Rudnev Sergey Gennad'evich

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. Due to the wide variety of ethnogeographic features and ecological niches, environmental differences as well as changes in living conditions, the study of the morphological status of indigenous populations of Russia retains its significance. Our aim was to study the somatic status and BIA body composition of young women of Altai and Russian ethnicities aged 17-23 years living in urban and rural areas of the Altai Republic.

Materials and methods. In 2021–2023, 230 young women aged 17 to 23 years (117 Altai-Kizhi and 113 Russians) living in urban and rural areas were examined. The examination program included anthropometry, the Heath-Carter somatotyping, and BIA. Ethnic differences and city-village differences were assessed using parametric and non-parametric methods.

Results. Ethnically Russian women were, in general, somewhat larger than Altai women, significant differences were found for height (Ht), weight (Wt), waist circumference (WC) and waist-to-hip ratio (WHR). Significant differences were also observed for the resistance R50, phase angle and fat-free mass (FFM) values. The somatotype distributions by enlarged classes were close with a predominance of mesomorphic and endomorphic types. When testing for city-village differences in ethnic subgroups, the total body dimensions (Wt, Ht, chest circumference), as well as WC, hip circumference (HC) and body mass index were slightly higher in urban residents (not significant differences). The urban Altai women had a statistically significantly higher endomorphy rating with a noticeable increase in fat mass (FM), %FM and fat mass index. Ethnic differences were more pronounced in rural (Ht, Wt, HC, WHR, R50, phase angle, FFM and fat-free mass index were significantly different) than in urban residents (significant differences only for Ht and FFM).

Conclusions. The results of our study suggest that permanent residence in urban or rural areas, along with ethnic differences, is a significant factor associated with the somatic status of young Altai-Kizhi and ethnically Russian women belonging to the modern indigenous population of the Altai Republic. In the subgroup of young women who are inherently living in the city, less pronounced ethnic differences in somatic status were observed as compared to residents of rural areas. © 2024. This work is licensed under a CC BY 4.0 license.

Introduction. In recent years, laser-based rangefinders have been considered as a possible alternative to mechanical anthropometers. One of these instruments is the KAFA-Laser anthropometer (KAFA, Russia). Our aim was to test the accuracy and reproducibility of the KAFA-Laser anthropometer when measuring height of anthropometric points.

Materials and methods. Using anthropometers GPM (DKSH, Switzerland) and KAFA-Laser, paired measurements of the height of 9 anthropometric points were carried out on 10 males aged 18-47 years. The measurements were performed by 3 researchers having different experience, 3 times in succession. The accuracy of measurements with the KAFA-Laser instrument was assessed by comparison with the GPM data. Intergroup differences were assessed using Wilcoxon signed rank test. Technical measurement errors and reliability coefficients were assessed.

Results and discussion. The difference in the height of anthropometric points when measured with the KAFA-Laser and GPM anthropometers significantly depended on the qualification of the measurers and was minimal (+0.0-0.5 cm) for researcher 1, a more experienced user of the KAFA-Laser anthropometer (absence of significant differences for 7 out of 9 points). The mean standard deviations for researcher 1 were lower than those for researchers 2 and 3 and were consistent with traditional anthropometry. Measurements with the GPM anthropometer showed lower individual, inter-individual, and total technical errors. Measurements of the vertex point were characterized by low values of technical measurement errors and high coefficients of reliability (0.94 and 0.95, respectively), and for the remaining points varied widely, which indicates the relevance of implementing objective quality control of anthropometric measurements.

Conclusion. The results of testing KAFA-Laser anthropometer suggest the possibility of obtaining comparable results of measurements of the height of anthropometric points in terms of accuracy and reproducibility to that of the conventional anthropometry with the proper level of mastery of the measurement techniques. © 2024. This work is licensed under a CC BY 4.0 license

Introduction. A number of diseases, including craniosynostosis, basal encephaloceles, and fibrous dysplasia, can be accompanied by deformities in the facial skeleton and the skull base. To quantify the degree of pathological deformity and the dynamics of skull bone growth in these patients, data from healthy children’s growth processes is needed. The aim of this study is to describe the normal growth of the main craniometric variables of the facial skeleton and the anterior skull base in healthy children aged 0 to 18 years old, and to create percentile standards for these variables.

Materials and methods. Our study uses cross-sectional retrospective computed tomography (CT) data of the head and face of 1,034 children, aged 0-18 years, who had sustained traumatic brain injuries without damage to the bone structures. Craniometric landmarks used in anthropological and medical craniometry were mapped onto 3D models of patient skull. Twenty linear distances between the landmarks, as well as the volumes of the left orbit and nasal cavity, were calculated. The data were analyzed separately for male and female participants. The RefCurv version 0.4.2 software was used to create percentile reference curves using the LMS method.

Results. The gender and age-related characteristics of the growth dynamics of the various structures of the facial skeleton and anterior base of the skull are characterized. The centile standards for normal variability of the craniometric data are provided for use in medical practice.

