Background/Objectives: Body composition measurements derived from bioelectrical impedance analysis (BIA) are known to be affected by several variables, implying the need for standardization. The main aim of this study was to evaluate the impact of plantar callosities, arm posture, and the use of electrolyte wipes on the body composition measurements by BIA in morbidly obese adults. For validity purposes, body composition measurements from BIA were compared with those obtained from air displacement plethysmography (ADP).
Subjects/Methods: Thirty-six morbidly obese patients (13 males, 23 females, aged 28-70 years, BMI 41.6 ± 4.3 kg/m2) with moderate to severe plantar callosities were recruited for this study. Body composition was measured at a fasted state using multi-frequency BIA (InBody 720, Biospace, Korea), before and after removal of plantar callosities (pedicure), with and without InBody electrolyte wipes and with and without custom-built axillary pads. Body composition was also assessed using ADP (BodPod, Cosmed, Italy).
Results: Percentage of body fat (%BF) was found to be significantly higher with axillary pads than without (1.04± 0.87%, p<0.001). No statistically significant differences were found in %BF pre to post pedicure, and with versus without usage of electrolyte wipes. There was also no statistically significant difference in %BF between BIA and ADP.
Conclusion: Multiple-frequency BIA (InBody 720) is a valid method for estimating %BF in morbidly obese adults. Arm posture appears to have a significant impact on %BF as assessed by BIA, as opposed to the presence of plantar callosities and usage of InBody electrolyte wipes. For clinical and scientific purposes, standardization of arm posture during BIA for body composition assessment is, therefore, recommended.
Keywords: bioelectrical impedance analysis; body composition; morbid obesity; callosities; arm posture; electrolyte wipes