Foot-to-foot bioelectrical impedance accurately tracks direction of adiposity change in overweight and obese 7- to 13-year-old children

Differences in air displacement plethysmography, bioelectrical impedance analysis and dual-energy X-ray absorptiometry for estimating body composition in Chinese children and adolescents

AIM

This study aimed to compare body composition (BC) measurements obtained by three widely used BC measuring methods, air displacement plethysmography (ADP), bioelectrical impedance analysis (BIA) and dual-energy X-ray absorptiometry (DXA), in Chinese children and adolescents by sex and different BMI categories.

METHODS

We used three BC measuring methods to evaluate healthy Chinese children and adolescents aged 5-17 years with BMI categories ranging from underweight to obese. Fat mass (FM, kg), fat mass percentage (FMP, %), fat-free mass (FFM, kg) and appendicular skeletal muscle mass (ASM, kg) were measured by DXA, BIA and ADP on the same day within 1 h.

RESULTS

A total of 172 Chinese children and adolescents were included in this study. The agreements for FM, FFM and ASM estimated by the three methods were excellent or good at the population level (intraclass correlation coefficient > 0.850, P < 0.05). However, ADP or BIA estimated lower body fat content and higher FFM than DXA (P < 0.001 for all). Moreover, the precise estimates significantly varied across BMI categories. In addition, the limit of agreements was wide, and the differences might not be clinically acceptable at the individual level.

CONCLUSIONS

Body fat and FFM obtained by the three commonly used methods were highly correlated, but systematically different and influenced by BMI. This study provided a basis for mutual reference of measurements between three widely used methods.

Body fat assessment in youth with overweight or obesity by an automated bioelectrical impedance analysis device, in comparison with the dual-energy x-ray absorptiometry: a cross sectional study

BACKGROUND

Bioelectrical impedance analysis (BIA) is a widely used method to assess total body fat (TBF) depots characterising obesity. Automated BIA devices provide an inexpensive and easy assessment of TBF, making them widely available to the general public and healthcare providers without specific qualification to assess body composition. The equations included in the automated BIA devices have been developed in very few specific populations, which means that they are not suitable to assess TBF for everyone and need to be validated before use in other populations. The aim of the present work is to evaluate the accuracy of the automated BIA device Tanita® BC-532 in youth of White European ethnicity, compared with the dual-energy x-ray absorptiometry (DEXA), gold standard measurement of TBF.

METHODS

Total body fat percentage (TBF%) was measured with the BIA device Tanita® BC-532 and DEXA (Hologic® QDR4500W) in 197 youth of White European ethnicity (N = 104 girls), 7-17 years old, and visiting the Diabetes & Endocrinology Care Paediatrics Clinic, Centre Hospitalier de Luxembourg, for overweight or obesity management.

RESULTS

TBF% evaluated with BIA was significantly correlated with TBF% measured with DEXA in both boys (r _Pearson = 0.617) and girls (r _Pearson = 0.648) (p <  10^- 4). However, the residual mean between the assessment of TBF% by BIA and by DEXA [TBF _BIA (%)-TBF _DEXA (%)] is extremely high (mean ± standard deviation = 10.52% ± 5.22% in boys, respectively 9.96% ± 4.40% in girls). The maximal absolute residual value is also very high, about 24% in both genders.

CONCLUSIONS

The automated BIA device Tanita® BC-532 appears to be not accurate to assess total body fat in youth with overweight or obesity. There is a need to calibrate the BIA device before its use in the populations where it was not previously validated.

NUTRITIONAL STATUS IN CHILDREN WITH CANCER: COMPARISON OF DEUTERIUM OXIDE DILUTION WITH BIOELECTRIC IMPEDANCE ANALYSIS AND ANTHROPOMETRY

Objective:

To explore changes in the nutritional status of pediatric cancer patients before and after chemotherapy and evaluate the correlation between deuterium oxide dilution, bioelectric impedance analysis, and anthropometry for assessment of body composition.

Methods:

This study included 14 children (aged 5.6 to 13.6 years) and classified them as having hematologic or solid tumors. They had their body composition analyzed according to deuterium oxide, bioelectric impedance, and anthropometric measurements before the first chemotherapy cycle and after three and six months of therapy.

