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Air-displacement plethysmography pediatric option in 2-6 years old using the four-compartment model as a criterion
David A Fields1, David B Allison
1Department of Pediatrics, Section of Endocrinology and Diabetes, and Children's Hospital Foundation, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA. dfields@ouhsc.edu
Insights
Air-displacement plethysmography (ADP) with a pediatric option accurately measures body fat percentage in young children. This method is precise, reliable, and unbiased when compared to a criterion four-compartment model.
Area of Science:
- Pediatric Body Composition Analysis
- Human Physiology
- Biomedical Engineering
Background:
- Accurate body fat measurement is crucial for assessing pediatric health.
- Traditional methods may be less suitable for young children.
- Air-displacement plethysmography (ADP) offers a non-invasive approach.
Purpose of the Study:
- To evaluate the accuracy, precision, bias, and reliability of ADP with a pediatric option.
- To compare ADP-derived body fat percentage (%fat) against a four-compartment (4C) model criterion.
- To validate ADP for use in children aged 2-6 years.
Main Methods:
- Thirty-one children (4.1 ± 1.2 years) participated.
- Body fat % was measured using ADP (BOD POD) with a pediatric option.
- Criterion measures included total body water (isotope dilution) and bone mineral (DXA).
- The Lohman 4C model served as the criterion standard.
Main Results:
- ADP demonstrated strong agreement with the 4C model (regression: y = 0.849x + 4.291).
- ADP explained 75.2% of the variance in %fat, with a SEE of 2.09 %fat.
- Bland-Altman analysis revealed no significant bias across the range of fatness (r = 0.04, P = 0.81).
- High reliability was confirmed (CV = 3.5%, within-subject SD = 0.9%, Cronbach's α = 0.95).
Conclusions:
- ADP with the pediatric option is an accurate and reliable method for estimating %fat in children aged 2-6 years.
- The system provides precise measurements without significant bias.
- ADP is a valid tool for pediatric body composition assessment.
Abstract:
The objective of this study was to determine the accuracy, precision, bias, and reliability of percent fat (%fat) determined by air-displacement plethysmography (ADP) with the pediatric option against the four-compartment model in 31 children (4.1 ± 1.2 years, 103.3 ± 10.2 cm, 17.5 ± 3.4 kg). %Fat was determined by (BOD POD Body Composition System; COSMED USA, Concord, CA) with the pediatric option. Total body water (TBW) was determined by isotope dilution ((2)H(2)O; 0.2 g/kg) while bone mineral was determined by dual-energy X-ray absorptiometry (DXA) (Lunar iDXA v13.31; GE, Fairfield, CT and analyzed using enCore 2010 software). The four-compartment model by Lohman was used as the criterion measure of %fat. The regression for %fat by ADP vs. %fat by the four-compartment model did not deviate from the line of identity where: y = 0.849(x) + 4.291. ADP explained 75.2% of the variance in %fat by the four-compartment model while the standard error of the estimate (SEE) was 2.09 %fat. The Bland-Altman analysis showed %fat by ADP did not exhibit any bias across the range of fatness (r = 0.04; P = 0.81). The reliability of ADP was assessed by the coefficient of variation (CV), within-subject SD, and Cronbach's α. The CV was 3.5%, within-subject SD was 0.9%, and Cronbach's α was 0.95. In conclusion, ADP with the pediatric option is accurate, precise, reliable, and without bias in estimating %fat in children 2-6 years old.
