MAY 12, 2017 12:12 PM PDT

How Heart and Small Blood Vessel Function Weakens in Space

WRITTEN BY: Kara Marker

Whether it’s an elderly person with heart failure or an astronaut scheduled for a long-duration spaceflight to Mars, understanding how blood vessels function in special circumstances is important for human health. From Kansas State University in partnership with the Johnson Space center and funded by NASA, researchers investigated the toll taken on astronauts’ heart health in space.

Astronauts aboard the International Space Station experience decreased physical fitness because of a decrease in the way oxygen moves through the body. Credit: NASA

The new kinesiology study included exercise capacity measurements from astronauts before and after they spent six months aboard the International Space Station. A stationary bike test conducted before and after their space trip measured oxygen uptake, cardiac output, hemoglobin concentration, and arterial saturation. These measurements show how effectively - or not - the body transports oxygen to the muscle mitochondria.

Results from this classic before-and-after comparison were anything but surprising. The heart, which is made up of muscle tissue, is like any other muscle. You don’t use it, you lose it. It’s not that astronauts don’t need use of their heart in space, but they certainly don’t exercise it like they would on earth. "When your cardiovascular function decreases, your aerobic exercise capacity goes down,” explained a professor from the study, Carl Ade. “You can't perform physically challenging activities anymore.”

Specifically, analysis showed a decrease in maximal oxygen uptake between 30 and 50 percent, a serious reduction in how much oxygen can be consumed during physical exercise and reflected a serious loss of cardiorespiratory health. Past research studies have indicated a loss of heart function was causing this effect in astronauts, but the present study shows that it’s also capillary dysfunction that is to blame. The small blood vessels, in addition to the heart, become less effective at pumping oxygen to muscle tissues all over the body.

What do experts believe is causing the decrease in maximal oxygen uptake? Microgravity and its tendency to change the interaction between blood vessel capillaries and red blood cells; however, scientists are not quite sure yet what specifically happens in the capillaries to have this effect.

"If we can understand why maximal oxygen uptake is going down, that allows us to come up with targeted interventions, whether that be exercise or pharmacological interventions,” Ade explained. “This important new information can help these astronauts and prevent any adverse performance changes in their job."

The present study was published in the Journal of Applied Physiology.

Source: Kansas State University

About the Author
  • I am a scientific journalist and enthusiast, especially in the realm of biomedicine. I am passionate about conveying the truth in scientific phenomena and subsequently improving health and public awareness. Sometimes scientific research needs a translator to effectively communicate the scientific jargon present in significant findings. I plan to be that translating communicator, and I hope to decrease the spread of misrepresented scientific phenomena! Check out my science blog: ScienceKara.com.
You May Also Like
APR 27, 2020
Earth & The Environment
APR 27, 2020
Air pollution increasing in Africa
New research published in Environmental Research Letters reports that air pollution in Africa has increased significantl ...
APR 30, 2020
Cardiology
APR 30, 2020
Pregnancy Issues May be Associated with Future Heart Problems
New research presented at the American College of Cardiology Scientific Session virtual meeting found that a history of ...
MAY 11, 2020
Cell & Molecular Biology
MAY 11, 2020
3D Cell Culture Model Suggests Herpes Can Cause Alzheimer's
Alzheimer's is a common form of dementia that affects as many as 5.5 million Americans and the incidence is increasing a ...
MAY 13, 2020
Health & Medicine
MAY 13, 2020
Studying Skates for the Future of Cartilage Therapy
According to the Marine Biological Laboratory (MBL) at the University of Chicago, nearly 25% of Americans have arthritis ...
MAY 16, 2020
Cancer
MAY 16, 2020
Red Blood Cells: More than just an Oxygen Delivery Service
The human body is a complex network of systems that often interact and affect each other. Recent work shows that red blo ...
MAY 25, 2020
Microbiology
MAY 25, 2020
Assessing the Risk of COVID-19 Posed by Various Summer Activities
While we know a lot more about the pandemic virus SARS-CoV-2 and the illness it causes, COVID-19, there are still many u ...
Loading Comments...