BioImpedance Analysis

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	ARTICLES	PRE 1995	1995 - 2000	2000 - 2005

Authors - S

Saha, S.; Williams, P.A.
Title   Comparison of the electrical and dielectric behavior of wet
        human cortical and cancellous bone tissue from the distal tibia
Journal Journal of Orthopaedic Research
        13
        4
        JUL
Year    1995
Page    524-532
Address S Saha
        Loma Linda Univ
        Sch Med
        Dept Orthopaed Surg
        Bioelect Lab
        11234 Anderson
        POB 2000
        Loma Linda, CA 92354 USA
Serial# 0736-0266
Keys    FLUID-SATURATED BONE; PULSED ELECTROMAGNETIC-FIELDS; BOVINE
        FEMORAL BONE; IMPEDANCE TOMOGRAPHY; FREQUENCY; CONDUCTIVITY;
        DIAPHYSIS; PERMITTIVITY; STIMULATION; FRACTURES
Abs.    We compared the electrical and dielectric properties of wet
        human cortical and cancellous bone tissue from the distal
        tibia. The relationships between the electrical and
        dielectric behavior of cortical and cancellous bone and
        variables of measurement such as frequency and direction
        (orientation) were evaluated. In general, the resistivity
        of human cortical bone was found to be approximately 3.1
        times more than that of cancellous bone in the longitudinal
        direction and least 25 times more in the transverse
        directions. The dielectric permittivity of human cortical
        bone was approximately 3.9 times that of cancellous bone in
        the longitudinal direction, whereas in the transverse
        directions it was about 0.65 times greater. Measurement
        variables such as frequency and orientation appeared to
        affect cancellous and cortical bone differently. Strong
        correlations were found between the electrical properties
        in one direction and the electrical properties in the other
        two directions; however, these relationships differed for
        the samples of cortical and cancellous bone.

Saha, S.; Williams, P.A.
Title   Comparison of the electrical and dielectric behavior of wet
        human cortical and cancellous bone tissue from the distal
        tibia
Journal Journal of Orthopaedic Research
        13
        4
        JUL
Year    1995
Page    524-532
Address S Saha
        Loma Linda Univ
        Sch Med
        Dept Orthopaed Surg
        Bioelect Lab
        11234 Anderson
        POB 2000
        Loma Linda, CA 92354 USA
Serial# 0736-0266
Keys    FLUID-SATURATED BONE; PULSED ELECTROMAGNETIC-FIELDS; BOVINE
        FEMORAL BONE; IMPEDANCE TOMOGRAPHY; FREQUENCY; CONDUCTIVITY;
        DIAPHYSIS; PERMITTIVITY; STIMULATION; FRACTURES
Abs.    We compared the electrical and dielectric properties of wet
        human cortical and cancellous bone tissue from the distal
        tibia. The relationships between the electrical and
        dielectric behavior of cortical and cancellous bone and
        variables of measurement such as frequency and direction
        (orientation) were evaluated. In general, the resistivity
        of human cortical bone was found to be approximately 3.1
        times more than that of cancellous bone in the longitudinal
        direction and least 25 times more in the transverse
        directions. The dielectric permittivity of human cortical
        bone was approximately 3.9 times that of cancellous bone in
        the longitudinal direction, whereas in the transverse
        directions it was about 0.65 times greater. Measurement
        variables such as frequency and orientation appeared to
        affect cancellous and cortical bone differently. Strong
        correlations were found between the electrical properties
        in one direction and the electrical properties in the other
        two directions; however, these relationships differed for
        the samples of cortical and cancellous bone.

Author Schoeller, D.A.
Title   Bioelectrical impedance analysis for the measurement of human
        body composition: Where do we stand and what is the next step?
Journal Nutrition
        12
        11-12
        NOV-DEC
Year    1996
Page    760-762
Address DA Schoeller
        Univ Chicago
        Dept Med
        5841 S Maryland Ave
        MC 4080
        Chicago, IL 60637 USA
Serial# 0899-9007

Sasaki-E; Nakatani-T; Taenaka-Y; Takano-H; Hirose-H
Novel method to determine instantaneous blood volume in pulsatile
blood pump using electrical impedance.
Artificial Organs 18(8): 603-610
1994
English
A novel real-time volumetric method was developed for a pulsatile
pump. This method, the impedance method, used electrical impedance
change in the blood chamber according to volume change while
pumping. This method was evaluated with two kinds of air-driven
diaphragm pumps. During in vitro tests, the impedance method
indicated real-time volume change, and there was excellent
correlation between computed stroke volume with the impedance
method and measured stroke volume with the electromagnetic
flowmeter. In chronic animal tests with goats and in a clinical
case, the impedance method measured pump output accurately, and it
detected diaphragm motion in real-time. In addition, excellent
durability was seen. Full-fill to full-empty drive was realized
accurately with this method. Application of the impedance method
was easy, and it did not deteriorate native antithrombogencity of
the pump. The impedance method is practical and useful to estimate
the pumping condition of a pulsatile blood pump, especially a
diaphragm pump. This method would be useful in clinical
application.

