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Robin A, Van Ombergen A, Laurens C, Bergouignan A, Vico L, Linossier MT, Pavy-Le Traon A, Kermorgant M, Chopard A, Py G, Green DA, Tipton M, Choukér A, Denise P, Normand H, Blanc S, Simon C, Rosnet E, Larcher F, Fernandez P, de Glisezinski I, Larrouy D, Harant-Farrugia I, Antunes I, Gauquelin-Koch G, Bareille MP, Billette De Villemeur R, Custaud MA, Navasiolava N. Comprehensive assessment of physiological responses in women during the ESA dry immersion VIVALDI microgravity simulation. Nat Commun 2023; 14:6311. [PMID: 37813884 PMCID: PMC10562467 DOI: 10.1038/s41467-023-41990-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 09/26/2023] [Indexed: 10/11/2023] Open
Abstract
Astronauts in microgravity experience multi-system deconditioning, impacting their inflight efficiency and inducing dysfunctions upon return to Earth gravity. To fill the sex gap of knowledge in the health impact of spaceflights, we simulate microgravity with a 5-day dry immersion in 18 healthy women (ClinicalTrials.gov Identifier: NCT05043974). Here we show that dry immersion rapidly induces a sedentarily-like metabolism shift mimicking the beginning of a metabolic syndrome with a drop in glucose tolerance, an increase in the atherogenic index of plasma, and an impaired lipid profile. Bone remodeling markers suggest a decreased bone formation coupled with an increased bone resorption. Fluid shifts and muscular unloading participate to a marked cardiovascular and sensorimotor deconditioning with decreased orthostatic tolerance, aerobic capacity, and postural balance. Collected datasets provide a comprehensive multi-systemic assessment of dry immersion effects in women and pave the way for future sex-based evaluations of countermeasures.
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Affiliation(s)
- Adrien Robin
- Univ Angers, CRC, CHU Angers, Inserm, CNRS, MITOVASC, Equipe CARME, SFR ICAT, F-49000, Angers, France.
| | | | - Claire Laurens
- Institute of Metabolic and Cardiovascular Diseases, INSERM, Paul Sabatier University, UMR1297, Toulouse, France
| | - Audrey Bergouignan
- Anschutz Health and Wellness Center, Division of Endocrinology, University of Colorado, Aurora, CO, USA
| | - Laurence Vico
- INSERM, University Jean Monnet, Mines Saint-Etienne, U 1059, Saint Etienne, France
| | | | - Anne Pavy-Le Traon
- Department of Neurology, CHU Toulouse and I2MC-INSERM 1297, Toulouse, France
| | - Marc Kermorgant
- Department of Neurology, CHU Toulouse and I2MC-INSERM 1297, Toulouse, France
| | - Angèle Chopard
- DMEM, Montpellier University, INRAE, Montpellier, France
| | - Guillaume Py
- DMEM, Montpellier University, INRAE, Montpellier, France
| | - David Andrew Green
- Centre of Human and Applied Physiological Sciences, King's College London, London, UK
| | - Michael Tipton
- Extreme Environments Laboratory, School of Sport, Health and Exercise Science, University of Portsmouth, Portsmouth, PO1 2EF, UK
| | - Alexander Choukér
- Laboratory of Translational Research Stress and Immunity, Department of Anesthesiology, Hospital of the Ludwig-Maximilians-University (LUM), Munich, Germany
| | - Pierre Denise
- Université de Caen Normandie, Inserm, COMETE U1075, CYCERON, CHU de Caen, F-14000, Caen, France
| | - Hervé Normand
- Université de Caen Normandie, Inserm, COMETE U1075, CYCERON, CHU de Caen, F-14000, Caen, France
| | - Stéphane Blanc
- DEPE-IPHC - Département Ecologie, Physiologie et Ethologie, Strasbourg, France
| | - Chantal Simon
- CarMeN Laboratory, INSERM 1060, INRA 1397, University Claude Bernard Lyon1, Human Nutrition Research Center Rhône-Alpes, Oullins, France
| | - Elisabeth Rosnet
- Faculty of Sport Sciences, Université de Reims Champagne-Ardenne, Reims, France
| | | | - Peter Fernandez
- INSERM, University Jean Monnet, Mines Saint-Etienne, U 1059, Saint Etienne, France
| | - Isabelle de Glisezinski
- Institute of Metabolic and Cardiovascular Diseases, INSERM, Paul Sabatier University, UMR1297, Toulouse, France
| | - Dominique Larrouy
- Institute of Metabolic and Cardiovascular Diseases, INSERM, Paul Sabatier University, UMR1297, Toulouse, France
| | - Isabelle Harant-Farrugia
- Institute of Metabolic and Cardiovascular Diseases, INSERM, Paul Sabatier University, UMR1297, Toulouse, France
| | - Inês Antunes
- Telespazio Belgium S.R.L. for the European Space Agency, Noordwijk, The Netherlands
| | | | | | | | - Marc-Antoine Custaud
- Univ Angers, CRC, CHU Angers, Inserm, CNRS, MITOVASC, Equipe CARME, SFR ICAT, F-49000, Angers, France.
| | - Nastassia Navasiolava
- Univ Angers, CRC, CHU Angers, Inserm, CNRS, MITOVASC, Equipe CARME, SFR ICAT, F-49000, Angers, France.
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Schneider V, Siegel B, Allen JR. Human Health on the Moon and Beyond and the Results of the Spaceflight for Everybody Symposium. Aerosp Med Hum Perform 2023; 94:634-643. [PMID: 37501302 DOI: 10.3357/amhp.6138.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
INTRODUCTION:In 2022, the National Aeronautics and Space Administration (NASA) began launching missions to establish a sustainable human presence on the Moon. One key to success will be maintaining human health. In preparation for longer missions with more diverse crews, the Spaceflight for Everybody Symposium was held to review currently known human spaceflight biomedical knowledge, the future of exploration space medicine, and the ability of NASA to manage the spaceflight human health risks and enable exploration. The symposium highlighted the future of precision health/personalized medicine, the possible spaceflight health acute and lifetime illnesses, and the challenge of identifying appropriate prevention, treatment, rehabilitation, and autonomous medical systems for long-duration spaceflight. The symposium was organized to look back at NASA exploration, science, and leadership successes, celebrate NASA women's leadership, and focus on future Artemis activities, including research and development that will benefit both spaceflight and terrestrial life. NASA current preparations for returning to the Moon have led to increased acknowledgment of the importance of workforce diversity, i.e., to use the best candidate in every work position, including the plan for the first woman and person of color to land on the Moon. NASA is developing plans to use commercial spaceflight research opportunities when the International Space Station is no longer available. Astronaut health decisions will consist of individualized health risk determinations and mitigation strategies and increased medical self-care. Research findings include improved exploration cardiovascular, musculoskeletal, and radiation risk reduction and improved interpersonal support for both astronaut crews and mission control personnel.Schneider V, Siegel B, Allen JR. Human health on the Moon and beyond and the results of the Spaceflight for Everybody Symposium. Aerosp Med Hum Perform. 2023; 94(8):634-643.
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Popova OV, Rusanov VB. Is space flight arrhythmogenic? Front Physiol 2023; 14:1162355. [PMID: 37250132 PMCID: PMC10213435 DOI: 10.3389/fphys.2023.1162355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 04/17/2023] [Indexed: 05/31/2023] Open
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Homo sapiens—A Species Not Designed for Space Flight: Health Risks in Low Earth Orbit and Beyond, Including Potential Risks When Traveling beyond the Geomagnetic Field of Earth. Life (Basel) 2023; 13:life13030757. [PMID: 36983912 PMCID: PMC10051707 DOI: 10.3390/life13030757] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Revised: 03/03/2023] [Accepted: 03/08/2023] [Indexed: 03/18/2023] Open
Abstract
Homo sapiens and their predecessors evolved in the context of the boundary conditions of Earth, including a 1 g gravity and a geomagnetic field (GMF). These variables, plus others, led to complex organisms that evolved under a defined set of conditions and define how humans will respond to space flight, a circumstance that could not have been anticipated by evolution. Over the past ~60 years, space flight and living in low Earth orbit (LEO) have revealed that astronauts are impacted to varying degrees by such new environments. In addition, it has been noted that astronauts are quite heterogeneous in their response patterns, indicating that such variation is either silent if one remained on Earth, or the heterogeneity unknowingly contributes to disease development during aging or in response to insults. With the planned mission to deep space, humans will now be exposed to further risks from radiation when traveling beyond the influence of the GMF, as well as other potential risks that are associated with the actual loss of the GMF on the astronauts, their microbiomes, and growing food sources. Experimental studies with model systems have revealed that hypogravity conditions can influence a variety biological and physiological systems, and thus the loss of the GMF may have unanticipated consequences to astronauts’ systems, such as those that are electrical in nature (i.e., the cardiovascular system and central neural systems). As astronauts have been shown to be heterogeneous in their responses to LEO, they may require personalized countermeasures, while others may not be good candidates for deep-space missions if effective countermeasures cannot be developed for long-duration missions. This review will discuss several of the physiological and neural systems that are affected and how the emerging variables may influence astronaut health and functioning.
