BETHESDA, Md. (March 22, 2012)—Astronauts have been taking part in short spaceflight missions since 1961. They have only recently begun to spend significantly longer times in space, with missions extending for months, since the days of the Russian Mir space station (1986-2001) and extended stays on the International Space Station (ISS; November 2000). Though earlier studies clearly showed that astronauts on these extended missions suffered serious deficits from lengthy times in a low-gravity environment, including dizziness when standing up, considerable loss of bone mass, and impaired muscle function, little was known about the effects of long-term space flight on the heart and vascular system. In a new study, a research team has tested various cardiovascular measures in six astronauts on long-term missions aboard the International Space Station. These findings show that lengthy spaceflight indeed affects cardiovascular responses, but not as dramatically as the researchers predicted, suggesting that the intensive exercise routines astronauts on these long missions complete every day are doing their job.
The article is entitled "Cardiovascular Regulation During Long-Duration Spaceflights to the International Space Station." It appears in the current edition of the Journal of Applied Physiology, published by the American Physiological Society.
Methodology
Results
Importance of the Findings
"These post-flight changes were somewhat less than expected based on short-duration flights and early reports of long-duration missions and suggest that the current countermeasures on the ISS, which include exercise training, are keeping cardiovascular control mechanisms well prepared for return to Earth," the authors say.
The ISS astronauts in the current study represent the first six-person crew, signifying the transition to greater possibilities to conduct science on this major international laboratory, they note.
Study Team
The study was conducted by R. L. Hughson, D. K. Greaves, P. P. Pereira-Junior, and D. Xu of the University of Waterloo; J.K. Shoemaker of the University of Western Ontario; A. P. Blaber of Simon Fraser University; and P. Arbeille of CERCOM, EFMP CHU Trousseau.
NOTE TO EDITORS: The study is available online at http://bit.ly/FQW3kG To request an interview with a member of the research team, please contact Donna Krupa at dkrupa@the-aps.org , @Phyziochick, or 301.634.7209.
Physiology is the study of how molecules, cells, tissues and organs function to create health or disease. The American Physiological Society (APS; www.the-APS.org/press ) has been an integral part of the discovery process for 125 years. To keep up with the science, follow @Phyziochick on Twitter.
Journal of Applied Physiology