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Maïmoun L, Alonso S, Mahadea KK, Boudousq V, Mura T, Mariano-Goulart D. Cross-Calibration Study of The Stratos And Hologic QDR 4500A Dual-Energy X-Ray Absorptiometers to Assess Bone Mineral Density And Body Composition. J Clin Densitom 2023; 26:101434. [PMID: 37948835 DOI: 10.1016/j.jocd.2023.101434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 10/24/2023] [Accepted: 10/24/2023] [Indexed: 11/12/2023]
Abstract
The objective of the study was to assess the agreement between the Stratos (DMS) and QDR 4500A (Hologic) DXAs in determining whole body and regional aBMD, as well as whole body composition. Fifty-five individuals (46 women: 84%) with a mean age of 41 ± 13.0 years (range: 20 to 64) and a mean BMI of 31.9 ± 10 kg/m² (range: 12.2 to 49.5) were consecutively scanned on the same day using the two devices. Predictive equations for areal bone mineral density (aBMD) and whole body composition (WBC) were derived from linear regression of the data. The two DXAs were highly correlated (p<0.001 for all parameters) with a correlation coefficient (r) ranging from 0.89 to 0.99 for aBMD (r=0.89 for whole body, r=0.92 for radius, r=0.95 for femoral neck, r=0.96 for total hip, and r=0.99 for L1-L4). For WBC, the r value was 0.98 for lean tissue mass (LTM) and 1.0 for fat mass (FM). Paired t-tests indicated a statistically significant bias between the two DXAs for the majority of measurements, requiring the determination of specific cross-calibration equations. Compared to QDR 4500A, Stratos underestimated whole body aBMD and LTM and overestimated neck and hip aBMD and whole body FM. Conversely, no significant bias was demonstrated for mean aBMD at L1-L4 and radius. For whole body aBMD and FM, the concordance between the two DXAs was influenced by BMI. Despite a high concordance between the two DXAs, the systematic bias for aBMD and WBC measurements illustrates the need to define cross-calibration equations to compare data across systems.
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Affiliation(s)
- Laurent Maïmoun
- Service de Médecine Nucléaire, Hôpital Lapeyronie, CHU Montpellier, France; Physiologie et Médecine Expérimentale du Cœur et des Muscles (PhyMedExp), INSERM, CNRS, Université de Montpellier (UM).
| | - Sandrine Alonso
- Département d'Information Médicale, CHRU Nîmes et UM, Nîmes, France
| | | | - Vincent Boudousq
- Service de Médecine Nucléaire, Hôpital Carémeau, CHU de Nîmes, France
| | - Thibault Mura
- Département d'Information Médicale, CHRU Nîmes et UM, Nîmes, France
| | - Denis Mariano-Goulart
- Service de Médecine Nucléaire, Hôpital Lapeyronie, CHU Montpellier, France; Physiologie et Médecine Expérimentale du Cœur et des Muscles (PhyMedExp), INSERM, CNRS, Université de Montpellier (UM)
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Park SS, Lim S, Kim H, Kim KM. Comparison of Two DXA Systems, Hologic Horizon W and GE Lunar Prodigy, for Assessing Body Composition in Healthy Korean Adults. Endocrinol Metab (Seoul) 2021; 36:1219-1231. [PMID: 34911173 PMCID: PMC8743584 DOI: 10.3803/enm.2021.1274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 11/14/2021] [Accepted: 11/19/2021] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Dual-energy X-ray absorptiometry (DXA) is the most widely used method for evaluating muscle masses. The aim of this study was to investigate the agreement between muscle mass values assessed by two different DXA systems. METHODS Forty healthy participants (20 men, 20 women; age range, 23 to 71 years) were enrolled. Total and regional body compositional values for fat and lean masses were measured consecutively with two DXA machines, Hologic Horizon and GE Lunar Prodigy. Appendicular lean mass (ALM) was calculated as the sum of the lean mass of four limbs. RESULTS In both sexes, the ALM values measured by the GE Lunar Prodigy (24.8±4.3 kg in men, 15.8±2.9 kg in women) were significantly higher than those assessed by Hologic Horizon (23.0±4.0 kg in men, 14.8±3.2 kg in women). Furthermore, BMI values or body fat (%), either extremely higher or lower levels, contributed greater differences between two systems. Bland-Altman analyses revealed a significant bias between ALM values assessed by the two systems. Linear regression analyses were performed to develop equations to adjust for systematic differences (men: Horizon ALM [kg]=0.915×Lunar Prodigy ALM [kg]+0.322, R2=0.956; women: Horizon ALM [kg]=1.066×Lunar Prodigy ALM [kg]-2.064, R2=0.952). CONCLUSION Although measurements of body composition including muscle mass by the two DXA systems correlated strongly, significant differences were observed. Calibration equations should enable mutual conversion between different DXA systems.
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Affiliation(s)
- Seung Shin Park
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam,
Korea
| | - Soo Lim
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam,
Korea
| | - Hoyoun Kim
- Biomedical Research Institute, Seoul National University Bundang Hospital, Seongnam,
Korea
| | - Kyoung Min Kim
- Division of Endocrinology, Department of Internal Medicine, Yongin Severance Hospital, Yonsei University College of Medicine, Yongin,
Korea
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Yoon BH, Koh YD, Yoo JI, Kim S, Lee GY, Park SB, Ha YC. Does Bone Mineral Density Differ between Fan-Beam and Pencil-Beam?: A Meta-Analysis and Systemic Review. J Bone Metab 2021; 28:67-77. [PMID: 33730785 PMCID: PMC7973396 DOI: 10.11005/jbm.2021.28.1.67] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 02/16/2021] [Indexed: 11/18/2022] Open
Abstract
Background Dual energy X-ray absorptiometry (DXA) has evolved from pencil-beam (PB) to narrow fan-beam (FB) densitometers. We performed a meta-analysis of the available observational studies to determine how different modes of DXA affect bone mineral density (BMD) measurements. Methods A total of 1,233 patients (808 women) from 14 cohort studies were included. We evaluated the differences in BMD according to the DXA mode: PB and FB. Additionally, we evaluated the differences in BMD between the 2 types of FB mode: FB (Prodigy) and the most recent FB (iDXA). Pairwise meta-analysis was performed, and weighted mean differences (WMD) were calculated for (total lumbar, total hip, and total body). Results No significant difference was observed in total lumbar (pooled WMD, −0.013; P=0.152) and total hip BMD (pooled WMD, −0.01; P=0.889), between PB and FB. However, total body BMD was significantly lower in the PB compared to the FB group (pooled WMD, −0.014; P=0.024). No significant difference was observed in lumbar BMD (pooled WMD, −0.006; P=0.567), total hip (pooled WMD, −0.002; P=0.821), and total body (pooled WMD, 0.015; P=0.109), between Prodigy and iDXA. Conclusions The results of this study warrant the recommendation that correction equations should not be used when comparing BMD from different modes. Further research is still needed to highlight the ways in which differences between DXA systems can be minimized.
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Affiliation(s)
- Byung-Ho Yoon
- Department of Orthopaedic Surgery, Seoul Paik Hospital, Inje University College of Medicine, Seoul, Korea
| | - Young Do Koh
- Department of Orthopaedic Surgery, Ewha Womans University Mokdong Hospital, Ewha Womans University College of Medicine, Seoul, Korea
| | - Jun-Il Yoo
- Department of Orthopaedic Surgery, Gyeongsang National University Hospital, Gyeongsang National University, Jinju, Korea
| | - Sujin Kim
- Department of Radiology, Chung-Ang University College of Medicine, Seoul, Korea
| | - Guen Young Lee
- Department of Radiology, Chung-Ang University College of Medicine, Seoul, Korea
| | - Sung Bin Park
- Department of Radiology, Chung-Ang University College of Medicine, Seoul, Korea
| | - Yong-Chan Ha
- Department of Orthopaedic Surgery, Chung-Ang University College of Medicine, Seoul, Korea
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Raymond-Pope CJ, Bosch TA, Dengel DR. Assessing Agreement of Lateral Leg Muscle and Bone Composition Using Dual X-ray Absorptiometry. J Clin Densitom 2020; 23:451-458. [PMID: 31133502 DOI: 10.1016/j.jocd.2019.04.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 04/28/2019] [Accepted: 04/30/2019] [Indexed: 11/25/2022]
Abstract
BACKGROUND Recently, a lateral-view dual X-ray absorptiometry (DXA) scanning method for measuring leg total, lean, and fat masses demonstrated accuracy vs the standard whole-body frontal DXA scanning view on the GE Lunar iDXA. The current study examined the lateral scanning method's agreement using a Hologic Horizon A DXA scanner. METHODOLOGY Thirty healthy college-age participants (16 female; X̅age = 21.5 ± 1.7 yr) received 3 DXA scans (1 whole-body, 2 lateral leg scans) to quantify leg composition in the frontal and lateral plane. To mark regions of interest for postscan analysis, metallic markers were placed at 60% of the length above and below each leg's lateral epicondyle. Using lateral subject positioning, leg composition was measured with participants lying on their right and left sides. Paired t tests examined the lateral DXA scanning method's agreement when quantifying total, fat, and lean masses, bone mineral content, and bone mineral density compared to measurements of equal area in the whole-body frontal scanning view. RESULTS Comparisons of frontal and lateral view DXA scan measurements for right leg total mass (7.12 ± 0.91kg vs 6.39 ± 0.85kg), fat mass (1.70 ± 0.44kg vs 1.36 ± 0.33kg), lean mass (5.14 ± 1.05kg vs 4.77 ± 0.92kg), bone mineral content (0.28 ± 0.06kg vs 0.23 ± 0.05kg), and bone mineral density (1.39 ± 0.14g/cm2vs 1.36 ± 0.15g/cm2), respectively, were significantly different (p < 0.001-0.028). Similarly, comparisons of frontal and lateral left leg total mass (7.12 ± 0.97kg vs 6.38 ± 0.92kg), fat mass (1.70 ± 0.44kg vs 1.39 ± 0.36kg), lean mass (5.15 ± 1.12kg vs 4.76 ± 0.97kg), bone mineral content (0.28 ± 0.06kg vs 0.24 ± 0.06kg), and bone mineral density (1.39 ± 0.15g/cm2vs 1.36 ± 0.17g/cm2), respectively, were significantly different (p < 0.001-0.046). CONCLUSION Unlike a previous study in which agreement of lateral vs frontal leg composition measurements of equal area was reported utilizing the GE Lunar iDXA, agreement was not observed using the Hologic Horizon A DXA scanner. Therefore, lateral view assessment may not be reliably performed on DXA scanner models produced by different manufacturers.
