Cardiovascular Health Consequences of Long-Duration Space Flight (Vascular) - 07.19.17

Overview | Description | Applications | Operations | Results | Publications | Imagery

ISS Science for Everyone

Science Objectives for Everyone
Cardiovascular Health Consequences of Long-Duration Space Flight (Vascular) investigates the impact of long-duration space flight on the blood vessels of astronauts. Space flight accelerates the aging process, and it is important to understand this process to develop specific countermeasures. Data is collected before, during, and after space flight to assess inflammation of the artery walls, changes in blood vessel properties, and cardiovascular fitness.
Science Results for Everyone
Spaceflight can cause stiffening of the arteries, affecting the body’s ability to control blood pressure. This investigation assessed the blood vessels of astronauts and found decreased flexibility of the carotid artery during flight. Researchers found no relationship between the level of physical fitness and this decrease. The experiment also provided data on the mechanisms behind increased arterial stiffness from spaceflight.  Further research is needed to establish effective ways to counter the cardiovascular consequences of spaceflight and ultimately help treat increased arterial stiffness from aging on Earth, which can cause high blood pressure and organ damage.

The following content was provided by Richard Lee Hughson, Ph.D., and is maintained in a database by the ISS Program Science Office.
Experiment Details


Principal Investigator(s)
Richard Lee Hughson, Ph.D., University of Waterloo, Waterloo, Ontario, Canada

Philippe Arbeille, M.D., Universite Francois-Rabelais, Tours, France
Marc-Antoine Custaud, Ph.D., M.D., University of Angers, Angers, France
Joel Kevin Shoemaker, Ph.D., University of Western Ontario, London, Ontario, Canada
James W. Rush, Ph.D., University of Waterloo, Waterloo, Ontario, Canada
Danielle Kathleen Greaves, M.Sc., University of Waterloo, Waterloo, Ontario, Canada

Information Pending

Sponsoring Space Agency
Canadian Space Agency (CSA)

Sponsoring Organization
Information Pending

Research Benefits
Information Pending

ISS Expedition Duration
October 2009 - March 2014

Expeditions Assigned

Previous Missions
Vascular first began operations on Increment 21/22.

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Experiment Description

Research Overview

  • Cardiovascular Health Consequences of Long-Duration Space Flight (Vascular) aims to investigate the effects of long-duration space flight on the cardiovascular system of astronauts crewmembers on aboard the International Space Station (ISS). The changes on the human body brought by this unique environment could impact the vascular system and accelerate the stiffening of blood vessels that parallels the aging process.

  • Recent advances in medicine have linked certain blood proteins and hormones to cardiovascular stress and disease. Levels of these markers are used by doctors as early indicators of cardiovascular health. Astronauts Crewmembers will undergo blood tests before, during and after their space flights to look for these proteins and hormones, and particularly for any changes in their levels when they return from space. The astronauts crewmembers will also have images taken and pressure measurements done that measure the elasticity of their arteries before and after their flight.

  • These experiments can provide new information on cardiovascular structural and functional adaptations to long-duration space flight - changes that might impact the crewmember’s lifelong health, even beyond their return from ISS. It is important to establish clear patterns of response regarding cardiovascular risk factors for long-duration stays on ISS before longer missions are undertaken.

The Cardiovascular Health Consequences of Long-Duration Space Flight (Vascular) investigation studies the impact of space flight on the blood vessels of long-duration space explorers. Long-term habitation on board the International Space Station can expose the human body to many unique stressors that could have life-long implications concerning cardiovascular health. The chronic change in gravitational forces, the alteration in physical activity patterns, and social factors associated with confinement, could impact structural and functional properties of the vascular system and induce changes such as accelerated stiffening and the development of atherosclerosis which may parallel the aging process. Scientists hypothesize that long-duration space travel will be associated with increased blood concentrations of markers (e.g. blood proteins) indicative of vascular growth, inflammation and oxidative stress. Scientists also hypothesize that these blood markers will accompany gravity-induced alterations in structure of arterial walls (e.g. smaller arteries), especially in the crewmember’s legs. These blood markers of vascular growth, inflammation and stress will be obtained from blood samples before launch, in flight and return to Earth. The blood markers are correlated with non-invasive functional testing including ultrasounds of vascular dimensions, vascular compliance (elasticity), endothelium dependent dilation of arteries in the arm and the leg (using simple exercises and cuff occlusion) and endothelium independent dilation of arteries in the arm and the leg (by administering a nitroglycerin spray). The impact of these functional tests will also be evaluated for short-term cardiovascular health by comparing the altered vascular dilatory processes to the results from the upright posture testing phases of the current experiments (sit and stand) on return from ISS. These experiments will provide new information on cardiovascular structural and functional adaptations to long-duration space flight, changes that might impact crewmember’s lifelong health, even beyond their return from ISS or during future long-duration missions.

