[Bioelectrical impedance vectors in the Colombian university population]

Introduction: body composition (BC) analysis is an essential element in clinical nutritional practice. Bioelectrical impedance is one of the most widely used techniques for estimating BC. Several approaches have been proposed to reduce the margin of error it presents, ensuring its application in all populations. One of them is the use of impedance vectors, using tolerance ellipses. Objective: to compare the sample vectors with the Italian population and to determine specific tolerance ellipses for the Colombian university population. Materials and methods: observational cross-sectional study in 608 university students. Participation was at convenience and voluntary, between February 2022 and March 2023. BIVA 2002 software was used to calculate the tolerance ellipses and BIVA confidence to compare the vectors of the ellipses with the Italian population using Hotelling's T2 test, which was considered as significant at p < 0.05. Results: R/H and Xc/H measurements were higher in females (420.75 ± 56.012 Ω/m vs 308.7508 ± 41.81 Ω/m) and (46.15 ± 5.79 Ω/m vs 39.44 ± 5.01 Ω/m), respectively. The impedance vectors were positioned over the upper quadrants of the RXc plot, evidencing significant differences in the distribution of the composition vectors between samples. Conclusions: the vectors of the Colombian university students were different from the reference population, so it was necessary to determine the specific ellipses.