Conclusion. This study provides the most comprehensive data on the growth patterns of the facial skeleton and the anterior part of the skull base in healthy children aged between birth and 18 years old. The dimensions of the cribriform plate at birth are close to the adult size and change little during postnatal ontogenesis. The features of the orbital region reach 55-60% of the adult size at birth, grow very rapidly in the first year of life, and by the age of 5 constitute 80-85% of the adult size. The latitudinal dimensions of the facial skeleton, such as the width of the pyriform aperture, the zygomatic and inferior orbital diameters, as well as the sagittal dimensions of the nasal cavity reach about 50-55% of the adult size at birth and then grow uniformly, reaching 65-70% of the definitive value by the second year of life, and, with the exception of the width of the nose, about 80% by the age of 5. The height dimensions of the facial skeleton (the height of the pyriform aperture, face, maxilla, choanae and alveolar process), at birth are only about 40% of the adult size, but then grow rapidly, reaching about 70% of the definitive value by the age of 5. According to the relative sizes of most of the variables, a higher maturity level in girls at the time of birth is revealed, which persists until puberty. A pronounced pubertal acceleration of growth is observed only in boys, based on the following characteristics: the width of the orbit, the length of the medial wall of the orbit, the height of the upper jaw, the height of the nose, the lower length of the nasal septum, the volume of the nasal cavity, and the width of the cribriform plate. Understanding the differences in the developmental dynamics of various skull structures, as well as sex differences in these dynamics and the use of growth standards, is essential for an objective evaluation of the extent of pathological changes to these structures and for planning treatment and monitoring its outcomes.

© 2025. This work is licensed under a CC BY 4.0 license

Introduction. One of the traditional tasks of biological anthropology is the study of the morphological status of the indigenous populations. Our aim was to study the somatic status and bioimpedance body composition of young men of Altai and Russian ethnicities aged 17–24 years living in urban and rural areas of the Altai Republic.

Materials and methods. In 2021–2023, 167 men aged 17 to 24 years (87 Altai-Kizhi and 80 Russians) living in urban and rural areas were examined. The examination program included anthropometry, the Heath-Carter somatotyping, and BIA. Ethnic differences and urban-rural differences were assessed using parametric and non-parametric methods.

Results. Ethnically Russian men were, in general, somewhat larger than the Altai men. Significant ethnic differences were found for Ht (174.7 and 172.3 cm), Wt (72.2 and 66.8 kg), BMI (23.6 and 22.5 kg/m²), WC (79.6 and 76.9 cm) and HC (95.5 and 92.4 cm). Significant ethnic differences were also observed for the mesomorphy rating (5.44 and 4.96), the resistance R50 (521.4 and 541.3 Ohms), phase angle (7.35 and 7.08 degrees), FFM (55.1 and 50.9 kg) and FFMi (18.0 and 17.1 kg/m²). The distributions of the somatotype in the subgroups of Altai and Russian men were close, with a predominance of the mesomorphic type. In both ethnic subgroups, there was a tendency to increased body size and body composition parameters’ values in urban residents, with the statistically significant differences in Ht, Wt, BMI, WC, HC and FFM among the Altaians. The urban Russian residents, as compared to urban Altaians, had significantly higher mesomorphy rating and FFM. The rural Russian residents, as compared to rural Altaians (taking into account age differences between the subgroups) had significantly higher age-related z-scores of Ht, Wt, HC, phase angle, FFM and FFMi.

Conclusions. The results of our study suggest that permanent residence in urban or rural areas, along with ethnic differences, is a significant factor associated with the somatic status of young Altai-Kizhi and ethnically Russian men belonging to the modern indigenous population of the Altai Republic. In the subgroup of young men who are inherently living in the city, there was a tendency to smooth out ethnic differences in somatic status in comparison with residents of rural areas. © 2025. This work is licensed under a CC BY 4.0 license

Introduction. In our recent publications, we have established the possibility of using bioimpedance measurements to assess the Heath-Carter somatotype in different age groups. We aimed to develop unified formulas for calculating the somatotype in children and adults, evaluate their accuracy based on age and body mass index, and improve the somatotyping protocol in bioimpedance analyzer software.

Materials and methods. Data from our previous studies on comprehensive anthropometry and related BIA measurements were considered. The main group consisted of ethnic Russians aged 7-59, who were examined in Moscow, Arkhangelsk, Arkhangelsk Region, Elista, and Samara (N=4,296). The comparison group 1 included ethnic Russians aged 16-86 from the Krasnoyarsk Region (N=3,954). The comparison group 2 consisted of ethnic Kalmyks aged 8-25 from Elista (N=940). Using the data of the main group, bioimpedance predictive formulas for Endomorphy (ENDO_BIA) and Mesomorphy (MESO_BIA) ratings were obtained. We evaluated their accuracy in different subgroups of the main group and the comparison groups.

Results. The obtained formulas were as follows: ENDO_BIA = -3,411.8/R50 + 0.942´BMI – 0.00938´BMI² – 0.0235´Ht – 0.28´Sex + 0.034´Age – 2.69 (N=4,296; R²=0.84; SEE=0.76); MESO_BIA = 1,531.8/R50 + 0.302´BMI – 0.0529´Ht + 0.57´Sex – 0.032´Age + 4.52 (N=4,296; R²=0.87; SEE=0.48). These were relatively accurate for the age range 7-40 years for males and 7-59 years for females, but less accurate outside these age ranges or at high BMI values. Based on this, we also suggested formulas for obese people: ENDO_BIA = -2,569/R50 + 0.854´BMI – 0.0087´BMI² – 0.0263´Ht – 0.032´Sex + 0.018´Age – 1.60 (N=296; R²=0.69; SEE=0.87); MESO_BIA = 1,567/R50 + 0.55´BMI – 0.00512´BMI² – 0.0524´Ht + 0.42´Sex – 0.035´Age + 1.66 (N=296; R²=0.62; SEE=0.64). The formulas were integrated into the ABC-02 'Medas' (SRC Medas, Russia) BIA instrument software.

Conclusions. Our findings expand the possibilities for assessing the somatotype and studying its variability. Using uniform calculation formulas for children and adults will help improve comparability of estimates and validity of comparisons. © 2025. 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.