title: The potential of classic and specific bioelectrical impedance vector analysis for the assessment of sarcopenia and sarcopenic obesity.
abstract: OBJECTIVE
  The aim of this paper is to investigate whether bioelectrical impedance vector analysis (BIVA) can be a suitable technique for the assessment of sarcopenia. We also investigate the potential use of specific BIVA as an indicator of sarcopenic obesity.
  
  
  METHODS
  The sample comprised 207 free-living elderly individuals of both sexes, aged 65 to 93 years. Anthropometric and bioelectrical measurements were taken according to standard criteria. The "classic" and "specific" BIVA procedures, which respectively correct bioelectrical values for body height and body geometry, were used. Dual energy X-ray absorptiometry (DXA) was used as the reference method for identifying sarcopenic and obese sarcopenic individuals. Bioelectrical and DXA values were compared using Student's t-test and Hotelling's T(2) test, as well as Pearson's correlation coefficient.
  
  
  RESULTS
  According to classic BIVA, sarcopenic individuals of both sexes showed higher values of resistance/height (R/H; p < 0.01) and impedance/height (Z/H; p < 0.01), and a lower phase angle (p < 0.01). Similarly, specific BIVA showed significant differences between sarcopenic and nonsarcopenic individuals (men: T(2) = 15.7, p < 0.01; women: T(2) = 10.7, p < 0.01), with the sarcopenic groups showing a lower specific reactance and phase angle. Phase angle was positively correlated with the skeletal muscle mass index (men: r = 0.52, p < 0.01; women: r = 0.31, p < 0.01). Specific BIVA also recognized bioelectrical differences between sarcopenic and sarcopenic obese men (T(2) = 13.4, p < 0.01), mainly due to the higher values of specific R in sarcopenic obese individuals.
  
  
  CONCLUSIONS
  BIVA detected muscle-mass variations in sarcopenic individuals, and specific BIVA was able to discriminate sarcopenic individuals from sarcopenic obese individuals. These procedures are promising tools for screening for presarcopenia, sarcopenia, and sarcopenic obesity in routine practice.
authors.affiliation: Department of Environmental and Life Sciences, University of Cagliari, Italy. emarini@unica.it
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Marini
authors.forename: Roberto
authors.initials: R
authors.lastname: Buffa
authors.forename: Bruno
authors.initials: B
authors.lastname: Saragat
authors.forename: Alessandra
authors.initials: A
authors.lastname: Coin
authors.forename: Elena Debora
authors.initials: ED
authors.lastname: Toffanello
authors.forename: Linda
authors.initials: L
authors.lastname: Berton
authors.forename: Enzo
authors.initials: E
authors.lastname: Manzato
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Sergi
mesh_terms: D015502:Absorptiometry, Photon; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D001823:Body Composition / Q000502:physiology*; D001837:Body Weights and Measures; D017097:Electric Impedance; D005260:Female; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000503:physiopathology*; D009765:Obesity / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology*; D055948:Sarcopenia / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology*; D012737:Sex Factors