Schwingshandl, J.; Borkenstein, M.
Title   Changes in lean body mass in obese children during a weight
        reduction program: Effect on short term and long term outcome
Journal International Journal of Obesity
        19
        10
        OCT
Year    1995
Page    752-755
Address J Schwingshandl
        Graz Univ
        Kinderklin
        Dept Paediat
        Auenbruggerpl
        A-8036 Graz, Austria
Serial# 0307-0565
Keys    children; body-composition; longterm outcome
        BIOELECTRICAL IMPEDANCE; ENERGY-EXPENDITURE; WATER
Abs.    OBJECTIVE: To study the changes in body composition during
        a weight reduction program in obese children and
        adolescents.
        DESIGN: A short-term longitudinal study.
        SUBJECTS: Forty-one obese children and adolescents 19 M, 22
        F, age 8.5-14.8 [median 11.8] years.
        MEASUREMENTS: Lean body mass (LBM) was estimated from
        Resistance Index (RI) obtained by Bioelectrical Impedance
        Analysis (BIA) before and after the 3 week program.
        RESULTS: Mean percentage weight for height at baseline was
        151 (s.d. 20)% and significantly decreased at the end of
        the three weeks (139 (s.d. 18)%, P = 0.005). The mean
        percentage body fat also decreased (from 46.0 s.d. 5.8% to
        41.5 s.d. 6.5%, P = 0.0015). All individuals lost body fat
        during the three weeks, whereas the change in LBM was
        heterogeneous. The individual change in body fat was
        inversely correlated with the change in LBM (r = -0.64, P =
        0.0001). After 4 months, 18 out of the 41 children could be
        reevaluated for height and weight. The regain in body
        weight during these 4 months was inversely correlated with
        the change in LBM during the weight reduction program (r = -
        0.55, P = 0.018).
        CONCLUSIONS: Changes in LBM during a weight reduction
        program can predict the short term result those children
        who manage to increase LBM having the greatest reduction in
        body fat. Changes in LBM during weight reduction seem also
        to predict the longterm outcome, a reduction in LBM being
        associated with greater regain of weight. Weight reduction
        programs for obese children should focus not only on weight
        loss but also on maintenance or increase of lean body mass
        to improve longterm results.

Selberg, O.; Suttmann, U.; Melzer, A.; Deicher, H.;
        Muller, M.J.; Henkel, E.; Mcmillan, D.C.
Title   Effect of increased protein intake and nutritional status on
        whole-body protein metabolism of AIDS patients with weight
        loss
Journal Metabolism - Clinical and Experimental
        44
        9
        SEP
Year    1995
Page    1159-1165
Address O Selberg
        Hannover Med Sch
        Chem Klin 1
        Pasteurallee 5
        D-30655 Hannover, Germany
Serial# 0026-0495
Keys    ACQUIRED-IMMUNODEFICIENCY-SYNDROME; RESTING ENERGY-
        EXPENDITURE; IMPEDANCE ANALYSIS; DIETARY-INTAKE; TURNOVER;
        NITROGEN; N-15; CANCER; BALANCE; DISEASE
Abs.    The aim of this study was to investigate nutritional status
        and protein metabolism during total parenteral nutrition
        (TPN) in AIDS patients with weight loss. Six patients on
        treatment for AIDS-associated complications were
        investigated and received TPN that supplied energy
        equivalent to 1.5 times the resting energy expenditure
        (REE). Amino acid (AA) supply increased from 0.6 g/kg body
        weight (BW)/d on days 1 to 3 and 1.2 on days 4 to 6 to 1.8
        on days 7 to 9. Nonprotein energy was given as equicaloric
        amounts of glucose and fat emulsion. There were repeated
        measurements of nitrogen balance and whole-body protein
        turnover (WEPT) using a bolus N-15-glycine method on the
        morning of days 3, 6, and 9. Principal findings were as
        follows: (1) increasing the supply of AAs significantly
        improves nitrogen balance in AIDS patients; (2) there is no
        simple linear effect of increasing amounts of AAs on WEPT
        in AIDS patients; (3) WEPT is high and variable in these
        patients; and (4) mean WEPT of each patient is
        significantly correlated with body cell mass (BCM) as a
        proportion of BW (P < .001, r = .92). We conclude that poor
        nutritional status in AIDS patients with weight loss is
        associated with high WEPT. However, these patients can
        attain at least transiently positive nitrogen balance with
        sufficient protein intake, predominantly through an
        increase in whole-body protein synthesis (WBPS). Copyright
        (C) 1995 by W.B. Saunders Company

Seo-A; Kakehashi-M; Uda-S; Tsuru-S; Yoshinaga-F
Bioelectrical impedance measuring method for standing load
evaluation.
Journal of Occupational Health 37(2): 83-87
1995
English
A bioelectrical impedance method was used to evaluate the workload
in standing jobs. This method is designed to indirectly evaluate
swelling of the lower leg by measuring the change in the rate of
impedance of the lower leg. In this paper, we studied the
relationship between the methods used for swelling evaluation, and
studied the measuring conditions of the impedance method by using
bioelectrical models. Furthermore, impedance in ten male subjects
in three types of standing conditions was measured to check the
validity of the model analysis. The results are as follows; 1) The
result of theoretical analysis showed that the change in impedance
caused by leg swelling is equal to the value obtained by the leg
volume measuring method, and twice as great as the value obtained
by the leg circumference measuring method. The rate of change in
impedance at low frequency is about 4 times greater than that at
high frequency. The low frequency impedance measuring method is
therefore much more sensitive than the other methods. 2) The
results of experimental studies showed that the impedance in the
lower legs was reduced as the function of time when quietly
standing for 30 mins. The change in the rate of impedance was 6.86
+- 4.54% (mean +- SD). This rate is 3-5 times greater than the
data reported by other researchers who used volume measurement or
impedance measurement at high frequency. This difference fits the
results of model analysis, and proved the validity of model
analysis and the usefulness of the impedance method as an index of
the standing load. The effect of exercise on impedance and the
relationship between impedance and subjective discomfort in the
lower leg is also discussed.

