Reliability of 2 Different Positioning Protocols for Dual-Energy X-ray Absorptiometry Measurement of Body Composition in Healthy Adults

Kerr, Ava; Slater, Gary; Byrne, Nuala M.; Nana, Alisa

doi:10.1016/j.jocd.2015.08.002

Cited by 34 publications

(42 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Following BP, participants walked~50 feet and laid down on the DXA. Participants removed all metal objects and laid in a supine position centred in the scanning area (Kerr et al, 2016). Participants were asked to relax and remain motionless.…”

Section: Methodsmentioning

confidence: 99%

Reliability and validity of various laboratory methods of body composition assessment in young adults

Schubert

Seay

Spain

et al. 2018

Clin Physio Funct Imaging

View full text Add to dashboard Cite

Summary Accurate measures of body composition (BC) are essential for performance and health. In addition to accuracy, BC measures should be practical and be minimally invasive to maximize their utility. The purpose of the present study was to compare the day‐to‐day variability and validity of four common laboratory‐based body composition assessments to a criterion four‐compartment model. Dual x‐ray absorptiometry (DXA), air displacement plethysmography (BP), multi‐frequency bioelectrical impedance (MF‐BIA) and underwater weighing (UWW) were performed twice in a sample of 32 young men and women. Participants were assessed in a fasted, euhydrated state 2–7 days apart. All methods were compared to a criterion four‐compartment model using BP‐derived body volume, DXA‐derived bone mineral content and MF‐BIA‐derived total body water (4CBP). Additional four‐compartment models using UWW‐ and DXA‐derived body volume were also examined (4CUWW) and (4CDXA). Validity results were conducted with paired t‐tests and Bland–Altman analysis. Reliability was determined using intraclass correlations (ICC), coefficients of variation (CV) and standard error of the measurement (SEM). Validity analysis revealed that all methods overestimated per cent body fat and fat mass, and underestimated fat‐free mass when compared with 4CBP, but only DXA and BP were significantly different (P<0·008). All measures were highly reliable across days (ICCs > 0·9, CVs < 12%). Results of the present study indicate that typical laboratory‐based methods of body composition are valid and reliable. However, we caution that results should not be translated between methods and assessments should be performed with the same instrument when the goal is to monitor changes in body composition over time.

show abstract

Section: Methodsmentioning

confidence: 99%

Reliability and validity of various laboratory methods of body composition assessment in young adults

Schubert

Seay

Spain

et al. 2018

Clin Physio Funct Imaging

View full text Add to dashboard Cite

show abstract

“…Due to its reliance on x‐ray absorptiometry, DXA, similar to CT, has a number of technical and physiological limitations that influence attenuation measurements. Technological limitations include patient positioning and device and software differences 64 – 67 . Physiological limitations include depth and length of the patient, hydration status, and timing of the scan in relation to activities of daily living (meal timing, bathroom habits, and exercise) 58 , 68 , 69 .…”

Section: Dxamentioning

confidence: 99%

The Use of Technology for Estimating Body Composition

et al. 2016

View full text Add to dashboard Cite

Assessment of body composition, both at single time points and longitudinally, is particularly important in clinical nutrition practice. It provides a means for the clinician to characterize nutrition status at a single time point, aiding in the identification and diagnosis of malnutrition, and to monitor changes over time by providing real-time information on the adequacy of nutrition interventions. Objective body composition measurement tools are available clinically but are often underused in nutrition care, particularly in the United States. This is, in part, due to a number of factors concerning their use in a clinical context: cost and accessibility of equipment, as well as interpretability of the results. This article focuses on the factors influencing interpretation of results in a clinical setting. Body composition assessment, regardless of the method, is inherently limited by its indirect nature. Therefore, an understanding of the strengths and limitations of any method is essential for meaningful interpretation of its results. This review provides an overview of body composition technologies available clinically (computed tomography, dual-energy x-ray absorptiometry, bioimpedance, ultrasound) and discusses the strengths and limitations of each device.

