Anisimova Anna V.

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 study of adiposity in children and adolescents is an important issue in the era of the global epidemic of obesity. Body mass index is the most common, but not the only body fat index. There are also indexes based on waist and hip circumferences. The purpose of this work is to analyze the age variability and correlation between various anthropometric indices and bioimpedance estimates of the percentage of body fat in children and adolescents.

Materials and methods. We analyzed the data of children and adolescents of both sexes 7-17 years old, 1885 boys and 1453 girls, collected in the course of cross-sectional anthropological surveys of schoolchildren in Moscow, Arkhangelsk and the Arkhangelsk region. Body mass index (BMI), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR), hip-to-height ratio (HHtR) were calculated. The percentage of fat mass (% FM) was obtained by bioimpedance with the ABC-01 “Medas” device. Correlation analysis was used to assess the relationship between indices and %FM.

Results and discussion. The paper analyzes the age-related variability of height and weight, BMI, waist circumference, hip circumference, WHR, WHtR, HHtR and % FM in children and adolescents of both sexes. Age-related changes in % FM have clear sex differences. In girls, during puberty, there is an accumulation of fat mass, while in boys – its decrease. Body weight, BMI, waist circumference, hip circumference, HHtR increase in the process of growth, WHR and WHtR decrease. For all indicators, except for WHR, in boys and girls in younger age groups, correlations with % FM are high and decrease with age, reaching average values. While the correlations of WHR with %FM are weak in all studied age groups.

Conclusion. Based on the analysis performed, it is shown that body mass, waist circumference, hip circumference, BMI, WHtR, HHtR are good predictors of relative body fat mass, they significantly correlate with % FM, while WHR correlates very weakly. © 2023. This work is licensed under a CC BY 4.0 license.