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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.

Summary Approximately 40% of Japanese physicians report working more than 960 hr of overtime annually, with 10% exceeding 1860 hr. To protect their health, annual overtime limits went into effect in 2024. The objective of this study was to investigate associations of self‐reported sleep duration with psychological health and objective alertness. This was a cross‐sectional National Survey for The Work Style Reform of Long Working Physicians. Physicians self‐reported daily sleep duration, burnout (Abbreviated Maslach Burnout Inventory), depression (Center for Epidemiologic Studies Depression Scale) and traffic accidents. Alertness was then evaluated using the brief Psychomotor Vigilance Test. Of 20,382 physicians invited, 1226 completed the survey and brief Psychomotor Vigilance Test. Daily sleep duration was inversely associated with weekly work hours (β = −5.4; 95% confidence interval −6.8 to −4.0, p < 0.0001). Sleep duration < 6 hr and ≥ 8 hr per day was associated with slower responses on the brief Psychomotor Vigilance Test (adjusted p < 0.05). An additional 10 hr worked per week was associated with a 0.40 point (95% confidence interval 0.08–0.72) increase in burnout severity and a 1.7% (95% confidence interval 0.1–3.3%) increase in odds of reporting a traffic accident. Increased brief Psychomotor Vigilance Test lapses, indicating lower alertness, were associated with worse symptoms of depression (β = 0.23 points; 95% confidence interval 0.14–0.31, p < 0.0001) and burnout (β = 0.25 points; 95% confidence interval 0.13–0.36, p < 0.0001). This study emphasizes the importance of sufficient sleep to maintain alertness, and supports limiting work hours for Japanese physicians to protect psychological health. Performance on the brief Psychomotor Vigilance Test may be a useful indicator of psychological health. [ABSTRACT FROM AUTHOR]

Summary: Chronic sleep restriction, common in today's 24/7 society, causes cumulative neurobehavioural impairment, but the dynamics of the build‐up and dissipation of this impairment have not been fully elucidated. We addressed this knowledge gap in a laboratory study involving two, 5‐day periods of sleep restriction to 4 hr per day, separated by a 1‐day dose–response intervention sleep opportunity. We measured sleep physiological and waking neurobehavioural responses in 70 healthy adults, each randomized to one of seven dose–response intervention sleep doses ranging from 0 to 12 hr, or a non‐sleep‐restricted control group. As anticipated, sleep physiological markers showed homeostatic dynamics throughout the study, and waking neurobehavioural impairment accumulated across the two sleep restriction periods. Unexpectedly, there was only a slight and short‐lived effect of the 1‐day dose–response intervention sleep opportunity. Whether the dose–response intervention sleep opportunity involved extension, further restriction or total deprivation of sleep, neurobehavioural functioning during the subsequent second sleep restriction period was dominated by prior sleep–wake history. Our findings revealed a profound and enduring influence of long‐term sleep–wake history as a fundamental aspect of the dynamic regulation of the neurobehavioural response to sleep loss. [ABSTRACT FROM AUTHOR]

Background: Nighttime noise carries a significant disease burden. The World Health Organization (WHO) recently published guidelines for the regulation of environmental noise based on a review of evidence published up to the year 2015 on the effects of environmental noise on sleep. OBJECTIVES: This systematic review and meta-analysis will update the WHO evidence review on the effects of environmental noise on sleep disturbance to include more recent studies. Methods: Investigations of self-reported sleep among residents exposed to environmental traffic noise at home were identified using Scopus, PubMed, Embase, and PsycINFO. Awakenings, falling asleep, and sleep disturbance were the three outcomes included. Extracted data were used to derive exposure-response relationships for the probability of being highly sleep disturbed by nighttime noise [average outdoor A-weighted noise level ([L.sub.night]) 2300-0700 hours] for aircraft, road, and rail traffic noise, individually. The overall quality of evidence was assessed using Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) criteria. Results: Eleven studies (n = 109,070 responses) were included in addition to 25 studies (n = 64,090 responses) from the original WHO analysis. When sleep disturbance questions specifically mentioned noise as the source of disturbance, there was moderate quality of evidence for the probability of being highly sleep disturbed per 10-dB increase in [L.sub.night] for aircraft [odds ratio (OR) =2.18; 95% confidence interval (CI): 2.01, 2.36], road (OR = 2.52; 95% CI: 2.28, 2.79), and railway (OR = 2.97; 95% CI: 2.57, 3.43) noise. When noise was not mentioned, there was low to very low quality of evidence for being sleep disturbed per 10-dB increase in [L.sub.night] for aircraft (OR= 1.52; 95% CI: 1.20, 1.93), road (OR= 1.14; 95% CI: 1.08, 1.21), and railway (OR = 1.17; 95% CI: 0.91, 1.49) noise. Compared with the original WHO review, the exposure-response relationships closely agreed at low (40 dB [L.sub.night]) levels for all traffic types but indicated greater disturbance by aircraft traffic at high noise levels. Sleep disturbance was not significantly different between European and non-European studies. Discussion: Available evidence suggests that transportation noise is negatively associated with self-reported sleep. Sleep disturbance in this updated meta-analysis was comparable to the original WHO review at low nighttime noise levels. These low levels correspond to the recent WHO noise limit recommendations for nighttime noise, and so these findings do not suggest these WHO recommendations need revisiting. Deviations from the WHO review in this updated analysis suggest that populations exposed to high levels of aircraft noise may be at greater risk of sleep disturbance than determined previously. https://doi.org/10.1289/EHP10197, Introduction Sleep is a vital component of human life that serves many critical roles in physical and mental health and well-being. (1) Sufficient quantity and quality of sleep are requirements [...]

Sleep loss impacts a broad range of brain and cognitive functions. However, how sleep deprivation affects risky decision‐making remains inconclusive. This study used functional MRI to examine the impact of one night of total sleep deprivation (TSD) on risky decision‐making behavior and the underlying brain responses in healthy adults. In this study, we analyzed data from N = 56 participants in a strictly controlled 5‐day and 4‐night in‐laboratory study using a modified Balloon Analogue Risk Task. Participants completed two scan sessions in counter‐balanced order, including one scan during rested wakefulness (RW) and another scan after one night of TSD. Results showed no differences in participants' risk‐taking propensity and risk‐induced activation between RW and TSD. However, participants showed significantly reduced neural activity in the anterior cingulate cortex and bilateral insula for loss outcomes, and in bilateral putamen for win outcomes during TSD compared with RW. Moreover, risk‐induced activation in the insula negatively correlated with participants' risk‐taking propensity during RW, while no such correlations were observed after TSD. These findings suggest that sleep loss may impact risky decision‐making by attenuating neural responses to decision outcomes and impairing brain‐behavior associations. Previous studies have suggested that sleep loss affects various neurobehavioral functions including decision‐making. However, the impact of sleep deprivation on risky decision‐making remains controversial. This study examined the impact of total sleep deprivation on risky decision‐making in the brain through a modified Balloon Analogue Risk Task. Results demonstrate that sleep loss may impact risky decision‐making by attenuating the brain's responses to the decision outcomes and impairing the relationship between brain and behavior. [ABSTRACT FROM AUTHOR]