ArticleHeliyon2016
Long-term exposure to space's microgravity alters the time structure of heart rate variability of astronauts.
Article in Heliyon, 2016. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 23 papers, 3 of them syntheses that pooled it.
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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.
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Who cites it
23 citing papers in PubMed, 3 syntheses or guidelines pooled it, 33 citations in OpenAlex.
- Biological clocks and blood clots in space: circadian disruption-induced modulation of thrombosis risk.Research and practice in thrombosis and haemostasis · 2026Pooled it
- Effects of weightlessness on the cardiovascular system: a systematic review and meta-analysis.Frontiers in physiology · 2024Pooled it
- Cardiovascular Adaptations of Space Travel: A Systematic Review.Cardiology · 2023Pooled it
- The Effects of Microgravity on the Structure and Function of Cardiomyocytes.Biomolecules · 2025Review
- Altered gravity and time perception: a brief review.Frontiers in psychology · 2025Review
- Effects of repeated gravity changes during parabolic flight: Evidence of the need to assist space tourists to outer space.PloS one · 2025Article
- Systematic review of the effectiveness of standalone passive countermeasures on microgravity-induced physiologic deconditioning.NPJ microgravity · 2024Review
- Thiamine-modified metabolic reprogramming of human pluripotent stem cell-derived cardiomyocyte under space microgravity.Signal transduction and targeted therapy · 2024Article
- Restless nights when sick: ectoparasite infections alter rest-activity cycles of diurnal fish hosts.Parasitology · 2024Article
- Evidence for ~12-h ultradian gene programs in humans.Npj biological timing and sleep · 2024Article
- Basic research and opportunities for translational advancement in the field of mammalian ∼12-hour ultradian chronobiology.Frontiers in physiology · 2024Review
- Genetic diversity, clinical uses, and phytochemical and pharmacological properties of safflower (Frontiers in pharmacology · 2024Review
- Methods for assessing change in brain plasticity at night and psychological resilience during daytime between repeated long-duration space missions.Scientific reports · 2023Article
- Unconscious mind activates central cardiovascular network and promotes adaptation to microgravity possibly anti-aging during 1-year-long spaceflight.Scientific reports · 2022Article
- Simulated Galactic Cosmic Rays Modify Mitochondrial Metabolism in Osteoclasts, Increase Osteoclastogenesis and Cause Trabecular Bone Loss in Mice.International journal of molecular sciences · 2021Article
- Astronauts well-being and possibly anti-aging improved during long-duration spaceflight.Scientific reports · 2021Article
- Revealing the hidden reality of the mammalian 12-h ultradian rhythms.Cellular and molecular life sciences : CMLS · 2021Review
- Modelling physiology of haemodynamic adaptation in short-term microgravity exposure and orthostatic stress on Earth.Scientific reports · 2021Article
- Smart Wearables for Cardiac Autonomic Monitoring in Isolated, Confined and Extreme Environments: A Perspective from Field Research in Antarctica.Sensors (Basel, Switzerland) · 2021Article
- Anti-aging effects of long-term space missions, estimated by heart rate variability.Scientific reports · 2019Article
Corrections and comments
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Authors and funding
10 authors at 5 institutions in 2 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundSpaceflight alters human cardiovascular dynamics. The less negative slope of the fractal scaling of heart rate variability (HRV) of astronauts exposed long-term to microgravity reflects cardiovascular deconditioning. We here focus on specific frequency regions of HRV.
methodsTen healthy astronauts (8 men, 49.1 ± 4.2 years) provided five 24-hour electrocardiographic (ECG) records: before launch, 20.8 ± 2.9 (ISS01), 72.5 ± 3.9 (ISS02) and 152.8 ± 16.1 (ISS03) days after launch, and after return to Earth. HRV endpoints, determined from normal-to-normal (NN) intervals in 180-min intervals progressively displaced by 5 min, were compared in space versus Earth. They were fitted with a model including 4 major anticipated components with periods of 24 (circadian), 12 (circasemidian), 8 (circaoctohoran), and 1.5 (Basic Rest-Activity Cycle; BRAC) hours.
findingsThe 24-, 12-, and 8-hour components of HRV persisted during long-term spaceflight. The 90-min amplitude became about three times larger in space (ISS03) than on Earth, notably in a subgroup of 7 astronauts who presented with a different HRV profile before flight. The total spectral power (TF; p < 0.05) and that in the ultra-low frequency range (ULF, 0.0001-0.003 Hz; p < 0.01) increased from 154.9 ± 105.0 and 117.9 ± 57.5 msec
interpretationMost HRV changes observed in space relate to a frequency window centered around one cycle in about 90 min. Since the BRAC component is amplified in space for only specific HRV endpoints, it is likely to represent a physiologic response rather than an artifact from the International Space Station (ISS) orbit. If so, it may offer a way to help adaptation to microgravity during long-duration spaceflight.
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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.