Risk of Early Onset Osteoporosis Evidence Report: Risk of Early Onset Osteoporosis Due to Space Flight Human Research Program Human Health and Countermeasures Element

Concern about the risk of bone loss in astronauts as a result of prolonged exposure to microgravity prompted the National Aeronauticsand Space Administration to convene a Bone Summit with a panel of experts at the Johnson Space Center to review themedical data andresearch evidence from astronauts who have had prolonged exposure to spaceflight. Data were reviewed from 35 astronauts who hadserved on spaceflightmissions lasting between 120 and 180 dayswith attention focused on astronauts who (1) were repeat fliers on long‐duration missions, (2) were users of an advanced resistive exercise device (ARED), (3) were scanned by quantitative computedtomography (QCT) at the hip, (4) had hip bone strength estimated by finite elementmodeling, or (5) had lost>10% of areal bonemineraldensity (aBMD) at the hip or lumbar spine as measured by dual‐energy X‐ray absorptiometry (DXA). Because of the limitations of DXAin describing the effects of spaceflight on bone strength, the panel recommended that the U.S. space program use QCT and finiteelement modeling to further study the unique effects of spaceflight (and recovery) on bone health in order to better inform clinicaldecisions. © 2013 American Society for Bone and Mineral Research.