Sergi-G; Bussolotto-M; Perini-P; Calliari-I; Giantin-V; Ceccon-A;
Scanferla-F; Bressan-M; Moschini-G; Enzi-G
Accuracy of Bioelectrical Impedance Analysis in Estimation of
Extracellular Space in Healthy Subjects and in Fluid Retention
States.
Annals of Nutrition & Metabolism 38(3): 158-165
1994
English
Bioelectrical impedance analysis (BIA) is a noninvasive method
recently introduced for body fluid evaluation in healthy subjects.
The purpose of this paper is to verify the reliability of
bioelectrical measurements in extracellular water (ECW) prediction
in healthy subjects and in fluid retention states. We studied 40
subjects (19 males and 21 females) aged 21-81 years; 22 were
healthy subjects, 12 were affected by chronic heart failure, and 6
by chronic renal failure. In all subjects resistance (R) and
reactance (Xc) at 1 and 50 kHz corrected for height were compared
with ECW measured by the bromide dilution method. Our results
suggested a different behavior of the current in fluid-retention
states with respect to healthy subjects. ECW was best predicted by
resistance at 1 kHz corrected for height, group (considered as
dummy variable), weight and gender (R-2 = 0.89, p lt 0.001, SEE =
1.7 liters). The bioelectrical impedance analysis at 50 kHz
explained the 89% of ECW variability when resistance and reactance
corrected for height are considered with gender group and weight (
R-2 = 0.89, p lt 0.001, SEE = 1.7 liters). In conclusion, the
bioelectrical method at 1 kHz can be considered sufficiently
accurate in ECW prediction in healthy subjects and in fluid
retention states. Also, the bioelectrical impedance analysis at 50
kHz is useful for predicting ECW, but his role must be further
investigated.

Sharp, D.S.; Benowitz, N.L.; Bath, P.M.W.; Martin, J.F.;
        Beswick, A.D.; Elwood, P.C.
Title   Cigarette smoking sensitizes and desensitizes impedance-
        measured ADP-induced platelet aggregation in whole blood
Journal Thrombosis and Haemostasis
        74
        2
        AUG
Year    1995
Page    730-735
Address DS Sharp
        Kuakini Med Ctr
        Honolulu Heart Program
        347 N Kuakini
        Honolulu, HI 96817 USA
Serial# 0340-6245
Keys    COLLABORATIVE HEART-DISEASE; POLYMORPHONUCLEAR LEUKOCYTES;
        PHYSICAL EXERCISE; HABITUAL SMOKERS; NICOTINE; COUNT;
        INHIBITION; PLASMA; MEN; AGGREGOMETRY
Abs.    The effect of smoking on platelet aggregation appears to
        produce conflicting results, with some studies indicating
        an enhancement and others a decrease of aggregation. This
        epidemiological study of 120 male smokers, a subset of the
        Caerphilly Heart Disease Study, examined the relationship
        of two dimensions of smoking (time proximity of last
        cigarette before venepuncture and serum nicotine
        concentration) with threshold dose of adenosine diphosphate
        (ADP) necessary to induce platelet aggregation in whole
        blood. Means (range) of ADP threshold dose and nicotine
        concentration were 1.66 (0.5-2.5, censored) mu M and 12.2
        (0-35.2) ng/ml. Men smoking within 30 min of venepuncture
        demonstrated lower ADP threshold doses (-0.48 mu M lower
        [95% C. I.: -0.95, -0.02]) - reflecting increased
        sensitivity. Men with higher nicotine concentration had
        higher ADP threshold doses (Regression Coefficient: +0.032
        mu M per ng/ml [95% C. I.: 0.003, 0.062]) - reflecting
        decreased sensitivity. Men smoking 30 min or more before
        venepuncture who also had high nicotine concentration (25-
        30 ng/ml) demonstrated the highest ADP threshold doses
        compared to never smokers and to men smoking the previous
        day (approximate to 2.20 vs 1.86 and 1.81 mu M). Relations
        involving nicotine concentration do not necessarily reflect
        a pharmacological effect although the potential for a short
        term nicotine mediated tolerance effect cannot be
        dismissed. These observations support an hypothesis
        suggesting a temporal sequence of platelet sensitization
        and desensitization during smoking.

Author Siconolfi, S.F.; Nusynowitz, M.L.; Suire, S.S.; Moore, A.D.; Leig, J.
Title   Determining blood and plasma volumes using bioelectrical
        response spectroscopy
Journal Medicine and Science in Sports and Exercise
        28
        12
        DEC
Year    1996
Page    1510-1516
Address SF Siconolfi
        NASA
        Lyndon B Johnson Space Ctr
        Space Biomed Res Inst
        Exercise Physiol Lab
        SD5
        Houston, TX 77058 USA
Serial# 0195-9131
Keys    bioimpedance; body fluids; resistance; inductance
        TOTAL-BODY WATER; IMPEDANCE ANALYSIS; FLUID; IMMERSION;
        POSTURE; REST
Abs.    We hypothesized that an electric field (inductance)
        produced by charged blood components passing through the
        many branches of arteries and veins could assess total
        blood Volume (TBV) or plasma volume (PV). Individual (N =
        29) electrical circuits (inductors, two resistors, and a
        capacitor) were determined from bioelectrical response
        spectroscopy (BERS) using a Hewlett Packard 4284A Precision
        LCR Meter. Inductance, capacitance, and resistance from the
        circuits of 19 subjects modeled TBV (sum of PV and computed
        red cell volume) and PV based on I-125- albumin). Each
        model (N = 10, cross validation group) had good validity
        based on 1) mean differences (-2.3 to 1.5%) between the
        methods that were not significant and less than the
        propagated errors (+/- 5.2% for TBV and PV), 2) high
        correlations (r >0.92) with low SEE (<7.7%) between
        dilution and BERS assessments, and 3) Bland-Altman pairwise
        comparisons that indicated ''clinical equivalency'' between
        the methods. Given the limitation of this study (10
        validity subjects), we concluded that BERS models
        accurately assessed TBV and PV. Further evaluations of the
        models' validities are needed before they are used in
        clinical or research settings.

