Accuracy of Bioelectrical Impedance Consumer Devices for Measurement of Body Composition in Comparison to Whole Body Magnetic Resonance Imaging and Dual X-Ray Absorptiometry

TLDR

The study compares body composition estimates from consumer BIA devices with MRI and DXA in healthy, overweight, and obese adults. In 106 adults, fat mass, skeletal muscle mass, lean mass, and visceral fat were measured by three foot‑to‑foot and one tetrapolar BIA devices and compared to MRI and DXA using Bland‑Altman and regression analyses. BIA measurements from two bipolar and one tetrapolar devices agreed well with MRI/DXA (r² = 0.92–0.96, bias < 1.5 % FM), whereas another bipolar device showed poorer agreement (r² = 0.82–0.84, bias ≈ 3 % FM); the tetrapolar device had the narrowest limits of agreement and no systematic bias, making it preferable for individual assessments, while bipolar devices are suitable for group studies.

Abstract

Objective: To compare body composition determined by bioelectrical impedance (BIA) consumer devices against criterion estimates determined by whole body magnetic resonance imaging (MRI) and dual energy X-ray absorptiometry (DXA) in healthy normal weight, overweight and obese adults. Methods: In 106 adults (54 females, 52 males, age 54.2 ± 16.1 years, BMI 25.8 ± 4.4 kg/m2) fat mass (FM), skeletal muscle mass (SM), total body bone-free lean mass (TBBLM), and level of visceral fat mass (VF) were estimated by 3 single-frequency bipedal (foot-to-foot) and one tretrapolar BIA device, and compared to body composition measured by MRI and DXA. Bland-Altman and simple linear regression analyses were used to determine agreement between methods. Results: %FMDXA, SMMRI or TBBLMDXA showed good relative and absolute agreement with two bipolar and one tetrapolar instrument (r2 = 0.92–0.96; all p < 0.001; mean bias <1.5 %FM and <1 kg SM or TBBLM) and less relative and absolute agreement for another bipolar device (r2 = 0.82 and 0.84, mean bias ∼3 %FM and ∼3 kg SM). The 95% limits of agreement (bias ± 2 SD) were narrowest for the tetrapolar device (–6.59 to 4.61 %FM and –4.62 to 4.74 kg SM) and widest for bipolar instruments (up to –14.54 to 8.58 %FM and –9.52 to 3.92 kg SM). Systematic biases for %FM were found for all bipedal devices, but not for the tetrapolar instrument. Conclusion: Because of the lower agreement between foot-to-foot BIA and DXA or MRI for the assessment of body composition in individuals, tetrapolar electrode arrangement should be preferred for individual or public use. Bipolar devices provide accurate results for field studies with group estimation.