title: New specific bioelectrical impedance vector reference values for assessing body composition in the Italian-Spanish young adult population.
abstract: OBJECTIVE
  Specific bioelectrical impedance vector analysis (spBIVA) is a recently proposed technique for the analysis of body composition. The aim of this study was to apply spBIVA to a sample of Italian and Spanish young adults and to define the new bioelectrical references for this Western Mediterranean population.
  
  
  METHODS
  A sample of 440 individuals (220 from Italy, 220 from Spain; 213 men, 227 women) aged 18-30 years was considered. Anthropometric (height, weight, relaxed upper arm, waist, and calf girths) and bioelectrical (resistance, reactance; 50 kHz, 800 μA) measurements were taken. In order to verify the need for new references, specific bioelectrical values were compared to the reference values for U.S. adults and Italian elderly by tolerance ellipses and Student's t test.
  
  
  RESULTS
  The mean specific bioelectrical values (resistivity, Rsp, and reactivity, Xcsp, Ohm·cm) were: Rsp (332.7 ± 41.7 Ω·cm), Xcsp (44.4 ± 6.8 Ω·cm), Zsp (335.6 ± 41.9 Ω·cm) and phase (7.6 ± 0.8°) in men; Rsp (388.6 ± 60 Ω·cm), Xcsp (43.7 ± 7.5 Ω·cm), Zsp (391.0 ± 60.3 Ω·cm) and phase (6.4 ± 0.7°) in women. Italo-Spanish bioelectrical vectors were mainly distributed (>90%) in the lower part of the tolerance ellipses for U.S. young adults, due to a shorter impedance (P < 0.001), indicative of a lower percent fat mass. Compared to Italian elders, they were mainly located in the left side (>90%), due to a higher phase (P < 0.001), indicative of higher body cell mass.
  
  
  CONCLUSIONS
  These population and age-related differences indicate the need for new specific tolerance ellipses that can be used as references for assessing body composition in young adults from Western Mediterranean populations.
authors.affiliation: Department of Genetics, Physical Anthropology and Animal Physiology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), Bilbao, 48080, Spain.
authors.forename: Maria E
authors.initials: ME
authors.lastname: Ibáñez
authors.affiliation: Department of Life and Environmental Sciences, University of Cagliari, Monserrato, 09042, (Cagliari), Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Mereu
authors.affiliation: Department of Life and Environmental Sciences, University of Cagliari, Monserrato, 09042, (Cagliari), Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Buffa
authors.affiliation: Department of Biomedical and Specialty Surgical Sciences, University of Ferrara, Ferrara, 44121, Italy.
authors.forename: Emanuela
authors.initials: E
authors.lastname: Gualdi-Russo
authors.affiliation: Department of Biomedical and Specialty Surgical Sciences, University of Ferrara, Ferrara, 44121, Italy.
authors.forename: Luciana
authors.initials: L
authors.lastname: Zaccagni
authors.affiliation: Department of Life and Environmental Sciences, University of Cagliari, Monserrato, 09042, (Cagliari), Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Cossu
authors.affiliation: Department of Genetics, Physical Anthropology and Animal Physiology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), Bilbao, 48080, Spain.
authors.forename: Esther
authors.initials: E
authors.lastname: Rebato
authors.affiliation: Department of Life and Environmental Sciences, University of Cagliari, Monserrato, 09042, (Cagliari), Italy.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Marini
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000886:Anthropometry / Q000379:methods*; D001823:Body Composition; D017097:Electric Impedance; D005260:Female; D006801:Humans; D007558:Italy; D008297:Male; D012016:Reference Values; D015203:Reproducibility of Results; D013030:Spain; D044465:White People; D055815:Young Adult