Results:

The patients in the hematologic tumor group had an increase in weight, height, body mass index, waist, hip, and arm circumference, subscapular skinfold thickness, and fat mass with the isotope dilution technique during chemotherapy. In the solid tumor group, the children showed a reduction in fat-free mass when assessed by bioimpedance analysis. We found a positive correlation between the triceps skinfold thickness and fat mass determined by bioimpedance analysis and deuterium oxide. The arm muscle circumference correlated with the fat-free mass estimated by bioimpedance analysis and deuterium oxide.

Conclusions:

Patients with hematologic tumors had an increase in body weight, height, and fat mass, which was not identified in the solid tumor group. The positive correlation between anthropometry (triceps skinfold thickness and arm muscle circumference), deuterium oxide dilution, and bioelectric impedance analysis shows the applicability of anthropometry in clinical practice.

Assessment of body composition in pediatric overweight and obesity: A systematic review of the reliability and validity of common techniques

Accurate measurement of body composition is required to improve health outcomes in children and adolescents with overweight or obesity. This systematic review aimed to summarize the reliability and validity of field and laboratory body composition techniques employed in pediatric obesity studies to facilitate technique selection for research and clinical practice implementation. A systematic search in MEDLINE (via PubMed), EMBASE, CINAHL, and SPORTDiscus from inception up to December 2019 was conducted, using a combination of the following concepts: body composition, pediatric overweight/obesity, and reliability/validity. The search strategy resulted in 66 eligible articles reporting reliability (19.7%), agreement between body composition techniques cross sectionally (80.3%), and/or diagnostic test accuracy (10.6%) in children and adolescents with overweight or obesity (mean age range = 7.0-16.5 years). Skinfolds, air-displacement plethysmography (ADP), dual-energy X-ray absorptiometry (DXA), and ultrasound presented as reliable techniques. DXA, ADP, and isotope dilution showed similar and the best agreement with reference standards. Compared with these laboratory techniques, the validity of estimating body composition by anthropometric equations, skinfolds, and BIA was inferior. In conclusion, the assessment of body composition by laboratory techniques cannot be replaced by field techniques due to introduction of measurement errors, which potentially conceal actual changes in body components.

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

OBJECTIVE

This study aimed to 1) analyze the criterion validity of the Slaughter equations (Slg-Eq) and bioelectrical impedance analysis (BIA) to estimate body fat percentage (BFP) and fat mass index (FMI) at different degrees of obesity in children compared with dual-energy x-ray absorptiometry (DXA) and 2) determine their agreement over time.

METHODS

Ninety-two children with overweight or obesity (10.0 [SD 1.2] years; 34.8% girls) participated in this 20-week study. Anthropometric, BIA, and DXA measurements were performed.

RESULTS

Both Slg-Eq and BIA methods underestimated BFP and FMI against DXA, and the bias was markedly larger with BIA (mean absolute percentage error = 11% for Slg-Eq vs. 18%-21% for BIA); a larger underestimation was observed in girls compared with boys for Slg-Eq (P ≤ 0.001), and the observed underestimation in adiposity was reduced as weight status increased. Systematic errors were kept constant over time, so no large differences between methods were observed in the change in adiposity.

CONCLUSIONS

At the group level, Slg-Eq provides a more valid estimation of BFP and FMI than BIA. At the individual level, Slg-Eq shows larger estimation errors. The validity of these methods might differ in sex and weight status. Nevertheless, both methods seem to be valid for monitoring changes in adiposity.

Percentage of free fat mass is associated with elevated blood pressure in healthy Chinese children

Previous studies have reported that a high free fat mass (FFM) was associated with elevated blood pressure in children. However, the observed relationship could be confounded by body weight. Thus, we performed cross-sectional analyses to understand the differences between the percentage of free fat mass (FFM%) and FFM in relation to blood pressure in healthy Chinese children. A total number of 2671 (1264 girls; aged 6-14 years) healthy Chinese children was recruited in 2014 (baseline). We further prospectively examined whether these indices predicted hypertension risk during the 2 years of follow-up (2014-2016) among 2094 participants who were free of hypertension at the baseline. Blood pressure was repeatedly measured in 2014, 2015 and 2016. Hypertension was defined as either high systolic blood pressure and/or high diastolic blood pressure (≥age- and sex-specific 95^th percentile for Chinese children). The baseline FFM was assessed by bio-impedance analysis, and FFM% was calculated as FFM divided by the body weight. A high FFM was associated with a high baseline blood pressure and high hypertension risk after adjustment for potential confounders (all p < 0.001). By contrast, a high FFM% was associated with a low baseline blood pressure and low hypertension risk in the fully adjusted model (all p < 0.001). Each one-percent increment of FFM% was associated with a 9% lower risk of developing hypertension (adjusted hazard ratio = 0.91; 95% confidence interval: 0.89, 0.94). A high FFM% was associated with a low blood pressure and low hypertension risk in healthy Chinese children.

