title: A critical evaluation of bioimpedance spectroscopy analysis in estimating body composition during GH treatment: comparison with bromide dilution and dual X-ray absorptiometry.
abstract: OBJECTIVE
  To compare estimates by bioimpedance spectroscopy analysis (BIS) of extracellular water (ECW), fat mass (FM), and fat-free mass (FFM) against standard techniques of bromide dilution and dual energy X-ray absorptiometry (DXA) during intervention that causes significant changes in water compartments and body composition.
  
  
  METHODS
  Body composition analysis using BIS, bromide dilution, and DXA was performed in 71 healthy recreational athletes (43 men, 28 women; aged 18-40 years; BMI 24 ± 0.4 kg/m(2)) who participated in a double-blinded, randomized, placebo-controlled study of GH and testosterone treatment. The comparison of BIS with bromide dilution and DXA was analyzed using linear regression and the Bland-Altman method.
  
  
  RESULTS
  At baseline, there was a significant correlation between BIS and bromide dilution-derived estimates for ECW, and DXA for FM and FFM (P<0.001). ECW by BIS was 3.5 ± 8.1% lower compared with bromide dilution, while FM was 22.4 ± 26.8% lower and FFM 13.7 ± 7.5% higher compared with DXA (P<0.01). During treatment, the change in ECW was similar between BIS and bromide dilution, whereas BIS gave a significantly greater reduction in FM (19.4 ± 44.8%) and a greater increase in FFM (5.6 ± 3.0%) compared with DXA (P<0.01). Significant differences in body composition estimates between the BIS and DXA were observed only in men, particularly during the treatment that caused greatest change in water compartments and body composition.
  
  
  CONCLUSIONS
  In healthy adults, bioimpedance spectroscopy is an acceptable tool for measuring ECW; however, BIS overestimates FFM and substantially underestimates FM compared with DXA.
authors.affiliation: Garvan Institute of Medical Research and Department of EndocrinologySt Vincent's Hospital, Sydney, New South Wales, AustraliaThe University of NSWSydney, New South Wales, AustraliaSchool of MedicineUniversity of Western Sydney, Sydney, New South Wales, AustraliaCentre for Pediatric EndocrinologyZurich, SwitzerlandCentres for Health ResearchPrincess Alexandra Hospital, Brisbane, Queensland, Australia Garvan Institute of Medical Research and Department of EndocrinologySt Vincent's Hospital, Sydney, New South Wales, AustraliaThe University of NSWSydney, New South Wales, AustraliaSchool of MedicineUniversity of Western Sydney, Sydney, New South Wales, AustraliaCentre for Pediatric EndocrinologyZurich, SwitzerlandCentres for Health ResearchPrincess Alexandra Hospital, Brisbane, Queensland, Australia Garvan Institute of Medical Research and Department of EndocrinologySt Vincent's Hospital, Sydney, New South Wales, AustraliaThe University of NSWSydney, New South Wales, AustraliaSchool of MedicineUniversity of Western Sydney, Sydney, New South Wales, AustraliaCentre for Pediatric EndocrinologyZurich, SwitzerlandCentres for Health ResearchPrincess Alexandra Hospital, Brisbane, Queensland, Australia.
authors.forename: Vita
authors.initials: V
authors.lastname: Birzniece
authors.affiliation: Garvan Institute of Medical Research and Department of EndocrinologySt Vincent's Hospital, Sydney, New South Wales, AustraliaThe University of NSWSydney, New South Wales, AustraliaSchool of MedicineUniversity of Western Sydney, Sydney, New South Wales, AustraliaCentre for Pediatric EndocrinologyZurich, SwitzerlandCentres for Health ResearchPrincess Alexandra Hospital, Brisbane, Queensland, Australia.
authors.forename: Chong-Hui
authors.initials: CH
authors.lastname: Khaw
authors.affiliation: Garvan Institute of Medical Research and Department of EndocrinologySt Vincent's Hospital, Sydney, New South Wales, AustraliaThe University of NSWSydney, New South Wales, AustraliaSchool of MedicineUniversity of Western Sydney, Sydney, New South Wales, AustraliaCentre for Pediatric EndocrinologyZurich, SwitzerlandCentres for Health ResearchPrincess Alexandra Hospital, Brisbane, Queensland, Australia.
authors.forename: Anne E
authors.initials: AE
authors.lastname: Nelson
authors.affiliation: Garvan Institute of Medical Research and Department of EndocrinologySt Vincent's Hospital, Sydney, New South Wales, AustraliaThe University of NSWSydney, New South Wales, AustraliaSchool of MedicineUniversity of Western Sydney, Sydney, New South Wales, AustraliaCentre for Pediatric EndocrinologyZurich, SwitzerlandCentres for Health ResearchPrincess Alexandra Hospital, Brisbane, Queensland, Australia Garvan Institute of Medical Research and Department of EndocrinologySt Vincent's Hospital, Sydney, New South Wales, AustraliaThe University of NSWSydney, New South Wales, AustraliaSchool of MedicineUniversity of Western Sydney, Sydney, New South Wales, AustraliaCentre for Pediatric EndocrinologyZurich, SwitzerlandCentres for Health ResearchPrincess Alexandra Hospital, Brisbane, Queensland, Australia.
authors.forename: Udo
authors.initials: U
authors.lastname: Meinhardt
authors.affiliation: Garvan Institute of Medical Research and Department of EndocrinologySt Vincent's Hospital, Sydney, New South Wales, AustraliaThe University of NSWSydney, New South Wales, AustraliaSchool of MedicineUniversity of Western Sydney, Sydney, New South Wales, AustraliaCentre for Pediatric EndocrinologyZurich, SwitzerlandCentres for Health ResearchPrincess Alexandra Hospital, Brisbane, Queensland, Australia Garvan Institute of Medical Research and Department of EndocrinologySt Vincent's Hospital, Sydney, New South Wales, AustraliaThe University of NSWSydney, New South Wales, AustraliaSchool of MedicineUniversity of Western Sydney, Sydney, New South Wales, AustraliaCentre for Pediatric EndocrinologyZurich, SwitzerlandCentres for Health ResearchPrincess Alexandra Hospital, Brisbane, Queensland, Australia Garvan Institute of Medical Research and Department of EndocrinologySt Vincent's Hospital, Sydney, New South Wales, AustraliaThe University of NSWSydney, New South Wales, AustraliaSchool of MedicineUniversity of Western Sydney, Sydney, New South Wales, AustraliaCentre for Pediatric EndocrinologyZurich, SwitzerlandCentres for Health ResearchPrincess Alexandra Hospital, Brisbane, Queensland, Australia k.ho@uq.edu.au.
authors.forename: Ken K Y
authors.initials: KK
authors.lastname: Ho
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods / Q000592:standards*; D000293:Adolescent; D000328:Adult; D001823:Body Composition / Q000502:physiology*; D001965:Bromides / Q000097:blood*; D058266:Dielectric Spectroscopy / Q000379:methods / Q000592:standards*; D004311:Double-Blind Method; D005260:Female; D019382:Human Growth Hormone / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D001965:Bromides; D019382:Human Growth Hormone