Analysis of raw parameters of localized bioelectrical impedance, phase angle, and impedance vectors and relationship with the strength of body segments in public employees and direct family members

• Grant number: 25/03771-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2025
• End date: August 31, 2026
• Field of knowledge: Health Sciences - Physical Education
• Principal Investigator: Luis Alberto Gobbo
• Grantee: Gustavo Monteiro Lima
• Host Institution: Faculdade de Ciências e Tecnologia (FCT). Universidade Estadual Paulista (UNESP). Campus de Presidente Prudente. Presidente Prudente , SP, Brazil

Abstract

Bioelectrical impedance analysis (BIA) has been established as a non-invasive and accessible method for assessing body composition, widely used in various clinical and sports contexts. Among the main parameters derived from BIA, resistance (R), reactance (Xc), phase angle (AngF), and bioelectrical impedance vector analysis (BIVA) stand out, reflecting cellular integrity, hydration status, and muscle functionality. Localized BIA (L-BIA) emerges as an innovative approach for segmented body composition analysis, allowing specific assessment of limbs and muscle groups. Additionally, muscle strength is a key predictor of health and functionality, often evaluated through maximal voluntary isometric contraction (MVIC) using electronic dynamometry. However, gaps remain in the understanding of the relationship between raw BIA parameters and segmented muscle strength. This study aims to analyze the correlation between raw L-BIA parameters (R, Xc, and AngF) and MVIC in upper limbs (elbow flexion and handgrip strength) and lower limbs (knee flexion and extension) in public employees and their immediate family members. This cross-sectional study will be conducted with a sample of 322 public employees from higher education institutions and their immediate family members. Data collection will take place at the São Paulo State University (UNESP), Faculty of Science and Technology, in Presidente Prudente. Raw L-BIA parameters (R, Xc, and AngF) will be assessed and correlated with segmented muscle strength, measured through MVIC in upper limbs (elbow flexion and handgrip strength) and lower limbs (knee flexion and extension) using electronic dynamometry. Sociodemographic variables, lifestyle habits, and body composition will also be analyzed. Statistical analysis will include linear and multiple regressions, as well as bioelectrical impedance vector analysis (BIVA) to compare different muscle strength groups. The findings of this research may contribute to a better understanding of BIA's applicability in muscle functionality assessment, enabling new strategies for health monitoring and personalized interventions. (AU)