ADVANCES IN UNDERSTANDING THE SKELETAL BIOLOGY OF SPACEFLIGHT

Abstract

Spaceflight causes a negative calcium balance and loss of skeletal mass selectively in those bones that are normally loaded on earth. This bone loss can be quite severe in some individuals, posing a potential risk for astronauts in space, during initial recovery on earth, and with subsequent aging. Over the past 25 years, substantive advances in ground based animal models and technical innovations made it possible to apply cutting edge methods, particularly in imaging and molecular biology, to the problem of spaceflight-induced bone loss. This approach yields new scientific insight into how bone adapts to altered gravity environments at the cellular and molecular level and better defines the risks of spaceflight to the skeletal health of astronauts. Despite this progress, further research is needed to both identify mechanisms and protect skeletal health from the adverse consequences of long duration spaceflight.