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Dubé S, Santaguida M, Anctil D, Giaccari L, Lapierre J. The Case for Space Sexology. JOURNAL OF SEX RESEARCH 2023; 60:165-176. [PMID: 34878963 DOI: 10.1080/00224499.2021.2012639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Space poses significant challenges for human intimacy and sexuality. Life in space habitats during long-term travel, exploration, or settlement may: detrimentally impact the sexual and reproductive functions of astronauts, restrict privacy and access to intimate partners, impose hygiene protocols and abstinence policies, and heighten risks of interpersonal conflicts and sexual violence. Together, this may jeopardize the health and well-being of space inhabitants, crew performance, and mission success. Yet, little attention has been given to the sexological issues of human life in space. This situation is untenable considering our upcoming space missions and expansion. It is time for space organizations to embrace a new discipline, space sexology: the scientific study of extraterrestrial intimacy and sexuality. To make this case, we draw attention to the lack of research on space intimacy and sexuality; discuss the risks and benefits of extraterrestrial eroticism; and propose an initial biopsychosocial framework to envision a broad, collaborative scientific agenda on space sexology. We also underline key anticipated challenges faced by this innovative field and suggest paths to solutions. We conclude that space programs and exploration require a new perspective - one that holistically addresses the intimate and sexual needs of humans - in our pursuit of a spacefaring civilization.
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Affiliation(s)
- S Dubé
- Department of Psychology, Concordia University
| | | | - D Anctil
- Department of Philosophy, Jean-de-Brébeuf College
- International Observatory on the Societal Impacts of Artificial Intelligence and Digital Technology, Laval University
| | - L Giaccari
- Department of Psychology, Concordia University
| | - J Lapierre
- Faculty of Nursing Science, Laval University
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Rabineau J, Issertine M, Hoffmann F, Gerlach D, Caiani EG, Haut B, van de Borne P, Tank J, Migeotte PF. Cardiovascular deconditioning and impact of artificial gravity during 60-day head-down bed rest—Insights from 4D flow cardiac MRI. Front Physiol 2022; 13:944587. [PMID: 36277205 PMCID: PMC9586290 DOI: 10.3389/fphys.2022.944587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Accepted: 09/13/2022] [Indexed: 12/03/2022] Open
Abstract
Microgravity has deleterious effects on the cardiovascular system. We evaluated some parameters of blood flow and vascular stiffness during 60 days of simulated microgravity in head-down tilt (HDT) bed rest. We also tested the hypothesis that daily exposure to 30 min of artificial gravity (1 g) would mitigate these adaptations. 24 healthy subjects (8 women) were evenly distributed in three groups: continuous artificial gravity, intermittent artificial gravity, or control. 4D flow cardiac MRI was acquired in horizontal position before (−9 days), during (5, 21, and 56 days), and after (+4 days) the HDT period. The false discovery rate was set at 0.05. The results are presented as median (first quartile; third quartile). No group or group × time differences were observed so the groups were combined. At the end of the HDT phase, we reported a decrease in the stroke volume allocated to the lower body (−30% [−35%; −22%]) and the upper body (−20% [−30%; +11%]), but in different proportions, reflected by an increased share of blood flow towards the upper body. The aortic pulse wave velocity increased (+16% [+9%; +25%]), and so did other markers of arterial stiffness (CAVI; CAVI0). In males, the time-averaged wall shear stress decreased (−13% [−17%; −5%]) and the relative residence time increased (+14% [+5%; +21%]), while these changes were not observed among females. Most of these parameters tended to or returned to baseline after 4 days of recovery. The effects of the artificial gravity countermeasure were not visible. We recommend increasing the load factor, the time of exposure, or combining it with physical exercise. The changes in blood flow confirmed the different adaptations occurring in the upper and lower body, with a larger share of blood volume dedicated to the upper body during (simulated) microgravity. The aorta appeared stiffer during the HDT phase, however all the changes remained subclinical and probably the sole consequence of reversible functional changes caused by reduced blood flow. Interestingly, some wall shear stress markers were more stable in females than in males. No permanent cardiovascular adaptations following 60 days of HDT bed rest were observed.
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Affiliation(s)
- Jeremy Rabineau
- LPHYS, Département de Cardiologie, Université Libre de Bruxelles, Brussels, Belgium
- TIPs, École Polytechnique de Bruxelles, Université Libre de Bruxelles, Brussels, Belgium
- *Correspondence: Jeremy Rabineau,
| | - Margot Issertine
- LPHYS, Département de Cardiologie, Université Libre de Bruxelles, Brussels, Belgium
| | - Fabian Hoffmann
- Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
| | - Darius Gerlach
- Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
| | - Enrico G. Caiani
- Electronic, Information and Biomedical Engineering Department, Politecnico di Milano, Milan, Italy
| | - Benoit Haut
- TIPs, École Polytechnique de Bruxelles, Université Libre de Bruxelles, Brussels, Belgium
| | | | - Jens Tank
- Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
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Computational modeling of orthostatic intolerance for travel to Mars. NPJ Microgravity 2022; 8:34. [PMID: 35945233 PMCID: PMC9363491 DOI: 10.1038/s41526-022-00219-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 07/15/2022] [Indexed: 11/12/2022] Open
Abstract
Astronauts in a microgravity environment will experience significant changes in their cardiopulmonary system. Up until now, there has always been the reassurance that they have real-time contact with experts on Earth. Mars crew however will have gaps in their communication of 20 min or more. In silico experiments are therefore needed to assess fitness to fly for those on future space flights to Mars. In this study, we present an open-source controlled lumped mathematical model of the cardiopulmonary system that is able simulate the short-term adaptations of key hemodynamic parameters to an active stand test after being exposed to microgravity. The presented model is capable of adequately simulating key cardiovascular hemodynamic changes—over a short time frame—during a stand test after prolonged spaceflight under different gravitational conditions and fluid loading conditions. This model can form the basis for further exploration of the ability of the human cardiovascular system to withstand long-duration space flight and life on Mars.
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Reyes DP, Masterova KS, Walton M, Kerstman EL, Antonsen EL. Assessment of Sex-Dependent Medical Outcomes During Spaceflight. J Womens Health (Larchmt) 2022; 31:1145-1155. [PMID: 35549913 DOI: 10.1089/jwh.2021.0636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
Introduction: In this study sex-differences in medical outcomes during spaceflight are reviewed and probabilistic risk assessment (PRA) is used to assess the impact on spaceflight missions of varying lengths. Materials and Methods: We use PRA to simulate missions of 42 days, 6 months, and 2.5 years. We model medical outcomes using three crews: two men and two women, four women, or four men. Total medical events (TME), crew health index (CHI), probability (0-1) of medical evacuation (pEVAC), probability of loss of crew life (pLOCL), and influential medical conditions were determined. Results: No differences were seen in any metric for the 42-day mission. There were no differences seen for any mission length, in any crew, for TME, CHI, pLOCL, or environmental causes of pEVAC. Sex-dependent differences are seen for rates of nonemergent pEVAC during the 6 month and 2.5-year missions, where women have a higher pEVAC in the 182-day (0.0388 vs. 0.0354) and 2.5-year missions (0.350 vs. 0.228). These differences were driven by higher incidence of partially treated urinary tract infection (UTI). In the 2.5 year mission, with resupply of medical resources, the influence of UTI in women on pEVAC decreases (0.35-0.11). Discussion: Although resupply is unlikely for deep space missions, modeled results suggest that sex-specific medical needs can be readily managed through preventive measures and inclusion of appropriate medical capabilities. Within its many limitations, PRA is a useful tool to estimate medical risks in unique environments where only expert opinion was previously available.
