To meet the objectives of the study, 12 astronauts will be studied before, during, and up to 5 years after long duration missions aboard the International Space Station (ISS). Biomarkers of oxidative and inflammatory stress, some of which we have previously shown to be elevated with spaceflight, will be measured from blood and urine samples taken before, during and after spaceflight. Arterial structure and function will be assessed before, during, and after spaceflight using standard clinical ultrasound measures that are well-established clinical indices of atherosclerosis risk. Pre- and post-flight ultrasound measures will be obtained in the laboratory by trained sonographers, and astronauts will obtain ultrasound images on-orbit with real-time guidance from experts on the ground using remote guidance. This is the first study to assess immediate and long-term risk for atherosclerosis using biochemical, structural and functional measures before, during, immediately after, and up to five years after spaceflight.
Additionally, data from one subject on NASA’s first one-year mission will be shared with a complementary project in the suite of Twins Studies, entitled Metabolomic and genomic markers of atherosclerosis as related to oxidative stress, inflammation, and vascular function in twin astronauts. NNJ13ZSA002N-TWINS: Differential Effects on Homozygous Twin Astronauts Associated with Differences in Exposure to Spaceflight Factors.
Ten astronauts have participated in pre-flight testing, seven have completed in- and immediate post-flight testing (R+5), and four have participated in testing at R+365. No crewmember has participated in testing at R+3 years. Ultrasound data analysis is in progress. Analysis of blood and urine samples predicated on delivery of in-flight samples has been delayed due to re-entry vehicle availability.
Samples from pre-flight data collections have been archived so that they may be batch processed with in- and post-flight samples. Inflight data collection is in progress; timing of the analysis of inflight samples will be dependent upon return of the samples from the ISS. Data sharing of relevant measurements collected as medical requirements or part of a complementary studies will be leveraged to inform the study results.
NOTE: Stuart M. C. Lee has taken over the project as of March 2016. Project continues with the same title with Dr. Lee as the Principal Investigator.