Khomyakova Irina Anatol'evna

Introduction. This paper discusses the results of the analysis of intra- and inter-population variability in spatial and temporal aspects among the indigenous population of the Republic of Tuva, who have preserved to a certain extent the traditional way of life.

Materials and methods. The material for the article is the results of complex anthropological expeditions of the Anuchin Research Institute and the Museum of Anthropology to the Republic of Tuva, implemented in the period from 2016 to 2022 in cooperation with Tuva State University and the Medical Genetic Research Center.

Results and discussion. According to the results of the conducted research, the existing ideas about the structure of intergroup variability of related Altai-Sayan peoples (Tuvans, Tuvans-Todzhins, Tsaatans, Altaians) have been expanded, the anthropological and genetic community of Tsaatans and the indigenous population of Tuva has been confirmed. Also, for the population of the republic over the past 40 years, the detected maladaptive changes caused by socio-cultural changes and violation of the traditional way of life have been described for the first time. Among other things, a significant (2.5-3 years) acceleration of ontogenesis in the younger generation was shown in both urban and rural conditions, an increase in total body size (secular trend), acceleration of puberty, changes in body composition, which confirms a violation of adaptation in the populations of the indigenous Tuvan population. Based on the latest data obtained, data on changes in the structure of intra-population variability and manifestations of the secular trend in most regions of the Republic have been confirmed and supplemented.

Conclusion. The further task of anthropological research of an ethnogenetic orientation is to assess as many aspects as possible that fall under the influence of the described factors, both in Tuvan and in other groups. © 2024. This work is licensed under a CC BY 4.0 license

Introduction. The article presents the results of a comparative analysis of descriptive traits of indigenous peoples of Kyrgyzstan, Kalmykia, South Siberia and Western Mongolia.

Materials and methods. The data were collected during comprehensive anthropological expeditions in 2013-2017 in the populations of Sart-Kalmaks, Kalmyks, Mongols, Tuvinians, and Altaians. The program included following descriptive characteristics: the shape of legs was noted in the body structure, the pigmentation of skin, hair and eyes, the shape of hair and the development of tertiary hair on the face and chest in men were determined in the racial-diagnostic complex. Standard scales, point characteristics, and the method of generalized photographic portraits were used.

Results. It is shown that all studied groups are close to each other by the totality of descriptive features, while ethnic groups with the greatest Caucasoid admixture in their genesis deviate towards lighter shades of skin, eyes and hair. The occurrence of O-shaped legs, especially in men, correlates with genetic and historical data on the presence or absence of a Caucasoid component. Generalized photographic portraits of each sub-ethnic group confirm the general similarity of anthropological appearance due to the manifestation of a single racial component in all series.

Discussion. In general, according to descriptive features, all studied individuals are bright representatives of different anthropological types of the large mongoloid race and are characterized by darkly pigmented hair and eyes. New information for anthropological differentiation was introduced by the study of the shape of legs, associated with the frequency of occurrence of the O-shape. The application of the method of generalized photographic portraits allowed to make a more complete picture of the appearance of representatives of the studied ethnic groups. © 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.