Silley, P.; Forsythe, S.
Impedance microbiology - A rapid change for microbiologists
Journal of Applied Bacteriology
80
3
MAR
1996
233-243
S Forsythe
Nottingham Trent Univ
Dept Life Sci
Clifton Lane
Nottingham BG11 8NS, England
0021-8847
INDIRECT CONDUCTIMETRY; CONDUCTANCE MEDIUM; CONFECTIONERY
PRODUCTS; ELECTRICAL-IMPEDANCE; AUTOMATED DETECTION; ANIMAL
PROTEIN; RAW-MILK; SALMONELLAS; BACTERIA; CORROSION

Author Skopnik, H.; Silny, J.; Heiber, O.; Schulz, J.; Rau, G.;
        Heimann, G.
Title   Gastroesophageal reflux in infants: Evaluation of a new
        intraluminal impedance technique
Journal Journal of Pediatric Gastroenterology and Nutrition
        23
        5
        DEC
Year    1996
Page    591-598
Address H Skopnik
        Rhein Westfal Th Aachen
        Kinderklin
        Pauwelsstr 30
        D-52057 Aachen, Germany
Serial# 0277-2116
Keys    gastroesophageal reflux; pH monitoring; intraluminal
        electrical impedance technique; infants
        CHILDREN; SCINTIGRAPHY; ESOPHAGUS; CLEARANCE; PATTERNS;
        MOTILITY; ACID
Abs.    In this study, pH metry was simultaneously applied with a
        new technique, the intraluminal multiple electrical
        impedance (IMP) procedure, for measuring gastrointestinal
        motility for gastroesophageal reflux (GER) detection.
        Seventeen infants with clinical symptoms of GER disease
        such as recurrent apnea, aspiration pneumonia, wheezing,
        and failure to thrive were investigated during two feeding
        periods. A single catheter combining a pH electrode with
        seven electrodes for impedance measurements over a distance
        of 8.5 cm was used for the investigation. In all patients,
        185 acid episodes were detected by pH metry. In 106 of
        these 185 acid episodes, a unique pattern in the IMP
        readings was noted, indicated by a retrograde esophageal
        volume flow. These episodes were regarded as acid GER
        episodes. Seventy-one of the 185 acid episodes occurred
        during the clearance process of a preceding acid GER
        characterized by typical IMP readings of an anterograde
        bolus transport. Eight of 185 acid episodes were missed in
        the IMP readings for technical reasons. The IMP pattern
        described as characteristic for a GER was observed in 490
        other episodes not detected by pH merry. More than 75% of
        all GER detected by IMP reached the pharyngeal space; 73%
        of all GER occurred during feeding and the first 2
        postprandial hours and 27% occurred during the remaining
        time until the next feeding. Even during the latter period,
        34% of GER were detected by IMP only; they were missed by
        pH metry. Volume clearance indicated by IMP was always
        completed earlier than acidity clearance. The results show
        that IMP technique facilitates the detection of all GER,
        whereas pH metry is confined to the measurement of acid
        GER. Therefore, this technique might improve the evaluation
        of GER disease and detection of GER in conditions with
        gastric hypoacidity.

Smallwood, R.H.; Hampshire, A.R.
Title   Data processing techniques for serial EIT spectroscopy images:
        A review of some preliminary results
Journal Physiological Measurement
        16
         Suppl. 3A
        AUG
Year    1995
Page    A129-A142
Address RH Smallwood
        Univ Sheffield
        Royal Hallamshire Hosp
        Dept Med Phys & Clin Engn
        Sheffield S10 2JF
        S Yorkshire, England
Serial# 0967-3334
Keys    APPLIED POTENTIAL TOMOGRAPHY
Abs.    Multifrequency EIT imaging should allow specific organs
        within the body to be identified by their impedance
        spectrum, and the use of parametric imaging should lead to
        a much greater freedom from movement artefacts. This will
        make EIT more attractive as a monitoring technique, but the
        data rate will require automated processing of the images.
        The application of dynamic regions of interest, generated
        on a frame by frame basis, is described, with examples from
        the imaging of neonatal lungs and adult stomach. The lung
        can be objectively identified on a single frame from the
        f(RSC), SC and RC images, but the stomach could only be
        identified on the dynamic images.

Snel, Y.E.M.; Brummer, R.J.M.; Bol, E.; Doerga, M.E.;
        Zelissen, P.M.J.; Zonderland, M.L.; Boer, P.; Koomans, H.A.;
        Koppeschaar, H.P.F.
Title   Direct assessment of extracellular water volume by the
        bromide-dilution method in growth hormone-deficient adults
Journal European Journal of Clinical Investigation
        25
        9
        SEP
Year    1995
Page    708-714
Address YEM Snel
        Univ Utrecht Hosp
        Dept Endocrinol L00408
        Postbox 85500
        3508 Ga Utrecht, Netherlands
Serial# 0014-2972
Keys    anthropometry; bioelectrical impedance; bromide-dilution
        method; extracellular water volume; growth hormone-deficiency;
        hydrodensitometry
        BIOELECTRICAL IMPEDANCE ANALYSIS; BODY-COMPOSITION;
        HYPOPITUITARY DWARFS; DENSITY; FLUID; MASS; SECRETION; WOMEN;
        BONE; MEN
Abs.    Body composition and water content were assessed in 36
        growth hormone deficient (GHD) patients (M:23, F:13) and 14
        controls (M:7, F:7) using anthropometry, hydrodensitornetry,
        bioelectrical impedance measurement and the bromide-
        dilution method, with which extracellular water volume can
        be measured directly. GHD patients, compared to controls,
        did not differ in extracellular water volume, in hydration
        state and water distribution. A higher BMI (P = 0.002) and
        a higher body fat mass (P < 0.0001) were found in the
        patients. Based on circumference measurements, the GHD
        patients had a higher waist/hip ratio (P = 0.0001). This
        study shows that GHD patients, in comparison with healthy
        controls, have a normal extracellular water volume. The
        finding that extracellular water volume is within the
        normal range in GHD patients may be clinically relevant as
        it is well known that in the first months after initiating
        GH-replacement therapy, most patients have signs and
        symptoms of excessive water retention.

