Phase Angle Reference Values Measured Using InBody770 in Japanese Individuals With Normal Fluid Balance

Area of Science:

• Body Composition Analysis
• Physiological Reference Values
• Bioelectrical Impedance Analysis

Background:

• Phase angle (PhA) is a marker of cell integrity and nutritional status.
• Establishing population-specific reference values is essential for accurate interpretation.
• InBody770 is a widely used bioelectrical impedance analysis device.

Purpose of the Study:

• To present reference values for phase angle (PhA) in Japanese individuals using the InBody770.
• To define reference values for individuals with normal fluid balance (ECW/TBW ratio <0.4).
• To provide a basis for standardized PhA (SPA) calculations in Asian populations.

Main Methods:

• Retrospective analysis of 2,562 Japanese individuals (aged 10-99 years) using InBody770 data.
• Exclusion criteria included impedance errors, multiple records, BMI ≥40.0, and ECW/TBW ratio ≥0.4.
• Data analyzed included age, sex, BMI, and whole-body PhA.

Main Results:

• Established PhA reference values stratified by age, sex, and BMI.
• PhA generally decreased with age.
• PhA was higher in men and individuals with higher BMI (overall mean: 5.4° in men, 4.7° in women).

Conclusions:

• The established PhA reference values provide a benchmark for Japanese populations.
• These values can aid in the interpretation of body composition assessments.
• The findings support further research and the calculation of standardized PhA (SPA) in Asian populations.