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Affiliation(s)
- David P Reyes
- Department of Preventive Medicine and Population Health, University of Texas Medical Branch, Galveston, Texas, USA
| | - Kseniya S Masterova
- School of Medicine and The Graduate School of Biomedical Sciences, University of Texas Medical Branch, Galveston, Texas, USA
| | | | - Eric L Kerstman
- Department of Preventive Medicine and Population Health, University of Texas Medical Branch, Galveston, Texas, USA
| | - Erik L Antonsen
- Exploration Medical Capability, Johnson Space Center, National Aeronautics and Space Administration, Houston, Texas, USA.,Department of Emergency Medicine and Center for Space Medicine, Baylor College of Medicine, Houston, Texas, USA
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Hart DA. Sex Differences in Biological Systems and the Conundrum of Menopause: Potential Commonalities in Post-Menopausal Disease Mechanisms. Int J Mol Sci 2022; 23:ijms23084119. [PMID: 35456937 PMCID: PMC9026302 DOI: 10.3390/ijms23084119] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 03/30/2022] [Accepted: 04/05/2022] [Indexed: 02/04/2023] Open
Abstract
Sex-specific differences in biology and physiology likely start at the time of conception and progress and mature during the pre-puberty time frame and then during the transitions accompanying puberty. These sex differences are impacted by both genetics and epigenetic alterations during the maturation process, likely for the purpose of preparing for successful reproduction. For females, later in life (~45–50) they undergo another transition leading to a loss of ovarian hormone production at menopause. The reasons for menopause are not clear, but for a subset of females, menopause is accompanied by an increased risk of a number of diseases or conditions that impact a variety of tissues. Most research has mainly focused on the target cells in each of the affected tissues rather than pursue the alternative option that there may be commonalities in the development of these post-menopausal conditions in addition to influences on specific target cells. This review will address some of the potential commonalities presented by an integration of the literature regarding tissue-specific aspects of these post-menopausal conditions and data presented by space flight/microgravity (a condition not anticipated by evolution) that could implicate a loss of a regulatory function of the microvasculature in the risk attached to the affected tissues. Thus, the loss of the integration of the paracrine relationships between endothelial cells of the microvasculature of the tissues affected in the post-menopausal environment could contribute to the risk for post-menopausal diseases/conditions. The validation of this concept could lead to new approaches for interventions to treat post-menopausal conditions, as well as provide new understanding regarding sex-specific biological regulation.
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Affiliation(s)
- David A. Hart
- Department of Surgery and Faculty of Kinesiology, University of Calgary, Calgary, AB T2N 4N1, Canada; ; Tel.: +1-403-220-4571
- Bone & Joint Health Strategic Clinical Network, Alberta Health Services, Edmonton, AB T5J 3E4, Canada
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Mehta RK, Nuamah J. Relationship Between Acute Physical Fatigue and Cognitive Function During Orthostatic Challenge in Men and Women: A Neuroergonomics Investigation. HUMAN FACTORS 2021; 63:1437-1448. [PMID: 32686497 DOI: 10.1177/0018720820936794] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
BACKGROUND Postflight orthostatic challenge (OC), resulting from blood pooling in lower extremities, is a major health concern among astronauts that fly long-duration missions. Additionally, astronauts undergo physical demanding tasks resulting in acute fatigue, which can affect performance. However, the effects of concurrent OC and acute physical fatigue on performance have not been adequately investigated. OBJECTIVE The purpose of this study was to determine the relationship between acute physical fatigue and cognitive function during OC. METHODS Sixteen healthy participants performed the mental arithmetic task and psychomotor tracking tasks in the absence and presence of a prior 1-hour physically fatiguing exercise, on separate days under OC (induced via lower body negative pressure). We recorded task performances on the cognitive tests and prefrontal cortex oxygenation using functional near-infrared spectroscopy, along with physiological and subjective responses. RESULTS The introduction of the cognitive tasks during OC increased cerebral oxygenation; however, oxygenation decreased significantly with the cognitive tasks under the acute fatigue conditions, particularly during the tracking task and in males. These differences were accompanied by comparable task performances. DISCUSSION The findings suggest that mental arithmetic is a more effective countermeasure than psychomotor tracking under acute physical fatigue during OC. Whereas females did not show a significant difference in cerebral oxygenation due to task, males did, suggesting that it may be important to consider gender differences when developing countermeasures against OC.
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Nosikova I, Riabova A, Amirova L, Kitov V, Tomilovskaya E. NAIAD-2020: Characteristics of Motor Evoked Potentials After 3-Day Exposure to Dry Immersion in Women. Front Hum Neurosci 2021; 15:753259. [PMID: 34924980 PMCID: PMC8671694 DOI: 10.3389/fnhum.2021.753259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 11/15/2021] [Indexed: 11/13/2022] Open
Abstract
As female astronauts participate in space flight more and more frequently, there is a demand for research on how the female body adapts to the microgravity environment. In particular, there is very little research on how the neuromuscular system reacts to gravitational unloading in women. We aimed to estimate changes in motor evoked potentials (MEPs) in the lower leg muscles in women after 3-day exposure to Dry Immersion (DI), which is one of the most widely used ground models of microgravity. Six healthy female volunteers (mean age 30.17 ± 5.5 years) with a natural menstrual cycle participated in this experiment. MEPs were recorded from the gastrocnemius and soleus muscles twice before DI, on the day of DI completion, and 3 days after DI, during the recovery period. To evoke motor responses, transcranial and trans-spinal magnetic stimulation was applied. We showed that changes in MEP characteristics after DI exposure were different depending on the stimulation site, but were similar for both muscles. For trans-spinal stimulation, MEP thresholds decreased compared to baseline values, and amplitudes, on the contrary, increased, resembling the phenomenon of hypogravitational hyperreflexia. This finding is in line with data observed in other experiments on both male and female participants. MEPs to transcranial stimulation had an opposing dynamic, which may have resulted from the small group size and large inter-subject variability, or from hormonal fluctuations during the menstrual cycle. Central motor conduction time remained unchanged, suggesting that pyramidal tract conductibility was not affected by DI exposure. More research is needed to explore the underlying mechanisms.
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Tomilovskaya E, Amirova L, Nosikova I, Rukavishnikov I, Chernogorov R, Lebedeva S, Saveko A, Ermakov I, Ponomarev I, Zelenskaya I, Shigueva T, Shishkin N, Kitov V, Riabova A, Brykov V, Abu Sheli N, Vassilieva G, Orlov O. The First Female Dry Immersion (NAIAD-2020): Design and Specifics of a 3-Day Study. Front Physiol 2021; 12:661959. [PMID: 34194336 PMCID: PMC8236811 DOI: 10.3389/fphys.2021.661959] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 05/19/2021] [Indexed: 11/17/2022] Open
Abstract
This article describes procedures and some results of the first study of females undergoing 3-day Dry Immersion. The experiment “NAIAD-2020” was carried out at the Institute of Biomedical Problems (Moscow, Russia) with the participation of six healthy women volunteers (age 30.17 ± 5.5 years, height 1.66 ± 0.1 m, weight 62.05 ± 8.4 kg, BMI 22.39 ± 2.2 kg/m2) with a natural menstrual cycle. During the study, a standard protocol was used, the same as for men, with a minimum period of time spent outside the immersion bath. Before, during and after Immersion, 22 experiments were carried out aimed at studying the neurophysiological, functional, metabolic and psychophysiological functions of the body, the results of which will be presented in future publications. The total time outside the bath for women did not exceed that for men. Systolic and diastolic pressure did not significantly change during the immersion. In the first 24 h after the end of the immersion, heart rate was significantly higher than the background values [F(4,20) = 14.67; P < 0.0001]. Changes in body temperature and water balance were consistent with the patterns found in men. No significant changes in height and weight were found during immersion. All women reported general discomfort and pain in the abdomen and back. The results of this study did not find significant risks to women’s health and showed the feasibility of using this model of the effects of space flight in women of reproductive age.
