Bioimpedance Resistance Indices and Cell Membrane Capacitance Used to Assess Disease Status and Cell Membrane Integrity in Children with Nephrotic Syndrome

Table 1

Abbreviations and concepts used in this paper.

Abbreviation	Description
General:
NS	Nephrotic syndrome
SFBIA	Single-frequency bioimpedance analysis
BIS	Bioelectric impedance spectroscopy (many frequencies)
Study groups:
ANS	Children with active NS (n = 8)
ANS	Subgroup of ANS, same children as NSR group (n = 5)
NSR	Children from ANS group re-studied at the time of NS remission (n = 5)
HC	Healthy control children (n = 38)
Physiological parameters:
ECW	Extracellular water (L)
ICW	Intracellular water (L)
TBW	Total body water (TBW = ECW + ICW)
Impedance:
Z	Impedance for alternating current (Ohm, Ω).
R	Resistance (Ω)
BIS parameters:
R	R of the extracellular water (ECW)
R	R of the intracellular water (ICW)
R	R of the total body water (TBW, measured at infinite frequency)
C	Cell membrane capacitance (nanofarad, nF)
Resistance indices:
RI	RI = H^2/R (cm^2/Ω) of the ECW
RI	RI of the ICW
RI	RI of the TBW