Snel, Y.E.M.; Brummer, R.J.M.; Doerga, M.E.; Zelissen, P.M.J.;
        Koppeschaar, H.P.F.
Title   Validation of extracellular water determination by
        bioelectrical impedance analysis in growth hormone-deficient
        adults
Journal Annals of Nutrition and Metabolism
        39
        4
        JUL-AUG
Year    1995
Page    242-250
Address YEM Snel
        Univ Utrecht Hosp
        Dept Endocrinol
        Postbox 85500
        3508 Ga Utrecht, Netherlands
Serial# 0250-6807
Keys    growth hormone-deficient adults; extracellular water,
        validation; bromide-dilution method; bioelectrical impedance
        TOTAL-BODY WATER
Abs.    We validated the determination of extracellular water (ECW)
        by the bioelectrical impedance method (BIA), using the RJL
        manufacturer-supplied equation and the equation of Lukaski
        in 34 growth hormone-deficient (GHD) patients before and
        after replacement with recombinant human growth hormone
        (rhGH), using the bromide-dilution (Br-) method as the
        reference method. At baseline, paired comparisons showed no
        significant differences between mean ECW assessed by the Br-
        method and by BIA using both equations in the placebo and
        rhGH group. At 6 months, no significant difference was
        found between ECW assessed by the Br- method and by BIA
        using the manufacturer-supplied equation, both in the
        placebo and rhGH group. High coefficients of reliability
        (0.88-0.98) and high correlations (0.79-0.98; p < 0.001)
        were found between ECW assessed by the Br- method and by
        BIA applying two different regression equations in the
        placebo and rhGH groups at baseline and after 6 months.
        Mean differences in ECW assessed by the Br- method and BIA
        were between 2.6 and 4.1 % of the mean ECW determined by
        the Br- method at baseline and between 2.7 and 8.5% after 6
        months. Multiple comparisons showed a significantly greater
        ECW assessed by the Br- method than by BIA using the
        equation of Lukaski (p < 0.0001). This difference was found
        in the placebo and rhGH replacement group. The difference
        changed with time (p = 0.005), indicating that the
        usefulness of the formula of Lukaski seems to be affected
        by rhGH replacement therapy. We conclude that the
        noninvasive BIA technique might be a useful method to
        predict ECW in GHD patients. For assessing ECW during rhGH
        replacement, the manufacturer-supplied equation seems to be
        preferable.

Spungen-A-M; Bauman-W-A; Wang-J; Pierson-R-N-Jr
Measurement of body fat in individuals with tetraplegia: A
comparison of eight clinical methods.
Paraplegia 33(7): 402-408
1995
English
Spinal cord injury (SCI) is a unique condition that markedly
alters body composition, raising the possibility of having
undefined effects on the traditional assumptions for body
composition. In order to determine appropriate methods for the
analysis of body composition in this population, 12 subjects with
tetraplegia were studied for absolute weight as fat and percent
fat by the following methods; bioelectrical impedance (BIA), dual
energy X-ray absorptiometry (DEXA), total body potassium (TBK),
total body water (TBW), and four anthropometric methods: Durnin
and Womersley (DUR), Jackson and Pollack (J and P), Sloan (SLN)
and Steinkamp et at (STK). The eight methods were compared with
the mean of all means (24.4 +- 2.2% fat), which was assumed to be
the best estimate of percent fat. Four methods: BIA, DEXA, TBW and
STK were not significantly different, while TBK, DUR, J-PI and SLN
were significantly (P lt 0.009) different from the mean of the
means. Using only the non-significantly different methods, repeat
computation revealed TBW to have the smallest difference from the
mean (0.1 +- 2.8%), and DEXA to have the strongest correlation
with the line of identity (r = 0.96, P lt 0.0001). In conclusion,
BIA, DEXA, TBW, and STK are equally valuable for estimating fat in
those with tetraplegia.

