A multinational study to develop universal standardization of whole-body bone density and composition using GE Healthcare Lunar and Hologic DXA systems

• Published in: Journal of bone and mineral research Vol. 27; no. 10; pp. 2208 - 2216
• Main Authors: Shepherd, John A, Fan, Bo, Lu, Ying, Wu, Xiao P, Wacker, Wynn K, Ergun, David L, Levine, Michael A
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.10.2012; Wiley; Wiley Subscription Services, Inc
• Subjects: Absorptiometry, Photon - methods; Absorptiometry, Photon - standards; Adiposity - physiology; Adolescent; Adult; Age; Aged; Aged, 80 and over; Biological and medical sciences; BODY COMPOSITION; Body Composition - physiology; Body Weight - physiology; Bone and Bones - diagnostic imaging; Bone and Bones - physiology; Bone Density - physiology; Bone mineral content; Bone mineral density; Calibration; Child; Child, Preschool; CROSS-CALIBRATION; Demography; Dual energy X-ray absorptiometry; Female; Fundamental and applied biological sciences. Psychology; Humans; Internationality; Male; Mathematical models; Middle Aged; OBESITY; OSTEOPOROSIS; Pediatrics; PERCENT BODY FAT; Reference Standards; Reproducibility of Results; Skeleton and joints; Soft tissues; Standardization; Vertebrates: osteoarticular system, musculoskeletal system; Young Adult; Obesity; Adipose tissue; Diseases of the osteoarticular system; Nutrition disorder; Standardization; PERCENT BODY FAT; Density; Body composition; Osteoarticular system; Osteoporosis; CROSS-CALIBRATION; Vertebrata; Mammalia; Bone; Nutritional status
• ISSN: 0884-0431; 1523-4681
• DOI: 10.1002/jbmr.1654

Dual‐energy x‐ray absorptiometry (DXA) is used to assess bone mineral density (BMD) and body composition, but measurements vary among instruments from different manufacturers. We sought to develop cross‐calibration equations for whole‐body bone density and composition derived using GE Healthcare Lunar and Hologic DXA systems. This multinational study recruited 199 adult and pediatric participants from a site in the US (n = 40, ages 6 through 16 years) and one in China (n = 159, ages 5 through 81 years). The mean age of the participants was 44.2 years. Each participant was scanned on both GE Healthcare Lunar and Hologic Discovery or Delphi DXA systems on the same day (US) or within 1 week (China) and all scans were centrally analyzed by a single technologist using GE Healthcare Lunar Encore version 14.0 and Hologic Apex version 3.0. Paired t‐tests were used to test the results differences between the systems. Multiple regression and Deming regressions were used to derive the cross‐conversion equations between the GE Healthcare Lunar and Hologic whole‐body scans. Bone and soft tissue measures were highly correlated between the GE Healthcare Lunar and Hologic and systems, with r ranging from 0.96 percent fat [PFAT] to 0.98 (BMC). Significant differences were found between the two systems, with average absolute differences for PFAT, BMC, and BMD of 1.4%, 176.8 g and 0.013 g/cm2, respectively. After cross‐calibration, no significant differences remained between GE Healthcare Lunar measured results and the results converted from Hologic. The equations we derived reduce differences between BMD and body composition as determined by GE Healthcare Lunar and Hologic systems and will facilitate combining study results in clinical or epidemiological studies. © 2012 American Society for Bone and Mineral Research.