Zubko Aleksandr Vladimirovich

Introduction. Bioelectrical impedance analysis (BIA) is an indirect method of body composition assessment. The equipment for BIA measurements is produced in many countries including Russia and may differ in electrical current frequencies, measurement schemes and built-in algorithms for the evaluation of body composition. In view of this, body composition estimates from various BIA instruments may be inconsistent which limits the ability to combine and generalize BIA data. Our purpose was to analyze the consistency and possibility of joint use of the BIA data obtained using the ABC-01 ‘Medas’ (SRC Medas, Moscow) and Diamant-AIST (LLC Diamant, St. Petersburg) instruments in adults.

Materials and methods. 185 adult volunteers (107 women and 78 men) aged 18 to 61 years were examined according to the standard anthropometric measurement protocol and on the basis of paired consecutive measurements with the bioimpedance body composition instruments ABC-01 ‘Medas’ and Diamant-AIST. The estimates of fat-free mass (FFM), body fat (BF) and percentage body fat (%BF) were compared. Mutual calibration of the bioimpedance data was carried out based on transformation of the Diamant-AIST data using a conversion formula between the ABC-01 ‘Medas’ and Diamant-AIST resistances and subsequent application the ABC-01 ‘Medas’ body composition assessment algorithm.

Results. There were significant differences in the median values of FFM, BF and %BF estimates provided by the ABC-01 ‘Medas’ and Diamant-AIST instruments. The FFM values in females using the ABC-01 ‘Medas’ instrument were significantly lower, and the BF and %BF were significantly higher as compared to the Diamant-AIST data. In males, the inverse relationship was observed while maintaining significant differences between the medians.

The differences in paired estimates of body composition data provided by the ABC-01 ‘Medas’ instrument and the transformed Diamant-AIST data in males and females, respectively, were statistically insignificant. Also, the confidence intervals for the differences of paired body composition estimates reduced essentially, but still not ensured good consistency of individual body composition data.

Conclusions. Significant differences in paired values of fat-free mass, fat mass and relative body fat using the ABC-01 ‘Medas’ and Diamant-AIST bioimpedance instruments are obtained. The possibility of mutual calibration and joint analysis of the related bioimpedance data at the group level is established. © 2023. This work is licensed under a CC BY 4.0 license.

Introduction. The differences between bioimpedance instruments, electrodes, measurement techniques, and data processing algorithms raise questions about the consistency of bioimpedance data and body composition estimates. This study aims to compare the results of measurements taken with various bioimpedance devices and electrode types, including those used in Russian health centers.

Material and methods. Bioimpedance measurements were conducted on 20 adult volunteers, 10 women and 10 men, aged between 21 and 54 years. Four instruments were used in the study: ABC-01 "Medas" (SRC Medas, Moscow), Diamant-AIST (Diamant LLC, St. Petersburg), the prototype bioimpedance analyzer as part of the "Zdorovye-Express" hardware and software system with EK6C-03-"CARDi2/4" cardio amplifier (Medical Computer Systems LLC, Moscow, Zelenograd) and Tanita MC-780MA (Tanita, Japan). Eight types of disposable electrodes were used with the ABC-01 "Medas" instrument: Ambu White Sensor 0415M (Ambu, Denmark), Bianostic AT (Data Input, Germany), Eurotrode PFR2034 (Pirrone srl, Italy), F9049 / RU2234 TAB (FIAB, Italy), Schiller Biotabs 23x34 mm (Schiller, Switzerland), Skintact RT-34 (Leonhard Lang GmbH, Austria), TopTrace MedTab (Ceracarta, Italy), and 2100 Swaro-tab (Tyrolmed, Austria). Two types of reusable electrodes, manufactured by Diamant LLC and Medical Computer Systems (MCS) LLC, were used with the Diamant-AIST and Zdorovye-Express instruments. Electric properties of the bioadhesive electrodes were assessed using a sandwich test. A comparison of the data obtained from volunteers using different bioimpedance instruments and electrodes was conducted using the Wilcoxon signed rank test for paired observations, as well as one-way analysis of variance, with a significance level set at p=0.05.

Results and discussion. Our study showed the presence of significant inter-instrument differences in bioelectrical parameters and body composition estimates. The maximum difference in the average value of fat-free mass and body fat between the ABC-01 "Medas", Diamant-AIST and Tanita MC-780MA instruments was 2.8 kg for men and 2.2 kg for women, whereas for the percentage body fat it was 3.9% for men and 3.7% for women. There were also significant deviations in body composition estimates obtained with the Zdorovye-Express analyzer compared to estimates from the other instruments. The BIA measurements data using the ABC-01 "Medas" instrument and the types of disposable bioadhesive electrodes commonly used in Russian Health Centers were in good agreement, despite the wide variation in electrical properties of the electrodes (their intrinsic impedance ranged from 96.8 ohm for 2100 Swaro-tab to 694.3 ohm for Eurotrode PFR2034). However, compared to the reference Bianostic AT electrodes, which had an intrinsic impedance of 18.9 ohm, the subgroups of women and men showed an average overestimation of 0.15 degrees in phase angle, while the subgroup of men also showed an overestimation in fat-free mass and an underestimation in fat mass, averaging between 0.3 and 0.4 kilograms. When comparing the reusable electrodes from Diamant LLC and MCS LLC, there were no significant differences in the bioelectrical parameters or body composition estimates in the study group.

Conclusion. To directly compare the results of measurements from different BIA instruments, their preliminary mutual calibration is necessary. The bioimpedance data obtained in Russian Health Centers using the ABC-01 "Medas" instrument and the specified types of disposable bioadhesive electrodes can be combined and analyzed together subject to the measurement procedure being followed. The reusable electrodes for bioimpedance measurements produced by Diamant LLC and Medical Computer Systems LLC are effectively interchangeable.

Funding. The study was performed at the Federal State Budgetary Institution "RIH" (“Russian research Institute of Health”) of the Ministry of Health of the Russian Federation within the framework of the Russian Science Foundation project No. 20-15-00386 (directed by V.I. Starodubov).

Acknowledgements. The study was conducted under the state assignment of Lomonosov Moscow State University (Godina E.Z., Zadorozhnaya L.V., Khomyakova I.A., Permiakova E.Yu.)The authors would like to thank the management and staff of Medical Computer Systems LLC (Zelenograd), and personally I.S. Reshetnikov and D.A. Prilutsky, for their help in organizing and conducting the study.