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Affiliation(s)
- Christiana J Raymond-Pope
- Laboratory of Integrative Human Physiology, School of Kinesiology, University of Minnesota, Minneapolis, MN, USA.
| | - Tyler A Bosch
- College of Education and Human Development, University of Minnesota, Minneapolis, MN, USA
| | - Donald R Dengel
- Laboratory of Integrative Human Physiology, School of Kinesiology, University of Minnesota, Minneapolis, MN, USA; Department of Pediatrics, University of Minnesota Medical School, Minneapolis, MN, USA
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Poinsot P, Geoffroy P, Braillon P, Denis A, Loras-Duclaux I, Marotte S, Boutroy S, Bacchetta J, Touzet S, Lachaux A, Peretti N. Longitudinal Bone Mineralization Assessment in Children Treated With Long-Term Parenteral Nutrition for Severe Intestinal Failure. JPEN J Parenter Enteral Nutr 2017; 42:613-622. [PMID: 28355492 DOI: 10.1177/0148607117701399] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 03/01/2017] [Indexed: 11/16/2022]
Abstract
BACKGROUND Metabolic bone disease is common in children receiving home parenteral nutrition (HPN) for intestinal failure (IF). Long-term evolution of bone mass in pediatric IF is poorly documented. The aims of this study were (1) to determine the prevalence of low bone mass (LBM) in children receiving HPN for IF, (2) to evaluate the evolution of total bone mineral content (TBMC) during HPN with dual-energy x-ray absorptiometry (DXA), and (3) to identify related factors. METHODS All children referred in our HPN center from 2004 to 2014 were eligible. Inclusion criteria were HPN dependence due to noninflammatory IF, at least 2 TBMC assessments, and HPN duration of at least 2 years at last DXA. TBMC was expressed in z score for ideal weight for height (WFH). LBM was defined by a TBMC WFH z score ≤-2 standard deviations (SD). RESULTS A total of 175 DXAs for 31 children were performed, mean of 5.6 ± 2.9 assessments per child. The median time between first and last DXA recorded was 6.2 years (0.7-16.6). At the first DXA, 14 children (45%) had a LBM. TBMC increased by +0.1 ± 0.04 SD per year of HPN (P = .012). The risk of LBM decreased with an odds ratio of 0.9 per year of HPN (95% confidence interval, 0.92-0.99; P = .018). Lean mass z score and calcium parenteral intakes were related to the TBMC improvement. CONCLUSION LBM is common in pediatric IF, but bone status could improve during HPN in these children.
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Affiliation(s)
- Pierre Poinsot
- Hepatology, Gastroenterology and Pediatric Nutrition Unit, Femme Mere Enfant Hospital, Hospices Civils de Lyon, University Claude Bernard Lyon 1, Lyon, France
| | - Perrine Geoffroy
- Hepatology, Gastroenterology and Pediatric Nutrition Unit, Femme Mere Enfant Hospital, Hospices Civils de Lyon, University Claude Bernard Lyon 1, Lyon, France
| | - Pierre Braillon
- Radiology Department, Hopital Femme Mere Enfant, Hospices Civils de Lyon, Lyon, France
| | - Angelique Denis
- Medical Information and Research Analysis Department, Hospices Civils de Lyon, Lyon, France
| | - Irene Loras-Duclaux
- Hepatology, Gastroenterology and Pediatric Nutrition Unit, Femme Mere Enfant Hospital, Hospices Civils de Lyon, University Claude Bernard Lyon 1, Lyon, France
| | - Stéphanie Marotte
- Hepatology, Gastroenterology and Pediatric Nutrition Unit, Femme Mere Enfant Hospital, Hospices Civils de Lyon, University Claude Bernard Lyon 1, Lyon, France
| | - Stéphanie Boutroy
- INSERM U1033, Lyos, Pathophysiology, Hospices Civils de Lyon, Lyon, France
| | - Justine Bacchetta
- INSERM U1033, Lyos, Pathophysiology, Hospices Civils de Lyon, Lyon, France.,Pediatric Nephrology, Rheumatology, Dermatology Unit, Femme Mere Enfant Hospital, Hospices Civils de Lyon, University Claude Bernard Lyon 1, Lyon, France
| | - Sandrine Touzet
- Medical Information and Research Analysis Department, Hospices Civils de Lyon, Lyon, France
| | - Alain Lachaux
- Hepatology, Gastroenterology and Pediatric Nutrition Unit, Femme Mere Enfant Hospital, Hospices Civils de Lyon, University Claude Bernard Lyon 1, Lyon, France
| | - Noel Peretti
- Hepatology, Gastroenterology and Pediatric Nutrition Unit, Femme Mere Enfant Hospital, Hospices Civils de Lyon, University Claude Bernard Lyon 1, Lyon, France.,INSERM U1060, CarMeN laboratory, Hospices Civils de Lyon, F-69003 Lyon, France
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Chen KT, Chen YY, Wang CW, Chuang CL, Chiang LM, Lai CL, Lu HK, Dwyer GB, Chao SP, Shih MK, Hsieh KC. Comparison of Standing Posture Bioelectrical Impedance Analysis with DXA for Body Composition in a Large, Healthy Chinese Population. PLoS One 2016; 11:e0160105. [PMID: 27467065 PMCID: PMC4965215 DOI: 10.1371/journal.pone.0160105] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 07/11/2016] [Indexed: 01/19/2023] Open
Abstract
Bioelectrical impedance analysis (BIA) is a common method for assessing body composition in research and clinical trials. BIA is convenient but when compared with other reference methods, the results have been inconclusive. The level of obesity degree in subjects is considered to be an important factor affecting the accuracy of the measurements. A total of 711 participants were recruited in Taiwan and were sub-grouped by gender and levels of adiposity. Regression analysis and Bland-Altman analysis were used to evaluate the agreement of the measured body fat percentage (BF%) between BIA and DXA. The BF% measured by the DXA and BIA methods (Tanita BC-418) were expressed as BF%DXA and BF%BIA8, respectively. A one-way ANOVA was used to test the differences in BF% measurements by gender and levels of adiposity. The estimated BF%BIA8 and BF%DXA in the all subjects, male and female groups were all highly correlated (r = 0.934, 0.901, 0.916, all P< 0.001). The average estimated BF%BIA8 (22.54 ± 9.48%) was significantly lower than the average BF%DXA (26.26 ± 11.18%). The BF%BIA8 was overestimated in the male subgroup (BF%DXA< 15%), compared to BF%DXA by 0.45%, respectively. In the other subgroups, the BF%BIA8 values were all underestimated. Standing BIA estimating body fat percentage in Chinese participants have a high correlation, but underestimated on normal and high obesity degree in both male and female subjects.
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Affiliation(s)
- Kuen-Tsann Chen
- Department of Applied Math, National Chung Hsing University, Taichung, Taiwan
| | - Yu-Yawn Chen
- Department of Physical Education, National Taiwan University of Sport, Taichung, Taiwan
- Department of Cosmetic Application & Management, St. Mary's Junior College of Medicine, Nursing and Management, Ilan, Taiwan
| | - Chia-Wei Wang
- Department of Applied Math, National Chung Hsing University, Taichung, Taiwan
| | | | - Li-Ming Chiang
- Department of Hospitality, Recreation, and Tourism Management, East Stroudsburg University, Pennsylvania, United States of America
| | - Chung-Liang Lai
- Department of Physical Medicine and Rehab, Taichung Hospital, Ministry of Health and Welfare, Taichung, Taiwan
| | - Hsueh-Kuan Lu
- Sport Science Research Center, National Taiwan University of Sport, Taichung, Taiwan
| | - Gregory B. Dwyer
- Department of Exercise Science, East Stroudsburg University, Pennsylvania, United States of America
| | - Shu-Ping Chao
- Department of Exercise Health Science, National Taiwan University of Sport, Taichung, Taiwan
| | - Ming-Kuei Shih
- Department of Food and Beverage management, National Kaohsiung University of Hospitality and Tourism, Kaohsiung, Taiwan
| | - Kuen-Chang Hsieh
- Fundamental Education Center, National Chin-Yi University of Technology, Taichung, Taiwan
- Research Center, Charder Electronic Co., Ltd, Taicung, Taiwan
- * E-mail:
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Solid anthropomorphic infant whole-body DXA phantom: design, evaluation, and multisite testing. Pediatr Res 2013; 74:486-93. [PMID: 23999072 DOI: 10.1038/pr.2013.148] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Accepted: 04/08/2013] [Indexed: 11/08/2022]
Abstract
BACKGROUND Dual-energy X-ray absorptiometry (DXA) requires phantoms for quality control and cross-calibration. No commercially available phantoms are designed specifically for whole-body scanning of infants. METHODS We fabricated a phantom closely matching a 7-kg human infant in body habitus using polyvinyl chloride (PVC), nylon mix, and polyethylene for bone, lean tissue, and fat, respectively, for evaluating the comparability of instruments used in studies on infant body composition. We scanned the phantom multiple times for short- and long-term repeatability and then shipped it to six other sites for comparison scans. All instruments were Hologic Delphi or Discovery models. Scan analyses were in-house procedures (Hologic V12.1). RESULTS Short- and long-term results were not significantly different. Nylon mix underrepresented expected lean mass values by 5%, PVC underrepresented bone by 12%, and polyethylene overrepresented fat by 30%. Precision values were as follows: lean mass ≈ 3%; bone ≈ 3.5%; and fat = 5.5-7.5%. Instruments differed significantly for bone mineral content and density results in most instances. Three instruments differed in fat and lean mass. The two Hologic models differed significantly in all compartments except bone density. CONCLUSION The phantom design came close to emulating bone, lean tissue, and fat and showed good reproducibility. Significant differences among various DXA instruments highlight the necessity of cross-calibration for any multicenter studies.
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Bandini LG, Fleming RK, Scampini R, Gleason J, Must A. Is body mass index a useful measure of excess body fatness in adolescents and young adults with Down syndrome? JOURNAL OF INTELLECTUAL DISABILITY RESEARCH : JIDR 2013; 57:1050-7. [PMID: 22974061 PMCID: PMC4019440 DOI: 10.1111/j.1365-2788.2012.01605.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
BACKGROUND To determine the validity of body mass index (BMI) to identify excess fatness in youth with Down syndrome (DS). METHODS Using the Centers for Disease Control and Prevention (CDC) growth reference, we defined overweight (≥ 85th percentile) and obesity (≥ 95th percentile) based on participants' age- and sex-specific BMI z-scores, calculated from measured height and weight. Percentage body fat was measured by dual-energy X-ray absorptiometry. We determined sensitivity, specificity, positive predictive value, negative predictive value and efficiency of BMI percentiles to identify excess adiposity relative to elevated percentage body fat cut-offs developed from the Pediatric Rosetta Body Composition project in 32 youth (20 boys/12 girls), ages 13-21 years with Down syndrome. RESULTS For adolescents with Down syndrome using the cut-off points of 95th percentile for BMI (obesity), sensitivity and specificity were 71% and 96% respectively. Positive predictive value was 83% and negative predictive value was 92%. Overall efficiency was 91%. Sensitivity and specificity for BMI cut-offs above the 85th percentile (overweight) were 100% and 60% respectively. The positive predictive value was 41% and negative predictive value was 100%. Overall efficiency was 69%. CONCLUSION On the whole, the obesity (≥ 95th percentile) cut-off performs better than the overweight cut-off (85th-94th percentile) in identifying elevated fatness in youth with DS.
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Affiliation(s)
- L. G. Bandini
- Eunice Kennedy Shriver Center, University of Massachusetts Medical School, Waltham, MA, USA
- Department of Health Sciences, Boston University, Boston, MA, USA
- Dr Linda Bandini, Eunice Kennedy Shriver Center, University of Massachusetts Medical School, 200 Trapelo Road, Waltham, MA 02452, USA,
| | - R. K. Fleming
- Eunice Kennedy Shriver Center, University of Massachusetts Medical School, Waltham, MA, USA
| | - R. Scampini
- Eunice Kennedy Shriver Center, University of Massachusetts Medical School, Waltham, MA, USA
| | - J. Gleason
- Eunice Kennedy Shriver Center, University of Massachusetts Medical School, Waltham, MA, USA
| | - A. Must
- Department of Public Health and Community Medicine, Tufts University School of Medicine, Boston, MA, USA
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Hangartner TN, Warner S, Braillon P, Jankowski L, Shepherd J. The Official Positions of the International Society for Clinical Densitometry: acquisition of dual-energy X-ray absorptiometry body composition and considerations regarding analysis and repeatability of measures. J Clin Densitom 2013; 16:520-36. [PMID: 24183641 DOI: 10.1016/j.jocd.2013.08.007] [Citation(s) in RCA: 175] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Accepted: 08/14/2013] [Indexed: 11/26/2022]
Abstract
In preparation for the International Society for Clinical Densitometry Position Development Conference of 2013 in Tampa, Florida, Task Force 2 was created as 1 of 3 task forces in the area of body composition assessment by dual-energy X-ray absorptiometry (DXA). The assignment was to review the literature, summarize the relevant findings, and formulate positions covering (1) accuracy and precision assessment, (2) acquisition of DXA body composition measures in patients, and (3) considerations regarding analysis and repeatability of measures. There were 6 primary questions proposed to the task force by the International Society for Clinical Densitometry board and expert panel. Based on a series of systematic reviews, 14 new positions were developed, which are intended to augment and define good clinical practice in quantitative assessment of body composition by DXA.
