Comparison of Body Composition Assessment Methods in Pediatric Intestinal Failure

Abstract

Objectives To examine the agreement of multifrequency bioelectric impedance analysis (BIA) and anthropometry with reference methods for body composition assessment in children with intestinal failure (IF). Methods We conducted a prospective pilot study in children 14 years of age or younger with IF resulting from either short bowel syndrome (SBS) or motility disorders. Bland Altman analysis was used to examine the agreement between BIA and deuterium dilution in measuring total body water (TBW) and lean body mass (LBM); and between BIA and dual X-ray absorptiometry (DXA) techniques in measuring LBM and FM. Fat mass (FM) and percent body fat (%BF) measurements by BIA and anthropometry, were also compared in relation to those measured by deuterium dilution. Results Fifteen children with IF, median (IQR) age 7.2 (5.0, 10.0) years, 10 (67%) male, were studied. BIA and deuterium dilution were in good agreement with a mean bias (limits of agreement) of 0.9 (-3.2, 5.0) for TBW (L) and 0.1 (-5.4 to 5.6) for LBM (kg) measurements. The mean bias (limits) for FM (kg) and %BF measurements were 0.4 (-3.8, 4.6) kg and 1.7 (-16.9, 20.3)% respectively. The limits of agreement were within 1 SD of the mean bias in 12/14 (86%) subjects for TBW and LBM, and in 11/14 (79%) for FM and %BF measurements. Mean bias (limits) for LBM (kg) and FM (kg) between BIA and DXA were 1.6 (-3.0 to 6.3) kg and -0.1 (-3.2 to 3.1) kg, respectively. Mean bias (limits) for FM (kg) and %BF between anthropometry and deuterium dilution were 0.2 (-4.2, 4.6) and -0.2 (-19.5 to 19.1), respectively. The limits of agreement were within 1 SD of the mean bias in 10/14 (71%) subjects. Conclusions In children with intestinal failure, TBW and LBM measurements by multifrequency BIA method were in agreement with isotope dilution and DXA methods, with small mean bias. In comparison to deuterium dilution, BIA was comparable to anthropometry for FM and %BF assessments with small mean bias. However, the limits of agreement were wide and clinically unacceptable for some patients. BIA is a reliable method for TBW and LBM assessments in population studies. However, its reliability in individual patients, especially for FM assessments, cannot be guaranteed.

Metabolic Assessment and Individualized Nutrition in Children Dependent on Mechanical Ventilation at Home

“…16,39 BIA is a practical alternative for body composition determination, and its accuracy has been reported in comparison with DXA and isotope dilution methods in different cohorts of children. 17,33,38 In our current study, there was no agreement between BIA and anthropometry for body composition assessments. The optimal bedside method for body composition assessment in this cohort remains elusive but is a priority in the setting of inadequate nutrition and unintended underfeeding and overfeeding.…”

“…33 We recently reported greater fat mass % in a cohort of children with intestinal failure as well. 17 It is plausible that a simultaneous increase in fat mass could mask underlying loss of skeletal muscle mass with a falsely reassuring weight stability or weight gain in some cases. The impact of undernutrition, in particular, and altered body composition on clinical and functional outcomes is likely significant in children on long-term ventilatory support.…”

“…Details of the BIA method have been previously described. 17 In brief, currentinjector and detector electrodes were placed on the right upper and lower extremities per manufacturer's instructions. The procedure was completed with the patients in a resting, supine position.…”

Impact of Individualized Diet Intervention on Body Composition and Respiratory Variables in Children With Respiratory Insufficiency

“…BIA procedures have been previously described. [1, 15] Using the principle of differential electrical conduction through body tissues, BIA calculates total body water from measured impedance values to 4 current frequencies flowing through the body. Current injector electrodes are placed on upper and lower extremities for this test.…”

Resonant cavity perturbation: a promising new method for the assessment of total body water in children

“…With paediatric care in particular, determining an accurate and timely measurement of whole body fluid volumes in patients can be problematic. Existing body water assessment methods in children include isotope dilution, equations based on anthropometry and single frequency (50KHz) bioimpedance (SF-BIA) (Horlick et al 2002) -multi-frequency bioelectrical impedance (MFBIA) at 5,50,100 and 200KHz (Mehta et al 2014) -multi-frequency (50 frequencies from 5KHz to 1MHz) bio-impedance spectroscopy (MFBIS) (Scharfetter et al 1997, Zhu et al 2006. TBW has been measured isotopically using dilution measurements of deuterium oxide (TBW dil ).…”