The use of bioelectrical impedance analysis (BIA) is widespread both in healthy subjects and patients. BIA allows the determination of the fat-free mass (FFM), skeletal muscle mass (SMM), fat mass (FM), extracellular water (ECW) and total body water (TBW) when using appropriate population, age or pathology-specific BIA equations and established procedures. BIA equations are based on validation studies where BIA is compared with reference methods such as Air Displacement Plethysmography (ADP), Dual-Energy X-Ray Absorptiometry (DXA), Magnetic Resonance Imaging (MRI) and isotope dilution.~The predicate device seca mBCA 515 was compared to the gold standard methods MRI, DXA, ADP, D2O- and NaBr-dilution in previous clinical investigations in Kiel (Germany) and New York City (USA) to generate prediction equations for calculating body composition (FFM, SMM, ECW, TBW and VAT) in different populations. Furthermore, normal ranges for body composition were generated in a previous study conducted at the University Hospital Hamburg-Eppendorf.~The mBCA 555 is a new body composition analyzer measuring bioimpedance in standing position developed by seca.~Primary objective is to test whether the mBCA 515 prediction equations can be applied to the new mBCA 555. If necessary, to proof substantial equivalence, prediction equations should be adjusted for the mBCA 555.~Secondary objective is to compare Impedance, phase angle, reactance and resistance for different frequencies in order to clarify if normal ranges for BIVA and phase angle generated with the mBCA 515 need to be adjusted for the new mBCA 555.~Bioimpedance was measured using the seca mBCA 555 and mBCA 515. Body height was measured using the seca 274.
The mBCA 515 was compared to the gold standard methods MRI, DXA, ADP, D2O- and NaBr-dilution in previous clinical investigations (BCA-01, BCA-02, BCA-20) to generate prediction equations for calculating body composition (FFM, SMM, ECW, TBW and VAT) in different populations. Furthermore, normal ranges for body composition were generated based on the previous study BCA-03 conducted at the UKE.~The mBCA 555 is a new body composition analyzer measuring bioimpedance in standing position developed by seca.~In order to apply prediction equations and normal ranges from previous clinical investigations BCA-01, BCA-02, BCA-03 and BCA-20 to the new mBCA 555 it shall be compared to the mBCA 515.