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Kendler DL, Borges JLC, Fielding RA, Itabashi A, Krueger D, Mulligan K, Camargos BM, Sabowitz B, Wu CH, Yu EW, Shepherd J. The Official Positions of the International Society for Clinical Densitometry: Indications of Use and Reporting of DXA for Body Composition. J Clin Densitom 2013; 16:496-507. [PMID: 24090645 DOI: 10.1016/j.jocd.2013.08.020] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Accepted: 08/20/2013] [Indexed: 11/21/2022]
Abstract
The technique of body composition by dual-energy X-ray absorptiometry (DXA) has been used for several years in the research environment. Its ability to accurately and precisely measure lean, fat, and mineral composition in various body compartments has been well validated. Furthermore, the technique is widely available to clinical patients on existing DXA instruments throughout the world through the use of specific software packages and scanning algorithms. There have been few clear statements regarding the clinical indications for body composition measurement in patients outside the research setting. This is in part because of the lack of specific documented interventions that would be affected by body composition test results, beyond usual clinical advice. We have examined a few of the most common, specific scenarios (HIV therapy, sarcopenia, bariatric surgery, obesity) and proposed indications for body composition assessment. We have also discussed contraindications to body composition testing.
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Assessing body composition in taller or broader individuals using dual-energy X-ray absorptiometry: a systematic review. Eur J Clin Nutr 2013; 67:1012-21. [PMID: 23942178 DOI: 10.1038/ejcn.2013.148] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Revised: 07/13/2013] [Accepted: 07/16/2013] [Indexed: 12/17/2022]
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Hruschka DJ, Rush EC, Brewis AA. Population differences in the relationship between height, weight, and adiposity: an application of Burton's model. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2013; 151:68-76. [PMID: 23553559 DOI: 10.1002/ajpa.22258] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2012] [Revised: 02/10/2013] [Accepted: 02/11/2013] [Indexed: 11/10/2022]
Abstract
The study of human variation in adiposity and lean mass is important for understanding core processes in human evolution, and is increasingly a public health concern as the "obesity epidemic" expands globally. The dominant measure of population differences in adiposity is Body Mass Index (BMI), which suffers from systematic biases across populations due to variation in the relationship between true body fat, height and weight. Here we develop simplified corrections for such anthropometric-based measures of adiposity that can take into account this population variation. These corrections derive from a recent model proposed by Burton that assumes humans accrue mass in two ways-growth in height that adds bone and muscle, and growth in body fat and the ancillary fat-free mass (FFM) needed to support this additional body fat. We analyze two ethnically diverse datasets with dual X-ray absorptiometry-measured (DXA) fat mass, assessing the fit of Burton's model and deriving novel corrections based on estimated musculoskeletal slenderness. The resulting model provides excellent fit to fat mass within populations (average R2 = 0.92 for women and R2 = 0.83 for men). World populations differ dramatically in musculoskeletal slenderness (up to a difference of 4.4 kg/m2), as do men and women (differences of 3.3-4.5 kg/m2), leading to clear population corrections. These findings point to a conceptually straightforward tool for estimating true differences in adiposity across populations, and suggest an alternative to BMI that provides a more accurate and theoretically based estimate of body fat than that traditionally derived from height and weight measures.
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Affiliation(s)
- Daniel J Hruschka
- School of Human Evolution and Social Change, Arizona State University, Tempe, AZ 85287-2402, USA.
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Santos DA, Gobbo LA, Matias CN, Petroski EDIOL, Gonçalves EM, Cyrino ES, Minderico CS, Sardinha LB, Silva AM. Body composition in taller individuals using DXA: A validation study for athletic and non-athletic populations. J Sports Sci 2013; 31:405-13. [PMID: 23092580 DOI: 10.1080/02640414.2012.734918] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Litaker MS, Barbeau P, Humphries MC, Gutin B. Comparison of Hologic QDR-1000/W and 4500W DXA Scanners in 13- to 18-Year Olds. ACTA ACUST UNITED AC 2012; 11:1545-52. [PMID: 14694220 DOI: 10.1038/oby.2003.206] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE Body composition measurements made using Hologic QDR-1000/W pencil-beam and QDR-4500W fan-beam scanners (Bedford, MA) were compared in a sample of 13- to 18-year-old white and black youth (n = 219). RESEARCH METHODS AND PROCEDURES Total fat (FAT), fat-free soft tissue (FFST), bone mineral content (BMC), bone mineral density (BMD), and percent body fat (%BF) were compared between repeated measurements using the QDR-4500 and between the two scanners using mixed model ANOVA. Intraclass correlation coefficients and Bland-Altman limits of agreement were used to evaluate inter- and intrascanner reliability. RESULTS Intraclass correlation coefficients for repeated measurements using the QDR-4500 ranged from 0.997 to 0.999 for FAT, %BF, FFST, and BMC and 0.987 for BMD. Mean measurements made using the two scanners differed significantly for FAT, %BF, BMC, and BMD (p < 0.0001), and scan by sex interactions were significant (all p < 0.0005). There were no significant differences in mean measurements between repeat scans using the QDR-4500 (all p > 0.19). Limits of agreement for measurements of FAT, FFST, and %BF made using the two scanners were approximately three times as wide as those for two measurements using the QDR-4500. For lower values of FAT and %BF, the QDR-4500 gave higher measurements than the QDR-1000, whereas at higher values, this relationship was reversed. The QDR-1000 tended to give higher BMC measurements, with larger differences for higher values. DISCUSSION Using different models of DXA scanners within a study may reduce precision of body composition measurement. This issue needs to be considered in the design of longitudinal studies.
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Affiliation(s)
- Mark S Litaker
- Office of Biostatistics and Bioinformatics, Georgia Prevention Institute, Augusta, Georgia 3912-4900, USA.
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DongMei N, Iki M, Tamaki J, Sato Y, Kagamimori S, Kagawa Y, Yoneshima H. Association between weight changes and changes in hip geometric indices in the Japanese female population during 10-year follow-up: Japanese Population-based Osteoporosis (JPOS) Cohort Study. Osteoporos Int 2012; 23:1581-91. [PMID: 21811865 DOI: 10.1007/s00198-011-1733-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2010] [Accepted: 06/01/2011] [Indexed: 11/27/2022]
Abstract
UNLABELLED During a 10-year follow-up of 893 women of various ages from the Japanese Population-based Osteoporosis Cohort Study, we evaluated the relationship between weight changes and hip geometric strength assessed by hip structure analysis. Our findings suggest that maintaining weight may help retain geometric strength and reduce hip fracture risk. INTRODUCTION The effects of changes in anthropometric indices on hip geometry in women of various ages are unclear. We evaluated these effects by analyzing 10-year longitudinal data from a representative sample of Japanese women. METHODS Dual-energy X-ray absorptiometry scans of the proximal femur were performed at baseline and at the 10-year follow-up. Data were analyzed with the Hip Structure Analysis (HSA) program, which yields geometric strength indices including cross-sectional area (CSA), section modulus (SM) and subperiosteal diameter (PD) at regions of interest (ROIs) in the narrow neck (NN), intertrochanter, and femoral shaft (FS) regions. Annual percent change of each HSA index was determined. Height and weight were measured at baseline and follow-up. RESULTS After excluding subjects with factors affecting bone metabolism, we evaluated 893 women (18-79 years old at baseline). The greatest changes in most HSA indices during the follow-up were observed in subjects aged ≥ 70 years at all ROIs. PD modestly but significantly expanded with age, but this change was not significant in subjects aged ≥ 70 years or those who had entered menopause ≥ 20 years before baseline. An increasing trend in weight was associated with an increase or smaller decline in CSA and SM at the NN and FS regions regardless of menopausal status after adjusting for age, height, and weight at baseline and change of estimated volumetric bone mineral density. Changes in height showed a much weaker association with HSA indices. CONCLUSIONS Maintaining weight may help retain hip geometric strength and reduce the risk of hip fracture.
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Affiliation(s)
- N DongMei
- Department of Public Health, Kinki University Faculty of Medicine, 377-2 Oono-higashi, Osaka-Sayama, Osaka 589-8511, Japan
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Ackland TR, Lohman TG, Sundgot-Borgen J, Maughan RJ, Meyer NL, Stewart AD, Müller W. Current Status of Body Composition Assessment in Sport. Sports Med 2012; 42:227-49. [DOI: 10.2165/11597140-000000000-00000] [Citation(s) in RCA: 308] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Normative data for bone mass in healthy term infants from birth to 1 year of age. J Osteoporos 2012; 2012:672403. [PMID: 23091773 PMCID: PMC3468026 DOI: 10.1155/2012/672403] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Revised: 08/25/2012] [Accepted: 08/26/2012] [Indexed: 11/26/2022] Open
Abstract
For over 2 decades, dual-energy X-ray absorptiometry (DXA) has been the gold standard for estimating bone mineral density (BMD) and facture risk in adults. More recently DXA has been used to evaluate BMD in pediatrics. However, BMD is usually assessed against reference data for which none currently exists in infancy. A prospective study was conducted to assess bone mass of term infants (37 to 42 weeks of gestation), weight appropriate for gestational age, and born to healthy mothers. The group consisted of 33 boys and 26 girls recruited from the Winnipeg Health Sciences Center (Manitoba, Canada). Whole body (WB) as well as regional sites of the lumbar spine (LS 1-4) and femur was measured using DXA (QDR 4500A, Hologic Inc.) providing bone mineral content (BMC) for all sites and BMD for spine. During the year, WB BMC increased by 200% (76.0 ± 14.2 versus 227.0 ± 29.7 g), spine BMC by 130% (2.35 ± 0.42 versus 5.37 ± 1.02 g), and femur BMC by 190% (2.94 ± 0.54 versus 8.50 ± 1.84 g). Spine BMD increased by 14% (0.266 ± 0.044 versus 0.304 ± 0.044 g/cm(2)) during the year. This data, representing the accretion of bone mass during the first year of life, is based on a representative sample of infants and will aid in the interpretation of diagnostic DXA scans by researchers and health professionals.
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Toombs RJ, Ducher G, Shepherd JA, De Souza MJ. The impact of recent technological advances on the trueness and precision of DXA to assess body composition. Obesity (Silver Spring) 2012; 20:30-9. [PMID: 21760631 DOI: 10.1038/oby.2011.211] [Citation(s) in RCA: 217] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The introduction of dual-energy X-ray absorptiometry (DXA) in the 1980s for the assessment of areal bone mineral density (BMD) greatly benefited the field of bone imaging and the ability to diagnose and monitor osteoporosis. The additional capability of DXA to differentiate between bone mineral, fat tissue, and lean tissue has contributed to its emergence as a popular tool to assess body composition. Throughout the past 2 decades, technological advancements such as the transition from the original pencil-beam densitometers to the most recent narrow fan-beam densitometers have allowed for faster scan times and better resolution. The majority of reports that have compared DXA-derived body composition measurements to the gold standard method of body composition appraisal, the four-compartment model, have observed significant differences with this criterion method; however, the extent to which the technological advancements of the DXA have impacted its ability to accurately assess body composition remains unclear. Thus, this paper reviews the evidence regarding the trueness and precision of DXA body composition measurements from the pencil-beam to the narrow fan-beam densitometers.