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Affiliation(s)
- Elena Tomilovskaya
- Russian Federation State Scientific Center - Institute of Biomedical Problems of the Russian Academy of Sciences, Moscow, Russia
| | - Liubov Amirova
- Russian Federation State Scientific Center - Institute of Biomedical Problems of the Russian Academy of Sciences, Moscow, Russia
| | - Inna Nosikova
- Russian Federation State Scientific Center - Institute of Biomedical Problems of the Russian Academy of Sciences, Moscow, Russia
| | - Ilya Rukavishnikov
- Russian Federation State Scientific Center - Institute of Biomedical Problems of the Russian Academy of Sciences, Moscow, Russia
| | - Roman Chernogorov
- Russian Federation State Scientific Center - Institute of Biomedical Problems of the Russian Academy of Sciences, Moscow, Russia
| | - Svetlana Lebedeva
- Russian Federation State Scientific Center - Institute of Biomedical Problems of the Russian Academy of Sciences, Moscow, Russia
| | - Alina Saveko
- Russian Federation State Scientific Center - Institute of Biomedical Problems of the Russian Academy of Sciences, Moscow, Russia
| | - Ivan Ermakov
- Russian Federation State Scientific Center - Institute of Biomedical Problems of the Russian Academy of Sciences, Moscow, Russia
| | - Ivan Ponomarev
- Russian Federation State Scientific Center - Institute of Biomedical Problems of the Russian Academy of Sciences, Moscow, Russia
| | - Inna Zelenskaya
- Russian Federation State Scientific Center - Institute of Biomedical Problems of the Russian Academy of Sciences, Moscow, Russia
| | - Tatiana Shigueva
- Russian Federation State Scientific Center - Institute of Biomedical Problems of the Russian Academy of Sciences, Moscow, Russia
| | - Nikita Shishkin
- Russian Federation State Scientific Center - Institute of Biomedical Problems of the Russian Academy of Sciences, Moscow, Russia
| | - Vladimir Kitov
- Russian Federation State Scientific Center - Institute of Biomedical Problems of the Russian Academy of Sciences, Moscow, Russia
| | - Alexandra Riabova
- Russian Federation State Scientific Center - Institute of Biomedical Problems of the Russian Academy of Sciences, Moscow, Russia
| | - Vitaly Brykov
- Russian Federation State Scientific Center - Institute of Biomedical Problems of the Russian Academy of Sciences, Moscow, Russia
| | - Nelly Abu Sheli
- Russian Federation State Scientific Center - Institute of Biomedical Problems of the Russian Academy of Sciences, Moscow, Russia
| | - Galina Vassilieva
- Russian Federation State Scientific Center - Institute of Biomedical Problems of the Russian Academy of Sciences, Moscow, Russia
| | - Oleg Orlov
- Russian Federation State Scientific Center - Institute of Biomedical Problems of the Russian Academy of Sciences, Moscow, Russia
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Whittle RS, Diaz-Artiles A. Modeling individual differences in cardiovascular response to gravitational stress using a sensitivity analysis. J Appl Physiol (1985) 2021; 130:1983-2001. [PMID: 33914657 DOI: 10.1152/japplphysiol.00727.2020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The human cardiovascular (CV) system elicits a physiological response to gravitational environments, with significant variation between different individuals. Computational modeling can predict CV response, however model complexity and variation of physiological parameters in a normal population makes it challenging to capture individual responses. We conducted a sensitivity analysis on an existing 21-compartment lumped-parameter hemodynamic model in a range of gravitational conditions to 1) investigate the influence of model parameters on a tilt test CV response and 2) to determine the subset of those parameters with the most influence on systemic physiological outcomes. A supine virtual subject was tilted to upright under the influence of a constant gravitational field ranging from 0 g to 1 g. The sensitivity analysis was conducted using a Latin hypercube sampling/partial rank correlation coefficient methodology with subsets of model parameters varied across a normal physiological range. Sensitivity was determined by variation in outcome measures including heart rate, stroke volume, central venous pressure, systemic blood pressures, and cardiac output. Results showed that model parameters related to the length, resistance, and compliance of the large veins and parameters related to right ventricular function have the most influence on model outcomes. For most outcome measures considered, parameters related to the heart are dominant. Results highlight which model parameters to accurately value in simulations of individual subjects' CV response to gravitational stress, improving the accuracy of predictions. Influential parameters remain largely similar across gravity levels, highlighting that accurate model fitting in 1 g can increase the accuracy of predictive responses in reduced gravity.NEW & NOTEWORTHY Computational modeling is used to predict cardiovascular responses to altered gravitational environments. However, considerable variation between subjects and model complexity makes accurate parameter assignment for individuals challenging. This computational effort studies sensitivity in cardiovascular model outcomes due to varying parameters across a normal physiological range. This allows determination of which parameters have the largest influence on outcomes, i.e., which parameters must be most carefully selected to give accurate predictions of individual responses.
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Affiliation(s)
- Richard S Whittle
- Department of Aerospace Engineering, Texas A&M University, College Station, Texas
| | - Ana Diaz-Artiles
- Department of Aerospace Engineering, Texas A&M University, College Station, Texas.,Department of Health and Kinesiology, Texas A&M University, College Station, Texas
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14
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Approaching Gravity as a Continuum Using the Rat Partial Weight-Bearing Model. Life (Basel) 2020; 10:life10100235. [PMID: 33049988 PMCID: PMC7599661 DOI: 10.3390/life10100235] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 09/30/2020] [Accepted: 10/03/2020] [Indexed: 12/12/2022] Open
Abstract
For decades, scientists have relied on animals to understand the risks and consequences of space travel. Animals remain key to study the physiological alterations during spaceflight and provide crucial information about microgravity-induced changes. While spaceflights may appear common, they remain costly and, coupled with limited cargo areas, do not allow for large sample sizes onboard. In 1979, a model of hindlimb unloading (HU) was successfully created to mimic microgravity and has been used extensively since its creation. Four decades later, the first model of mouse partial weight-bearing (PWB) was developed, aiming at mimicking partial gravity environments. Return to the Lunar surface for astronauts is now imminent and prompted the need for an animal model closer to human physiology; hence in 2018, our laboratory created a new model of PWB for adult rats. In this review, we will focus on the rat model of PWB, from its conception to the current state of knowledge. Additionally, we will address how this new model, used in conjunction with HU, will help implement new paradigms allowing scientists to anticipate the physiological alterations and needs of astronauts. Finally, we will discuss the outstanding questions and future perspectives in space research and propose potential solutions using the rat PWB model.
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15
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Kermorgant M, Nasr N, Czosnyka M, Arvanitis DN, Hélissen O, Senard JM, Pavy-Le Traon A. Impacts of Microgravity Analogs to Spaceflight on Cerebral Autoregulation. Front Physiol 2020; 11:778. [PMID: 32719617 PMCID: PMC7350784 DOI: 10.3389/fphys.2020.00778] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 06/15/2020] [Indexed: 12/16/2022] Open
Abstract
It is well known that exposure to microgravity in astronauts leads to a plethora physiological responses such as headward fluid shift, body unloading, and cardiovascular deconditioning. When astronauts return to Earth, some encounter problems related to orthostatic intolerance. An impaired cerebral autoregulation (CA), which could be compromised by the effects of microgravity, has been proposed as one of the mechanisms responsible for orthostatic intolerance. CA is a homeostatic mechanism that maintains cerebral blood flow for any variations in cerebral perfusion pressure by adapting the vascular tone and cerebral vessel diameter. The ground-based models of microgravity are useful tools for determining the gravitational impact of spaceflight on human body. The head-down tilt bed rest (HDTBR), where the subject remains in supine position at −6 degrees for periods ranging from few days to several weeks is the most commonly used ground-based model of microgravity for cardiovascular deconditioning. head-down bed rest (HDBR) is able to replicate cephalic fluid shift, immobilization, confinement, and inactivity. Dry immersion (DI) model is another approach where the subject remains immersed in thermoneutral water covered with an elastic waterproof fabric separating the subject from the water. Regarding DI, this analog imitates absence of any supporting structure for the body, centralization of body fluids, immobilization and hypokinesia observed during spaceflight. However, little is known about the impact of microgravity on CA. Here, we review the fundamental principles and the different mechanisms involved in CA. We also consider the different approaches in order to assess CA. Finally, we focus on the effects of short- and long-term spaceflight on CA and compare these findings with two specific analogs to microgravity: HDBR and DI.
