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Long-term Cardiovascular Risk in Astronauts

Comparing NASA Mission Astronauts With a Healthy Cohort From the Cooper Center Longitudinal Study

      Abstract

      Objective

      To determine the long-term cardiovascular disease risk of astronauts with spaceflight exposure compared with a well-matched cohort.

      Methods

      National Aeronautics and Space Administration (NASA) astronauts are selected into their profession based upon education, unique skills, and health and are exposed to cardiovascular disease risk factors during spaceflight. The Cooper Center Longitudinal Study (CCLS) is a generally healthy cohort from a preventive medicine clinic in Dallas, Texas. Using a matched cohort design, astronauts who were selected beginning April 1, 1959, (and each subsequent selection class through 2009) and exposed to spaceflight were matched to CCLS participants who met astronaut selection criteria; 1514 CCLS participants matched to 303 astronauts in a 5-to-1 ratio on sex, date of birth, and age. The outcome of cardiovascular mortality through December 31, 2016, was determined by death certificate or National Death Index.

      Results

      There were 11 deaths caused by cardiovascular disease (CVD) among astronauts and 46 among CCLS participants. There was no evidence of increased mortality risk in astronauts (hazard ratio [HR]=1.10; 95% confidence interval [CI], 0.50 to 2.45) with adjustment for baseline cardiovascular covariates. However, the secondary outcome of CVD events showed an increased adjusted risk in astronauts (HR=2.41; 95% CI, 1.26 to 4.63).

      Conclusion

      No increased risk of CVD mortality was observed in astronauts with spaceflight exposure compared with a well-matched cohort, but there was evidence of increased total CVD events. Given that the duration of spaceflight will increase, particularly on missions to Mars, continued surveillance and mitigation of CVD risk is needed to ensure the safety of those who venture into space.

      Abbreviations and Acronyms:

      BMI (body mass index), CABG (coronary artery bypass graft), CCLS (Cooper Center Longitudinal Study), CI (confidence interval), CRF (cardiorespiratory fitness), CV (cardiovascular), CVD (cardiovascular disease), DOB (date of birth), FMC (Flight Medicine Clinic), HR (hazard ratio), ICD (International Classification of Disease), IRB (Institutional Review Board), JSC (Johnson Space Center), LSAH (Lifetime Surveillance of Astronaut Health), MI (myocardial infarction), NASA (National Aeronautics and Space Administration), PCI (percutaneous coronary intervention), PY (person years)
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      References

