each household mailed, the higher response rates meant that they were more cost-effective overall for obtaining an equivalent number of responses. Interest in participating in the field study decreased with age, but was unaffected by the mailing strategies or cash incentives for field study participation. The likelihood that a respondent would participate in the field study was unaffected by survey incentive, survey length, number of follow-up waves, field study incentive, age or sex.
Pre-issued cash incentives and sending follow-up waves could maximize the representativeness and numbers of people from which to recruit, and may be an effective strategy for improving recruitment into field studies.
The Psychomotor Vigilance Test (PVT) objectively assesses fatigue-related changes in alertness associated with sleep loss, extended wakefulness, circadian misalignment, and time on task. The standard ...10-min PVT is often considered impractical in applied contexts. To address this limitation, we developed a modified brief 3-min version of the PVT (PVT-B). The PVT-B was validated in controlled laboratory studies with 74 healthy subjects (34 female, aged 22–45 years) that participated either in a total sleep deprivation (TSD) study involving 33
h awake (
N=31 subjects) or in a partial sleep deprivation (PSD) protocol involving 5 consecutive nights of 4
h time in bed (
N=43 subjects). PVT and PVT-B were performed regularly during wakefulness. Effect sizes of 5 key PVT outcomes were larger for TSD than PSD and larger for PVT than for PVT-B for all outcomes. Effect size was largest for response speed (reciprocal response time) for both the PVT-B and the PVT in both TSD and PSD. According to Cohen's criteria, effect sizes for the PVT-B were still large (TSD) or medium to large (PSD, except for fastest 10% RT). Compared to the 70% decrease in test duration the 22.7% (range 6.9–67.8%) average decrease in effect size was deemed an acceptable trade-off between duration and sensitivity. Overall, PVT-B performance had faster response times, more false starts and fewer lapses than PVT performance (all
p<0.01). After reducing the lapse threshold from 500 to 355
ms for PVT-B, mixed model ANOVAs indicated no differential sensitivity to sleep loss between PVT-B and PVT for all outcome variables (all
P>0.15) but the fastest 10% response times during PSD (
P<0.001), and effect sizes increased from 1.38 to 1.49 (TSD) and 0.65 to 0.76 (PSD), respectively. In conclusion, PVT-B tracked standard 10-min PVT performance throughout both TSD and PSD, and yielded medium to large effect sizes. PVT-B may be a useful tool for assessing behavioral alertness in settings where the duration of the 10-min PVT is considered impractical, although further validation in applied settings is needed.
► The Psychomotor Vigilance Test (PVT) measures behavioral alertness. ► A brief 3
min version of the PVT remains sensitive to the effects of sleep loss. ► Its utility is currently evaluated on astronauts on board the International Space Station ISS. ► The brief PVT may be practical for many operational and clinical environments.
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