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Affiliation(s)
- Rebecca J Toombs
- Women's Health and Exercise Laboratory, Department of Kinesiology, Penn State University, University Park, Pennsylvania, USA
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Bosy-Westphal A, Later W, Schautz B, Lagerpusch M, Goele K, Heller M, Glüer CC, Müller MJ. Impact of intra- and extra-osseous soft tissue composition on changes in bone mineral density with weight loss and regain. Obesity (Silver Spring) 2011; 19:1503-10. [PMID: 21372803 DOI: 10.1038/oby.2011.40] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Recent studies report a significant gain in bone mineral density (BMD) after diet-induced weight loss. This might be explained by a measurement artefact. We therefore investigated the impact of intra- and extra-osseous soft tissue composition on bone measurements by dual X-ray absorptiometry (DXA) in a longitudinal study of diet-induced weight loss and regain in 55 women and 17 men (19-46 years, BMI 28.2-46.8 kg/m(2)). Total and regional BMD were measured before and after 12.7 ± 2.2 week diet-induced weight loss and 6 months after significant weight regain (≥30%). Hydration of fat free mass (FFM) was assessed by a 3-compartment model. Skeletal muscle (SM) mass, extra-osseous adipose tissue, and bone marrow were measured by whole body magnetic resonance imaging (MRI). Mean weight loss was -9.2 ± 4.4 kg (P < 0.001) and was followed by weight regain in a subgroup of 24 subjects (+6.3 ± 2.9 kg; P < 0.001). With weight loss, bone marrow and extra-osseous adipose tissue decreased whereas BMD increased at the total body, lumbar spine, and the legs (women only) but decreased at the pelvis (men only, all P < 0.05). The decrease in BMD(pelvis) correlated with the loss in visceral adipose tissue (VAT) (P < 0.05). Increases in BMD(legs) were reversed after weight regain and inversely correlated with BMD(legs) decreases. No other associations between changes in BMD and intra- or extra-osseous soft tissue composition were found. In conclusion, changes in extra-osseous soft tissue composition had a minor contribution to changes in BMD with weight loss and decreases in bone marrow adipose tissue (BMAT) were not related to changes in BMD.
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Affiliation(s)
- Anja Bosy-Westphal
- The Institute of Human Nutrition and Food Science, Christian-Albrechts University, Kiel, Germany
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Pearson D, Horton B, Green DJ. Cross calibration of Hologic QDR2000 and GE lunar prodigy for whole body bone mineral density and body composition measurements. J Clin Densitom 2011; 14:294-301. [PMID: 21600823 DOI: 10.1016/j.jocd.2011.03.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/01/2011] [Revised: 03/25/2011] [Accepted: 03/28/2011] [Indexed: 11/17/2022]
Abstract
The objective of this study was to undertake an in vivo cross calibration of body composition, whole body bone mineral content (BMC) and bone mineral density (BMD) between a Hologic QDR2000 and a GE Healthcare Lunar Prodigy. Twenty-one subjects attending for routine bone densitometry were recruited to the study (19 female and 2 male, aged 30-79 yr). Phantom cross calibrations were carried out using the Bio-Imaging Variable Composition Phantom (VCP) for percentage fat (%fat) and the Bona Fide Phantom (BFP) for BMD. There was no significant difference in whole body lean body mass between the QDR2000 and the Prodigy. Fat mass (FM) and %fat were significantly higher on the QDR2000. BMC and whole body BMD were significantly higher on Prodigy. As the BMC increased, so did the difference between the 2 instruments. The VCP did not provide an adequate cross calibration of %fat compared with in vivo. The BFP provided a good cross calibration of whole body BMD compared with in vivo. The results suggest that the partitioning of the soft tissue component between lean and fat in the 2 instruments is systematically different. The variation between instruments from the same and different manufacturers reported in the literature varies widely, as does the comparison with criterion methods. This makes it difficult to generalize the results of this study to other centers and it is recommended that each center would have to cross calibrate when changing equipment.
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Affiliation(s)
- Derek Pearson
- Department of Medical Physics and Clinical Engineering, Nottingham University Hospitals NHS Trust, Nottingham, UK.
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Bammann K, Sioen I, Huybrechts I, Casajús JA, Vicente-Rodríguez G, Cuthill R, Konstabel K, Tubić B, Wawro N, Rayson M, Westerterp K, Mårild S, Pitsiladis YP, Reilly JJ, Moreno LA, De Henauw S. The IDEFICS validation study on field methods for assessing physical activity and body composition in children: design and data collection. Int J Obes (Lond) 2011; 35 Suppl 1:S79-87. [PMID: 21483426 DOI: 10.1038/ijo.2011.38] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE To describe the design, measurements and fieldwork of the IDEFICS (Identification and prevention of dietary- and lifestyle-induced health effects in children and infants) physical activity and body composition validation study, and to determine the potential and limitations of the data obtained. DESIGN Multicentre validation study. SUBJECTS A total of 98 children from four different European countries (age: 4-10 years). METHODS An 8-day measurement protocol was carried out in all children using a collaborative protocol. Reference methods were the doubly labelled water method for physical activity, and a three- and a four-compartment model for body composition. Investigated field methods were accelerometers, a physical activity questionnaire and various anthropometric measurements. RESULTS For the validation of physical activity field methods, it was possible to gather data from 83 to 89 children, laying the basis for age- and sex-specific results. The validation of body composition field methods is possible in 64-80 children and allows sex-specific analyses but has only limited statistical power in the youngest age group (<6 years). The amount of activity energy expenditure (AEE) varied between centres, sexes and age groups, with boys and older children having higher estimates of AEE. After normalisation of AEE by body weight, most group-specific differences diminished, except for country-specific differences. CONCLUSION The IDEFICS validation study will allow age- and sex-specific investigation of questions pertaining to the validity of several field methods of body composition and physical activity, using established reference methods in four different European countries. From the participant analyses it can be concluded that the compliance for the investigated field methods was higher than that for the reference methods used in this validation study.
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Affiliation(s)
- K Bammann
- Department of Biometry, Bremen Institute for Prevention Research and Social Medicine, University of Bremen, Germany.
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Pludowski P, Jaworski M, Matusik H, Kobylinska M, Klimek P, Lorenc RS. The evaluation of consistency between body composition assessments in pediatric population using pencil beam and fan beam dual-energy x-ray absorptiometers. J Clin Densitom 2010; 13:84-95. [PMID: 20171570 DOI: 10.1016/j.jocd.2009.11.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2009] [Revised: 11/16/2009] [Accepted: 11/17/2009] [Indexed: 10/19/2022]
Abstract
The replacement of the old dual-energy X-ray absorptiometry system with a novel one should be preceded by a cross-calibration procedure. Therefore, the study was aimed at investigating the consistency of bone and body composition measures performed in pediatric population using pencil beam (DPX-L; GE Healthcare, GE Healthcare, Madison, WI) and fan beam (Prodigy; GE Healthcare, GE Healthcare, Madison, WI) densitometers. The study group consisted of 212 healthy children aged 4-18yr. Total body (TB) and lumbar spine (S) (L2-L4) measurements were performed using DPX-L and Prodigy during the same visit. Bland-Altman analysis, linear regressions, and paired t-test were performed to evaluate the consistency of measurements and to establish a cross-calibration equation. The average Prodigy values for TB and lumbar spine bone mineral density (BMD) and content (BMC) were 2.7%, 2.4% and 1.6%, 1.6% higher than those of DPX-L, respectively (p<0.0001). Prodigy-assessed bone area (BA) was lower by 1.4% for TBBA (p<0.0001) and 1.1% for SBA (p<0.001). Lean body mass (LBM) from Prodigy was higher by 6.9% (p<0.0001), whereas fat mass (FM) was lower by 8.4% compared with those from DPX-L (p<0.0001). Bland-Altman analyses revealed the effect of magnitude that was nonlinear (2nd degree polynomial) for TBBMD (r=0.32, p=0.001), TBBMC (r=0.51, p<0.0001), TBBA (r=0.34, p<0.0001), and LBM (r=0.56, p<0.0001), but not for FM (r=0.14, not significant [n.s.]). In contrast, in lumbar spine, the magnitude dependence was linear and significant for SBMC (r=0.46, p<0.0001) and SBA (r=0.34, p<0.0001) but not for SBMD (r=0.12, n.s.). Both skeletal and body composition variables assessed by DPX-L and Prodigy devices were highly correlated, showing R(2) values ranging from 0.976 for FM to 0.994 for SBMC. The results of this study document a necessity for implementation of calculated cross-calibration equations to transform DPX-L-based local pediatric references into a novel Prodigy system.
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Affiliation(s)
- Pawel Pludowski
- The Department of Biochemistry and Experimental Medicine, The Children's Memorial Health Institute, Warsaw, Poland.
| | - Maciej Jaworski
- The Department of Biochemistry and Experimental Medicine, The Children's Memorial Health Institute, Warsaw, Poland
| | - Halina Matusik
- The Department of Biochemistry and Experimental Medicine, The Children's Memorial Health Institute, Warsaw, Poland
| | - Maria Kobylinska
- The Department of Biochemistry and Experimental Medicine, The Children's Memorial Health Institute, Warsaw, Poland
| | - Paulina Klimek
- The Department of Biochemistry and Experimental Medicine, The Children's Memorial Health Institute, Warsaw, Poland
| | - Roman S Lorenc
- The Department of Biochemistry and Experimental Medicine, The Children's Memorial Health Institute, Warsaw, Poland
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Aasen G, Fagertun H, Halse J. Body composition analysis by dual X‐ray absorptiometry:in vivoandin vitrocomparison of three different fan‐beam instruments. Scand J Clin Lab Invest 2009; 66:659-66. [PMID: 17101558 DOI: 10.1080/00365510600898214] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
BACKGROUND Dual X-ray absorptiometry (DXA) is the preferred method for measuring body composition in clinical practice, but interchange between devices may pose problems with the interpretation of results. OBJECTIVE To establish conversion equations for body composition variables between three fan-beam DXA systems. METHODS Body composition was assessed in 21 subjects using Lunar Expert (Expert), Lunar Prodigy (Prodigy) and Hologic Delphi W (Delphi). Weekly measurements of Hologic whole body phantom 164 were performed. RESULTS There were no significant differences between DXA-measured means of body weight, fat mass and lean body mass. Bland-Altman analysis revealed that Lunar Expert increasingly overestimated fat mass with increasing total mass (p<0.001) relative to Delphi and Prodigy, while Delphi produced a constant underestimation of fat mass. Correlations between scale weights and DXA-measured body weights, and between DXA-measured body weights and the sum of fat masses, lean body masses and bone mineral contents (BMC) between the three instruments, were excellent (Rsqr 0.998-0.910; p<0.001). Conversion factors to Prodigy for Expert and Delphi were respectively 1.003 and 1.011 for total body mass, 0.954 and 1.079 for fat mass, 1.018 and 0.967 for lean body mass and 1.049 and 1.136 for BMC (Rsqr 0.999-0.991; p<0.001). Standard error of estimate (SEE) for the slopes ranged from 0.20% to 2.10%. Phantom studies revealed stable instrument function with CV% commonly<2%, except for lean mass for Delphi (5.5%). CONCLUSIONS Despite the significant differences in measurement of body composition between DXA fan-beam instruments, clinically relevant conversion factors can be established.
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Affiliation(s)
- G Aasen
- Spesialistsenteret Pilestredet Park, Oslo, Norway.
