Lack of clinical Interchangeability between electrical impedance myography and multifrequency bioimpedance: Functional and physiological validation in young adults
Abstract
Body composition is a fundamental health marker that distinguishes fat mass from lean mass.
Objective
To determine the agreement between electrical impedance myography (EIM) and multifrequency bioelectrical impedance analysis (BIA) for body fat estimation, and to assess how muscle quality markers correlate with functional strength.
Materials and Methods
An observational, cross-sectional study evaluated 53 university students. Body fat percentage (BF%), muscle mass, phase angle, and active cell mass were measured via BIA (Biody Expert ZM II). Segmental BF% and muscle quality (MQ) were assessed via EIM (Skulpt AIM). Functional strength was measured by dynamometry. Statistical analysis utilized Spearman’s correlation and Bland-Altman agreement.
Results
EIM reports higher values for BF% by 3.65% compared to BIA, exhibiting wide limits of agreement (−5.20% to 12.51%). Functional grip strength showed strong positive correlations with BIA-derived muscle mass p= 0.821, p < 0.001) and active cell mass (p= 0.804, p < 0.001). Conversely, the EIM-derived MQ index showed no significant correlation with strength (p = 0.745).
Conclusions
EIM reports higher body fat values compared to BIA and lacks clinical interchangeability due to individual variability. BIA compartments strongly predict functional muscle strength, whereas proprietary EIM quality indices do not.
© 2026 Ma. Fidelina Peñaloza-Talavera, Mariana Toledo Dambrós, Clara H. Gonzalez-Correa, Jhony A. Diaz-Vallejo, Aida María González-Correa, published by University of Oslo
This work is licensed under the Creative Commons Attribution 4.0 License.