Comparative study by electrical bioimpedance of bioelectrical parameters in adolescents.

INTRODUCTION: electrical bioimpedance is increasingly utilized for evaluating the nutritional status of both healthy and ill individuals. This technique is simple, practical, cost-effective, and noninvasive. The objective of this study is to demonstrate that specific resistivity, estimated at 50 kHz, and the slope derived from the linear model of normalized bioelectrical parameter evolution in Cuban children and adolescents, can serve as predictive indicators of their health status. METHODS: an analytical, descriptive, retrospective, cross-sectional, and randomized study was conducted. The research was conducted on a sample of 1,079 children and adolescents of both sexes, aged 12 to 18 years, selected from this database. Measurements were taken using the BioScan® 98 bioimpedance analyzer at a frequency of 50 kHz. For the study, participants were categorized into three groups: healthy individuals, athletes, and patients. Specific resistivity, slope, and phase angle were estimated. RESULTS: specific resistivity decreases in patients with chronic renal failure, reflecting fluid retention and alterations in electrolyte distribution. Electrical resistance and capacitive reactance decrease in these patients, indicating relative overhydration and impaired cell mass, respectively. However, higher values of this parameter in athletes could indicate a higher proportion of muscle mass. CONCLUSIONS: specific resistivity, slope, and phase angle are essential parameters that provide a comprehensive assessment of an individual's physiological state: body composition, hydration status, and cellular integrity. Specific resistivity estimated at 50 kHz and the slope of the linear model could serve as complementary reliable predictors of an individual's health status, alongside the robustness of the phase angle.