Sleep, performance, circadian rhythms, and light-dark cycles during two space shuttle flights

Harvard University, Cambridge, Massachusetts, United States
AJP Regulatory Integrative and Comparative Physiology (Impact Factor: 3.11). 12/2001; 281(5):R1647-64.
Source: PubMed


Sleep, circadian rhythm, and neurobehavioral performance measures were obtained in five astronauts before, during, and after 16-day or 10-day space missions. In space, scheduled rest-activity cycles were 20-35 min shorter than 24 h. Light-dark cycles were highly variable on the flight deck, and daytime illuminances in other compartments of the spacecraft were very low (5.0-79.4 lx). In space, the amplitude of the body temperature rhythm was reduced and the circadian rhythm of urinary cortisol appeared misaligned relative to the imposed non-24-h sleep-wake schedule. Neurobehavioral performance decrements were observed. Sleep duration, assessed by questionnaires and actigraphy, was only approximately 6.5 h/day. Subjective sleep quality diminished. Polysomnography revealed more wakefulness and less slow-wave sleep during the final third of sleep episodes. Administration of melatonin (0.3 mg) on alternate nights did not improve sleep. After return to earth, rapid eye movement (REM) sleep was markedly increased. Crewmembers on these flights experienced circadian rhythm disturbances, sleep loss, decrements in neurobehavioral performance, and postflight changes in REM sleep.

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    • "Other negative effects include increased levels of fatigue, depression, and confusion as well as decreased immunological function and concentration (Belenky et al., 1987; Giam, 1997; Naitoh and Kelly, 1992). Potential chronic health effects include increased risk of gastrointestinal illness , loss of bone mineral density, coronary artery disease, depression, some forms of cancer (Antunes et al., 2010; Dijk et al., 2001; Schernhammer et al., 2001), and alterations in metabolic profile, mood, and appetite (Arendt, 2010; Dijk et al., 2001; Scheer et al., 2009; Schernhammer et al., 2001). "
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    ABSTRACT: United States Navy submariners have historically lived with circadian disruption while at sea due to 18-h-based watchschedules. Previous research demonstrated that circadian entrainment improved with 24-h-based watchschedules. Twenty-nine male crew members participated in the study, which took place on an actual submarine patrol. The crew were exposed, first, to experimental high correlated color temperature (CCT = 13,500 K) fluorescent light sources and then to standard-issue fluorescent light sources (CCT = 4100 K). A variety of outcome measures were employed to determine if higher levels of circadian-effective light during on-watch times would further promote behavioral alignment to 24-h-based watchschedules. The high CCT light source produced significantly higher circadian light exposures than the low CCT light source, which was associated with significantly greater 24-h behavioral alignment with work schedules using phasor analysis, greater levels of sleep efficiency measured with wrist actigraphy, lower levels of subjective sleepiness measured with the Karolinska Sleepiness Scale, and higher nighttime melatonin concentrations measured by morning urinary 6-sulfatoxymelatonin/creatinine ratios. Unlike these diverse outcome measures, performance scores were significantly worse under the high CCT light source than under the low CCT light source, due to practice effects. As hypothesized, with the exception of the performance scores, all of the data converge to suggest that high CCT light sources, combined with 24-h watchschedules, promote better behavioral alignment with work schedules and greater sleep quality on submarines. Since the order and the type of light sources were confounded in this field study, the results should only be considered as consistent with our theoretical understanding of how regular, 24-h light-dark exposures combined with high circadian light exposures can promote greater behavioral alignment with work schedules and with sleep.
    Full-text · Article · Apr 2015 · Journal of Biological Rhythms
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    • "), or sometimes even unchanged (Frost et al. 1976). Studies on sleep during Space Shuttle Missions reported that astronauts had more wakefulness and less SWS in the third part of the night (Dijk et al. 2001) compared to other times during their sleep cycles. Unfortunately, due to methodological concerns, lack of objective measures, and a general paucity of data regarding sleep in space, it is not known whether sleep architecture would be affected over long-duration missions, including planetary habitation. "
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    Full-text · Article · Jun 2014 · Arbeitsphysiologie
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    • "typically observed in short-term space missions, due to circadian rhythm phase shifts, heightened workload demand, emergencies, and more in general, extraordinary stressful environmental conditions (Dijk et al., 2001; Mallis and DeRoshia, 2005). In this light, a crucial problem for long lasting manned missions in space is represented by sleep alterations. "
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    Full-text · Article · May 2014 · International journal of psychophysiology: official journal of the International Organization of Psychophysiology
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