NASA's Cardio Ox investigation will consist of the analysis of twelve International Space Station crewmembers over the course of five years. The astronauts will provide blood and urine samples before, during, and after their launches to help scientists find answers about heart health in space.
For the first time ever, researchers will examine how conditions of space flight affect oxidative stress and inflammation in the hearts of astronauts for up to five years after their time spent on the International Space Station. The Cardio Ox investigation is short for, "Defining the Relation Between Biomarkers of Oxidative and Inflammatory Stress and Atherosclerosis Risk in Astronauts During and After Long-duration Spaceflight." Research began in September of 2013 with an ISS expedition crew.
According to part of the Cardio Ox study published earlier this year and presented at American College of Cardiology's Annual Scientific Session, the hearts of astronauts become more spherical in space, based on the examination of 12 astronauts who were exposed to long periods of microgravity. Images of the astronauts' hearts were taken via ultrasound machines that were installed aboard the ISS. Their hearts became more spherical by a factor of 9.4% during a six-month ISS mission.
"The heart doesn't work as hard in space, which can cause a loss of muscle mass," said James Thomas, M.D., Moore Chair of Cardiovascular Imaging and Lead Scientist for Ultrasound at NASA, and senior author of the study, in this Science Daily news release. "That can have serious consequences after the return to Earth, so we're looking into whether there are measures that can be taken to prevent or counteract that loss."
The astronauts involved in the Cardio Ox investigation will provide blood and urine samples 15 and 60 days after launch, 15 days before returning to Earth, and a few days after landing. The researchers will follow up with the participants over the course of five years and perform regular check-ups at one, three, and five years after the launch. The crew will also take ultrasound scans (at the same time they will provide the blood and urine samples) of carotid artery thickness and brachial artery dilation to help measure cardiovascular health.
Scientists are concerned about rising levels of oxidative stress in the hearts of astronauts because it produces peroxides and free radicals, which are associated with a number of degenerative conditions, including heart disease, stroke, and cancer. Additionally, inflammation is known to be common among heart disease and stroke patients because it accelerates the development of atherosclerosis.
The study and its ongoing research is likely to provide telling evidence about the heart health of astronauts for long-term deep space missions, and could affect the decisions made in NASA's Asteroid Initiative as well as the MARS One project.
You can read more about the Cardio Ox investigation in this NASA news release.