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Cole JH, Dowthwaite JN, Scerpella TA, van der Meulen MCH. Correcting fan-beam magnification in clinical densitometry scans of growing subjects. J Clin Densitom 2009; 12:322-9. [PMID: 19647670 PMCID: PMC2720880 DOI: 10.1016/j.jocd.2009.05.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2008] [Revised: 05/07/2009] [Accepted: 05/08/2009] [Indexed: 11/26/2022]
Abstract
As children grow, body and limb girths increase. For serial densitometric measurements, growth increases the distance between the bone region of interest and X-ray source over time, thereby increasing fan-beam magnification. To isolate bone accrual from magnification error in growing subjects, we developed a correction method based on waist girth, a common anthropometric measure. This correction was applied to dual-energy X-ray absorptiometry output obtained in a cohort of premenarcheal gymnasts and nongymnasts. After correcting for magnification, results for projected area and bone mineral content (BMC) increased by 0.4-1.1% at the lumbar spine and 8-16% at the femoral neck, decreasing areal bone mineral density (aBMD) by 0.4-2.3% at both sites. The effects of magnification correction were similar in magnitude to BMC and aBMD gains previously reported in longitudinal studies of normoactive children. Because of body size differences, the effect of correction for BMC and aBMD was 10-20% greater in nongymnasts than in gymnasts, which increased the observed aBMD differential between gymnasts and nongymnasts. Fan-beam magnification distorts true changes in bone mineral measures in growing premenarcheal girls and, therefore, may obscure additional activity-related changes during growth. Our correction technique may enhance detection of skeletal adaptation, particularly in pediatric populations.
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Affiliation(s)
- Jacqueline H Cole
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY, USA.
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Hull H, He Q, Thornton J, Javed F, Wang J, Pierson RN, Gallagher D. iDXA, Prodigy, and DPXL dual-energy X-ray absorptiometry whole-body scans: a cross-calibration study. J Clin Densitom 2009; 12:95-102. [PMID: 19028125 PMCID: PMC2661815 DOI: 10.1016/j.jocd.2008.09.004] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2008] [Revised: 09/23/2008] [Accepted: 09/25/2008] [Indexed: 11/26/2022]
Abstract
PURPOSE Total body fat, lean, and bone mineral content (BMC) in addition to regional fat and lean mass values for arms, legs, and trunk were compared across a pencil-beam (Lunar DPXL) and 2 fan-beam (GE Lunar Prodigy and GE Lunar iDXA) dual-energy X-ray absorptiometry (DXA) systems. METHODS Subjects were a multiethnic sample of 99 healthy adult males (47%) and females (mean+/-SD: age, 46.3+/-16.9 yr; weight, 73.4+/-16.6 kg; height, 167.6+/-9.7 cm; body mass index, 26.0+/-5.2 kg/m2) who had whole-body scans performed within a 3-h period on the 3 systems. Repeated measures ANOVA was used to test the null hypothesis that the mean values for the 3 systems were equal. Translation equations between the methods were derived using regression techniques. RESULTS Bone mineral content (BMC): For both genders, total BMC by iDXA was lower (p<or=0.004) than the other systems. Lean: for males, iDXA was lower (p<or=0.03) than the other systems for total, trunk, and arms. For females, DPXL estimated higher (p<0.001) lean mass compared with the other systems for total, trunk, and arms, but iDXA estimated greater legs lean mass. For both genders, all DPXL mean values were greater than Prodigy mean values (p<0.001). Fat: in females, all the 3 systems were different from each other for total, trunk, and legs (p<or=0.04). For arms, DPXL and iDXA were higher than Prodigy (p<0.0004). For males, DPXL was less (p<0.001) for total body, trunk, and legs compared with the other 2 systems and greater than Prodigy only for arms (p<0.0007). These data were used to derive translation equations between systems. For several measurements, the differences between systems were related to gender. CONCLUSION For estimation of BMC and body composition, there was high agreement between all DXA systems (R2=0.85-0.99). Even so, cross-calibration equations should be used to examine data across systems to avoid erroneous conclusions.
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Affiliation(s)
- Holly Hull
- Obesity Research Center, Department of Medicine, St. Luke’s-Roosevelt Hospital
| | - Qing He
- Obesity Research Center, Department of Medicine, St. Luke’s-Roosevelt Hospital
- Institute of Human Nutrition, Columbia University, New York
| | - John Thornton
- Obesity Research Center, Department of Medicine, St. Luke’s-Roosevelt Hospital
| | - Fahad Javed
- Obesity Research Center, Department of Medicine, St. Luke’s-Roosevelt Hospital
| | - Jack Wang
- Obesity Research Center, Department of Medicine, St. Luke’s-Roosevelt Hospital
| | - Richard N. Pierson
- Obesity Research Center, Department of Medicine, St. Luke’s-Roosevelt Hospital
| | - Dympna Gallagher
- Obesity Research Center, Department of Medicine, St. Luke’s-Roosevelt Hospital
- Institute of Human Nutrition, Columbia University, New York
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Bolland MJ, Grey AB, Gamble GD, Reid IR. CLINICAL Review # : low body weight mediates the relationship between HIV infection and low bone mineral density: a meta-analysis. J Clin Endocrinol Metab 2007; 92:4522-8. [PMID: 17925333 DOI: 10.1210/jc.2007-1660] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT HIV infection has been associated with low bone mineral density (BMD) in many cross-sectional studies, although longitudinal studies have not demonstrated accelerated bone loss. The cross-sectional studies may have been confounded by the failure to control for low body weight in HIV-infected patients. OBJECTIVE Our objective was to determine whether low body weight might explain the association of HIV infection with low BMD. DATA SOURCES MEDLINE and EMBASE were searched for English language studies published from 1966 to March 2007, and conference abstracts prior to 2007 were hand-searched. STUDY SELECTION All studies reporting BMD and weight or body mass index in adult patients with HIV and a healthy age- and sex-comparable control group were included. Nine of 40 identified studies and one of 68 identified abstracts were eligible. DATA SYNTHESIS We adjusted for the between-groups weight differences using regression coefficients from published cohorts of healthy men and women. On average, HIV-infected patients were 5.1 kg [95% confidence interval (CI), -6.8, -3.4; P < 0.001] lighter than controls. At all skeletal sites, unadjusted BMD was lower by 4.4-7.0% in the HIV-infected groups than the controls (P < 0.01). After adjustment for body weight, residual between-groups differences in BMD were small (2.2-4.7%) [lumbar spine, -0.02 (95% CI, -0.05, 0.01) g/cm2; P = 0.12; total hip, -0.02 (95% CI, -0.04, 0.00) g/cm2; P = 0.031; femoral neck, -0.04 (95% CI, -0.07, -0.01) g/cm2; P = 0.013; and total body, -0.03 (95% CI, -0.07, 0.01) g/cm2, P = 0.11]. CONCLUSION HIV-infected patients are lighter than controls and low body weight may largely account for the high prevalence of low BMD reported in HIV-infected patients. However, in the setting of current treatment practice, HIV infection per se is not a risk factor for low BMD.
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Affiliation(s)
- Mark J Bolland
- Osteoporosis Research Group, Department of Medicine, University of Auckland, Private Bag 92 019, Auckland, New Zealand.
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Tothill P, Hannan WJ. Precision and accuracy of measuring changes in bone mineral density by dual-energy X-ray absorptiometry. Osteoporos Int 2007; 18:1515-23. [PMID: 17483864 DOI: 10.1007/s00198-007-0382-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2007] [Accepted: 04/11/2007] [Indexed: 11/28/2022]
Abstract
UNLABELLED Long-term precision of two Hologic DXA scanners was derived from repeated clinical measurements. With typical subjects, the long-term coefficients of variation were about twice the short-term. The accuracy of the measurement of changes was compromised by anomalies, but this did not seriously affect clinical conclusions. INTRODUCTION Long-term precision and accuracy of BMD measurements need review. METHODS Long-term precision was examined by selecting, from Hologic databases, subjects who had had four scans over a period of 2 to 5 years and was calculated from the SEE of a regression of BMD against time. Accuracy was assessed from relationships between changes (delta) in BA, BMD and BMC. RESULTS For one group of subjects, the long-term precision was 2.4% for lumbar spine, 2.3% for total hip and 2.7% for femoral neck when expressed as CVs. These values were nearly twice the short-term CVs of 1.3% for spine, 1.2% for total hip and 1.4% for femoral neck. For another group, a negative exponential regression gave a better fit, leading to CVs of 1.3% for the spine, 1.4% for total hip and 2.1% for femoral neck. Significant correlations between deltaBA and deltaBMC were found. These led to an underestimate of deltaBMD in spine and hip by 25%. CONCLUSIONS The poorer long-term precision for typical patients should be borne in mind in monitoring progress. The underestimate of changes could account for only a part of the underestimation by BMD measurements of the anti-fracture effects of anti-resorptive drugs.
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Affiliation(s)
- P Tothill
- Department of Medical Physics, Western General Hospital, Edinburgh EH4 2XU, UK.
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Valentine RJ, Misic MM, Kessinger RB, Mojtahedi MC, Evans EM. Location of body fat and body size impacts DXA soft tissue measures: a simulation study. Eur J Clin Nutr 2007; 62:553-9. [PMID: 17457339 DOI: 10.1038/sj.ejcn.1602770] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE The aim of this study was to determine the ability of dual X-ray absorptiometry (DXA) to detect exogenous fat in men and women simulating typical sex-specific weight changes. SUBJECTS A diverse sample including 29 elderly (52-83 years) and 61 young (18-40 years) individuals (45 women, 45 men) of varying body mass index (BMI; M+/-s.d.: 26.1+/-4.9 kg/m2, range=16.4-39 kg/m2). METHODS Whole body (WB) DXA scans (Hologic QDR 4500A) were completed with Scan 1 performed as a normal baseline scan, Scan 2 with 1 kg packet of lard placed on each thigh and Scan 3 with two 1 kg lard packets placed on the abdomen (men) or chest and abdomen (women). RESULTS Measurement error of fat mass (FM) was more pronounced in the trunk as lard packets were detected with 59% accuracy (error=0.82+/-0.42 kg, P<0.001), whereas 94% of thigh lard (error=0.11+/-0.45 kg, P<0.001) was determined to be FM, while the remainder in both conditions was determined to be mineral free lean mass. Initial FM (r=0.37, P<0.001) for thigh loading and trunk bone mineral content (r=0.30, P<0.01) for trunk-loaded conditions had the most impact on measurement error of WB FM. CONCLUSIONS Regional differences impact measurement error of simulated changes in FM with greater measurement error in the trunk compared to the thigh region and initial FM and higher levels of bone mineral content in the trunk region impacting error.
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Affiliation(s)
- R J Valentine
- Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, IL, USA
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31
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Güler-Yüksel M, Bijsterbosch J, Goekoop-Ruiterman YPM, de Vries-Bouwstra JK, Ronday HK, Peeters AJ, de Jonge-Bok JM, Breedveld FC, Dijkmans BAC, Allaart CF, Lems WF. Bone mineral density in patients with recently diagnosed, active rheumatoid arthritis. Ann Rheum Dis 2007; 66:1508-12. [PMID: 17456523 PMCID: PMC2111640 DOI: 10.1136/ard.2007.070839] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVES Osteoporosis is a well-known extra-articular phenomenon in patients with uncontrolled, long-standing rheumatoid arthritis (RA). In the present study, the extent of osteoporosis and reduced bone mineral density (BMD) and the disease-related and demographic factors that are associated with osteoporosis and reduced BMD were examined in patients with recently diagnosed, active RA. METHODS BMD of the total hip and the lumbar spine was measured using dual-energy x ray absorptiometry in 381 patients with recently diagnosed active RA, who had never been treated with DMARDs or corticosteroids. Osteoporosis was defined as a T score <or=-2.5 SD and reduced BMD as Z score <or=-1 SD. Multivariate logistic regression analyses were performed to detect associations of osteoporosis and reduced BMD with disease activity, functional disability, joint damage (Sharp-van der Heijde score) and demographic factors. RESULTS Osteoporosis and reduced BMD were found in the spine and/or the hip in 11% and 25%, respectively, of the patients. Longer symptom duration and presence of rheumatoid factor (RF) were the only RA-specific markers for osteoporosis and reduced BMD. Further, postmenopausal status in women, a low body mass index, familial osteoporosis, and, remarkably, male gender, were independently associated with osteoporosis and reduced BMD. CONCLUSION In patients with recently diagnosed active RA who had never been treated with DMARDs or corticosteroids, BMD seems to be well-preserved and predominantly related to demographic factors. Longer symptom duration and a positive RF, but not higher disease activity or more joint damage, were related to osteoporosis and reduced BMD.
