Changes in body composition in adolescents with anorexia nervosa. Comparison of bioelectrical impedance analysis and total body potassium.

Abstract

Introduction: Patients with anorexia nervosa (AN) have low body weight, depleted fat stores, and reduced muscle mass. Both total body potassium (TBK) and bioelectrical impedance analysis (BIA) have been used to measure the body composition of these patients. Whereas TBK accurately measures body cell mass, the metabolically active compartment of the body, whole body potassium counters are expensive and not readily available. The purpose of this study was to investigate the potential of multiple frequency BIA (MFBIA) to monitor changes in body compartments in patients with AN. Conclusion: These results confirm the tenets of the physiology of malnutrition, where both intracellular potassium and water are in a state of flux, with correlations between changes in TBK and intracellular water volumes but not between changes in TBK and extracellular water volumes. MFBIA may be a valuable tool for monitoring changes in body compartments during the treatment of anorexia nervosa.