Patterns of bone loss in bed-ridden healthy young male subjects: results from the long term bed rest study in Toulouse

摘要

Loss of bone mineral is one of the main concerns of theSpace Agencies in the planning of long-term space missions.Therefore, the Agencies are at present supporting bed reststudies. Because the effects on muscles and bones in thelower extremity during space flight are very similar1,2, bedrest is accepted as a ground-based model for it. The lattersuggests also that the main cause of the bone loss observedduring space flight is immobilization and not weightlessnessper se.Obviously, such bed rest studies provide a chance to studythe specific effects of immobilization, without interferenceof other diseases. In that sense, and also because the countermeasuresthat the Space Agencies have started to developmay be efficient in the near future, bed rest studies may alsobe of interest for clinical medicine. So far, two types of countermeasureshave been considered. Resistance exercise isthought to preserve the leg musculature, and hopefully itthus will conserve the bones. Secondly, bisphosphonates as apotent inhibitor to bone resorption should be considered asa possible countermeasure.