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Affiliation(s)
- M Güler-Yüksel
- Leiden University Medical Centre, PO Box 9600, 2300 RC, Leiden, The Netherlands.
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In vivo quantification of fat content in mice using the Hologic QDR 4500A densitometer. Obes Res Clin Pract 2007; 1:1-78. [DOI: 10.1016/j.orcp.2006.11.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2006] [Revised: 11/08/2006] [Accepted: 11/09/2006] [Indexed: 11/18/2022]
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Evans EM, Mojtahedi MC, Kessinger RB, Misic MM. Simulated change in body fatness affects Hologic QDR 4500A whole body and central DXA bone measures. J Clin Densitom 2006; 9:315-22. [PMID: 16931350 DOI: 10.1016/j.jocd.2006.04.117] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2006] [Accepted: 04/21/2006] [Indexed: 11/23/2022]
Abstract
Changes in body fatness may impact the accuracy of dual energy X-ray absorptiometry (DXA) measures of bone mineral content (BMC) and bone mineral density (BMD). The aim of this study was to determine if DXA can accurately assess BMC and BMD with changes in exogenous fat (lard) placed to simulate weight change. Whole body (WB), lumbar spine (LS), and proximal femur (PF) DXA scans (Hologic QDR 4500A) were performed on 30 elderly (52-83 yr) and 60 young (18-40 yr) individuals (i.e., 45 females and 45 males) of varying body mass index (mean+/-standard deviation: 26.1+/-4.9 kg/m2). When scans were repeated with lard packets (2.54 cm thick, 25.4x17.8 cm, 1 kg), WB BMD decreased 1.1% and 1.6% after chest and thigh packet placement, respectively (p=0.001), PF BMD increased 0.7% (p=0.02) and LS BMD decreased 1.6% (p=0.001) primarily due to a 2.2% reduction in LS BMC (p<0.001). Initial LS BMC and trunk mass were related to error in LS BMC measures due to lard-loading (r=0.64 and 0.45, respectively, p<0.001). We conclude that on average simulated weight change minimally impacts PF bone measures and moderately impacts WB and LS bone measures; however, individual variability in measurement error was noteworthy and may be impacted by body thickness.
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Affiliation(s)
- Ellen M Evans
- Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
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Sakai Y, Ito H, Meno T, Numata M, Jingu S. Comparison of body composition measurements obtained by two fan-beam DXA instruments. J Clin Densitom 2006; 9:191-7. [PMID: 16785080 DOI: 10.1016/j.jocd.2006.03.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2005] [Revised: 02/04/2006] [Accepted: 03/17/2006] [Indexed: 10/24/2022]
Abstract
Although dual-energy X-ray absorptiometry (DXA) has been widely used for measuring body composition, discrepancies have been reported to exist among results obtained from different instruments. In the course of longitudinal studies lasting for many years, old instruments may be required to be replaced with new ones, necessitating comparison and validation between the values obtained by the old and new instruments. We compared the data obtained by the two fan-beam DXA instruments, QDR-2000 (Hologic, Waltham, MA) and Delphi (Hologic). Body composition was first measured by the Hologic QDR-2000 and next by the Delphi W within 30 days in 99 healthy subjects. Whole-body fat mass (FM), percentage of FM, arm FM, and leg FM measured by the Hologic QDR-2000 were significantly larger than those measured by the Delphi W. Lean tissue mass (LTM), bone mineral content, and bone mineral density of the whole body, trunk FM, arm LTM, and leg LTM measured by the QDR-2000 were significantly smaller than those measured by the Delphi W. After converting the QDR-2000 values by equations developed by multiple regression analysis, they were not significantly different from the corresponding Delphi values. Measurements by the QDR-2000 and the Delphi W were not interchangeable and the conversion equations reduced the discrepancy to a level that enabled direct comparison of the data obtained by the two instruments. However, cautious interpretation is necessary when the conversion equations are applied to other instruments even of the same type or when evaluating data of individual subjects.
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Affiliation(s)
- Yumiko Sakai
- Fukuoka Health Promotion Foundation, Fukuoko, Japan
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Robotham DR, Schoeller DA, Mercado AB, Mirch MC, Theim KR, Reynolds JC, Yanovski JA. Estimates of body fat in children by Hologic QDR-2000 and QDR-4500A dual-energy X-ray absorptiometers compared with deuterium dilution. J Pediatr Gastroenterol Nutr 2006; 42:331-5. [PMID: 16540807 PMCID: PMC1861847 DOI: 10.1097/01.mpg.0000189373.31697.15] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
We evaluated the accuracy with which the Hologic QDR-4500A and QDR-2000 densitometers measure fat mass (FM) in 95 children. FM was derived from total body water measured by deuterium dilution (DD) in all children, by QDR-4500A in 50, and by QDR-2000 in 45 children. Compared with DD, both instruments underestimated FM (QDR-4500A: 3.35 +/- 2.5 kg, P < 0.0001; QDR-2000: 1.05 +/- 1.5 kg, P < 0.0001). Both absorptiometers showed magnitude biases relative to DD (QDR-4500: r = +0.70, P < 0.001; QDR-2000: r = -0.51, P < 0.001). We conclude that neither densitometer is equivalent to DD for estimation of children's FM. The QDR-4500A's current calibration seems to provide an even greater underestimate of FM than the QDR-2000.
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Affiliation(s)
- Delphine R. Robotham
- Unit on Growth and Obesity, Developmental Endocrinology Branch, NICHD, Bethesda, MD
| | - Dale A. Schoeller
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI
| | - Arlene B. Mercado
- Unit on Growth and Obesity, Developmental Endocrinology Branch, NICHD, Bethesda, MD
| | - Margaret C. Mirch
- Unit on Growth and Obesity, Developmental Endocrinology Branch, NICHD, Bethesda, MD
| | - Kelly R. Theim
- Unit on Growth and Obesity, Developmental Endocrinology Branch, NICHD, Bethesda, MD
| | - James C. Reynolds
- Nuclear Medicine Department, Warren Grant Magnuson Clinical Center, National Institutes of Health, DHHS, Bethesda, MD
| | - Jack A. Yanovski
- Unit on Growth and Obesity, Developmental Endocrinology Branch, NICHD, Bethesda, MD
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Newton RL, Alfonso A, York-Crowe E, Walden H, White MA, Ryan D, Williamson DA. Comparison of body composition methods in obese African-American women. Obesity (Silver Spring) 2006; 14:415-22. [PMID: 16648612 DOI: 10.1038/oby.2006.55] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE To compare the accuracy of percentage body fat (%BF) estimates between bioelectrical impedance analysis (BIA) and DXA in obese African-American women. RESEARCH METHODS AND PROCEDURES Fifty-five obese African-American women (mean age, 45 years; mean BMI, 38; mean %BF, 48%) were studied. BF was assessed by both BIA (RJL Systems BIA 101Q; RJL Systems, Clinton Township, MI) and DXA (Hologic QDR-2000 Bone Densitometer; Hologic Inc., Bedford, MA). Generalized and ethnicity- and obese-specific equations were used to calculate %BF from the BIA. Bland-Altman analyses were used to compare the agreement between the BIA and the DXA, with the DXA serving as the criterion measure. RESULTS Two of the generalized equations provided consistent estimates across the weight range in comparison with the DXA estimates, whereas most of the other equations increasingly underestimated %BF as BF increased. One of the generalized and one of the ethnicity-specific equations had mean differences that were not significantly different from the DXA value. DISCUSSION The findings show that the Lukaski equation provided the most precise and accurate estimates of %BF in comparison with the QDR 2000 and provide preliminary support for the use of this equation for obese African-American women.
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Affiliation(s)
- Robert L Newton
- Pennington Biomedical Research Center, Louisiana State University, 6400 Perkins Road, Baton Rouge, LA 70808, USA.
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Crabtree NJ, Shaw NJ, Boivin CM, Oldroyd B, Truscott JG. Pediatric in vivo cross-calibration between the GE Lunar Prodigy and DPX-L bone densitometers. Osteoporos Int 2005; 16:2157-67. [PMID: 16234997 DOI: 10.1007/s00198-005-2021-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2005] [Accepted: 08/18/2005] [Indexed: 11/24/2022]
Abstract
Dual energy x-ray absorptiometry (DXA) machine cross-calibration is an important consideration when upgrading from old to new technology. In a recent cross-calibration study using adult subjects, close agreement between GE Lunar DPX-L and GE Lunar Prodigy scanners was reported. The aim of this work was to cross-calibrate the two machines for bone and body composition parameters for pediatrics from age 5 years onwards. One-hundred ten healthy volunteers aged 5-20 years had total body and lumbar spine densitometry performed on DPX-L and Prodigy densitometers. Cross-calibration was achieved using linear regression and Bland-Altman analysis. There was close agreement between the machines, with r2 ranging from 0.85 to 0.99 for bone and body composition parameters. Paired t-tests demonstrated significant differences between machines that were dependent on scan acquisition mode, with the greatest differences reported for the smallest children. At the lumbar spine, Prodigy bone mineral density (BMD) values were on average 1.6% higher compared with DPX-L. For the total body, there were no significant differences in BMD; however, there were significant differences in bone mineral content (BMC) and bone area. For small children, the Prodigy measured lower BMC (9.4%) and bone area (5.8%), whereas for larger children the Prodigy measured both higher BMC (3.1%) and bone area (3.0%). A similar contrasting pattern was also observed for the body composition parameters. Prodigy values for lean body mass were higher (3.0%) for small children and lower (0.5%) for larger children, while fat body mass was lower (16.4%) for small children and higher (2.0%) for large children. Cross-calibration coefficients ranged from 0.84 to 1.12 and were significantly different from 1 (p<0.0001) for BMC and bone area. Bland-Altman plots showed that within the same scan acquisition modes, the magnitude of the difference increased with body weight. The results from this study suggest that the differences between machines are mainly due to differences in bone detection algorithms and that they vary with body weight and scan mode. In general, for population studies the differences are not clinically significant. However, for individual children being measured longitudinally, cross-over scanning may be required.
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Affiliation(s)
- Nicola J Crabtree
- Department of Nuclear Medicine, Queen Elizabeth Hospital, Metchley Park Road, Birmingham, B15 2TH, UK.