Stanko, R.T.; Arch, J.E.
Title   Inhibition of regain in body weight and fat with addition of
        3-carbon compounds to the diet with hyperenergetic refeeding
        after weight reduction
Journal International Journal of Obesity
        20
        10
        OCT
Year    1996
Page    925-930
Address RT Stanko
        Univ Pittsburgh
        Montefiore Hosp
        Med Ctr
        Dept Med
        Gastroenterol & Clin Nutr Div
        200 Lothrop St
        Pittsburgh, PA 15213 USA
Serial# 0307-0565
Keys    pyruvate; dihydroxyacetone; weight regain
        BIOELECTRICAL-IMPEDANCE ANALYSIS; NITROGEN-METABOLISM; ENERGY-
        UTILIZATION; PYRUVATE; DIHYDROXYACETONE; VALIDATION; OBESITY
Abs.    OBJECTIVE: To investigate the efficacy of the 3-carbon
        compounds pyruvate and dihydroxyacetone (PD) in inhibiting
        reaccumulation of body weight and fat with refeeding after
        weight loss.
        DESIGN: Longitudinal, in Clinical Research Center. After
        weight loss induced by hypoenergetic diet (1.3 MJ/d) for 3
        weeks, refeeding with hyperenergetic diet (1.5 x resting
        energy expenditure) for 3 weeks. Refeeding diet randomized
        to contain PC or placebo (PL, polyglucose) as approximately
        20% of energy intake.
        SUBJECTS: 17 obese healthy women (n = 8 in PL group, n = 9
        in PD group) (age: 22-60 y, weight: 72.5-139.7 kg).
        MEASUREMENTS: Resting energy expenditure (REE), body
        composition (by bioelectrical impedance), nitrogen balance,
        serum proteins, biochemical profile, thyroid hormones, and
        insulin, before and after refeeding and weight and fat
        gain.
        RESULTS: Refeeding with a hyperenergetic diet, weight gain
        was significantly less in patients receiving PD compared to
        placebo (1.8 +/- 0.2 kg vs 2.9 +/- 0.1 kg, P < 0.01). Body
        fat regain was also less with feeding of PD (0.8 +/- 0.2 kg
        vs 1.8 +/- 0.2 kg, P < 0.01). Body protein metabolism, as
        measured by nitrogen balance, serum protein concentrations
        and fat free mass, was similar in subjects consuming either
        PD or PL.
        CONCLUSIONS: We conclude that 3-carbon compounds decrease
        weight gain and reaccumulation of body fat, without
        decreasing body protein gain, in obese subjects with
        hyperenergetic refeeding subsequent to weight loss.

Stenlof, K.; Sjostrom, L.; Lonn, L.; Bosaeus, I.; Kvist, H.;
        Tolli, J.; Lindstedt, G.; Bengtsson, B.A.
Title   Effects of recombinant human growth hormone on basal
        metabolic rate in adults with pituitary deficiency
Journal Metabolism - Clinical and Experimental
        44
        1
        JAN
Year    1995
Page    67-74
Address L Sjostrom
        Gothenburg Univ
        Sahlgrens Hosp
        Dept Med
        S-41345 Gothenburg, Sweden
Serial# 0026-0495
Keys    BODY-COMPOSITION; COMPUTED-TOMOGRAPHY; THYROID-FUNCTION;
        ADIPOSE-TISSUE; HYPOTHYROIDISM; NITROGEN; WOMEN; K-40
Abs.    The effect of recombinant human growth hormone (rhGH) on
        basal metabolic rate (BMR) was studied in a placebo-
        controlled, double-blind, crossover trial. Ten patients
        with a history of complete pituitary insufficiency were
        randomized for 26 weeks in each period. Three patients were
        excluded due to withdrawal, fever, and claustrophobia,
        respectively. All patients had received adrenal, thyroid,
        and gonadal substitution therapy for at least 1 year before
        the study. The dose of rhGH was 0.25 to 0.5 U/kg/wk,
        administered subcutaneously once a day in the evening. BMR
        was determined by indirect calorimetry in a computerized
        ventilated open-hood system. Body composition was examined
        using four different methods-computed tomography (CT),
        tritium dilution, K-40 determinations, and total body
        nitrogen (TEN) measured with neutron activation. The body
        composition data have previously been reported. Fat-free
        mass (FFM) increased and body fat (BF) decreased during the
        first 6 weeks of rhGH treatment, but no further changes in
        body composition occurred between 6 and 26 weeks. Baseline
        BMRs in GH deficient (GHD) patients were in the lower part
        of the reference range, but BMR and the ratio between BMR
        and FFM (BMR/FFM) were not significantly lower than in a
        carefully selected control group. BMR increased between 0
        and 6 weeks (mean +/- SD: from 6.68 +/- 1.55 to 7.75 +/-
        1.35 MJ/24 h, P < .001) and then remained unchanged between
        6 and 26 weeks. The increase in BMR was closely related to
        the increase in FFM (r = .91, P < .01). However, the
        increase in BMR was not solely related to changes in FFM,
        since there was a significant increase in BMR/FFM at 6
        weeks that was maintained at 26 weeks. Pearson correlation
        analysis also revealed a close association between the
        increase in BMR after 6 weeks of rhGH treatment and
        increases in a number of metabolic variables, including
        total 3,5,3'-triiodothyronine ([T-3] r = .84, P < 0.05),
        procollagen III peptide ([pIIIp] r = .85, P < .05), and
        free fatty acids ([FFA] r = .95, P < .01). Therefore, the
        increase in BMR after rhGH treatment is not simply a
        reflection of altered body composition, but may also
        involve other mechanisms including lipolysis, increased
        thyroxine (T-4) deiodination resulting in increased
        circulating T-3 concentrations, and/or increased protein
        synthesis as demonstrated by increased circulating pIIIp
        levels. Copyright (C) 1995 by W.B. Saunders Company