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Affiliation(s)
- Marc Kermorgant
- INSERM UMR 1048, Institute of Cardiovascular and Metabolic Diseases (I2MC), Toulouse, France
| | - Nathalie Nasr
- INSERM UMR 1048, Institute of Cardiovascular and Metabolic Diseases (I2MC), Toulouse, France.,Department of Neurology, Institute for Neurosciences, Toulouse University Hospital, Toulouse, France
| | - Marek Czosnyka
- Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, Cambridge University Hospital, Cambridge, United Kingdom.,Institute of Electronic Systems, Warsaw University of Technology, Warsaw, Poland
| | - Dina N Arvanitis
- INSERM UMR 1048, Institute of Cardiovascular and Metabolic Diseases (I2MC), Toulouse, France
| | - Ophélie Hélissen
- INSERM UMR 1048, Institute of Cardiovascular and Metabolic Diseases (I2MC), Toulouse, France
| | - Jean-Michel Senard
- INSERM UMR 1048, Institute of Cardiovascular and Metabolic Diseases (I2MC), Toulouse, France.,Department of Clinical Pharmacology, Toulouse University Hospital, Toulouse, France
| | - Anne Pavy-Le Traon
- INSERM UMR 1048, Institute of Cardiovascular and Metabolic Diseases (I2MC), Toulouse, France.,Department of Neurology, Institute for Neurosciences, Toulouse University Hospital, Toulouse, France
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16
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Lee SMC, Ribeiro LC, Martin DS, Zwart SR, Feiveson AH, Laurie SS, Macias BR, Crucian BE, Krieger S, Weber D, Grune T, Platts SH, Smith SM, Stenger MB. Arterial structure and function during and after long-duration spaceflight. J Appl Physiol (1985) 2020; 129:108-123. [PMID: 32525433 DOI: 10.1152/japplphysiol.00550.2019] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Spaceflight missions expose astronauts to increased risk of oxidative stress and inflammatory damage that might accelerate the development of asymptomatic cardiovascular disease. The purpose of this investigation was to determine whether long-duration spaceflight (>4 mo) results in structural and functional changes in the carotid and brachial arteries. Common carotid artery (CCA) intima-media thickness (cIMT), CCA distensibility and stiffness, and brachial artery endothelium-dependent and -independent vasodilation were measured in 13 astronauts (10 men, 3 women) ~180 and 60 days before launch, during the mission on ~15, 60, and 160 days of spaceflight, and within 1 wk after landing. Biomarkers of oxidative stress and inflammation were measured at corresponding times in fasting blood samples and urine samples from 24- or 48-h pools. Biomarkers of oxidative stress and inflammation increased during spaceflight, but most returned to preflight levels within 1 wk of landing. Mean cIMT, CCA stiffness, and distensibility were not significantly different from preflight at any time. As a group, neither mean endothelium-dependent nor -independent vasodilation changed from preflight to postflight, but changes within individuals in endothelial function related to some biomarkers of oxidative stress. Whereas biomarkers of oxidative stress and inflammation are elevated during spaceflight, CCA and brachial artery structure and function were not changed by spaceflight. It is unclear whether future exploration missions, with an extended duration in altered gravity fields and higher radiation exposure, may be problematic.NEW & NOTEWORTHY Carotid artery structure and stiffness did not change on average in astronauts during long-duration spaceflight (<12 mo), despite increased oxidative stress and inflammation. Most oxidative stress and inflammation biomarkers returned to preflight levels soon after landing. Brachial artery structure and function also were unchanged by spaceflight. In this group of healthy middle-aged male and female astronauts, spaceflight in low Earth orbit does not appear to increase long-term cardiovascular health risk.
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Affiliation(s)
| | | | | | - Sara R Zwart
- University of Texas Medical Branch, Galveston, Texas
| | | | | | | | | | | | - Daniela Weber
- Department of Molecular Nutrition, German Institute of Human Nutrition Potsdam-Rehbruecke (DIfE), Nuthetal, Germany
| | - Tilman Grune
- Department of Molecular Nutrition, German Institute of Human Nutrition Potsdam-Rehbruecke (DIfE), Nuthetal, Germany.,German Center for Cardiovascular Research (DZHK), Berlin, Germany
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17
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Sandal PH, Kim D, Fiebig L, Winnard A, Caplan N, Green DA, Weber T. Effectiveness of nutritional countermeasures in microgravity and its ground-based analogues to ameliorate musculoskeletal and cardiopulmonary deconditioning-A Systematic Review. PLoS One 2020; 15:e0234412. [PMID: 32516346 PMCID: PMC7282646 DOI: 10.1371/journal.pone.0234412] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 05/24/2020] [Indexed: 12/13/2022] Open
Abstract
A systematic review was performed to evaluate the effectiveness of nutrition as a standalone countermeasure to ameliorate the physiological adaptations of the musculoskeletal and cardiopulmonary systems associated with prolonged exposure to microgravity. A search strategy was developed to find all astronaut or human space flight bed rest simulation studies that compared individual nutritional countermeasures with non-intervention control groups. This systematic review followed the guidelines of the Cochrane Handbook for Systematic Reviews and tools created by the Aerospace Medicine Systematic Review Group for data extraction, quality assessment of studies and effect size. To ensure adequate reporting this systematic review followed the guidelines of the Preferred Reporting Items for Systematic Review and Meta-Analyses. A structured search was performed to screen for relevant articles. The initial search yielded 4031 studies of which 10 studies were eligible for final inclusion. Overall, the effect of nutritional countermeasure interventions on the investigated outcomes revealed that only one outcome was in favor of the intervention group, whereas six outcomes were in favor of the control group, and 43 outcomes showed no meaningful effect of nutritional countermeasure interventions at all. The main findings of this study were: (1) the heterogeneity of reported outcomes across studies, (2) the inconsistency of the methodology of the included studies (3) an absence of meaningful effects of standalone nutritional countermeasure interventions on musculoskeletal and cardiovascular outcomes, with a tendency towards detrimental effects on specific muscle outcomes associated with power in the lower extremities. This systematic review highlights the limited amount of studies investigating the effect of nutrition as a standalone countermeasure on operationally relevant outcome parameters. Therefore, based on the data available from the included studies in this systematic review, it cannot be expected that nutrition alone will be effective in maintaining musculoskeletal and cardiopulmonary integrity during space flight and bed rest.
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Affiliation(s)
- Peter H. Sandal
- Space Medicine Team, European Astronaut Centre, European Space Agency, Köln, Germany
| | - David Kim
- Space Medicine Team, European Astronaut Centre, European Space Agency, Köln, Germany
- Faculty of Medicine, University of British Columbia, Vancouver, Canada
| | - Leonie Fiebig
- Space Medicine Team, European Astronaut Centre, European Space Agency, Köln, Germany
- Institute of Biomechanics und Orthopaedics, German Sport University, Cologne, Germany
| | - Andrew Winnard
- Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, United Kingdom
| | - Nick Caplan
- Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, United Kingdom
| | - David A. Green
- Space Medicine Team, European Astronaut Centre, European Space Agency, Köln, Germany
- Centre of Human & Applied Physiological Sciences, King’s College London, London, United Kingdom
- KBR GmbH, Köln, Germany
| | - Tobias Weber
- Space Medicine Team, European Astronaut Centre, European Space Agency, Köln, Germany
- KBR GmbH, Köln, Germany
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18
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Steele J, Androulakis-Korakakis P, Perrin C, Fisher JP, Gentil P, Scott C, Rosenberger A. Comparisons of Resistance Training and "Cardio" Exercise Modalities as Countermeasures to Microgravity-Induced Physical Deconditioning: New Perspectives and Lessons Learned From Terrestrial Studies. Front Physiol 2019; 10:1150. [PMID: 31551818 PMCID: PMC6746842 DOI: 10.3389/fphys.2019.01150] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 08/26/2019] [Indexed: 11/13/2022] Open
Abstract
Prolonged periods in microgravity (μG) environments result in deconditioning of numerous physiological systems, particularly muscle at molecular, single fiber, and whole muscle levels. This deconditioning leads to loss of strength and cardiorespiratory fitness. Loading muscle produces mechanical tension with resultant mechanotransduction initiating molecular signaling that stimulates adaptations in muscle. Exercise can reverse deconditioning resultant from phases of detraining, de-loading, or immobilization. On Earth, applications of loading using exercise models are common, as well as in μG settings as countermeasures to deconditioning. The primary modalities include, but are not limited to, aerobic training (or "cardio") and resistance training, and have historically been dichotomized; the former primarily thought to improve cardiorespiratory fitness, and the latter primarily improving strength and muscle size. However, recent work questions this dichotomy, suggesting adaptations to loading through exercise are affected by intensity of effort independent of modality. Furthermore, similar adaptations may occur where sufficient intensity of effort is used. Traditional countermeasures for μG-induced deconditioning have focused upon engineering-based solutions to enable application of traditional models of exercise. Yet, contemporary developments in understanding of the applications, and subsequent adaptations, to exercise induced muscular loading in terrestrial settings have advanced such in recent years that it may be appropriate to revisit the evidence to inform how exercise can used in μG. With the planned decommissioning of the International Space Station as early as 2024 and future goals of manned moon and Mars missions, efficiency of resources must be prioritized. Engineering-based solutions to apply exercise modalities inevitably present issues relating to devices mass, size, energy use, heat production, and ultimately cost. It is necessary to identify exercise countermeasures to combat deconditioning while limiting these issues. As such, this brief narrative review considers recent developments in our understanding of skeletal muscle adaptation to loading through exercise from studies conducted in terrestrial settings, and their applications in μG environments. We consider the role of intensity of effort, comparisons of exercise modalities, the need for concurrent exercise approaches, and other issues often not considered in terrestrial exercise studies but are of concern in μG environments (i.e., O2 consumption, CO2 production, and energy costs of exercise).
