The use of phase angle in patients with digestive and liver diseases.

Diseases of the liver and the digestive system can lead to malnutrition through an action of reduced food intake or nutrient use, inflammation and impaired metabolism, which result in substantial changes in body composition. Frequently, malnutrition manifests itself with weight loss and reduced muscle mass. However, weight loss and body mass index lack sensitivity to detect the loss of muscle mass and are not informative in distinguishing body water compartments and in characterizing their distribution. This issue is particularly relevant to these two disease models, which are frequently associated with fluid volume imbalances. Phase angle is a useful indicator for cell membrane integrity, water distribution between the intracellular and extracellular spaces and prediction of body cell mass as it is described by measured components of electrical impedance. Malnutrition, inflammation and oxidative stress impair electric tissue properties leading to lower values of PhA. In patients with inflammatory bowel and liver diseases, PhA was consistently found to be related to nutritional status and body composition, particularly the depletion of lean body mass and sarcopenia. It has been associated with prognosis, disease stage and severity and found to be helpful in monitoring fluid shifts and response to interventions.