Body Composition By Simple Anthropometry, Bioimpedance And Dxa In Preschool Children: Interrelationships Among Methods

Objective. To examine the interrelationships of body composition variables derived from simple anthropometry, bioelectrical impedance (BIA) and dual-energy X-ray absorptiometry (DXA).Population, material and methods. A total of 230 healthy preschool children (118 males and 112 females) age 4-6 years, attending a day care center, were examined to determine body mass index (BMI) and waist circumference (WC). Percentage of body fat content (% BF) was predicted by BIA (Maltron BF900) and DXA (Lunar DPX-L, pediatric software).Results. BMI and WC did not show significant differences among sex, while % BF by BIA or DXA did. BIA measures were lower than DXA's (p < 0.0001). Correlation between BIA vs. anthropometric methods and WC vs. DXA were moderate (Pearson r= 0.43 to 0.53), whereas the other correlations were strong (r= 0.71 to 0.83). However Bland Altman comparison showed wide limits of agreement between BIA and DXA; BIA significantly underestimated % BF as determined by DXA (p < 0.0001).Conclusion. The methods used to estimate body composition in healthy preschool children highly correlated. However, the Bland Altman procedure suggests that BIA and DXA should not be used interchangeably.