I. Mccarthy et al., Investigation of bone changes in microgravity during long and short duration space flight: comparison of techniques, EUR J CL IN, 30(12), 2000, pp. 1044-1054
Citations number
20
Categorie Soggetti
Research/Laboratory Medicine & Medical Tecnology","Medical Research General Topics
Background Loss of bone mass is a continuing problem in long-term space fli
ght. Although counter-measure programmes have been developed, effective ass
essment of these programmes is hampered by a lack of monitoring techniques
that can be used in-flight.
Materials and methods Three techniques were used to evaluate changes in bon
e during two missions of 180 and 20 days to the MIR space station, involvin
g three subjects. Dual energy X-ray absorptiometry (DXA) was used before an
d after flight to measure whole body and regional bone mineral density (BMD
). Ultrasonic measurements of velocity (SOS) and broadband attenuation (BUA
) of the calcaneus were measured during the 180 day mission and before and
after the 20 day mission. Phase velocity of flexural waves in the tibia was
also measured on the same days as the ultrasonic measurements of the calca
neus.
Results DXA measurements demonstrated significant variation between differe
nt sites in the body for changes in BMD, with the greatest changes occurrin
g in the lumbar spine and proximal femur. There was a trend for increasing
phase velocity in the tibia during the 180 mission, but this was not signif
icant. BUA and SOS measurements of the calcaneus showed consistent but dive
rgent patterns of changes during the mission.
Conclusion Although in-flight measurements of bone using ultrasound or phas
e velocity may provide information on the kinetics of bone loss in space fl
ight, the heterogeneity of response in the skeleton means that it is diffic
ult to predict overall bone loss from measurements at one particular site.