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Bioelectrical impedance analysis to estimate body composition, and change in adiposity, in overweight and obese adolescents: comparison with dual-energy x-ray absorptiometry.

Wan CS, Ward LC, Halim J, Gow ML, Ho M, Briody JN, Leung K, Cowell CT, Garnett SP - BMC Pediatr (2014)

Bottom Line: The Tanita BIA8 manufacturers equations significantly (P < 0.001) overestimated FFM (4.3 kg [-5.3 to 13.9]) and underestimated %BF (-5.0% [-15 to 5.0]) compared to DXA.The mean differences between BIA derived equations and DXA measured body composition parameters were small (0.4 to 2.1%), not significant, but had large limits of agreements (~ ±15% for FFM).After the intervention mean %BF loss was similar by both methods (~1.5%), but with wide limits of agreement.

View Article: PubMed Central - PubMed

Affiliation: Institute of Endocrinology & Diabetes, The Children's Hospital at Westmead, Locked Bag 4001, Westmead NSW2145, Australia. sarah.garnett@health.nsw.gov.au.

ABSTRACT

Background: There is a need for a practical, inexpensive method to assess body composition in obese adolescents. This study aimed to 1) compare body composition parameters estimated by a stand-on, multi-frequency bioelectrical impendence (BIA) device, using a) the manufacturers' equations, and b) published and derived equations with body composition measured by dual-energy x-ray absorptiometry (DXA) and 2) assess percentage body fat (%BF) change after a weight loss intervention.

Methods: Participants were 66 obese adolescents, mean age (SD) 12.9 (2.0) years. Body composition was measured by Tanita BIA MC-180MA (Tanita BIA8) and DXA (GE-Lunar Prodigy). BIA resistance and reactance data at frequencies of 5, 50, 250 and 500 kHz, were used in published equations, and to generate a new prediction equation for fat-free mass (FFM) using a split-sample method. Approximately half (n = 34) of the adolescents had their body composition measured by DXA and BIA on two occasions, three to nine months apart.

Results: The correlations between FFM (kg), fat mass (kg) and %BF measured by BIA and DXA were 0.92, 0.93 and 0.78, respectively. The Tanita BIA8 manufacturers equations significantly (P < 0.001) overestimated FFM (4.3 kg [-5.3 to 13.9]) and underestimated %BF (-5.0% [-15 to 5.0]) compared to DXA. The mean differences between BIA derived equations and DXA measured body composition parameters were small (0.4 to 2.1%), not significant, but had large limits of agreements (~ ±15% for FFM). After the intervention mean %BF loss was similar by both methods (~1.5%), but with wide limits of agreement.

Conclusion: The Tanita BIA8 could be a valuable clinical tool to measure body composition at the group level, but is inaccurate for the individual obese adolescent.

No MeSH data available.


Related in: MedlinePlus

Mean-vs-difference plots of body composition parameters determined by dual-energy x-ray absorptiometry (DXA), and in-built Tanita BIA8equations (n = 66). 1A Fat-free mass. 1B Fat mass. 1C Percentage of body fat. Key ○ Boys ● Girls. ……. Limits of agreement (±1.96 SD) (dotted). ―Bias (solid). ----Line of best fit (short dash).
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Fig1: Mean-vs-difference plots of body composition parameters determined by dual-energy x-ray absorptiometry (DXA), and in-built Tanita BIA8equations (n = 66). 1A Fat-free mass. 1B Fat mass. 1C Percentage of body fat. Key ○ Boys ● Girls. ……. Limits of agreement (±1.96 SD) (dotted). ―Bias (solid). ----Line of best fit (short dash).

Mentions: Figure 1 compares FFM, FM and %BF predicted by the in-built Tanita BIA8 equations and measured by DXA. The correlations (rp) between measures were 0.92, 0.93 and 0.78 for FFM, FM and %BF, respectively. However, the strength of agreement between pairs of measures was poor; concordance correlations (rc) for FFM, FM and %BF were 0.86, 0.87 and 0.65 respectively. The manufacturers’, in-built Tanita BIA8 equations significantly (P < 0.001) overestimated FFM (mean difference 4.3 kg) and underestimated FM and %BF (mean difference 5.0%) compared to DXA, with large 95% limits of agreement, for example -15.1 to 5.0 for %BF.Figure 1


Bioelectrical impedance analysis to estimate body composition, and change in adiposity, in overweight and obese adolescents: comparison with dual-energy x-ray absorptiometry.