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Space Applications
The expected long-term outcome of this research involves the development of appropriate countermeasures to prevent astronauts, undertaking long-duration space flights, from experiencing long-term cardiovascular health problems as a result of their time spent in space.

Earth Applications
This experiment contributes to obtaining a better understanding of the mechanisms that might contribute to premature aging of the cardiovascular system, and to detect early markers of potential atherosclerosis (condition in which fatty material collects along the walls of arteries) and inflammation.

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Operational Requirements and Protocols

Vascular requires participation from astronauts during long-duration flights. Preflight operations (L-60 to L-30) involves structure and function testing, collection of 2 blood samples collected within a minimum separation of 2 days, and cardiac rate measurements via data sharing. During in flight operations, 2 blood samples are collected between NET FD 115, with a minimum separation of 2 days. Cardiac rate measurements and medication and exercise logs will be accessible via data sharing. Postflight operations (R+1) involves structure and function testing (R+1); collection of blood samples at R+1, and once again between R+2 and R+7; and cardiac rate measurements via data sharing.

Two blood sample collection sessions are scheduled in flight, NET FD 115; at least two days apart. Once tubes are collected, the samples are inserted in a centrifuge and spun over a period of 30 minutes to separate the blood components. Once spinning is completed, the samples are stored in MELFI or Glacier at -20 Celsius. Samples must remain frozen (-20°C or below) through landing and delivery to PI. Blood samples are not to be scheduled during or within three days after a sleep shift period of three hours or more. The Vascular Structure and Function sessions, and the blood draws, must be separated from the end of the SOLO diet session by at least 48 hrs.

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Decadal Survey Recommendations

Information Pending

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Results/More Information

Early evidence from the Cardiovascular and Cerebrovascular Control on Return from ISS (CCISS) and the Cardiovascular Health Consequences of Long-Duration Space Flight (Vascular) investigations highlighted some of the individual variability of astronaut’s responses related to regulation of arterial blood pressure and brain blood flow, as well as factors related to arterial stiffness and overall cardio-metabolic health.

Recent studies examined the spontaneous oscillations in blood pressure and heart rate to quantify the effectiveness of the arterial baroreflex response. The CCISS study revealed, in contrast to short-duration spaceflight, that the heart rate responses to changes in arterial blood pressure were well maintained during long-duration spaceflights on ISS. However, on return to Earth, the baroreflex response was significantly impaired with considerable variability between astronauts, potentially placing some of them at greater risk for dizziness and possibly for fainting. The study also found that the heart rate responses during periods of normal daily activities while in space were similar to pre-flight but importantly the astronauts had greatly reduced overall activity levels when measured with ankle-mounted sensors over 24-hours. The countermeasures employed by these astronauts on ISS were sufficient to maintain cardiovascular stability under resting conditions in space; however, the marked reduction in overall physical activity while in space did alter the heart rate control and could influence key aspects of cardiovascular health with potential long-term consequences.

Regulatory mechanisms are essential for continuous supply of oxygenated blood to the brain. The results of the CCISS study indicated impairment of dynamic cerebrovascular autoregulation and CO2 reactivity in astronauts on return to Earth. The chronic elevations in blood pressure in the brain while in space, compared to the normal upright posture on Earth, reductions in daily physical activity and the constant exposure to slightly elevated levels of CO2 during long-duration spaceflight might have impaired the ability of the blood vessels of the brain to respond to changes in arterial blood pressure and CO2. It is unclear, at the moment, whether these changes occur in astronauts and whether they might have harmful effects linked to the complications in vision in the Microgravity Ocular Syndrome.

