title: Body fluid volume determination via body composition spectroscopy in health and disease.
abstract: The assessment of extra-, intracellular and total body water (ECW, ICW, TBW) is important in many clinical situations. Bioimpedance spectroscopy (BIS) has advantages over dilution methods in terms of usability and reproducibility, but a careful analysis reveals systematic deviations in extremes of body composition and morbid states. Recent publications stress the need to set up and validate BIS equations in a wide variety of healthy subjects and patients with fluid imbalance. This paper presents two new equations for determination of ECW and ICW (referred to as body composition spectroscopy, BCS) based on Hanai mixture theory but corrected for body mass index (BMI). The equations were set up by means of cross validation using data of 152 subjects (120 healthy subjects, 32 dialysis patients) from three different centers. Validation was performed against bromide/deuterium dilution (NaBr, D2O) for ECW/TBW and total body potassium (TBK) for ICW. Agreement between BCS and the references (all subjects) was -0.4 +/- 1.4 L (mean +/- SD) for ECW, 0.2 +/- 2.0 L for ICW and -0.2 +/- 2.3 L for TBW. The ECW agreement between three independent reference methods (NaBr versus D2O-TBK) was -0.1 +/- 1.8 L for 74 subjects from two centers. Comparing the new BCS equations with the standard Hanai approach revealed an improvement in SEE for ICW and TBW by 0.6 L (24%) for all subjects, and by 1.2 L (48%) for 24 subjects with extreme BMIs (<20 and >30). BCS may be an appropriate method for body fluid volume determination over a wide range of body compositions in different states of health and disease.
authors.affiliation: Fresenius Medical Care Deutschland GmbH, Research and Development, Daimlerstrasse 15, D-61352 Bad Homburg, Germany. Ulrich.Moissl@fmc-ag.com
authors.forename: Ulrich M
authors.initials: UM
authors.lastname: Moissl
authors.forename: Peter
authors.initials: P
authors.lastname: Wabel
authors.forename: Paul W
authors.initials: PW
authors.lastname: Chamney
authors.forename: Ingvar
authors.initials: I
authors.lastname: Bosaeus
authors.forename: Nathan W
authors.initials: NW
authors.lastname: Levin
authors.forename: Anja
authors.initials: A
authors.lastname: Bosy-Westphal
authors.forename: Oliver
authors.initials: O
authors.lastname: Korth
authors.forename: Manfred J
authors.initials: MJ
authors.lastname: Müller
authors.forename: Lars
authors.initials: L
authors.lastname: Ellegård
authors.forename: Vibeke
authors.initials: V
authors.lastname: Malmros
authors.forename: Charoen
authors.initials: C
authors.lastname: Kaitwatcharachai
authors.forename: Martin K
authors.initials: MK
authors.lastname: Kuhlmann
authors.forename: Fansan
authors.initials: F
authors.lastname: Zhu
authors.forename: Nigel J
authors.initials: NJ
authors.lastname: Fuller
mesh_terms: D000328:Adult; D000465:Algorithms; D001823:Body Composition; D001826:Body Fluids; D003936:Diagnosis, Computer-Assisted / Q000379:methods; D005260:Female; D005858:Germany; D006801:Humans; D008297:Male; D008875:Middle Aged; D009518:New York; D010992:Plethysmography, Impedance / Q000379:methods*; D051437:Renal Insufficiency / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D012189:Retrospective Studies; D013548:Sweden; D014883:Water-Electrolyte Imbalance / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology