An Approach to Quantitative Risk Assessment for Combined Spaceflight Hazards: Evaluating the Impact of Short Sleep Durations on Space Crew Cardiovascular Health

Astronauts embarking on long-duration missions will be exposed to multiple spaceflight hazards including radiation, isolation and confinement, distance from Earth, hostile closed environments, and altered gravity. These hazards pose health risks to the crew in-mission and postflight, including risks to cardiovascular health. For radiation, quantitative risk models have been developed that are based on large-scale epidemiological evidence from exposed terrestrial populations, which are extrapolated to account for the difference in radiological effectiveness between ground-based and in-flight exposures.
•Cardiovascular diseases (CVD) are multifactorial, therefore multiple risk factors can influence disease risk estimates.
•Astronauts with spaceflight experience is a very small population.
•To overcome limitations of cohort, population data from presumed equivalent stressors on Earth can be used to quantitatively assess possible risks.
•Sleep disruption and short sleep duration are known consequences of spaceflight and are also established risk factors for cardiovascular disease on earth (Pateletal.,2020).
•Coronary Heart Disease (CHD), Myocardial Infarction (MI), and stroke are negative health effects due to short sleep durations and sleep disruptions (Yinetal.,2017); (Cappuccio et al., 2010).
•A combined CVD risk model including spaceflight stressor such as sleep, stress, radiation, etc.) will provide more precise estimate of risks.