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Affiliation(s)
- James Steele
- School of Sport, Health, and Social Sciences, Solent University, Southampton, United Kingdom
- Ukactive Research Institute, London, United Kingdom
| | | | - Craig Perrin
- School of Sport, Health, and Social Sciences, Solent University, Southampton, United Kingdom
| | - James Peter Fisher
- School of Sport, Health, and Social Sciences, Solent University, Southampton, United Kingdom
| | - Paulo Gentil
- Faculty of Physical Education and Dance, Federal University of Goias, Goiânia, Brazil
| | - Christopher Scott
- Department of Exercise, Health, and Sport Sciences, University of Southern Maine, Portland, ME, United States
| | - André Rosenberger
- Space Medicine Team, ISS Operations and Astronaut Group, Directorate of Human and Robotic Exploration Programmes, European Astronaut Centre, Cologne, Germany
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19
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Fu Q, Shibata S, Hastings JL, Platts SH, Hamilton DM, Bungo MW, Stenger MB, Ribeiro C, Adams-Huet B, Levine BD. Impact of Prolonged Spaceflight on Orthostatic Tolerance During Ambulation and Blood Pressure Profiles in Astronauts. Circulation 2019; 140:729-738. [DOI: 10.1161/circulationaha.119.041050] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Background:
Astronauts returning to earth usually demonstrate reduced orthostatic tolerance when assessed on a tilt table or quiet standing, but no studies have evaluated postflight orthostatic tolerance during activities of daily living, when it is most clinically relevant. Ambulatory blood pressure (BP) variability also is associated with orthostatic intolerance in certain patient populations and can capture clinically significant orthostatic hypotension during activities of daily living, especially when measured on a beat-to-beat basis. We evaluated the impact of prolonged spaceflight on orthostatic tolerance and BP profiles in astronauts.
Methods:
Ambulatory beat-to-beat BP was recorded using a portable device for multiple 24-hour time periods before, during, and after 6 months of spaceflight in 12 astronauts (4 women; age 48±5 [mean±SD] years). BP variability in the time domain was calculated as the SD. Systolic BP distribution during activities of daily living was characterized by skewness and kurtosis.
Results:
In contrast with results from previous studies that used tilt tables or stand tests, no astronaut experienced orthostatic intolerance/hypotension during activities of daily living before or after spaceflight. Also, 24-hour systolic BP decreased in space (120±10 mm Hg before spaceflight versus 106±9 mm Hg during spaceflight;
P
<0.01), but it returned to normal upon landing (122±13 mm Hg). Diastolic BP was unchanged during and after spaceflight. Systolic and diastolic BP variability remained the same before, during, and after spaceflight (both
P
>0.05). The skewness of systolic BP increased in space (0.74±0.51 versus 1.43±1.00;
P
=0.001), indicating that signal fluctuations became asymmetrical; however, it returned to preflight levels after landing (0.51±0.42). The kurtosis increased in space (5.01±7.67 versus 11.10±11.79;
P
=0.010), suggesting that fluctuations concentrated around the mean with a narrow distribution; however, it also returned to preflight levels (2.21±2.56) after return to earth.
Conclusions:
Given current countermeasures including in-flight exercise training and volume resuscitation on return, no astronauts experienced orthostatic hypotension or intolerance during routine (for landing day) activities in the initial 24 hours after landing following 6 months in space. Prolonged exposure to spaceflight had little impact on systolic BP variability and its distribution, although the latter showed a transient change in space (accompanied by mild relative hypotension), all of which returned to preflight values after return to earth.
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Affiliation(s)
- Qi Fu
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas (Q.F., S.S., B.D.L.)
- The University of Texas Southwestern Medical Center, Dallas (Q.F., S.S., J.L.H., B.A.-H., B.D.L.)
| | - Shigeki Shibata
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas (Q.F., S.S., B.D.L.)
- The University of Texas Southwestern Medical Center, Dallas (Q.F., S.S., J.L.H., B.A.-H., B.D.L.)
| | - Jeffrey L. Hastings
- The University of Texas Southwestern Medical Center, Dallas (Q.F., S.S., J.L.H., B.A.-H., B.D.L.)
| | - Steven H. Platts
- NASA Johnson Space Center, Houston, TX (S.H.P., D.M.H., M.B.S., C.R.)
| | - Douglas M. Hamilton
- NASA Johnson Space Center, Houston, TX (S.H.P., D.M.H., M.B.S., C.R.)
- The University of Calgary, Alberta, Canada (D.M.H.)
| | - Michael W. Bungo
- The University of Texas McGovern Medical School, Houston (M.W.B.)
| | | | - Christine Ribeiro
- NASA Johnson Space Center, Houston, TX (S.H.P., D.M.H., M.B.S., C.R.)
| | - Beverley Adams-Huet
- The University of Texas Southwestern Medical Center, Dallas (Q.F., S.S., J.L.H., B.A.-H., B.D.L.)
| | - Benjamin D. Levine
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas (Q.F., S.S., B.D.L.)
- The University of Texas Southwestern Medical Center, Dallas (Q.F., S.S., J.L.H., B.A.-H., B.D.L.)
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20
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Cromwell RL, Scott JM, Downs M, Yarbough PO, Zanello SB, Ploutz-Snyder L. Overview of the NASA 70-day Bed Rest Study. Med Sci Sports Exerc 2019; 50:1909-1919. [PMID: 29570535 DOI: 10.1249/mss.0000000000001617] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE The purpose of this article was to provide an overview of the National Aeronautics and Space Administration (NASA) 70-day Bed Rest Study. The integrated complement of investigations and the standardized bed rest environment that served as the platform for this study complement are described. Outcomes of the studies will not be presented here but will be reported in separate publications. METHODS A set of studies running in an integrated fashion along the entire period (pre-, in-, and post-bed rest) and using the same subjects is referred in this article as "the campaign" or "complement." NASA selected eight individual studies to participate in the 70-d bed rest campaign. These studies were integrated to increase efficiency in the utilization of resources and to share common measures among the investigations. In addition to the individual studies addressing specific aims, a battery of standardized measures was included. Standard measures target a wide range of physiologic systems and represent some of the testing routinely done on astronauts. Bed rest subjects underwent rigorous medical and psychological screening. Standardized conditions included 70 d of bed rest in a 6° head-down tilt position. Subjects' vital signs, body weight, and fluid intake and output were measured daily. A standardized diet was provided to ensure consistent nutritional intake across subjects. Exercising subjects were prescribed individualized aerobic and resistance training 6 d·wk performed in a horizontal body position. Subjects in the testosterone supplementation countermeasure group received testosterone enanthate injections at 2-wk intervals during bed rest. CONCLUSION Long-duration head-down tilt bed rest provided a suitable platform for examining physiologic effects of spaceflight and testing countermeasures in a ground-based model. Integrating studies into a complement is an effective way to support multiple investigations while minimizing the number of subjects to answer many research questions.
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21
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Diaz-Artiles A, Heldt T, Young LR. Short-Term Cardiovascular Response to Short-Radius Centrifugation With and Without Ergometer Exercise. Front Physiol 2018; 9:1492. [PMID: 30483141 PMCID: PMC6242912 DOI: 10.3389/fphys.2018.01492] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2018] [Accepted: 10/03/2018] [Indexed: 12/26/2022] Open
Abstract
Artificial gravity (AG) has often been proposed as an integrated multi-system countermeasure to physiological deconditioning associated with extended exposure to reduced gravity levels, particularly if combined with exercise. Twelve subjects underwent short-radius centrifugation along with bicycle ergometry to quantify the short-term cardiovascular response to AG and exercise across three AG levels (0 G or no rotation, 1 G, and 1.4 G; referenced to the subject's feet and measured in the centripetal direction) and three exercise intensities (25, 50, and 100 W). Continuous cardiovascular measurements were collected during the centrifugation sessions using a non-invasive monitoring system. The cardiovascular responses were more prominent at higher levels of AG and exercise intensity. In particular, cardiac output, stroke volume, pulse pressure, and heart rate significantly increased with both AG level (in most of exercise group combinations, showing averaged increments across exercise conditions of 1.4 L/min/g, 7.6 mL/g, 5.22 mmHg/g, and 2.0 bpm/g, respectively), and workload intensity (averaged increments across AG conditions of 0.09 L/min/W, 0.17 mL/W, 0.22 mmHg/W, and 0.74 bpm/W respectively). These results suggest that the addition of AG to exercise can provide a greater cardiovascular benefit than exercise alone. Hierarchical regression models were fitted to the experimental data to determine dose-response curves of all cardiovascular variables as a function of AG-level and exercise intensity during short-radius centrifugation. These results can inform future studies, decisions, and trade-offs toward potential implementation of AG as a space countermeasure.