Stolarczyk, L.M.; Heyward, V.H.; Goodman, J.A.; Grant, D.J.;
        Kessler, K.L.; Kocina, P.S.; Wilmerding, V.
Title   Predictive accuracy of bioimpedance equations in estimating
        fat-free mass of Hispanic women
Journal Medicine and Science in Sports and Exercise
        27
        10
        OCT
Year    1995
Page    1450-1456
Address LM Stolarczyk
        Univ New Mexico
        Ctr Exercise & Appl Human Physiol
        Albuquerque, NM 87131 USA
Serial# 0195-9131
Keys    body composition; body fatness; hydrodensitometry
        BIOELECTRICAL IMPEDANCE ANALYSIS; LEAN BODY-MASS; MEXICAN-
        AMERICANS; OBESITY; VALIDATION; ACCULTURATION; PREVALENCE
Abs.    This study assessed the predictive accuracy of previously
        published bioelectrical impedance analysis equations for
        estimating fat-free mass of young (20-39 yr) Hispanic women
        (N = 29). The reference method was hydrostatic weighing at
        residual lung volume. Body density was converted to percent
        body fat using the Siri equation. Resistance and reactance
        were measured with a Valhalla bioimpedance analyzer. The
        bioelectrical impedance analysis equations of Lohman,
        Rising, Stolarczyk, Segal, Gray, and Van Loan were cross-
        validated. There were significant correlations between
        criterion and predicted fat-free mass (r = 0.86-0.95) for
        all equations. The standard error of estimate for each
        equation was acceptable; however, the total error for the
        Stolarczyk (3.2 kg) and the Van Loan (4.6 kg) equations
        exceeded the recommended value (2.8 kg). For all equations,
        the difference between average criterion and predicted fat-
        free mass was significant (P < 0.05). However, the mean
        differences for the Lohman (0.8 kg), Segal (0.8 kg), and
        Gray (0.9 kg) equations were small. In conclusion, the
        Segal, Lohman, and Gray equations may have potential for
        assessing the body composition of healthy, acculturated,
        Hispanic women.

Stroud, D.B.; Cornish, B.H.; Thomas, B.J.; Ward, L.C.
Title   The use of Cole-Cole plots to compare two multifrequency
        bioimpedance instruments
Journal Clinical Nutrition
        14
        5
        OCT
Year    1995
Page    307-311
Address DB Stroud
        Monash Med Ctr
        Dept Med Phys
        Melbourne
        Vic, Australia
Serial# 0261-5614
Abs.    Two commercially available multi-frequency bioimpedance
        spectrometers (Xitron 4000B and SEAC SFB3) were compared by
        performing measurements on a set of electronic circuits and
        by studying 14 healthy volunteers. Output data were plotted
        as reactance versus resistance and fitted with a semicircle
        using a least squares fitting program. In tests with six
        electronic circuits both instruments produced impedance
        loci that were well described by semicircular Cole-Cole
        plots, though there were some minor discrepancies using the
        Xitron instrument at frequencies above 150 kHz. When tested
        on the volunteers the SEAC instrument gave very good fits
        (RMSE = 1.5 Omega) to a semicircle from 5-600 kHz on all
        volunteers. The Xitron instrument gave excellent fits to
        the semicircle between 5 and 55 kHz (RMSE = 0.7 Omega) but
        above 55 kHz the phase measurements stayed constant or even
        increased, confirming the anomalous behaviour reported by
        other authors. The conclusions to be drawn are that the
        semicircular plots predicted by the Cole-Cole theory give a
        very good description of multifrequency impedance data
        recorded by the SEAC SFB3 instrument, on human subjects,
        for frequencies between 5 and 600 kHz. The Xitron 4000B is
        not able to reproduce the theoretically expected results in
        humans above 55 kHz.

Sundberg, S.; Akkila, J.
Assessment of cardiac performance: Short- and medium-term
variability of impedance cardiography at rest and during
dynamic exercise
International Journal of Clinical Pharmacology and
Therapeutics
34
3
MAR
1996
93-95
S Sundberg
Orion Farmos
Res Ctr
POB 65
SF-02101 Espoo, Finland
0946-1965
impedance cardiography; healthy volunteers; reproducibility;
exercise
HEALTHY-VOLUNTEERS; TRANSTHORACIC BIOIMPEDANCE; ELECTRICAL
BIOIMPEDANCE; STROKE VOLUME; OUTPUT
Short- and medium-term variability of impedance
cardiography at rest and during exercise at a heart rate of
155 - 160 beats/min were assessed in 12 healthy men aged 21
- 28 years. Two consecutive measurements within 1 min were
performed 4 times at 2-hour intervals on 2 days 14 days
apart. Ejection fraction was the most reproducible of all
impedance cardiography parameters, the CV ranging from 3.3 -
5.9%. The short-term reproducibility of cardiac output and
stroke volume at rest was good, the between-repeats
coefficient of variation (CV) being 4 - 6%. The
reproducibility weakened with longer time span (between-day
CV being about 12%) and higher heart rates (exercise).
However, even the between-day reproducibility at rest was
as good as that of heart rate. Between-day CV during
exercise were about 20%.

