Archives of Physical Medicine and Rehabilitation
Volume 84, Issue 6 , Pages 854-861, June 2003

The use of bioelectric impedance analysis to measure fluid compartments in subjects with chronic paraplegia1 ☆

  • Andrea C Buchholz, RD, PhD(c)

      Affiliations

    • Department of Nutritional Sciences, University of Toronto, Toronto, ON Canada
    • The Research Institute, The Hospital for Sick Children, Toronto, ON, Canada
    • ,
  • Colleen F McGillivray, MD, FRCP(c)

      Affiliations

    • Department of Medicine, University of Toronto, Toronto, ON Canada
    • the Toronto Rehabilitation Institute, Toronto, ON, Canada
    • ,
  • Paul B Pencharz, MB, ChB, PhD, FRCP(c)

      Affiliations

    • Corresponding Author InformationReprint requests to Paul B. Pencharz, MB, ChB, PhD, FRCP(C), Rm 8263, Div of Gastroenterology and Nutrition, The Hospital for Sick Children, 555 University Ave, Toronto, ON M5G 1X8, Canada
    • Department of Nutritional Sciences, University of Toronto, Toronto, ON Canada
    • Department of Paediatrics, University of Toronto, Toronto, ON Canada
    • The Research Institute, The Hospital for Sick Children, Toronto, ON, Canada

Abstract 

Buchholz AC, McGillivray CF, Pencharz PB. The use of bioelectric impedance analysis to measure fluid compartments in subjects with chronic paraplegia.

Objectives:

To determine the sensitivity and specificity of body mass index (BMI) as a surrogate marker of obesity in individuals with chronic paraplegia and to validate bioelectric impedance analysis (BIA) as a method of measuring body composition in this group.

Design:

Cross-sectional study.

Setting:

University hospital.

Participants:

Convenience sample of 31 subjects with paraplegia (19 men, 12 women; mean age, 34.2±8.8y) and 62 able-bodied control subjects (30 men, 32 women; mean age, 28.6±7.2y).

Interventions:

Not applicable.

Main Outcome Measures:

Total-body water (TBW) by deuterium dilution; extracellular water (ECW) by corrected bromide space. Fat-free mass (FFM)=TBW/.732; fat mass (FM)=weight−FFM. Single-frequency whole-body and segmental BIA, and multifrequency whole-body BIA.

Results:

BMI had 100% specificity and 20% sensitivity in distinguishing obese from nonobese subjects with paraplegia. TBW was predicted by using the equation: TBW (inL)=2.11−0.1age+3.45sex+.34wt+.28(ht2/R)−.086sex×wt(r2=.95, standard error of the estimate [SEE]=1.86L, P<.0001). This equation had 81.8% specificity and 68.4% sensitivity. ECW was predicted by using the equation: ECW (in L)=−.025+1.03sex+.187wt+.0041(ht2/Xc) −.033sex×wt (r2=.75, SEE=1.62L, P<.0001). Multifrequency BIA offered no greater prediction of TBW or ECW than single-frequency BIA.

Conclusions:

BMI has excellent specificity but poor sensitivity in distinguishing obese from nonobese individuals with paraplegia. TBW (and therefore FFM and FM) and ECW can be reasonably well predicted by using single-frequency BIA.

Keywords:  Body composition, Body water, Electric impedance, Obesity, Paraplegia, Rehabilitation

 
  • 1 No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the author(s) or upon any organization with which the author(s) is/are associated.

☆ Supported in part by the Ontario Neurotrauma Foundation (grant no. ONBO-00026).

PII: S0003-9993(02)04950-X

doi:10.1016/S0003-9993(02)04950-X

Archives of Physical Medicine and Rehabilitation
Volume 84, Issue 6 , Pages 854-861, June 2003

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