ArticleNPJ microgravity2024
Effect of 60 days of head down tilt bed rest on amplitude and phase of rhythms in physiology and sleep in men.
Article in NPJ microgravity, 2024. The graph could read no effect estimate from its abstract, so it casts no vote on the map. An erratum has been issued. Cited by 6 papers.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
6 citing papers in PubMed, 8 citations in OpenAlex.
- Effects of the space environment on articular cartilage homeostasis: a review.NPJ microgravity · 2026Review
- The effect of spaceflight and simulated microgravity exposure on thermoregulation in humans: a systematic review.NPJ microgravity · 2026Article
- Performance of Blood-Based Biomarkers for Human Circadian Pacemaker Phase: Training Sets Matter As Much As Feature-Selection Methods.Journal of biological rhythms · 2025Article
- Distinct diurnal temperature rhythm patterns in critical illness myopathy: secondary analysis of two prospective trials.Annals of intensive care · 2025Article
- Blood flow restriction training in microgravity: a review of multisystem physiological benefits and implementation challenges for long-duration space missions.NPJ microgravity · 2025Review
- Cardiovascular adaptations and pathological changes induced by spaceflight: from cellular mechanisms to organ-level impacts.Military Medical Research · 2024Review
Corrections and comments
- Erratum issued
Authors and funding
7 authors at 1 institution in 2 countries.
Funding
Abstract
Twenty-four-hour rhythms in physiology and behaviour are shaped by circadian clocks, environmental rhythms, and feedback of behavioural rhythms onto physiology. In space, 24 h signals such as those associated with the light-dark cycle and changes in posture, are weaker, potentially reducing the robustness of rhythms. Head down tilt (HDT) bed rest is commonly used to simulate effects of microgravity but how HDT affects rhythms in physiology has not been extensively investigated. Here we report effects of -6° HDT during a 90-day protocol on 24 h rhythmicity in 20 men. During HDT, amplitude of light, motor activity, and wrist-temperature rhythms were reduced, evening melatonin was elevated, while cortisol was not affected during HDT, but was higher in the morning during recovery when compared to last session of HDT. During recovery from HDT, time in Slow-Wave Sleep increased. EEG activity in alpha and beta frequencies increased during NREM and REM sleep. These results highlight the profound effects of head-down-tilt-bed-rest on 24 h rhythmicity.
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.