University of Washington scientists one step closer to stopping bone loss during s...( Bone loss in long-duration spaceflig...),Health

Bone loss in long-duration spaceflight has been identified for decades as a significant problem affecting astronauts. More recently, scientists have found that the absence of gravity is causing astronauts on the International Space Station to lose up to 10 times more bone mass in key regions of the body each month than most post-menopausal women do in the same period of time back here on Earth.

Now, by simulating spaceflight conditions through the use of long-duration bedrest, researchers at the University of Washington have found -- for the first time -- a way to prevent bone loss in a specific region of the hip. Using bedrest as an analog of spaceflight, UW scientists are at the mid-point of a study in which 22 volunteers remain in bed, in a six-degree, head-down tilt position for 84 days.

The head-down tilt mimics many of the physiologic adaptations astronauts experience during spaceflight, such as bodily fluid shifts toward the head. The bedrest confinement mimics the complete "unloading" of the musculoskeletal system that astronauts feel as they float through space due to the lack of gravity, which accelerates bone loss. Half of the study participants are randomized to perform individually prescribed intermittent treadmill exercise similar to workouts by astronauts in space but with one important difference: they are pulled towards the treadmill surface by a harness applying greater force than what the research team has previously measured during walking and running on the International Space Station treadmill.

"We have found that we can, on average, prevent bone loss in an important region of the hip with this intervention," said Dr. Peter Cavanagh, UW professor of orthopaedics and sports medicine, and principal investigator of the study. "No bedrest study ever before has accomplished this."

The results from the first half of the study are "extremely promising," Cavanagh said. Of the five study subjects so far who have been ass
'/>"/>