show abstract

“…Comparison of precision errors of the body composition parameters between the two scan modes indicated increases in precision errors for most parameters with the thick scan mode. Elsewhere, there has only been one other previous study comparing the effects of prone and mid-prone hand positioning on total and regional body composition outcomes (17). The study was performed on a pencil beam GE-Lunar DPX densitometer using positioners at the hands and feet, and it was concluded that scanning subjects with the hands in the mid-prone position improves precision error for regional (arms and trunk) fat mass and BMC.…”

Section: Discussionmentioning

confidence: 99%

“…To our knowledge, only one study to date has investigated the effects of the two hand positioning protocols on DXA outcomes, using a pencil beam GE-Lunar DPX densitometer (17). It is important to ascertain any differences for all models of DXA and so that recommendations can be made for best practice.…”

mentioning

confidence: 99%

Effect of Hand Positioning on DXA Total and Regional Bone and Body Composition Parameters, Precision Error, and Least Significant Change

Thurlow

Oldroyd

Hind

2018

Journal of Clinical Densitometry

View full text Add to dashboard Cite

Effect of hand positioning on iDXA precision error for total and regional bone and body composition parameters. AbstractDual energy X-ray absorptiometry (DXA) body composition measurements are performed in both clinical and research settings for estimations of total and regional fat mass (FM), lean tissue mass (LM) and bone mineral content (BMC). Subject positioning influences precision and positioning instructions vary between manufacturers. The aim of the study was to determine the effect of hand position and scan mode on regional and total body bone and body composition parameters and determine protocol-specific body composition precision errors. Methods: Thirty eight healthy subjects (men; mean age: 27.1 ± 12.1 years) received four consecutive total body (TB) Lunar iDXA (enCORE v 15.0) scans with re-positioning, and scan mode was dependent on body size. Twenty three subjects received scans in standard mode and fifteen received scans in thick scan modes.Two scans per subject were conducted with subject hands prone and two with hands mid-prone.The precision error (RMS-SD; %CV) and least significant change (LSC) for each protocol were determined using the International Society for Clinical Densitometry calculator. Results: Hands placed in the mid-prone position increased arm BMD (standard mode: 0.185 g*cm-2, thick mode: 0.265 g*cm-2; p < 0.05), total body BMD (standard mode: 0.051 g*cm-2, thick mode: 0.069 g*cm-2; p < 0.001) and total body BMD Z-score (standard mode: 0.5. thick mode: 0.7; p < 0.001). This was due to reductions in bone area and BMC. In standard mode, hands mid-prone reduced fat mass (0.05 kg, p < 0.05) and increased lean mass (0.11 kg, p < 0.05). There were no differences in body composition for thick mode scans. Hands mid-prone reduced lean mass precision error at the arms, trunk and total body (p < 0.01). Conclusions: DXA clinical and research centres are advised to maintain consistency in their hand positioning and scan mode protocols, and consideration should be given to the hand positioning used for reference data. As a best practice recommendation, published DXA-based studies and reports for clinic-based total body assessments should ensure that subject positioning is fully described. 2Key words: DXA; precision error; measurement protocol; fat mass; lean mass; bone mineral content. IntroductionDual energy X-ray absorptiometry (DXA) is a non-invasive, rapid method of measuring three components of body composition: fat mass (FM), lean mass (LM) and bone mineral content (BMC), providing precise quantification at the total body and regional (left and right arms, legs and trunk) level. Over the last decade, there has been a rise in the use of DXA for the assessment of body composition in obesity (1), ageing (2) and in athletes (3-5), most likely reflecting increased availability, quicker scan acquisition times and improved resolution and image quality with fan beam densitometers. The low effective radiation dose of total body DXA, which is typically around 2-6 µSv depending on scan mode, means ...

show abstract

Reliability of 2 Different Positioning Protocols for Dual-Energy X-ray Absorptiometry Measurement of Body Composition in Healthy Adults

Cited by 34 publications

References 24 publications

Reliability and validity of various laboratory methods of body composition assessment in young adults

Reliability and validity of various laboratory methods of body composition assessment in young adults

The Use of Technology for Estimating Body Composition

Effect of Hand Positioning on DXA Total and Regional Bone and Body Composition Parameters, Precision Error, and Least Significant Change

Contact Info

Product

Resources

About