1. Clinical Assessment of Body Composition Marta Van Loan, Ph.D USDA, Western Human Nutrition Research Center mvanloan@whnrc.usda.gov

2. Objectives Overview and understanding of body composition and body compartments. Overview and understanding of methods. Application of methods assessment: examples with specific disease conditions.

3. What Compartments Can We Measure? 1 – Compartment Body Weight 2 – Compartment Fat Mass (FM) & Fat-Free Mass (FFM) Total Body Water (TBW) & Extracellular Fluid (ECF) 3 – Compartment FFM, TBW, FM FFM, Bone Mineral Content (BMC) FM

4. What Compartments Can We Measure? 4 – Compartment FFM, TBW, BMC & FM 6 – Compartment Elemental Analysis N, C, Ca, Na, Cl, and K

5. 4 – Compartment Model FAT MASS FAT-FREE MASS Mineral Protein Water Body Weight

6. Methods for Body Composition Assessment IN VIVO Neutron Activation Analysis Elemental Analysis Computed Tomography Site Specific images - IAAT Magnetic Resonance Imaging Site Specific images - IAAT Densitometry – reference method Hydrostatic Weighing, BodPod Dual Energy X-ray Absorptiometry (DXA)

7. Methods for Body Composition Assessment Tracer Techniques – reference method 2 H, 3 H, 18 O, NaBr Electrical Techniques BIA (single & multi- frequency) BIS – Cole-Cole Model Skinfolds & Anthropometric Body Mass or Weight

8. Principles of Methods Bod Pod – body density Archimedes Density of the body is determined – reference method Equations are used to convert body density to body fat Size Limitations – 450 pounds Dilution Techniques Deuterium ( 2 H) exchanges with H 2 O – reference method NaBr dilution doesn’t cross cell membrane – ECF space Requires pre- and post- dilution specimen (serum, urine) C1 x V1 = C2 x V2

9. Principles of Methods Bioelectrical Impedance (BIA) Water and electrolytes are conductors Fixed frequency (50kHz) transmitted through body Measures Resistance, Capacitance, Phase Angle Phase = cellular health and/or cellular death Equations are used to convert resistance measures to estimates of fat-free mass (FFM) Multiple Frequency Impedance (MFBIA) Frequencies vary from 5 kHz – 1MHz Use of prediction equations - not independent of TBW Cole-Cole model

10. BIA Measurement

11. Principles of Methods Dual Energy X-ray Absortiometry (DXA) X-ray is filtered into 2 energies Measures Bone Mineral Content (BMC) Bone Free Soft Tissue (BFST) BMC + BST = FFM Distribution of Fat and Lean Tissue Special Region Of Interest (ROI) for Specific Sites Size Limitations

12. DXA Lumbar Spine Measurement

13. DXA for Whole Body Composition

14. Clinical Use of Body Composition Anorexia & Obesity Renal Failure Liver Disorders: Ascites Chronic Obstructive Pulmonary Disease Cancer & AIDS associated wasting Burns & Trauma Congestive Heart Failure Spinal Cord Injuries Osteoporosis

15. BIS for Extra- and Intracellular Fluid, Total Body Water, and FFM Van Loan et al. Human Body Composition, 1993 MeanSTD ECF – NaBr14.6+ 2.1 ECF – BIS14.6+ 2.2 TBW – D 2 O33.6+ 5.6 TBW – BIS33.5+ 5.5 ICF – BIS19.1+ 4.0 ICF - BIS19.2+ 3.4 FFM – D 2 045.5+ 7.3 FFM – BIS45.5+ 7.2

16. Body Composition in AIDS Wasted Men on Gonadal Hormone Replacement Therapy Van Loan et al. AIDS 1999; 13: 241-248 18 men 21-d controlled in-patient intervention followed by 12 wk out-patient therapy Nitrogen balance from 21 d in-patient control period was reference method DXA, D 2 O, and BIS as experimental methods

17. Body Weight and FFM after 12 wk Nandrolone Deconate Therapy

18. Cumulative Changes at 12 Weeks

19. Fluid Changes During Pregnancy Van Loan et al. J Appl Physiol 1995; 78 : 1037-1042 10 Women tested at Baseline, 8-10wk, 24-26 wk, 34-36 wk, 4-6 wk PP. D 2 O & NaBr dilutions. Bioimpedance Spectroscopy (BIS) with Cole- Cole Model. BIS spectra for 18 logarithmically spaced frequencies Frequencies from 5 to 548 kHz.

20. Comparison Between Dilution and BIS Estimates of TBW and ECF Baseline8-10 wk 24-26 wk 34-36 wk 4-6 wk PP TBW D2O 33.2 ± 4.6 33.1 ± 5.1 36.1 ± 4.1 38.7 ± 3.9 33.4 ± 3.8 TBW BIS 31.6 ± 6.2 32.0 ± 5.2 35.1 ± 5.6 38.3 ± 5.0 33.2 ± 4.3 ECF NaBr 15.2 ± 1.3 18.1 ± 1.9 20.7 ± 3.6 18.3 ± 3.4 ECF BIS 16.9 ± 2.3 16.0 ± 2.3 19.4 ± 3.1 21.8 ± 2.4 17.0 ± 2.4

21. Potential Uses on Methods Found in Literature Bod Pod FFM & FM Adults Infant model – tested DXA BMC, BMD, FFM,and FM Tissue Distribution CT and MRI Site specific tissue analysis

22. Potential Uses on Methods Found in Literature BIA FFM & FM Adult and Pediatric Dialysis Survival Cancer, peritoneal dialysis, malnutrition, obesity Congestive Heart failure MFBIA or BIS FFM, FM, TBW, ECF Pregnancy, HIV+ wasting

23. Which Method to Use? Depends on compartment of interest. Availability of techniques. Technical training of staff. Condition of patient. Location where assessment will be done: Laboratory / clinic Field / remote site