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Affiliation(s)
- Ana Diaz-Artiles
- Department of Aerospace Engineering, Texas A&M University, College Station, TX, United States
| | - Thomas Heldt
- Institute for Medical Engineering and Science and Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Laurence R. Young
- Department of Aeronautics and Astronautics, Massachusetts Institute of Technology, Cambridge, MA, United States
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22
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Evans JM, Knapp CF, Goswami N. Artificial Gravity as a Countermeasure to the Cardiovascular Deconditioning of Spaceflight: Gender Perspectives. Front Physiol 2018; 9:716. [PMID: 30034341 PMCID: PMC6043777 DOI: 10.3389/fphys.2018.00716] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 05/24/2018] [Indexed: 12/11/2022] Open
Abstract
Space flight-induced physiological deconditioning resulting from decreased gravitational input, decreased plasma volume, and disruption of regulatory mechanisms is a significant problem in returning astronauts as well as in normal aging. Here we review effects of a promising countermeasure on cardiovascular systems of healthy men and women undergoing Earth-based models of space-flight. This countermeasure is produced by a centrifuge and called artificial gravity (AG). Numerous studies have determined that AG improves orthostatic tolerance (as assessed by various protocols) of healthy ambulatory men, of men deconditioned by bed rest or by immersion (both wet and dry) and, in one case, following spaceflight. Although a few studies of healthy, ambulatory women and one study of women deconditioned by furosemide, have reported improvement of orthostatic tolerance following exposure to AG, studies of bed-rested women exposed to AG have not been conducted. However, in ambulatory, normovolemic subjects, AG training was more effective in men than women and more effective in subjects who exercised during AG than in those who passively rode the centrifuge. Acute exposure to an AG protocol, individualized to provide a common stimulus to each person, also improved orthostatic tolerance of normovolemic men and women and of furosemide-deconditioned men and women. Again, men's tolerance was more improved than women's. In both men and women, exposure to AG increased stroke volume, so greater improvement in men vs. women was due in part to their different vascular responses to AG. Following AG exposure, resting blood pressure (via decreased vascular resistance) decreased in men but not women, indicating an increase in men's vascular reserve. Finally, in addition to counteracting space flight deconditioning, improved orthostatic tolerance through AG-induced improvement of stroke volume could benefit aging men and women on Earth.
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Affiliation(s)
- Joyce M. Evans
- Department of Biomedical Engineering, University of Kentucky, Lexington, KY, United States
| | - Charles F. Knapp
- Department of Biomedical Engineering, University of Kentucky, Lexington, KY, United States
| | - Nandu Goswami
- Physiology, Otto Loewi Research Center for Vascular Biology, Immunology and Inflammation, Medical University of Graz, Graz, Austria
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23
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Diaz-Artiles A, Heldt T, Young LR. Short-Term Cardiovascular Response to Short-Radius Centrifugation With and Without Ergometer Exercise. Front Physiol 2018. [PMID: 30483141 DOI: 10.3389/fphys.2018.00830/full] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2023] Open
Abstract
Artificial gravity (AG) has often been proposed as an integrated multi-system countermeasure to physiological deconditioning associated with extended exposure to reduced gravity levels, particularly if combined with exercise. Twelve subjects underwent short-radius centrifugation along with bicycle ergometry to quantify the short-term cardiovascular response to AG and exercise across three AG levels (0 G or no rotation, 1 G, and 1.4 G; referenced to the subject's feet and measured in the centripetal direction) and three exercise intensities (25, 50, and 100 W). Continuous cardiovascular measurements were collected during the centrifugation sessions using a non-invasive monitoring system. The cardiovascular responses were more prominent at higher levels of AG and exercise intensity. In particular, cardiac output, stroke volume, pulse pressure, and heart rate significantly increased with both AG level (in most of exercise group combinations, showing averaged increments across exercise conditions of 1.4 L/min/g, 7.6 mL/g, 5.22 mmHg/g, and 2.0 bpm/g, respectively), and workload intensity (averaged increments across AG conditions of 0.09 L/min/W, 0.17 mL/W, 0.22 mmHg/W, and 0.74 bpm/W respectively). These results suggest that the addition of AG to exercise can provide a greater cardiovascular benefit than exercise alone. Hierarchical regression models were fitted to the experimental data to determine dose-response curves of all cardiovascular variables as a function of AG-level and exercise intensity during short-radius centrifugation. These results can inform future studies, decisions, and trade-offs toward potential implementation of AG as a space countermeasure.
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Affiliation(s)
- Ana Diaz-Artiles
- Department of Aerospace Engineering, Texas A&M University, College Station, TX, United States
| | - Thomas Heldt
- Institute for Medical Engineering and Science and Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Laurence R Young
- Department of Aeronautics and Astronautics, Massachusetts Institute of Technology, Cambridge, MA, United States
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24
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Wostyn P, De Deyn PP. Intracranial pressure-induced optic nerve sheath response as a predictive biomarker for optic disc edema in astronauts. Biomark Med 2017; 11:1003-1008. [PMID: 28869392 DOI: 10.2217/bmm-2017-0218] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A significant proportion of the astronauts who spend extended periods in microgravity develop ophthalmic abnormalities. Understanding this syndrome, called visual impairment and intracranial pressure (VIIP), has become a high priority for National Aeronautics and Space Administration, especially in view of future long-duration missions (e.g., Mars missions). Moreover, to ensure selection of astronaut candidates who will be able to complete long-duration missions with low risk of the VIIP syndrome, it is imperative to identify biomarkers for VIIP risk prediction. Here, we hypothesize that the optic nerve sheath response to alterations in intracranial pressure may be a potential predictive biomarker for optic disc edema in astronauts. If confirmed, this biomarker could be used for preflight identification of astronauts at risk for developing VIIP-associated optic disc edema.
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Affiliation(s)
- Peter Wostyn
- Department of Psychiatry, PC Sint-Amandus, 8730 Beernem, Belgium
| | - Peter Paul De Deyn
- Laboratory of Neurochemistry & Behavior, Institute Born-Bunge, University of Antwerp, Department of Biomedical Sciences, 2610 Antwerp, Belgium.,Department of Neurology & Alzheimer Research Center, University of Groningen & University Medical Center Groningen, 9700 RB Groningen, The Netherlands.,Department of Neurology & Memory Clinic, Middelheim General Hospital (ZNA), 2020 Antwerp, Belgium
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25
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Lawley JS, Petersen LG, Howden EJ, Sarma S, Cornwell WK, Zhang R, Whitworth LA, Williams MA, Levine BD. Effect of gravity and microgravity on intracranial pressure. J Physiol 2017; 595:2115-2127. [PMID: 28092926 DOI: 10.1113/jp273557] [Citation(s) in RCA: 160] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Accepted: 12/19/2016] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Astronauts have recently been discovered to have impaired vision, with a presentation that resembles syndromes of elevated intracranial pressure on Earth. Gravity has a profound effect on fluid distribution and pressure within the human circulation. In contrast to prevailing theory, we observed that microgravity reduces central venous and intracranial pressure. This being said, intracranial pressure is not reduced to the levels observed in the 90 deg seated upright posture on Earth. Thus, over 24 h in zero gravity, pressure in the brain is slightly above that observed on Earth, which may explain remodelling of the eye in astronauts. ABSTRACT Astronauts have recently been discovered to have impaired vision, with a presentation that resembles syndromes of elevated intracranial pressure (ICP). This syndrome is considered the most mission-critical medical problem identified in the past decade of manned spaceflight. We recruited five men and three women who had an Ommaya reservoir inserted for the delivery of prophylactic CNS chemotherapy, but were free of their malignant disease for at least 1 year. ICP was assessed by placing a fluid-filled 25 gauge butterfly needle into the Ommaya reservoir. Subjects were studied in the upright and supine position, during acute zero gravity (parabolic flight) and prolonged simulated microgravity (6 deg head-down tilt bedrest). ICP was lower when seated in the 90 deg upright posture compared to lying supine (seated, 4 ± 1 vs. supine, 15 ± 2 mmHg). Whilst lying in the supine posture, central venous pressure (supine, 7 ± 3 vs. microgravity, 4 ± 2 mmHg) and ICP (supine, 17 ± 2 vs. microgravity, 13 ± 2 mmHg) were reduced in acute zero gravity, although not to the levels observed in the 90 deg seated upright posture on Earth. Prolonged periods of simulated microgravity did not cause progressive elevations in ICP (supine, 15 ± 2 vs. 24 h head-down tilt, 15 ± 4 mmHg). Complete removal of gravity does not pathologically elevate ICP but does prevent the normal lowering of ICP when upright. These findings suggest the human brain is protected by the daily circadian cycles in regional ICPs, without which pathology may occur.