Wan CS, Ward LC, Halim J, Gow ML, Ho M, Briody JN, Leung K, Cowell CT, Garnett SP - BMC Pediatr (2014)

Mean-vs-difference plots of body composition parameters determined by dual-energy x-ray absorptiometry (DXA), and in-built Tanita BIA8equations (n = 66). 1A Fat-free mass. 1B Fat mass. 1C Percentage of body fat. Key ○ Boys ● Girls. ……. Limits of agreement (±1.96 SD) (dotted). ―Bias (solid). ----Line of best fit (short dash).
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4288657&req=5

Fig1: Mean-vs-difference plots of body composition parameters determined by dual-energy x-ray absorptiometry (DXA), and in-built Tanita BIA8equations (n = 66). 1A Fat-free mass. 1B Fat mass. 1C Percentage of body fat. Key ○ Boys ● Girls. ……. Limits of agreement (±1.96 SD) (dotted). ―Bias (solid). ----Line of best fit (short dash).
Mentions: Figure 1 compares FFM, FM and %BF predicted by the in-built Tanita BIA8 equations and measured by DXA. The correlations (rp) between measures were 0.92, 0.93 and 0.78 for FFM, FM and %BF, respectively. However, the strength of agreement between pairs of measures was poor; concordance correlations (rc) for FFM, FM and %BF were 0.86, 0.87 and 0.65 respectively. The manufacturers’, in-built Tanita BIA8 equations significantly (P < 0.001) overestimated FFM (mean difference 4.3 kg) and underestimated FM and %BF (mean difference 5.0%) compared to DXA, with large 95% limits of agreement, for example -15.1 to 5.0 for %BF.Figure 1

Bottom Line: The Tanita BIA8 manufacturers equations significantly (P < 0.001) overestimated FFM (4.3 kg [-5.3 to 13.9]) and underestimated %BF (-5.0% [-15 to 5.0]) compared to DXA.The mean differences between BIA derived equations and DXA measured body composition parameters were small (0.4 to 2.1%), not significant, but had large limits of agreements (~ ±15% for FFM).After the intervention mean %BF loss was similar by both methods (~1.5%), but with wide limits of agreement.

View Article: PubMed Central - PubMed

Affiliation: Institute of Endocrinology & Diabetes, The Children's Hospital at Westmead, Locked Bag 4001, Westmead NSW2145, Australia. sarah.garnett@health.nsw.gov.au.

ABSTRACT

Background: There is a need for a practical, inexpensive method to assess body composition in obese adolescents. This study aimed to 1) compare body composition parameters estimated by a stand-on, multi-frequency bioelectrical impendence (BIA) device, using a) the manufacturers' equations, and b) published and derived equations with body composition measured by dual-energy x-ray absorptiometry (DXA) and 2) assess percentage body fat (%BF) change after a weight loss intervention.

Methods: Participants were 66 obese adolescents, mean age (SD) 12.9 (2.0) years. Body composition was measured by Tanita BIA MC-180MA (Tanita BIA8) and DXA (GE-Lunar Prodigy). BIA resistance and reactance data at frequencies of 5, 50, 250 and 500 kHz, were used in published equations, and to generate a new prediction equation for fat-free mass (FFM) using a split-sample method. Approximately half (n = 34) of the adolescents had their body composition measured by DXA and BIA on two occasions, three to nine months apart.

Results: The correlations between FFM (kg), fat mass (kg) and %BF measured by BIA and DXA were 0.92, 0.93 and 0.78, respectively. The Tanita BIA8 manufacturers equations significantly (P < 0.001) overestimated FFM (4.3 kg [-5.3 to 13.9]) and underestimated %BF (-5.0% [-15 to 5.0]) compared to DXA. The mean differences between BIA derived equations and DXA measured body composition parameters were small (0.4 to 2.1%), not significant, but had large limits of agreements (~ ±15% for FFM). After the intervention mean %BF loss was similar by both methods (~1.5%), but with wide limits of agreement.

Conclusion: The Tanita BIA8 could be a valuable clinical tool to measure body composition at the group level, but is inaccurate for the individual obese adolescent.

No MeSH data available.


Related in: MedlinePlus