        • Bogomolov V.V.
        • Duncan J.M.
        • Sargsyan A.E.
        • Pool S.L.
        Medical support for crewmembers of the international space station.
        in: Sawin C.F. Hanson S.I. House N.G. Pestov I.D. Space Biology and Medicine V: US and Russian Cooperation in Space Biology and Medicine. American Institute of Aeronautics and Astronautics, 2009: 331-394
        • Bogomolov V.V.
        • Castrucci F.
        • Comtois J.M.
        • et al.
        International space station medical standards and certification for space flight participants.
        Aviat Space Environ Med. 2007; 78: 1162-1169
        • Barger L.K.
        • Flynn-Evans E.E.
        • Kubey A.
        • et al.
        Prevalence of sleep deficiency and use of hypnotic drugs in astronauts before, during, and after spaceflight: an observational study.
        Lancet Neurol. 2014; 13: 904-912
        • Moore A.D.
        • Lee S.M.C.
        • Stenger M.B.
        • Platts S.H.
        Cardiovascular exercise in the US space program: past, present, and future.
        Acta Astronautica. 2010; 66: 974-988
        • Elgart S.R.
        • Little M.P.
        • Chappell L.J.
        • et al.
        Radiation exposure and mortality from cardiovascular disease and cancer in early NASA astronauts.
        Sci Rep. 2018; 8: 8480
        • Douglas G.L.
        • Zwart S.R.
        • Smith S.M.
        Space food for thought: challenges and considerations for food and nutrition on exploration missions.
        J Nutr. 2020; 150: 2242-2244
        • Lee S.M.C.
        • Ribeiro L.C.
        • Martin D.S.
        • et al.
        Arterial structure and function during and after long-duration spaceflight.
        J Appl Physiol. 2020; 129: 108-123
        • Hughson R.L.
        • Robertson A.D.
        • Arbeille P.
        • et al.
        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: 628-638
        • Reynolds R.J.
        • Day S.M.
        Mortality due to cardiovascular disease among Apollo lunar astronauts.
        Aerosp Med Hum Perform. 2017; 88: 492-496
        • Reynolds R.J.
        • Day S.M.
        Mortality among US astronauts: 1980-2009.
        Aviat Space Environ Med. 2010; 81: 1024-1027
        • Reynolds R.J.
        • Day S.M.
        The effect of competing risks on astronaut and cosmonaut mortality.
        Life Sci Space Res (Amst). 2018; 18: 35-41
        • Peterson L.E.
        • Pepper L.J.
        • Hamm P.B.
        • Gilbert S.L.
        Longitudinal study of astronaut health: mortality in the years 1959-1991.
        Radiat Res. 1993; 133: 257-264
        • Hamm P.B.
        • Nicogossian A.E.
        • Pool S.L.
        • Wear M.L.
        • Billica R.D.
        Design and current status of the longitudinal study of astronaut health.
        Aviat Space Environ Med. 2000; 71: 564-570
        • Ade C.J.
        • Broxterman R.M.
        • Charvat J.M.
        • Barstow T.J.
        Incidence rate of cardiovascular disease end points in the National Aeronautics and Space Administration Astronaut Corps.
        J Am Heart Assoc. 2017; 6
        • Willis B.L.
        • Morrow Jr., J.R.
        • Jackson A.W.
        • Defina L.F.
        • Cooper K.H.
        Secular change in cardiorespiratory fitness of men: Cooper Center Longitudinal Study.
        Med Sci Sports Exerc. 2011; 43: 2134-2139
        • Lovelace 2nd, W.R.
        • Schwichtenberg A.H.
        • Luft U.C.
        • Secrest R.R.
        Selection and maintenance program for astronauts for the National Aeronautics and Space Administration.
        Aerosp Med. 1962; 33: 667-684
        • Von Dobeln W.
        A simple bicycle ergometer.
        J Appl Physiol. 1954; 7: 222-224
        • Balke B.
        • Ware R.W.
        An experimental study of physical fitness of Air Force personnel.
        U S Armed Forces Med J. 1959; 10: 675-688
        • Bruce R.A.
        • Gey Jr., G.O.
        • Cooper M.N.
        • Fisher L.D.
        • Peterson D.R.
        Seattle heart watch: initial clinical, circulatory and electrocardiographic responses to maximal exercise.
        Am J Cardiol. 1974; 33: 459-469
      1. ACSM's Guidelines for Exercise Testing and Prescription. 9th ed. Lippincott Williams & Wilkins, Philadelphia, PA2014
        • Pollock M.L.
        • Bohannon R.L.
        • Cooper K.H.
        • et al.
        A comparative analysis of four protocols for maximal treadmill stress testing.
        Am Heart J. 1976; 92: 39-46
        • Pollock M.L.
        • Foster C.
        • Schmidt D.
        • Hellman C.
        • Linnerud A.C.
        • Ward A.
        Comparative analysis of physiologic responses to three different maximal graded exercise test protocols in healthy women.
        Am Heart J. 1982; 103: 363-373
        • Gray G.W.
        • Johnston S.L.
        • Saary J.
        Medical evaluations and standards.
        in: Barratt M.R. Baker E.S. Pool S.L. Principles of Clinical Medicine for Space Flight. 2nd ed. Springer Nature, New York, NY2020
        • Radford N.B.
        • DeFina L.F.
        • Barlow C.E.
        • et al.
        Progression of CAC score and risk of incident CVD.
        JACC Cardiovasc Imaging. 2016; 9: 1420-1429
      2. R Core Team. R: A language and environment for statistical computing. R Foundation for Statistical Computing.
        (Published) (Accessed ▪▪▪2020)
        • Berkelaar M.
        lpSolve: Interface to 'Lp_solve' v. 5.5 to Solve Linear/Integer Programs.
        • Hamilton D.R.
        • Murray J.D.
        • Kapoor D.
        • Kirkpatrick A.W.
        Cardiac health for astronauts: current selection standards and their limitations.
        Aviat Space Environ Med. 2005; 76: 615-626
        • Reynolds R.J.
        • Day S.M.
        Mortality of US astronauts: comparisons with professional athletes.
        Occup Environ Med. 2019; 76: 114-117