Assessing abdominal fatness with local bioimpedance analysis: basics and experimental findings.
OBJECTIVE
Abdominal fat is of major importance in terms of body fat distribution but is poorly reflected in conventional body impedance measurements. We developed a new technique for assessing the abdominal subcutaneous fat layer thickness (SFL) with single-frequency determination of the electrical impedance across the waist (SAI).


METHODS
The method uses a tetrapolar arrangement of surface electrodes which are placed symmetrically to the umbilicus in a plane perpendicular to the body axis. Twenty-four test subjects (12 male, 12 female) underwent SAI and abdominal magnetic resonance imaging (MRI). The SFL below the sensing electrodes was determined from MRI and correlated with the SAI data at four different frequencies (5, 20, 50 and 204 kHz).


RESULTS
A highly significant linear correlation (r2=0.99) between SFL and SAI over a wide range of the abdominal SFL was found. Separate regression models for female and male subjects did not differ significantly, except at 50 kHz.


CONCLUSIONS
SAI represents a good predictor of the SFL and provides an excellent tool for the assessment of central obesity.
Scharfetter
H
H
Institute for Biomedical Engineering, Technical University Graz, Austria. scharfetter@bmt.tu-graz.ac.at
Schlager
T
T
Stollberger
R
R
Felsberger
R
R
Hutten
H
H
Hinghofer-Szalkay
H
H
D000005:Abdomen; D000273:Adipose Tissue / Q000033:anatomy & histology*; D000328:Adult; D017097:Electric Impedance; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000145:classification; D015203:Reproducibility of Results