Phase angle: medical interpretations and applications

Abstract

Specialists are interested in using bioimpedance technology to assess the rate of metabolic processes and body composition; thus, this study aimed to determine the possibilities of the clinical application of the phase angle, which is a parameter that is specific for the bioimpedance method to obtain body composition information. In nutrition assessment, the phase angle is used as an indirect characteristic of the protein fraction of the body and the rate of metabolic processes.

In the early 2000s, low values of the phase angle in diseased catabolic orientation were shown to assess the survival rate whereas high values assess the muscular system fitness in athletes and other individuals who regularly experience physical exertion. Systematic reviews and Meta-analyzes of subsequent years have summarized the evidence based on these provisions and identified several new applications for sarcopenia, anorexia, and renal failure. Therefore, all the reviews presented in this study confirm that higher phase angle values correspond to a better state of the body and that phase angle can dynamically change in an individual patient. This feature of the parameter requires a detailed understanding of the variability of values depending on measurement conditions.

The phase angle is recognized as a convenient diagnostic tool and a convenient parameter for screening examinations. At high values, it reflects the degree of muscular system fitness, and at low values, the severity of catabolic disorders due to existing diseases or immobilization.

Keywords

phase angle / electric impedance / body composition

RIGHTS & PERMISSIONS

Nikolaev D.V., Shchelykalina S.P.