Although cardiovascular stability appears to be well maintained while on ISS by current countermeasures, the chronic changes in arterial blood pressure throughout the body, the reduction in overall physical activity and the restricted access to aerobic-type exercises might have long-term cardiovascular health consequences. Recent results of the Vascular study confirmed an increase in carotid artery stiffness indicators in male and female astronauts on return from 6-months on ISS. The magnitude of increased stiffness was similar to changes expected with 10-20 years of normal aging. Mechanisms underlying the changes in artery structure and function might relate to the higher blood pressure in the head and neck without daily exposure to gravity in an upright posture, as well as to the overall reduction in physical activity. An indication that long periods of sedentary-like behavior in astronauts has potential health impacts was observed in these male and female astronauts with the development of insulin resistance during space flight. Future studies are required to assess the magnitude of insulin resistance and explore appropriate countermeasures to maintain cardio-metabolic health.

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Results Publications

    Hughson RL, Shoemaker JK, Blaber AP, Arbeille P, Greaves DK, Pereira, Jr. PP, Xu D.  Cardiovascular regulation during long-duration spaceflights to the International Space Station. Journal of Applied Physiology. 2012 March; 112(5): 719-727. DOI: 10.1152/japplphysiol.01196.2011. PMID: 22134699.

    Zuj KA, Arbeille P, Shoemaker JK, Blaber AP, Greaves DK, Xu D, Hughson RL.  Impaired cerebrovascular autoregulation and reduced CO2 reactivity after long duration spaceflight. American Journal of Physiology: Heart and Circulatory Physiology. 2012 June 15; 302(12): H2592-H2598. DOI: 10.1152/ajpheart.00029.2012. PMID: 22492717.

    Blaber AP, Goswami N, Bondar RL, Kassam MS.  Impairment of Cerebral Blood Flow Regulation in Astronauts With Orthostatic Intolerance After Flight. Stroke. 2011 July; 42(7): 1844-1850. DOI: 10.1161/STROKEAHA.110.610576. PMID: 21617145.

    Hughson RL, Shoemaker JK, Arbeille P.  CCISS, Vascular and BP Reg: Canadian space life science research on ISS. Acta Astronautica. 2014 November; 104(1): 444-448. DOI: 10.1016/j.actaastro.2014.02.008.

    Xu D, Shoemaker JK, Blaber AP, Arbeille P, Fraser KS, Hughson RL.  Reduced heart rate variability during sleep in long-duration spaceflight. American Journal of Physiology: Regulatory, Integrative and Comparative Physiology. 2013 July 15; 305(2): R164-R170. DOI: 10.1152/ajpregu.00423.2012. PMID: 23637139.

    Robertson AD, Greaves DK, Shoemaker JK, Arbeille P, Rush JW, Hughson RL.  Carotid distensibility following a long-duration stay on the International Space Station. 62nd International Astronautical Congress, Cape Town, South Africa; 2011 74-77.

    Fraser KS, Greaves DK, Shoemaker JK, Blaber AP, Hughson RL.  Heart Rate and Daily Physical Activity with Long-Duration Habitation of the International Space Station. Aviation, Space, and Environmental Medicine. 2012 Jun; 83(6): 577-584. PMID: 22764612.

    Hughson RL, Robertson AD, Arbeille P, Shoemaker JK, Rush JW, Fraser KS, Greaves DK.  Increased post-flight carotid artery stiffness and inflight insulin resistance resulting from six-months spaceflight in male and female astronauts. American Journal of Physiology: Heart and Circulatory Physiology. 2016 January 8; epub: ajpheart.00802.2015. DOI: 10.1152/ajpheart.00802.2015. PMID: 26747504.

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Ground Based Results Publications

    Arbeille P, Kerbeci P, Mattar L, Shoemaker JK, Hughson RL.  Insufficient flow reduction during LBNP in both splanchnic and lower limb areas is associated with orthostatic intolerance after bed rest. American Journal of Physiology: Heart and Circulatory Physiology. 2008; 295(5): H1846-H1854. DOI: 10.1152/ajpheart.509.2008.