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King S, Wilson J, Kotsimbos T, Bailey M, Nyulasi I. Body composition assessment in adults with cystic fibrosis: comparison of dual-energy X-ray absorptiometry with skinfolds and bioelectrical impedance analysis. Nutrition 2005; 21:1087-94. [PMID: 16183254 DOI: 10.1016/j.nut.2005.04.005] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2004] [Accepted: 04/04/2005] [Indexed: 12/25/2022]
Abstract
OBJECTIVE We compared body composition measurement in adults with cystic fibrosis (CF) by using non-invasive methods (skinfold thicknesses and bioelectrical impedance analysis [BIA]) with dual-energy X-ray absorptiometry (DXA). METHODS Seventy-six adults with CF (mean age 29.9 +/- 7.9 y, mean body mass index 21.5 +/- 2.5 kg/m(2)) were studied. Body composition was measured to calculate fat-free mass (FFM) using DXA, the sum of four skinfold thicknesses, and BIA (predictive equations of Lukaski and of Segal). RESULTS Mean FFM values +/- standard deviation measured using DXA were 54.8 +/- 7.3 kg in men and 41.2 +/- 3.9 kg in women. Mean FFM values measured using BIA/Lukaski were 51.5 +/- 7.8 kg in men and 40.4 +/- 4.9 kg in women (P < 0.0005 for men, not significant for women for comparison with DXA). Mean FFM values measured using BIA/Segal were 54.2 +/- 7.5 kg for men and 44.1 +/- 5.9 kg for women (not significant for men, P < 0.0005 for women for comparison with DXA). Mean FFM values measured using skinfolds were significantly higher than those for FFM with DXA (57.2 +/- 7.2 kg in men, 43.3 +/- 4.3 kg in women, P < 0.0005 for comparison with DXA). The 95% limits of agreement with FFM using DXA were, for men and women, respectively, -8.3 to 1.7 kg and -6.4 to 4.8 kg for BIA/Lukaski, -4.8 to 3.6 kg and -3.1 to 8.9 kg for BIA/Segal, and -2.8 to 7.3 kg and -1.5 to 5.7 kg for skinfolds. CONCLUSION This study suggests that skinfold thickness measurements and BIA will incorrectly estimate FFM in many adults with CF compared with DXA measurements of FFM. These methods have limited application in the assessment of body composition in individual adult patients with CF.
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Affiliation(s)
- Susannah King
- Department of Medicine, Monash University, Alfred Hospital, Melbourne, Victoria, Australia.
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Wu XP, Liao EY, Dai RC, Shan PF, Fang TY, Luo XH, Pi YZ, Jiang Y. Comparison of spine and femur reference data in native Chinese women from different regions of China. Osteoporos Int 2005; 16:1215-24. [PMID: 15782285 DOI: 10.1007/s00198-004-1827-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2004] [Accepted: 12/02/2004] [Indexed: 10/25/2022]
Abstract
The aim of this study is to explore the differences of BMD reference curves at various skeletal sites among Chinese women from different regions of China and to investigate the feasibility of establishing a unified national BMD reference database for Chinese women. We measured BMD at the posteroanterior (PA) lumbar spine, femoral neck, trochanter and Ward's triangle by dual-energy X-ray absorptiometry bone densitometer in 3,422 Changsha women of South Central China, aged 20-84 years. The documented BMDs of reference populations of women in all other areas included Shanghai ( n =2,111) and Nanjing ( n =3,174) in the East, Shenyang ( n =1,213) in the Northeast, Kunming ( n =523) in the Southwest, Chongqing ( n =811) in the Midwest and Xian ( n =1,320) in the Northwest. We adopted the cubic regression as the fitting model for reference curves of BMD that varied with age, conducted conversions of BMD measured by various bone densitometers from different manufacturers and compared the differences between standardized BMD (sBMD) reference curves and combined ones for women from different areas. Our results revealed that by comparing variances in women from different areas, the average variances of non-standard BMD were 0.8-30.8% at the PA spine, 0.7-24.5% at the femoral neck, 0.6-29.9% at the trochanter and 1.1-54.7% at Ward's triangle, while average variances of sBMD either significantly decreased or disappeared (0.8-3.9% at the PA spine, 0.7-8.6% at the femoral neck, 0.6-8.3% at the trochanter and 1.1-29.9% at Ward's triangle). The sBMD reference curves were highly positive-dependent with combined ones ( r =0.913-0.999, P =0.000). At the PA spine and trochanter, the effect of combined sBMD curves presented well in women from different areas, except for those from Shanghai at the PA spine and Shenyang at the trochanter, indicating that sBMD curves were significantly different from pooled ones; at the femoral neck and Ward's triangle, the effect of combined sBMD reference curves was poor, indicating that sBMD curves demonstrated significant differences from pooled ones in women from a majority of these areas. We conclude that, in high density population areas, sBMD reference curves showed no significant geographic differences in women from various regions. In women from different areas, sBMD reference curves present good pooled results at the PA spine and trochanter. The less ideal combining effect of the sBMD curves at both femoral neck and Ward's triangle might be caused by the intrinsic differences from the different measuring instruments.
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Affiliation(s)
- Xian-Ping Wu
- Institute of Metabolism and Endocrinology, The Second Xiang-Ya Hospital of the Central South University, Changsha, 86 Renmin-Zhong Road, 410011 Hunan, P.R. China.
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Abstract
OBJECTIVE To evaluate interdevice reliability in body density (Db) and percent body fat (%BF) using air-displacement plethysmography, the BOD POD (BP) body composition system. DESIGN AND SETTING Duplicate body composition tests were performed in immediate succession on 50 adults (26 M, 24 F; 21-53 y) using two BP units located in the same body composition laboratory. RESULTS Mean Db and %BF between BP1 and BP2 did not differ significantly for men (DeltaDb = 0.0003+/-0.0008 g/ml, P = 0.632; Delta%BF = 0.1+/-1.3, P = 0.665), while for women, there were small but significant differences in Db and %BF between BP1 and BP2 (DeltaDb = 0.0018+/-0.0003 g/ml, P = 0.001; Delta%BF = 0.8+/-1.1, P = 0.001). The regression between %BF by BP1 and BP2 did not deviate significantly from the line of identity for both men and women (R2 = 0.95, standard error of estimate (s.e.e.) = 1.23 %BF for men; R2 = 0.97, s.e.e = 1.13 %BF for women). Individual variations in %BF estimates between the two BP units were within acceptable ranges (95% limits of agreement = -2.5-2.7 %BF for men; -1.4-3.0 %BF for women), and there was no trend in individual differences as %BF varied (r = -0.19, P = 0.359 for men; r = 0.09, P = 0.677 for women). Other subject characteristics, including age, body mass, height, and body mass index, did not significantly contribute to the differences in %BF estimates by the two BP units. CONCLUSIONS No clinically significant differences in Db and %BF estimates exist between the BP units, and the interdevice variability of the BP has minimal impact on %BF estimates. Further, test-to-test reliability between BP units appears to be as good as within one unit.
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Affiliation(s)
- S D Ball
- Department of Nutritional Sciences, University of Missouri-Columbia, Columbia, MO, USA.
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Schoeller DA, Tylavsky FA, Baer DJ, Chumlea WC, Earthman CP, Fuerst T, Harris TB, Heymsfield SB, Horlick M, Lohman TG, Lukaski HC, Shepherd J, Siervogel RM, Borrud LG. QDR 4500A dual-energy X-ray absorptiometer underestimates fat mass in comparison with criterion methods in adults. Am J Clin Nutr 2005; 81:1018-25. [PMID: 15883424 DOI: 10.1093/ajcn/81.5.1018] [Citation(s) in RCA: 202] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND Dual-energy X-ray absorptiometry (DXA) has become one of the most frequently used methods for estimating human body composition. Although the DXA technique has been validated for the measurement of fat-free mass and fat mass, differences in calibration between instruments produced by different manufacturers, as well as between different models produced by the same manufacturer, have been reported. OBJECTIVE The objective was to compare the calibration of the QDR 4500A against criterion methods in a large heterogeneous population. DESIGN DXA-derived body-composition data were obtained from 7 studies: 6 data sets were provided by the investigators, one of which was published. The data included fat mass and fat-free mass measured with a QDR 4500A and criteria measurements of body composition from total body water by dilution at 4 centers, densitometry from 1 center, and four-compartment analysis at 2 centers. RESULTS In the cohort of 1195 subjects, 602 men and 593 women aged 19-82 y with a body mass index (in kg/m2) of 16-44, the fan-beam DXA overestimated fat-free mass (P < 0.05). A significant difference was observed in all 7 data sets, and the mean (+/-SE) was 5 +/- 1%. CONCLUSIONS It is recommended that the lean soft tissue mass estimate with the fan-beam QDR 4500A be reduced by 5% and that for fat mass be increased by that same mass. This finding is particularly important because the National Health and Nutrition Examination Survey is using the QDR 4500A to assess body composition in a nationally representative sample of persons in the United States.
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Abstract
PURPOSE OF REVIEW Dual-energy X-ray absorptiometry is now widely adopted for the measurement of the fat, fat-free soft tissue and bone mineral compartments of the body. Whereas it is regarded by many as a reference technique for such measurements, it is not without limitations. Inter and intra-manufacturer differences have been areas of concern. This review focuses on recent literature addressing these areas and the issue of validity. RECENT FINDINGS Body composition measurements using newer generation dual-energy X-ray absorptiometry machines compared between different manufacturers and compared with earlier instruments continue to show differences that may be unacceptable, particularly for investigators upgrading their machines or involved in multicentre studies using different machines. In terms of validity, significant deviations at a group level are reported when compared with reference four-component models, and perhaps more importantly, wide limits of agreement are seen that are a concern for the interpretation of results at an individual level. SUMMARY It is important that investigators recognize the limitations of dual-energy X-ray absorptiometry technology in the interpretation of their results. There is a continuing need both for inter-machine comparisons and validation studies against accepted criterion methods, particularly as new software or technological changes are introduced. Such studies permit the development of translation equations for the cross-calibration of devices, and may be vital for cross-sectional studies. For longitudinal studies in many populations, dual-energy X-ray absorptiometry is without question a valuable technique for the measurement of compositional changes, both at the total body and regional levels.
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Brownbill RA, Ilich JZ. Measuring body composition in overweight individuals by dual energy x-ray absorptiometry. BMC Med Imaging 2005; 5:1. [PMID: 15748279 PMCID: PMC1079847 DOI: 10.1186/1471-2342-5-1] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2004] [Accepted: 03/04/2005] [Indexed: 11/19/2022] Open
Abstract
Background Dual energy x-ray absorptiometry (DXA) is widely used for body composition measurements in normal-weight and overweight/obese individuals. The limitations of bone densitometers have been frequently addressed. However, the possible errors in assessing body composition in overweight individuals due to incorrect positioning or limitations of DXA to accurately assess both bone mineral density and body composition in obese individuals have not received much attention and are the focus of this report. Discussion We discuss proper ways of measuring overweight individuals and point to some studies where that might not have been the case. It appears that currently, the most prudent approach to assess body composition of large individuals who cannot fit under the scanning area would be to estimate regional fat, namely the regions of thigh and/or abdomen. Additionally, using two-half body scans, although time consuming, may provide a relatively accurate measurement of total body fat, however, more studies using this technique are needed to validate it. Summary Researchers using bone densitometers for body composition measurements need to have an understanding of its limitations in overweight individuals and address them appropriately when interpreting their results. Studies on accuracy and precision in measurements of both bone and soft tissue composition in overweight individuals using available densitometers are needed.
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Affiliation(s)
- Rhonda A Brownbill
- School of Allied Health, University of Connecticut, Storrs, CT 06269, USA
| | - Jasminka Z Ilich
- School of Allied Health, University of Connecticut, Storrs, CT 06269, USA
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Cole JH, Scerpella TA, van der Meulen MCH. Fan-beam densitometry of the growing skeleton: are we measuring what we think we are? J Clin Densitom 2005; 8:57-64. [PMID: 15722588 DOI: 10.1385/jcd:8:1:057] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2004] [Revised: 07/02/2004] [Accepted: 08/07/2004] [Indexed: 11/11/2022]
Abstract
Magnification error in fan-beam densitometers varies with distance from the X-ray source to the bone measured and might obscure bone mineral changes in the growing skeleton. Magnification was examined by scanning aluminum rods of different shapes (square, rectangular, solid round, and hollow round) at four distances above the X-ray source in two orientations, with rods aligned parallel (SI) and perpendicular (ML) to the longitudinal axis of the scanning table. Measured area (cm(2)) decreased linearly with distance above the X-ray source for all rods in the SI orientation (p < 0.005). Measured mineral content (g) decreased linearly with distance but only for SI round rods (p < 0.0001) and for ML hollow round rods (p < 0.005). Area and mineral content decreased 1.6-1.8% per centimeter above the source for round rods. Measured mineral density (g/cm(2)) decreased linearly with distance from the source only for ML hollow round rods (p < 0.005). Variation in area, mineral content, and mineral density measurements was 6.6-6.9%, 6.9-7.5%, and 1.9-2.3%, respectively, for SI round rods. Magnification errors of this magnitude are problematic for clinical studies using fan-beam densitometry. Particularly in pediatric subjects, increases in soft tissue during normal growth could increase a bone's distance from the fan-beam source and result in apparent reductions in area and bone mineral content.
