[Normal values of bioimpedance vector in Spanish population].

Background And Objective: The bioelectrical impedance vector analysis is useful for the determination of body composition in patients with altered hydration status. The original tolerance ellipses were made in Italian healthy individuals. Due to differences in body composition between populations, the aim of the study was to establish specific tolerance ellipses for the Spanish population and compare them with those ellipses made in the original reference population.

Methods: We studied 311 Spanish healthy subjects of both sexes, between 18 and 80 years old, with a BMI between 18 and 31 Kg/m², who underwent measurements of weight, height and bioelectrical impedance. The values of resistance and reactance standardized by height (R/H and Xc/H) derived from the impedance measurement, were used to determine the body composition and construct the specific tolerance ellipses for this population.

Results: The characteristics of body composition were different between sex and age groups. We plotted values of R/H and Xc/H of the Spanish population on the Italian tolerance ellipses finding that vectors were placed in left quadrants, indicating different body composition. We therefore built specific tolerance ellipses for Spanish population based on values of R/H and Xc/H. Spanish tolerance ellipses were statistically different from the Italian.

Conclusions: The vectors of the Spanish population were different from those of the Italian, hence the importance of having a self-reference pattern.