Abstract
Discrepancies in body fluid estimates between segmental bioimpedance spectroscopy (SBIS) and gold-standard methods may be due to the use of a uniform value of tissue resistivity to compute extracellular fluid volume (ECV) and intracellular fluid volume (ICV). Discrepancies may also arise from the exclusion of fluid volumes of hands, feet, neck, and head from measurements due to electrode positions. The aim of this study was to define the specific resistivity of various body segments and to use those values for computation of ECV and ICV along with a correction for unmeasured fluid volumes. Twenty-nine maintenance hemodialysis patients (16 men) underwent body composition analysis including whole body MRI, whole body potassium ( 40K) content, deuterium, and sodium bromide dilution, and segmental and wrist-to-ankle bioimpedance spectroscopy, all performed on the same day before a hemodialysis. Segment-specific resistivity was determined from segmental fat-free mass (FFM; by MRI), hydration status of FFM (by deuterium and sodium bromide), tissue resistance (by SBIS), and segment length. Segmental FFM was higher and extracellular hydration of FFM was lower in men compared with women. Segment-specific resistivity values for arm, trunk, and leg all differed from the uniform resistivity used in traditional SBIS algorithms. Estimates for whole body ECV, ICV, and total body water from SBIS using segmental instead of uniform resistivity values and after adjustment for unmeasured fluid volumes of the body did not differ significantly from gold-standard measures. The uniform tissue resistivity values used in traditional SBIS algorithms result in under-estimation of ECV, ICV, and total body water. Use of segmental resistivity values combined with adjustment for body volumes that are neglected by traditional SBIS technique significantly improves estimations of body fluid volume in hemodialysis patients.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 717-724 |
| Number of pages | 8 |
| Journal | Journal of Applied Physiology |
| Volume | 100 |
| Issue number | 2 |
| DOIs | |
| State | Published - Feb 2006 |
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Keywords
- Bioimpedance
- Body composition
- Body fluid
- Magnetic resonance imaging
- Segments
- Whole body
ASJC Scopus subject areas
- Physiology
- Endocrinology
- Orthopedics and Sports Medicine
- Physical Therapy, Sports Therapy and Rehabilitation
Cite this
Segment-specific resistivity improves body fluid volume estimates from bioimpedance spectroscopy in hemodialysis patients. / Zhu, F.; Kuhlmann, M. K.; Kaysen, George; Sarkar, S.; Kaitwatcharachai, C.; Khilnani, R.; Stevens, L.; Leonard, E. F.; Wang, J.; Heymsfield, S.; Levin, N. W.
In: Journal of Applied Physiology, Vol. 100, No. 2, 02.2006, p. 717-724.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Segment-specific resistivity improves body fluid volume estimates from bioimpedance spectroscopy in hemodialysis patients
AU - Zhu, F.
AU - Kuhlmann, M. K.
AU - Kaysen, George
AU - Sarkar, S.
AU - Kaitwatcharachai, C.
AU - Khilnani, R.
AU - Stevens, L.
AU - Leonard, E. F.
AU - Wang, J.
AU - Heymsfield, S.
AU - Levin, N. W.
PY - 2006/2
Y1 - 2006/2
N2 - Discrepancies in body fluid estimates between segmental bioimpedance spectroscopy (SBIS) and gold-standard methods may be due to the use of a uniform value of tissue resistivity to compute extracellular fluid volume (ECV) and intracellular fluid volume (ICV). Discrepancies may also arise from the exclusion of fluid volumes of hands, feet, neck, and head from measurements due to electrode positions. The aim of this study was to define the specific resistivity of various body segments and to use those values for computation of ECV and ICV along with a correction for unmeasured fluid volumes. Twenty-nine maintenance hemodialysis patients (16 men) underwent body composition analysis including whole body MRI, whole body potassium ( 40K) content, deuterium, and sodium bromide dilution, and segmental and wrist-to-ankle bioimpedance spectroscopy, all performed on the same day before a hemodialysis. Segment-specific resistivity was determined from segmental fat-free mass (FFM; by MRI), hydration status of FFM (by deuterium and sodium bromide), tissue resistance (by SBIS), and segment length. Segmental FFM was higher and extracellular hydration of FFM was lower in men compared with women. Segment-specific resistivity values for arm, trunk, and leg all differed from the uniform resistivity used in traditional SBIS algorithms. Estimates for whole body ECV, ICV, and total body water from SBIS using segmental instead of uniform resistivity values and after adjustment for unmeasured fluid volumes of the body did not differ significantly from gold-standard measures. The uniform tissue resistivity values used in traditional SBIS algorithms result in under-estimation of ECV, ICV, and total body water. Use of segmental resistivity values combined with adjustment for body volumes that are neglected by traditional SBIS technique significantly improves estimations of body fluid volume in hemodialysis patients.
AB - Discrepancies in body fluid estimates between segmental bioimpedance spectroscopy (SBIS) and gold-standard methods may be due to the use of a uniform value of tissue resistivity to compute extracellular fluid volume (ECV) and intracellular fluid volume (ICV). Discrepancies may also arise from the exclusion of fluid volumes of hands, feet, neck, and head from measurements due to electrode positions. The aim of this study was to define the specific resistivity of various body segments and to use those values for computation of ECV and ICV along with a correction for unmeasured fluid volumes. Twenty-nine maintenance hemodialysis patients (16 men) underwent body composition analysis including whole body MRI, whole body potassium ( 40K) content, deuterium, and sodium bromide dilution, and segmental and wrist-to-ankle bioimpedance spectroscopy, all performed on the same day before a hemodialysis. Segment-specific resistivity was determined from segmental fat-free mass (FFM; by MRI), hydration status of FFM (by deuterium and sodium bromide), tissue resistance (by SBIS), and segment length. Segmental FFM was higher and extracellular hydration of FFM was lower in men compared with women. Segment-specific resistivity values for arm, trunk, and leg all differed from the uniform resistivity used in traditional SBIS algorithms. Estimates for whole body ECV, ICV, and total body water from SBIS using segmental instead of uniform resistivity values and after adjustment for unmeasured fluid volumes of the body did not differ significantly from gold-standard measures. The uniform tissue resistivity values used in traditional SBIS algorithms result in under-estimation of ECV, ICV, and total body water. Use of segmental resistivity values combined with adjustment for body volumes that are neglected by traditional SBIS technique significantly improves estimations of body fluid volume in hemodialysis patients.
KW - Bioimpedance
KW - Body composition
KW - Body fluid
KW - Magnetic resonance imaging
KW - Segments
KW - Whole body
UR - http://www.scopus.com/inward/record.url?scp=33646347693&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33646347693&partnerID=8YFLogxK
U2 - 10.1152/japplphysiol.00669.2005
DO - 10.1152/japplphysiol.00669.2005
M3 - Article
C2 - 16254072
AN - SCOPUS:33646347693
VL - 100
SP - 717
EP - 724
JO - Journal of Applied Physiology
JF - Journal of Applied Physiology
SN - 8750-7587
IS - 2
ER -