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Affiliation(s)
- Justin S Lawley
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Dallas, Dallas, TX, USA.,University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Lonnie G Petersen
- Department of Biomedical Sciences, Faculty of Health Sciences, University of Copenhagen, Denmark
| | - Erin J Howden
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Dallas, Dallas, TX, USA.,University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Satyam Sarma
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Dallas, Dallas, TX, USA.,University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - William K Cornwell
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Dallas, Dallas, TX, USA.,University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Rong Zhang
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Dallas, Dallas, TX, USA.,University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Louis A Whitworth
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Dallas, Dallas, TX, USA
| | - Michael A Williams
- Departments of Neurology and Neurological Surgery, University of Washington School of Medicine, Seattle, WA, USA
| | - Benjamin D Levine
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Dallas, Dallas, TX, USA.,University of Texas Southwestern Medical Center, Dallas, TX, USA
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26
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Alwood JS, Ronca AE, Mains RC, Shelhamer MJ, Smith JD, Goodwin TJ. From the bench to exploration medicine: NASA life sciences translational research for human exploration and habitation missions. NPJ Microgravity 2017. [PMID: 28649627 PMCID: PMC5460236 DOI: 10.1038/s41526-016-0002-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
NASA’s Space Biology and Human Research Program entities have recently spearheaded communications both internally and externally to coordinate the agency’s translational research efforts. In this paper, we strongly advocate for translational research at NASA, provide recent examples of NASA sponsored early-stage translational research, and discuss options for a path forward. Our overall objective is to help in stimulating a collaborative research across multiple disciplines and entities that, working together, will more effectively and more rapidly achieve NASA’s goals for human spaceflight.
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Affiliation(s)
- Joshua S Alwood
- Space BioSciences Division, NASA Ames Research Center, Moffett Field, CA USA
| | - April E Ronca
- Space BioSciences Division, NASA Ames Research Center, Moffett Field, CA USA.,Wake Forest School of Medicine, Winston-Salem, NC USA
| | | | - Mark J Shelhamer
- Human Research Program, NASA Johnson Space Center, Houston, TX USA
| | - Jeffrey D Smith
- Space BioSciences Division, NASA Ames Research Center, Moffett Field, CA USA
| | - Thomas J Goodwin
- Biomedical Research and Environmental Sciences Division, NASA Johnson Space Center, Houston, TX USA
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27
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Aubert AE, Larina I, Momken I, Blanc S, White O, Kim Prisk G, Linnarsson D. Towards human exploration of space: the THESEUS review series on cardiovascular, respiratory, and renal research priorities. NPJ Microgravity 2016; 2:16031. [PMID: 28725739 PMCID: PMC5515532 DOI: 10.1038/npjmgrav.2016.31] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Affiliation(s)
- André E Aubert
- Laboratory of Experimental Cardiology, Gasthuisberg University Hospital, KU Leuven, Leuven, Belgium
| | - Irina Larina
- Institute for Biomedical Problems, Moscow, Russia
| | - Iman Momken
- Université d’Evry Val d’Essonne, UBIAE (EA7362), Evry, France
- Université de Strasbourg, IPHC, Strasbourg, France
| | - Stéphane Blanc
- Université de Strasbourg, IPHC, Strasbourg, France
- CNRS, UMR7178, Strasbourg, France
| | | | - G Kim Prisk
- University of California, San Diego, CA, USA
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28
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Gemignani J, Gheysens T, Summerer L. Beyond astronaut's capabilities: The current state of the art. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2016; 2015:3615-8. [PMID: 26737075 DOI: 10.1109/embc.2015.7319175] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Space agencies have developed extensive expertise with sustaining human presence in low earth orbits and microgravity. Prolonged human presence in space beyond EarthâĂŹs orbit presents additional, some still unsolved issues. These are linked to the distance to Earth (impossibility of effective tele-operation, psychological effects linked to remoteness from Earth, required autonomy, the handling of emergencies, long mission durations), and to the environments beyond the Earth magnetosphere (radiation levels, local environments including atmospheres, dust, gravity, day-night cycles). These issues have impacts on the spacecraft design, the mission operations, astronaut selection and preparation and required supporting/ enabling technologies. This paper builds upon previous work by Rossini et al. , in critically reviewing and updating the current state of scientific research on enhancing astronaut's capabilities to face some of these challenges. In particular, it discusses the pertinence and feasibility of two approaches aiming at enhancing the chances of success of human missions: induced hibernation state and brain-machine interfaces.
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29
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Globus RK, Morey-Holton E. Hindlimb unloading: rodent analog for microgravity. J Appl Physiol (1985) 2016; 120:1196-206. [PMID: 26869711 DOI: 10.1152/japplphysiol.00997.2015] [Citation(s) in RCA: 136] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Accepted: 02/02/2016] [Indexed: 11/22/2022] Open
Abstract
The rodent hindlimb unloading (HU) model was developed in the 1980s to make it possible to study mechanisms, responses, and treatments for the adverse consequences of spaceflight. Decades before development of the HU model, weightlessness was predicted to yield deficits in the principal tissues responsible for structure and movement on Earth, primarily muscle and bone. Indeed, results from early spaceflight and HU experiments confirmed the expected sensitivity of the musculoskeletal system to gravity loading. Results from human and animal spaceflight and HU experiments show that nearly all organ systems and tissues studied display some measurable changes, albeit sometimes minor and of uncertain relevance to astronaut health. The focus of this review is to examine key HU results for various organ systems including those related to stress; the immune, cardiovascular, and nervous systems; vision changes; and wound healing. Analysis of the validity of the HU model is important given its potential value for both hypothesis testing and countermeasure development.
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Affiliation(s)
- Ruth K Globus
- Space Biosciences Division, NASA-Ames Research Center, Moffett Field, California
| | - Emily Morey-Holton
- Space Biosciences Division, NASA-Ames Research Center, Moffett Field, California
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30
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Hughson RL, Robertson AD, Arbeille P, Shoemaker JK, Rush JWE, Fraser KS, Greaves DK. Increased postflight carotid artery stiffness and inflight insulin resistance resulting from 6-mo spaceflight in male and female astronauts. Am J Physiol Heart Circ Physiol 2016; 310:H628-38. [PMID: 26747504 DOI: 10.1152/ajpheart.00802.2015] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Accepted: 01/04/2016] [Indexed: 12/25/2022]
Abstract
Removal of the normal head-to-foot gravity vector and chronic weightlessness during spaceflight might induce cardiovascular and metabolic adaptations related to changes in arterial pressure and reduction in physical activity. We tested hypotheses that stiffness of arteries located above the heart would be increased postflight, and that blood biomarkers inflight would be consistent with changes in vascular function. Possible sex differences in responses were explored in four male and four female astronauts who lived on the International Space Station for 6 mo. Carotid artery distensibility coefficient (P = 0.005) and β-stiffness index (P = 0.006) reflected 17-30% increases in arterial stiffness when measured within 38 h of return to Earth compared with preflight. Spaceflight-by-sex interaction effects were found with greater changes in β-stiffness index in women (P = 0.017), but greater changes in pulse wave transit time in men (P = 0.006). Several blood biomarkers were changed from preflight to inflight, including an increase in an index of insulin resistance (P < 0.001) with a spaceflight-by-sex term suggesting greater change in men (P = 0.034). Spaceflight-by-sex interactions for renin (P = 0.016) and aldosterone (P = 0.010) indicated greater increases in women than men. Six-month spaceflight caused increased arterial stiffness. Altered hydrostatic arterial pressure gradients as well as changes in insulin resistance and other biomarkers might have contributed to alterations in arterial properties, including sex differences between male and female astronauts.
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Affiliation(s)
- Richard L Hughson
- Schlegel-University of Waterloo Research Institute for Aging, Waterloo, Ontario, Canada;
| | - Andrew D Robertson
- Schlegel-University of Waterloo Research Institute for Aging, Waterloo, Ontario, Canada
| | - Philippe Arbeille
- Unite Medecine Physiologie Spatiale, CERCOM, EFMP, CHU Trousseau, Tours, France
| | - J Kevin Shoemaker
- School of Kinesiology and Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada; and
| | - James W E Rush
- Faculty of Applied Health Sciences, University of Waterloo, Waterloo, Ontario
| | - Katelyn S Fraser
- Schlegel-University of Waterloo Research Institute for Aging, Waterloo, Ontario, Canada
| | - Danielle K Greaves
- Schlegel-University of Waterloo Research Institute for Aging, Waterloo, Ontario, Canada
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