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

News | Heart Failure| October 02, 2015
Cyberonics Inc. announced results from the extension of the ANTHEM-HF clinical study (ENCORE Study). Results of the...
Tryton Side Branch Stent, clinical trial results, Catheterization and Cardiovascular Interventions

Tryton Side Branch Stent image courtesy of Tryton Medical

News | Stents Bifurcation| October 02, 2015
October 2, 2015 — Tryton Medical Inc.
Intact Vascular, TOBA II study, Tack Endovascular System

Image courtesy of Intact Vascular

News | Peripheral Arterial Disease (PAD)| October 01, 2015
Intact Vascular Inc. announced the U.S. Food and Drug Administration has granted conditional approval for a U.S. and...
Johns Hopkins, sticky gel, stem cells, rat hearts, heart attacks

Hydrogel applied to beating rat hearts improves stem cell uptake by the heart muscle and speeds up tissue healing after heart attack. Image courtesy of Johns Hopkins Medicine.

News | Stem Cell Therapies| September 29, 2015
A sticky, protein-rich gel created by Johns Hopkins researchers appears to help stem cells stay on or in rat hearts and...
News | Cath Lab| September 29, 2015
The Innovation Institute announced that Boston Scientific has signed an agreement to become the founding medical device...
Eluvia drug-eluting vascular stent system, 12-month primary patency, Boston Scientific, MAJESTIC trial, CIRSE

Image courtesy of Boston Scientific

News | Stents Peripheral| September 28, 2015
New 12-month clinical trial outcomes assessing the safety and performance of the Boston Scientific Eluvia drug-eluting...
predicting arrhythmias, mcgill university, alternans patterns
News | EP Lab| September 28, 2015
Researchers have discovered how to predict some cardiac arrhythmias several steps before they even occur. It’s a...
News | Antiplatelet and Anticoagulation Therapies| September 25, 2015
The Icahn School of Medicine at Mount Sinai has launched the international TWILIGHT clinical trial to test the safety...
Medisafe, medication management, mHealth platform, blood pressure study, hypertension, adherence
News | Hypertension| September 25, 2015
Medisafe, an mHealth platform for medication management, announced the results of its blood pressure study, which...
ContextVision, ultrasound image processing, low latency, portable devices

Image courtesy of Philips

News | Ultrasound Imaging| September 25, 2015
At the 2015 IEEE High Performance Extreme Computing Conference (HPEC ‘15), ContextVision presented new results of...
Overlay Init