Association between raw bioelectrical impedance parameters and muscle mass and strength measured by DXA and dynamometry in older adults: a pilot study

Abstract

Sarcopenia is a disease affecting muscle strength, muscle quantity/quality, and physical performance. Since the bioelectrical impedance analysis (BIA) is accessible in the clinical practice, its use may be helpful to estimate, from its BIA parameters [resistance (R/H), reactance (Xc/H), and phase angle (PA)], the components for sarcopenia diagnosis, muscle mass, and strength. We aimed to investigate the association between BIA parameters and measures of muscle mass and strength. A cross-sectional analysis was performed in 51 older adults assessed for the sarcopenia outcomes [Appendicular Skeletal Muscle Mass Index (ASMMI) from DXA and Handgrip Strength (HGS) from dynamometry] and predictors [BIA parameters (R/H, Xc/H, and phase angle)], anthropometric measures, physical activity, and demographic data (age and sex). Sarcopenia was classified according to the EWGSOP2. Association between the outcomes and predictors was analysed by correlation tests and linear regression models, adjusted by sex and age. A total of 17.65% of participants were classified with probable sarcopenia and 9.8% were diagnosed for sarcopenia. Significant negative correlations were found between ASMMI and HGS and R/H and Xc/H, in all participants. Regression models detected statistically significant association between ASMMI and R/H (B = −0.013, p <0.001) and Xc/H (B= −0.08, p= <0.01), adjusted for age and sex. We found significant associations between BIA raw parameters (R/H and Xc/H) and muscle mass assessed by ASMMI. More robust studies are necessary to determine the efficacy of raw BIA parameters to predict sarcopenia in older adults through predictive equations.