Snack cost and percentage of body fat in Chinese children and adolescents: a longitudinal study

PURPOSE

Only a few studies examined the relationship between snack cost and change in the percentage of body fat in children. We thus conducted a longitudinal study to investigate whether high snack cost is associated with fast increase in the percentage of body fat in Chinese children.

METHODS

The study included 2368 children (1126 girls and 1242 boys, aged 6-14 years). Percentage of body fat was repeatedly assessed by bioelectrical impedance analysis in 2014 (baseline), 2015 and 2016. Snack cost in 2014 was estimated by self-report associated with purchasing snacks at school and classified into low, moderate, and high group. Association between snack cost and repeated percentage of body fat was analyzed with linear mixed models, adjusting for demographic factors, diet, physical activity, and parental BMI and education.

RESULTS

High snack cost was significantly associated with a fast increase in the percentage of body fat over time (p trend = 0.04). Adjusted difference in annual increase rate in percentage of body fat between the high and low snack cost group was 0.31% [95% confident interval (CI) 0.04%, 0.58%], after adjusting for potential confounders. The impacts of snack cost on change in the percentage of body fat were more pronounced in boys, younger participants and those with higher BMI z-score at the baseline, relative to their counterparts (p interaction < 0.001 for all).

CONCLUSIONS

High snack cost was associated with more gain of body fat in Chinese school-aged children.

Handgrip strength cutoff for cardiometabolic risk index among Colombian children and adolescents: The FUPRECOL Study

Evidence shows an association between muscular strength (MS) and health among young people, however low muscular strength cut points for the detection of high metabolic risk in Latin-American populations are scarce. The aim of this study was twofold: to explore potential age- and sex-specific thresholds of MS, for optimal cardiometabolic risk categorization among Colombian children and adolescents; and to investigate whether cardiometabolic risk differed by MS group by applying the receiver operating characteristic curve (ROC) cut point. MS was estimated by using a handle dynamometer on 1,950 children and adolescents from Colombia, using MS relative to weight (handgrip strength/body mass). A metabolic risk score was computed from the following components: waist circumference, triglycerides, HDL-c, glucose, and systolic and diastolic blood pressure. ROC analysis showed a significant discriminatory accuracy of MS in identifying the low/high metabolic risk in children and adolescents and in both genders. In children, the handgrip strength/body mass levels for a low metabolic risk were 0.359 and 0.376 in girls and boys, respectively. In adolescents, these points were 0.440 and 0.447 in girls and boys, respectively. In conclusion, the results suggest an MS level relative to weight for having a low metabolic risk, which could be used to identify youths at risk.

Comparison between two methods of bioelectrical impedance analyses for accuracy in measuring abdominal visceral fat area

OBJECTIVES

To compare the accuracy of abdominal visceral fat area (VFA) measurements between abdominal dual bioelectrical impedance analysis (BIA) and whole-body BIA referenced to computed tomography (CT) measures.

METHODS

Abdominal VFAs were measured in 102 individuals: 59 men and 43 women with a mean age of 44.2 ± 16.3 years (range 21 - 76), body mass index 23.9 ± 7.8 kg/m(2) (range 18 - 35) using a DUALSCAN HDS-2000 machine (dual abdominal BIA) and an InBody720 machine (whole-body BIA). The VFA values from each machine were compared with those from CT under various conditions.

RESULTS

Mean abdominal VFAs were 116 ± 69 cm(2) by CT, 89 ± 47 cm(2) by dual abdominal BIA, and 84 ± 33 cm(2) by whole-body BIA. The former measure showed a higher correlation with the CT measure than the latter (r=0.89 vs. r=0.64, P<0.001). Both BIA methods tended to underestimate abdominal VFAs compared with CT scans when CT VFA was not small. The dual abdominal BIA had less bias than the whole-body BIA in the assessment of VFAs. The whole-body BIA was affected by subcutaneous fat area.

CONCLUSIONS

Dual BIA was more accurate in assessing abdominal VFA than whole-body BIA.