    Demiot C, Dignat-George F, Fortrat JO, Sabatier F, Gharib C, Larina IM, Gauquelin-Koch G, Hughson RL, Custaud M.  WISE 2005: Chronic bed rest impairs microcirculatory endothelium in women. American Journal of Physiology: Heart and Circulatory Physiology. 2007; 293(5): H3159-H3164. DOI: 10.1152/ajpheart.00591.2007.

    Fischer D, Arbeille P, Shoemaker JK, O'Leary DD, Hughson RL.  Altered hormonal regulation and blood flow distribution with cardiovascular deconditioning after short-duration head down bed rest. Journal of Applied Physiology. 2007 Dec; 103(6): 2018-2025. DOI: 10.1152/japplphysiol.00121.2007.

    Edgell H, Zuj KA, Greaves DK, Shoemaker JK, Custaud M, Kerbeci P, Arbeille P, Hughson RL.  WISE-2005: Adrenergic responses of women following 56-days, 6 degrees head-down bed rest with or without exercise countermeasures. American Journal of Physiology: Regulatory, Integrative and Comparative Physiology. 2007; 293(6): R2343-R2352. DOI: 10.1152/ajpregu.00187.2007. PMID: 17928515.

    Guinet P, Schneider SM, Macias BR, Watenpaugh DE, Hughson RL, Traon PL, Bansard J, Hargens AR.  Wise-2005: Aerobic and resistive exercises attenuate orthostatic intolerance during 60-days bed rest in women. European Journal of Applied Physiology. 2009 May; 106(2): 217-227. DOI: 10.1007/s00421-009-1009-6.

    Trudel G, Payne M, Madler B, Ramachandran N, Lecompte M, Wade C, Biolo G, Blanc S, Hughson RL, Bear L, Uhthoff HK.  Bone Marrow Fat Accumulation after 60 Days of Bedrest Persisted 1 Year after Resuming Activities Along with Hemopoietic Stimulation - the WISE Study. Journal of Applied Physiology. 2009; 107: 540-548. DOI: 10.1152/japplphysiol.91530.2008.

    Hughson RL.  Recent findings in cardiovascular physiology with space travel. Respiratory Physiology and Neurobiology. 2009; 169 Suppl 1: S38-S41. DOI: 10.1016/j.resp.2009.07.017.

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ISS Patents

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Related Publications

    Hughson RL, Shoemaker JK.  Autonomic responses to exercise: Deconditioning/inactivity. Autonomic Neuroscience: Basic and Clinical. 2015 March; 188: 32-35. DOI: 10.1016/j.autneu.2014.10.012. PMID: 25458429.

    Goswami N, Batzel JJ, Clement G, Stein TP, Hargens AR, Sharp MK, Blaber AP, Roma PG, Hinghofer-Szalkay HG.  Maximizing information from space data resources: a case for expanding integration across research disciplines. European Journal of Applied Physiology. 2013 July; 113(7): 1645-1654. DOI: 10.1007/s00421-012-2507-5.

    Blaber AP, Zuj KA, Goswami N.  Cerebrovascular autoregulation: lessons learned from spaceflight research. European Journal of Applied Physiology. 2013 August; 113(8): 1909-1917. DOI: 10.1007/s00421-012-2539-x.

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Related Websites
CSA: Vascular

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NASA Image: ISS027E014283 - Expedition 27 flight engineer Ron Garan pauses for a photo while working with the Minus Eighty-Degree Laboratory Freezer for ISS (MELFI) in the Kibo Japanese Experiment Pressurized Module (JPM).

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NASA Image: ISS025E006391 - NASA astronaut Shannon Walker, Expedition 25 flight engineer, prepares to stow a blood draw for the Canadian Space Agency (CSA) Vascular Blood Collection protocol in the Minus Eighty Laboratory Freezer for ISS (MELFI-1) in the Kibo laboratory of the International Space Station.

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NASA Image: ISS029E028495 - Japan Aerospace Exploration Agency (JAXA) astronaut Satoshi Furukawa, Expedition 29 flight engineer, prepares to put samples from the Canadian Space Agency (CSA) Vascular Blood Collection protocol into the MELFI-1 (Minus Eighty Laboratory Freezer for ISS 1) unit.

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