Suzuki-H; Robinson-M-K; Rounds-J-D; Gatzen-C; Wilmore-D-W
Glutathione deficiency accentuates hepatocellular fluid
accumulation after ischemia-reperfusion.
Journal of Surgical Research 57(5): 632-639
1994
English
Liver ischemia-reperfusion is known to be associated with free
radical-mediated hepatocellular damage but alterations in
hepatocellular fluid flux under these conditions are incompletely
understood. Deficiency of the antioxidant glutathione, which
increases the liver's susceptibility to ischemia-reperfusion
injury, may exacerbate pathological fluid shifts. This study
examined alterations in hepatic fluid dynamics during liver
ischemia-reperfusion in glutathione-deficient and
glutathione-replete rats. Normal and glutathione-deficient rats
underwent liver ischemia-reperfusion. Changes in hepatic extra-
and intracellular fluid were monitored by calculating extra- and
intracellular conductance from liver multifrequency bioelectrical
impedance measurements. Liver malonyl dialdehyde content and
plasma transaminase concentrations were measured and correlated
with changes in hepatic impedance. Hepatic extracellular
conductance decreased during ischemia and returned toward baseline
values during reperfusion in a similar fashion in both study
groups. Intracellular conductance increased during ischemia in
both groups and continued to rise during the initial phase of
reperfusion before falling toward normal. Glutathione-deficient
rats had a significantly higher intracellular conductance during
early reperfusion compared to controls. Glutathione-depleted rats
also had higher serum transaminases and liver malonyl dialdehyde
content following reperfusion. Intracellular and extracellular
conductance were significantly correlated with hepatic malonyl
dialdehyde content. We conclude that (1) liver
ischemia-reperfusion results in movement of fluid from the
extracellular to intracellular space with hepatocellular swelling;
(2) glutathione deficiency accentuates hepatocyte swelling
following ischemia-reperfusion; and (3) changes in extra- and
intracellular fluid are related to the severity of membrane
damage. Multifrequency impedance analysis can be used to monitor
real-time changes in hepatocyte injury and to study the effect of
potential therapeutic interventions.

Suzuki, H.; Rounds, J.D.; Wilmore, D.M.
Title   Does multifrequency bioelectrical impedance relate to body
        composition?
Journal Journal of Surgical Research
        65
        1
        SEP
Year    1996
Page    63-69
Address DM Wilmore
        Brigham & Womens Hosp
        Dept Surg
        Surg Metab & Nutr Lab
        75 Francis St
        Boston, MA 02115 USA
Serial# 0022-4804
Keys    CELLULAR FLUID SHIFT; ELECTRICAL-CONDUCTIVITY; WATER; VOLUME;
        CHROMATOGRAPHY; HEMODIALYSIS; VALIDATION; BROMIDE; RATS
Abs.    Background: There is need for a rapid, noninvasive,
        inexpensive yet accurate bedside technique to measure body
        composition. Bioelectrical impedance analysis measures the
        resistance and conductance of a weak electrical current
        passed through the body. It has been suggested that
        multifrequency impedance analysis can determine the
        distribution of fluid between the extracellular and
        intracellular compartments. Materials and Methods: The
        correlation between the resistance signals obtained from
        multifrequency bioelectrical impedance measurements and
        body composition was determined in normal rats ranging from
        150 to - 400 g in weight. Total body water, body fat, total
        body sodium, and total body potassium were measured using
        the carcass analysis technique, and extracellular water was
        derived from a dilutional marker using sodium bromide. Fat-
        free mass was calculated as the difference between body
        weight and body fat, and intracellular water was derived
        from total body water and extracellular water.
        Multifrequency bioelectrical impedance was measured at
        frequencies ranging from 3 to 300 kHz. Resistance at zero
        frequency and infinite frequency was calculated using the
        Cole and Cole equation. Results: Resistance index (i.e.,
        length of the animal(2)/resistance) was highly correlated
        with all body compartments (r = 0.879-0.996) at all
        frequencies. There was also a high correlation among all
        compartments of the body (r = 0.971-0.999). Because of this
        high intercorrelation among the body compartments, a
        specific relationship between the multifrequency
        bioelectrical impedance signal and a specific compartment
        was not identified. Conclusions: Resistance index at any
        frequency will be correlated with any body compartment in a
        normal population. The utility of this technique should be
        determined in situations where there is a disturbance in
        the relationship between various compartments of the body.
        (C) 1996 Academic Press, Inc.

Swinburn, B.A.; Craig, P.L.; Daniel, R.; Dent, D.P.D.;
        Strauss, B.J.G.
Title   Body composition differences between Polynesians and
        Caucasians assessed by bioelectrical impedance
Journal International Journal of Obesity
        20
        10
        OCT
Year    1996
Page    889-894
Address BA Swinburn
        Univ Auckland
        Sch Med
        Dept Community Hlth
        Auckland, New Zealand
Serial# 0307-0565
Keys    body composition; obesity; Polynesians; bioelectrical
        impedance
        CROSS-VALIDATION; WESTERN-SAMOA; PREVALENCE; OBESITY; BLACK;
        WHITE; MASS; PREDICTION; ADULTS; WOMEN
Abs.    OBJECTIVE: To assess differences in body composition
        between Polynesians and Caucasians subjects.
        SUBJECTS: 48 male and 80 female Polynesians from a village
        in Rarotonga, Cook Islands (81% response rate) and
        representative sample of 243 male and 250 female Caucasians
        from Melbourne, Australia.
        MEASUREMENTS: Body mass index, resistance from
        bioelectrical impedance, percent body fat derived from 4
        equations using resistance, weight, height, age and sex.
        RESULTS: Male and female Polynesians were younger (by 7.7
        years, P < 0.001 and 4.1 years, P < 0.05) and heavier (by
        10.7 kg and 12.5 kg, P < 0.0001) than their Caucasian
        counterparts. Electrical resistance was significantly lower
        in Polynesians of both sexes by over 130 Omega (P <
        0.0001). At every level of weight (adjusted for height and
        age), resistance was lower in the Polynesians (P < 0.0001)
        and at every level of body mass index, the predicted body
        fat from 4 different equations was lower in Polynesians (P
        < 0.0001).
        CONCLUSIONS: These results imply that, at any given body
        size, Polynesians are significantly leaner than Caucasians
        and that specific Polynesian standards for defining obesity
        need to be developed. The findings will need to be
        confirmed by other reference methods for measuring body
        composition.

Title    - Reproducibility of in vivo electrical impedance tomography
           images: Workshop discussion.
         - English
         - Editorial
Journal - Med Biol Eng Comput 1996 SEP;34(5):344-345