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Affiliation(s)
- Jacqueline H Cole
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY 14853, USA.
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Tothill P. Dual-energy x-ray absorptiometry measurements of total-body bone mineral during weight change. J Clin Densitom 2005; 8:31-8. [PMID: 15722585 DOI: 10.1385/jcd:8:1:031] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2004] [Revised: 08/23/2004] [Accepted: 09/08/2004] [Indexed: 11/11/2022]
Abstract
Bone mineral measurements were made using dual-energy X-ray absorptiometry during a multicenter diet trial. There were five centers, two using Hologic QDR4500 fan-beam scanners, two using Lunar Prodigy fan-beam scanners,and one using a pencil-beam Lunar DPX. Measurements were made at 0, 2.5, and 6 mo. The mean weight loss was 7.9 kg, but there was a wide range. With the Lunar instruments, the total-body bone mineral density reduced with weight loss, but with the Hologic scanners, it appeared to increase. This anomaly is similar to that observed previously with a Hologic QDR1000 pencil-beam scanner. It was shown that changes of fat distribution can lead to alterations in bone measurement without any real change in the skeleton. With all of the scanners, there was a strong correlation between the change in the bone mineral content and bone area, with some values of the latter being quite implausible. There was an associated worsening of long-term precision compared with that derived from short-term duplicated scans, more marked with the Lunar scanners. It is concluded that measurement artifacts preclude the valid assessment of total-body bone mineral during weight change.
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Affiliation(s)
- Peter Tothill
- Department of Medical Physics, Western General Hospital, Edinburgh, UK, EH4 2XU.
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Shypailo RJ, Ellis KJ. Bone assessment in children: comparison of fan-beam DXA analysis. J Clin Densitom 2005; 8:445-53. [PMID: 16311430 DOI: 10.1385/jcd:8:4:445] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2005] [Revised: 05/19/2005] [Accepted: 05/19/2005] [Indexed: 11/11/2022]
Abstract
The newest version of whole body dual-energy X-ray absorptiometry (DXA) analysis software from Hologic (Discovery 12.1) is designed to enhance bone detection in smaller subjects. We re-analyzed 1127 pediatric scans (ages 1.8-18.5 yr) previously analyzed using software version 11.2. Regression analysis compared new and original results for bone area (BA), bone mineral content (BMC), bone mineral density (BMD), and DXA-derived body weight. Changes in total and regional bone results were compared with age, weight, and height. New results were highly correlated with original analyses (R2 > or = 0.9), but there were large differences at the individual subject level. The BA and BMC values increased in subjects less than 40 kg weight, resulting in a lower BMD. Original and new results were equivalent by about age 14 yr in both genders. Regional bone data showed the greatest changes in the legs. The newest software produces significant changes in bone values in subjects weighing less than 40 kg, compared with earlier versions. This effect increases with decreasing body weight. This will impact interpretation of longitudinal pediatric DXA studies, as well as existing pediatric whole body bone reference databases. Investigators must recognize which DXAsoftware version they are using, and which version produced any reference database they may use for comparison.
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Affiliation(s)
- R J Shypailo
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA.
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von Mach MA, Stoeckli R, Bilz S, Kraenzlin M, Langer I, Keller U. Changes in bone mineral content after surgical treatment of morbid obesity. Metabolism 2004; 53:918-21. [PMID: 15254887 DOI: 10.1016/j.metabol.2004.01.015] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Weight loss reduces bone mass and increases the risk of osteoporosis. This study was undertaken to assess changes of bone metabolism following Roux-en-Y gastric bypass (RYGB) and adjustable silicone gastric banding (ASGB) as compared to nonoperated controls of morbidly obese subjects. Fourteen female and 5 male patients with a mean (+/-SEM) age of 44.3 +/- 1.8 years participated in the 24-month prospective study. Nine patients underwent ASGB, 4 patients RYGB operation, and 6 patients were included in the control group. Bone metabolism was assessed by determination of serum parathyroid hormone (PTH), osteocalcin, urinary deoxypyridinoline, and dual energy x-ray absorptiometry (DXA) before, and 6, 12, and 24 months after intervention. The body mass index (BMI) decreased from 41.0 +/- 1.1 to 34.0 +/- 1.4 kg/m2 in the ASGB group (P = .001), from 42.7 +/- 2.2 to 30.5 +/- 2.2 kg/m2 in the RYGB group (P = .006), and remained unchanged in the control group (from 41.2 +/- 1.2 to 41.4 +/- 1.4 kg/m2) after 24 months. Bone mineral content (BMC) showed no significant change in the ASGB group (from 3,079 +/- 140 to 3,064 +/- 129 g) and in the control group (from 2,945 +/- 130 to 2,940 +/- 111 g), whereas it decreased from 2,968 +/- 111 to 2,621 +/- 139 g in the RYGB group (P = .005). The loss in BMC was accompanied by significant increases in urinary deoxypyridinoline (P < .05) and in serum osteocalcin (P < .01) after RYGB, suggesting both, increased bone resorption and increased bone formation. The authors were aware of the fact that the study groups were small and conclusions need to be regarded as preliminary. However, the RYGB operation resulted in enhanced weight loss and significant net loss of bone mass in comparison to ASGB and obese control subjects. Patients losing large amounts of body weight should be monitored regularly regarding prevention of osteoporosis.
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Affiliation(s)
- M-A von Mach
- Division of Endocrinology, Diabetes and Clinical Nutrition, University Hospital, Basel, Switzerland
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Tothill P, James Hannan W. Dual-energy X-ray absorptiometry measurements of fat and lean masses in subjects with eating disorders. Int J Obes (Lond) 2004; 28:912-9. [PMID: 15098016 DOI: 10.1038/sj.ijo.0802536] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE The main objective was to use a dual-energy X-ray absorptiometer (DXA) to examine the total-body and regional fat and lean composition of soft tissue in subjects with and without eating disorders initially and after weight change. It was necessary also to study the effects of differences of calibration of different models of DXA scanner. DESIGN A total of 175 women with eating disorders, including anorexia nervosa (AN) and bulimia nervosa, and 43 age-matched controls were measured for soft-tissue composition with a pencil-beam Hologic QDR 1000W scanner and results converted to be equivalent to those from a fan-beam Hologic QDR 4500A, using previously determined crosscalibration factors. Some measurements were repeated at 6 and 12 months. RESULTS The baseline body composition of the patients covered a continuous range of fat proportions. Implausibly low fat proportions in some of the AN subjects were corrected by conversion to 4500 equivalents. The relationship between total lean mass and fat mass could be fitted equally well by a linear or linear/log regression. The relationship between leg and trunk fat was best fitted by a polynomial regression. There were weight changes in either direction in some of the subjects. The fat proportion in the total changed mass was a mean of 55%, higher in the legs and lower in the trunk, but not different between weight gainers and losers or clinical groups. The proportion was dependent on the initial fat proportion. CONCLUSIONS Relatively small differences in fat/lean calibration of DXA scanners may lead to anomalous results in very anorexic subjects and corrections are necessary in comparing results from different instruments. Concerns expressed about preferential trunk fat accumulation during weight recovery are not well founded. Previous claims of a relationship between fat proportion in regained weight and the amount of the weight gain are not justified.
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Affiliation(s)
- P Tothill
- Department of Medical Physics, Western General Hospital, Edinburgh, UK.
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Soriano JMP, Ioannidou E, Wang J, Thornton JC, Horlick MN, Gallagher D, Heymsfield SB, Pierson RN. Pencil-beam vs fan-beam dual-energy X-ray absorptiometry comparisons across four systems: body composition and bone mineral. J Clin Densitom 2004; 7:281-9. [PMID: 15319498 DOI: 10.1385/jcd:7:3:281] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We compared bone mineral density (BMD) and body fat percentage (%fat) between two pencil-beam (Lunar DPX and DPX-L) and two fan-beam (Lunar Prodigy, Hologic Delphi A) dual-energy X-ray absorptiometry (DXA) systems. We examined these values in the total-body, spine, femur, and forearm scans in 78 healthy adults across these four DXA systems. BMD and %fat values were highly correlated among the four instruments. DPX-L gave the lowest mean %fat and Prodigy gave the highest mean %fat for both sexes. The means were system dependent for %fat estimates across the four DXA machines. There was a significant difference detected in BMD estimates across manufacturers, with the Delphi A providing systematically lower values than the Lunar systems in the whole body, spine, and femur sites but higher values than the Lunar systems in the forearm. The present study results show that both %fat and bone mineral estimates between pencil-beam and fan-beam systems are highly correlated, but vary by system. Significant differences exist between the instruments, especially between different manufacturers, and most of the comparisons are sex dependent. We conclude that longitudinal studies should always be evaluated on the same system when possible, and translation models should be used to assess cross-instrument differences.
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Affiliation(s)
- Janet-Mae P Soriano
- Body Composition Unit and New York Obesity Research Center, St. Luke's-Roosevelt Hospital, Columbia University College of Physicians and Surgeons, New York, NY 10025, USA.
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50
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Oldroyd B, Smith AH, Truscott JG. Cross-calibration of GE/Lunar pencil and fan-beam dual energy densitometers--bone mineral density and body composition studies. Eur J Clin Nutr 2003; 57:977-87. [PMID: 12879093 DOI: 10.1038/sj.ejcn.1601633] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE In vitro and in vivo comparisons of bone mineral density (BMD) and body composition between GE/Lunar pencil (DPXL) and fan-beam (PRODIGY) absorptiometers. DESIGN Comparison of BMD, bone mineral content (BMC) and area of lumbar spine (L2-L4), femoral neck and total body. Total body composition compartments tissue (TBTissue), fat (TBF), lean tissue (TBLean) and %TBF were also compared. SETTING Centre for Bone and Body Composition Research, University of Leeds. PHANTOMS/SUBJECTS: A range of spine phantoms, a variable composition phantom (VCP) and total body phantom. A total of 72 subjects were included for the in vivo study. RESULTS In vitro: A small significant underestimation of BMD by the Prodigy compared to the DPXL ranging from 0.7 to 2% (p<0.05-0.001) for the spine phantoms. The Prodigy underestimated the VCP %Fat. Although the Prodigy underestimated phantom TBBMD by 1.1+/-1.0%, TBBMC and area were reduced by 8.2+/-1.4 and 7.3+/-1.0%, respectively. The Prodigy overestimated TBTissue 1508 g (2.2%), TBLean 588 g (1.2%), TBF 919 g (4.8%) and %TBF (0.8%). In vivo: BMD cross-calibration was only required in the femoral neck, DPXL(BMD)=0.08+0.906*PRODIGY(BMD). The Prodigy had higher estimates for TBTissue 1360 g (2.3%), TBLean 840 g (2.0%), TBF 519 g (3.4%), TBBMC 32.8 g (1.3%) and %TBF (0.3%). Cross-calibration equations were required for TBTissue(DPXL)=-1158+0.997*TBTissue(PRODIGY) and TBBMC(DPXL)= 89.7+0.949*TBBMC(PRODIGY). CONCLUSIONS Small differences between the two absorptiometers for both BMD and body composition can be made compatible by use of cross-calibration equations and factors. The discrepancy in body composition compartments requires further research.
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Affiliation(s)
- B Oldroyd
- Centre for Bone and Body Composition Research, University of Leeds, UK.
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