Comparison Of Body Composition And Bone Mineral Density Of GE And Hologic DXA Systems

OBJECTIVE To investigate the relationship of body composition of the most popular GE serie and Hologic serie DXA densitometer, and to establish the transcalibrating equation between them, providing a transcalibrating platform for multi-center research collaboration and evaluating the affect of drugs on body composition.METHODS We measured body composition of the318subjects on GE-Lunar Prodigy Advance and Hologic Delphi A respectively, used SPSS17.0to analyze the resulets. We used mean plus or minus standard deviation to show the results of the two densitometers, and used paired T-test to analyze the difference between them. The data transformation relationship between the two DXA systems was investigated by bivariate regression analysis. We took GE-Lunar Prodigy Advance and Hologic Delphi A as independent variables respectively to establish the transcalibrating equation between them by linear regression analysis, and we also made some scatter plots.RESULTS The bone area, fat mass, fat percentage and weight of the left, right upper limbs and both of them of GE-Lunar Prodigy Advance narrow beam X-ray densitometer are higher than Hologic Delphi A fan beam X-ray densitometer. The phenomena is still exist in bone area and bone mineral content of head, bone mineral density of ribs and pelvic, fat mass of trunk, weight of right lower limb, both lower limbs, whole body. The lean mass of all of the parts is higher than Hologic Delphi A fan beam X-ray densitometer except trunk. Our experiment showed that body composition of GE-Lunar Prodigy Advance narrow beam X-ray densitometer and Hologic Delphi A fan beam X-ray densitometer are highly correlated, in which total weight correlated best, while the correlation of bone mineral density is relatively poor. The results of the two DXA systems are comparable after transcalibration. CONCLUSION Our experiment show that body composition of GE-Lunar Prodigy Advance narrow beam X-ray densitometer and Hologic Delphi A fan beam X-ray densitometer are highly correlated, in which total weight correlated best, while the correlation of bone mineral density is relatively poor. The results of the two DXA systems are comparable after transcalibration.