Validation of body composition using bioelectrical impedance analysis in children according to the degree of obesity

Abstract

This study aimed to validate body composition analysis using bioelectrical impedance analysis (BIA) against dual-energy X-ray absorptiometry (DXA) in children with obesity and to compare agreement between BIA and DXA according to their degree of obesity. Three hundred and sixteen children aged 6-17 years participated in the Intervention for Childhood and Adolescents Obesity via Activity and Nutrition study. We divided participants by body mass index (BMI) percentile (group 1: mild to moderate obesity; group 2: severe obesity) and compared body composition variables, eg, percentage of body fat (%BF), fat mass (FM), and fat-free mass (FFM) using BIA and DXA. The %BF and FM of BIA were significantly lower (-1.8% and -0.8 kg, respectively), and the FFM of BIA was significantly higher (1.4 kg) than those of DXA. There were significant negative relationships between the absolute value of differences from BIA and DXA and BMI z-scores in %BF, FM, and FFM (regression coefficient [β]: -1.39, 95% confidence interval [CI]: -1.81 to -0.97; β: -0.34, 95%CI: -0.61 to -0.06; β: -0.73, 95%CI: -1.03 to -0.44, respectively). The gap of body compositions between BIA and DXA decreased as participants became more obese, and the differences of FM in boys with severe obesity and the differences of %BF and FFM in girls with severe obesity were much less than those in children with mild to moderate obesity. In conclusion, the agreement between DXA and BIA was better for children with severe obesity than for children with mild to moderate obesity.

Validity of Slaughter Equations and Bioelectrical Impedance Against Dual‐Energy X‐Ray Absorptiometry in Children

“…In our study, the biases of Slg‐Eq and BIA compared with DXA were lower as the adiposity levels increased, especially when Slg‐Eq was used. In line with our findings, the study of Seo et al found better agreement between BIA and DXA in the group of children and adolescents with severe obesity than the group with mild to moderate obesity. Opposite findings were found by Freedman et al in children and adolescents aged 5 to 18 years, ranked by the sum of SKF and classified in four sum categories according to the 33rd, 67th, and 90th percentiles within each sex.…”

“…In this regard, the available information has been scarce. Three studies have compared BIA with DXA in children and/or adolescents with obesity , and one study compared Slg‐Eq with DXA . 2) Although it has been widely used, BFP has not been suggested as a good measure for overall adiposity and to predict health‐related outcomes .…”

New bioelectrical impedance analysis equations for children and adolescents based on the deuterium dilution technique

“…Although no proportional bias was detected in the whole dataset, we observed marginally increased absolute bias within each subgroup, possibly due to fewer measurements and high leverage points of samples at low and high BMIZ (Table 4). Seo et al [44] performed validation of BIA versus DXA in children according to the degree of obesity and found better agreement between DXA and BIA for children with severe obesity than for children with mild to moderate obesity. Conversely, other studies suggested that bias is proportional to the level of body fat as either the adipose tissue or the high relative amount of extracellular water for overweight and TBW (kg) ¼ 0.44 RI (cm 2 /U) þ 0.12 weight (kg) þ 0.33 sex (male ¼ 1, female…”

Differences in total and truncal body fat mass in children using DXA and BIA method – multifactorial regression model

“…However, one must note that results of studies comparing the BIA method with DXA indicate that BIA in slim subjects will tend to overestimate body fatty tissue, while in overweight subject, the fatty tissue contents will be underestimated as compared with densitometry [6,17,18]. Studies conducted by Sluytera, Wan, Seo, and ourselves indicate that the rate of underestimation of body fatty tissue content, determined using the BIA method, as compared with DXA, increased with the increased fatty tissue contents [18][19][20][21]. Such results were observed in both children and adults.…”