VASCULAR: Cardio-fitness for astronauts and Earthlings

Cardiovascular space experiment may benefit everyday Canadians

Astronauts are living and working in space for longer periods of time, making it more important than ever to understand the physiological changes their bodies undergo. (Credit: NASA)

Space travel has come a long way in the last five decades, from trips lasting only a few hours to missions where astronauts now routinely spend three to six months on board the International Space Station (ISS). However, long-duration spaceflight and exposure to microgravity do take a toll on the health of astronauts.

Many years of research on how the human body adapts to space has shown that calcium is stripped from their bones, their muscles atrophy and their sense of "up" and "down" is affected (at least temporarily). Canadian studies have revealed that even the ageing process is accelerated during long stays in space, and returning astronauts have stiffer blood vessels—a change similar to that seen on Earth with normal ageing. The questions scientists now are asking is: do blood vessels age faster in space,  and how can the knowledge learned in space help keep Canadians healthy?

An ongoing Canadian experiment called VASCULAR has been investigating the effects of microgravity on the cardiovascular system of astronauts on board the orbiting laboratory. Dr. Richard Hughson of the University of Waterloo leads the VASCULAR science team, which is funded by the Canadian Space Agency (CSA) and supported by National Aeronautics and Space Administration (NASA).

In 2009, CSA Astronaut Robert Thirsk spent 186 days on board the orbiting laboratory, setting a new record for Canadians in space. Fellow Canadian Chris Hadfield's mission to the ISS will last five months, ending in May 2013.

During his mission, Hadfield will be the eighth subject to participate in VASCULAR.

Taking the Stress out of Space

Recent advances in medicine have linked certain blood proteins and hormones to cardiovascular stress and disease and the levels of these markers are used as indicators of health. Astronauts taking part in VASCULAR undergo blood tests before, during and after their spaceflights to look for these proteins and hormones, and particularly for any changes in their levels when they return from space. The astronauts also have ultrasounds done that measure the elasticity of their arteries and veins before and after their flight.

Dr. Hughson believes that space can be used to test potential solutions for combating this disabling disease, not only for space travelers but everyday Canadians.

"We are hoping from these astronauts to not only get a better understanding of these mechanisms that might cause changes in their bodies, but also have a much better focus on what we can do to prevent similar cardiovascular aging in the general population here on Earth," says Dr. Hughson.

According to the Heart and Stroke Foundation of Canada, there are approximately 70,000 heart attacks per year in Canada. VASCULAR could provide new information concerning factors that might contribute to cardiovascular disease.

VASCULAR's findings may also be important for long-duration space travel in the future, like the three years it might take to make a round-trip voyage to Mars. Understanding the effects on cardiovascular health could help prevent significant problems on a distant Martian surface and also help keep astronauts healthy later in life.

Keeping fit while in space is part of the daily routine of all astronauts. Canadian astronaut Robert Thirsk works out on the treadmill aboard the ISS during Expedition 20/21 in 2009. (Credit: NASA)