Urvashi Mulasi, Levi Teigen, Carrie Earthman
Purpose: Loss of muscle mass is a key characteristic of malnutrition. Bioimpedance is an available technology capable of generating measures of lean tissue at the bed-side. We compared the utility of two different bioimpedance approaches, multiple-frequency bioelectrical impedance analysis (MF-BIA) and bioimpedance spectroscopy (BIS) in head and neck cancer (HNC) patients. Variables of interest were 50 kHz phase angle (PA), 200 kHz/5 kHz impedance ratio (IR), fat-free mass (FFM), total body water (TBW), extracellular water (ECW), and the ratio of ECW/TBW.
Methods: This prospective study included 19 outpatients scheduled to undergo treatment with chemoradiotherapy. Participants were seen at five time-points during and up to 3 months after treatment completion. Measurements were
taken at each of the time points using MF-BIA (QuadScan 4000) and BIS (MultiScan 5000) devices (Bodystat Ltd, Douglas, UK); device software was used to generate measures. Bland-Altman analysis was used to assess agreement between devices (Quadscan 4000 – Multiscan 5000). Data were analyzed using the SAS software, Version 9.4 (SAS Institute Inc., Cary, NC, USA).
Results: Eighteen males and one female were included; mean age was 59 ± 7 years, 79% percent (15/19) were diagnosed with stage IV cancer, and 21% (4/19) had stage III disease. No difference was observed for most variables (Table 1). Only TBW was found to differ between devices (Figure 1).
Conclusions: Our results indicate that the bioimpedance devices assessed in this study produced similar measures of lean tissue and could be used interchangeably within this clinical population to assess lean tissue loss. Additional research is warranted to further evaluate the comparability of these devices to monitor changes in lean tissue over time in larger samples that include reference measures of muscle loss.