Changes in the electrical properties of the tissues in patients with anorexia nervosa measured by bioelectrical impedance analysis

Abstract

Introduction

Monitoring patient with anorexia nervosa (AN) include clinical, biological and psychological factors. In recent years many researchers criticize the BMI as useful measure for controlling evolution of AN.

Objectives

Bioelectrical impedance analysis (BIA) is one of the main methods for nutritional status assessment.

Aims

The aim of this study was the assessment of the nutrition status in a group of patients with anorexia nervosa in comparison to healthy population (HP).

Methods

The study involved 37 participants: 21 patients with AN and 16 healthy volunteers constituting the control group (HP). The patients were divided into two groups according a BMI: I group 14 < BMI < 15,5 (n = 11; age 18.0 ± 4.37) and II group: 15,5 < BMI < 17,5 (n = 10; age 17.82 ± 3.68). The mean age of HP was 17.68 ± 1.57 and BMI 20.56 ± 1.16 kg/m². BIA was performed by using ImpediMed bioimpedance analysis SFB7 BioImp. The parameters: phase angle (PA), TBW%, ECW, ICW, ECW/ICW were analyzed.

Results

PA was decreased significantly in the I (4.5°±0,6) and II group (4.7°±0,6) of AN patients’ in comparison with HP (5.6°±0,7). TBW was 9% higher in I group and ECW was increased 6% in the both AN groups compared with HP (P < 0.01). Additionally ECW/ICW ratio indicated the higher transfer of water into the extracellular compartment in AN group (P < 0.01).

Conclusions

BIA is accurate tool to indicate the valuable indicators of detecting malnutrition in AN. Further studies are needed to validate the significance of these parameters for the full identification of the nutrition status of AN patients’.

Disclosure of interest

The authors have not supplied their declaration of competing interest.