Composición corporal en ni？os preescolares: comparación entre métodos antropométricos simples, bioimpedancia y absorciometría de doble haz de rayos X

objective. to examine the interrelationships of body composition variables derived from simple anthropometry, bioelectrical impedance (bia) and dualenergy 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 bf- 900) 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.