Feature | July 31, 2014

The Heart of An Astronaut, Five Years After Space

Cardio Ox investigation will look at how oxidative stress and inflammation caused by conditions of spaceflight affect astronaut hearts for up to five years after astronauts fly on the International Space Station

Cardio Ox investigation Astronaut Oxidative Stress Cardiovascular Health

JAXA astronaut Koichi Wakata, Expedition 38 Flight Engineer, demonstrates the ultrasound used to collect data for the Cardio Ox investigation, in the Columbus Module. Image Credit: NASA

Cardio Ox investigation Astronaut Oxidative Stress Cardiovascular Health

NASA astronaut Reid Wiseman, currently a flight engineer aboard the International Space Station, during prelaunch ground training for use of the Ultrasound-2 device which is used for the Cardio Ox study. Image Credit: NASA

July 31, 2014 — The heart of an astronaut is a much-studied thing. Scientists have analyzed its blood flow, rhythms, atrophy and, through journal studies, even matters of the heart. But for the first time, researchers are looking at how oxidative stress and inflammation caused by the conditions of space flight affect those hearts for up to five years after astronauts fly on the International Space Station. Lessons learned may help improve cardiovascular health on Earth as well.

Oxidative stress reflects an imbalance in the body's ability to handle toxic byproducts from normal, oxygen-consuming cell metabolism. This imbalance produces peroxides and free radicals, which contribute to a number of degenerative conditions. Evidence indicates that oxidative stress and resulting inflammation can accelerate the development of atherosclerosis, a disease in which plaque builds up inside arteries. This disease can lead to heart attacks and strokes.

For this investigation, called Cardio Ox, researchers at NASA's Johnson Space Center in Houston will look at the function and structure of arteries along with specific biomarkers in the blood and urine that indicate inflammation and oxidative stress. These biological samples will be taken from astronauts before their launch, 15 and 60 days after launch, 15 days before returning to Earth, and within days after landing.

The crew will also take ultrasound scans of the carotid artery thickness and brachial artery dilation, recognized indicators of cardiovascular health, at the same time points, for comparison with the biomarkers. The same measurements will be taken and ultrasounds performed at the regular check-ups that all astronauts have one, three and five years after flight.

"This is the first cardiovascular study to cover such a long period," said Steven Platts, Ph.D., principal investigator. The data will create a picture over time, allowing researchers to examine whether blood vessel changes seen during flight returned to normal sometime after flight. They will also be able to determine if the effects of oxidative stress grow worse over time or if astronauts experience chronic inflammation post-flight.

Many studies have looked at oxidative stress on Earth, but only astronauts are simultaneously exposed to so many factors known to cause it. The unique environment of a space mission combines a number of factors that can increase the risk of oxidative damage and inflammation, including radiation, psychological stress, reduced physical activity and, in the case of extravehicular activity, increased oxygen exposure.

"It's a perfect storm of things known to cause oxidative stress all happening at the same time," Platts explained. "So this study will enable us to answer some important questions, such as, do these factors work together to make things worse? Are any of them at high enough exposure to cause damage?" Knowing more about how space may cause changes in cardiovascular health will help scientists develop measures to counter its negative effects, in space and on Earth.

The pre-flight data provide a snapshot of an astronaut's cardiovascular health before exposure to the space environment, which then makes it reasonable to assume that any changes are caused by exposure to the space environment and not by other factors. Other studies have looked at specific factors such as mental stress or exercise and their relationship to oxidative damage, but the space station provides a unique opportunity to integrate a variety of causes in a single person.

Typically, a study eliminates all variables except one and examines that one, but this investigation looks at how the entire workplace environment affects the body. The same factors also affect people in unique Earth-bound job environments, such as long-haul jet pilots or train engineers, those who work in a small room all day at a radiation plant, or in unique conditions such as Antarctica. Such situations subject people to stress similar to that experienced by astronauts. The disruption of daily rhythm and sleep patterns experienced in space could be extrapolated to shift workers on Earth as well.

Astronaut Scott Kelly participated in the investigation during his time in orbit and recently completed his one-year post-flight checkup. The study is continuing aboard the station, and a total of 12 astronauts in all will participate during the five-year investigation. You could say the subjects are really putting their hearts into it.

For more information: www.nasa.gov/mission_pages/station/research/news/cardio_ox/#.U9pIFIBdUhw

 

Related Content

Medtronic, Micra TPS pacemaker, transcatheter pacing system, global clinical trial, one-year results, ESC 2016
News | Pacemakers| August 29, 2016
August 29, 2016 — Medtronic plc announced new long-term results from the Medtronic Micra Transcatheter Pacing System
cardiac surgery, simulation training, University of Washington, case studies

Multiple repetitions of bypass grafts on a heart, using the Ramphal simulator. Courtesy of the University of Washington in Seattle.

News | Cardiovascular Surgery| August 25, 2016
August 25, 2016 — Simulation training fo
aortic dissection, family history, same age, clinical study, John A. Elefteriades, Annals of Thoracic Surgery
News | Structural Heart| August 25, 2016
People with a family member who had an aortic dissection — a spontaneous tear in one of the body’s main arteries —...
nanoparticles, blood clotting, internal bleeding, American Chemical Society study, Erin B. Lavik

Nanoparticles (green) help form clots in an injured liver. The researchers added color to the scanning electron microscopy image after it was taken. Image courtesy of Erin Lavik, Ph.D.

News | Hemostasis Management| August 24, 2016
August 24, 2016 — Whether severe trauma occurs on the battlefield or the highway, saving lives often comes down to...
Intact Vascular, TOBA clinical study, one-year results, Tack Endovascular System, Journal of Vascular Surgery
News | Peripheral Arterial Disease (PAD)| August 24, 2016
Intact Vascular Inc. announced that the one-year results from its Tack Optimized Balloon Angioplasty (TOBA) clinical...
News | Heart Failure| August 23, 2016
August 23, 2016 — A new study of more than 13,000 people has found that so-called morbid obesity appears to stand alo
Jason Burdick, injectable hydrogels, heart failure, heart attack, American Chemical Society

Compared to other types of hydrogels being developed (left), a new hydrogel (right) can form crosslinks after injection into the heart, making the material stiffer and longer-lasting. Image courtesy of American Chemical Society.

News | Heart Failure| August 23, 2016
August 23, 2016 — During a heart attack, clots or narrowed arteries block blood flow, harming or killing cells within
best ultrasound technician schools, 2016 ranking, College Choice
News | Ultrasound Imaging| August 22, 2016
August 22, 2016 — College Choice, a leading authority in college and university rankings and resources, has published
sleep apnea, hypertension, clinical study, Science Signaling, University of Chicago
News | Hypertension| August 22, 2016
Obstructive sleep apnea is a common cause of high blood pressure. In the Aug. 17, 2016, issue of the journal Science...
TAILOR-PCI study, antiplatelet medication, genotype, NHLBI grant
News | Antiplatelet and Anticoagulation Therapies| August 18, 2016
Researchers at the Peter Munk Cardiac Centre, Toronto, and at Mayo Clinic are leading the Tailored Antiplatelet Therapy...
Overlay Init