The validity of bioelectrical impedance phase angle for nutritional assessment in children

Background/Purpose: Bioelectrical impedance analysis (BIA) is a quick and n oninvasive method for estimating body composition. Many prediction equation s have been reported recently using bioelectrical impedance to calculate fa t free mass (FFM) and fat mass (FM). These equations are based on the assum ption that the composition and density of FFM are stable. In children, the composition and density of FFM vary according to age and clinical state, so the use of these equations is limited. However, phase angle is directly de termined from resistance (Rz) and reactance (Xc) without equations and refl ects body cell mass. The authors, therefore, investigated the validity of p hase angle for nutritional assessment in children. Methods: Bioelectrical impedance analysis and anthropometric measurements w ere performed in 81 patients, including 71 well-nourished and 10 malnourish ed children. Results: Phase angle correlated with body weight (R = 0.818) and arm muscle circumference (r = 0.901) in well-nourished children. Malnourished patient s showed lower phase angle than that of well-nourished children. Conclusion: Bioelectrical impedance phase angle is a useful parameter for n utritional assessment in children. Copyright (C) 2000 by W.B. Saunders Comp any.