bioelectric impedance analysis the breakdown of how it works and why you need it dr. june...
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Bioelectric Impedance Analysis
The Breakdown
Of How It Works
And
Why You Need It
Dr. June Riedlinger, R.Ph., Pharm.D., NDCertified First Line Therapy Provider
Clinical Relevance of BIA
“BIA is an important clinical tool for evaluating the metabolic status of patients. It is inexpensive and noninvasive, and it provides useful information concerning altered body composition and membrane potential at the tissue level measured by phase angle.”
Jeff Bland PhD.
Clinical Relevance of BIA
“BIA is a simple in-office test that converts easily obtained electrical measurements into information about the patient’s body composition and fluid distribution ...”
Robert Rakowski DC
Biomarkers 2000
• Portable
• Battery powered
• Highly accurate meter
• Mini-computer
• Inkless printer (thermal paper)
Pre-test Preparation
• No alcohol within 24 hours
• No exercise for 4 hours
• Avoid caffeine or food for 4 hours
• Consume 2-4 glasses of water within 2 hours
Bioelectric Impedance Analysis (BIA)
“Bioelectric impedance analysis is a simple, noninvasive, rapid, portable, reproducible, and convenient method of measuring body composition; it is sufficiently accurate for clinical use and makes fewer physical demands (than anthropometric techniques).”
JADA 2001;101(10):1209-1212
•Phase Angle, Capacitance,Resistance and ReactanceDo not rely on input of patient’sheight, weight, age or sex.
• Mass Distribution Results are based on findings from largepopulation studies.
• These numbers require accurate input of a patients height, weight, sex and age.
STEP 1 Total Body Water/Fat
Free Mass = TBW/FFM This marker refers to the
hydration of the patient. Must be higher than 69%
for a test to be valid. If <69%, patient should
be put on hydration protocol and retested in 24-48 hours.
Higher is typically better Accurate even when
subject is significantly overweight
STEP 1 (CONTINUED) TBW/Total Weight
Percentage of total weight that is water
Declines with age Shows dehydration if
person is significantly overweight.
STEP 2 Phase angle
General indicator of cellular health
Provides info on cell membrane potential at the tissue level
STEP 3 Intracellular Water
Healthy cells maintain their integrity and hold their fluid inside
>60% is optimal. Changes with age
Extracellular Water Water volume outside of
the body cell mass Higher values may be
related to fluid retention
STEP 4 Fat Free Mass vs. Fat
Determine the amount of metabolically active tissue in the person.
Optimal range depends on sex and age of person.
BIA can determine both subcutaneous fat (Love Handles) as well as visceral fat found around the organs of the body.
Advantage over calipers to assess true health status.
Do You Believe in Miracles?
•Lance Armstrong is monitored with the BIA during his preparation for the Tourde France.
“. . . we found that fat-free mass was lower and fat mass was higher in acutely ill and chronically ill patients than controls.”
“. . . we found that fat-free mass was lower and fat mass was higher in acutely ill and chronically ill patients than controls.”
J Amer Diet Assoc 2002;102(7):944-955
STEP 5 ECM/BCM
Ratio of extracellular mass (non-metabolically active) to body cell mass (metabolically active)
Low value is desirable Upward shift suggests
imbalanced weight loss. Downward shift suggests
balanced weight loss. Use Body Composition
Protocol to shift.
“Sarcopenia is the backdrop against which the drama of disease is played out: a body already depleted of protein because of aging is less able to with stand the protein catabolism that comes with acute illness or inadequate protein intake.”
“Sarcopenia is the backdrop against which the drama of disease is played out: a body already depleted of protein because of aging is less able to with stand the protein catabolism that comes with acute illness or inadequate protein intake.”
JAMA 286(10) (2001)
Am J Clin Nutrition 1996; 64:472S-477S
BIA may be clinically useful for demonstrating sarcopenic obesity in women at normal body mass indices, with additional studies necessary to determine the metabolic reasons underlying this change in body composition.
BIA may be clinically useful for demonstrating sarcopenic obesity in women at normal body mass indices, with additional studies necessary to determine the metabolic reasons underlying this change in body composition.
STEP 6 Body Mass Index
BMI correlates with a person’s health.
Studies show even moderate BMI shifts mean health consequences.
Lower is better Alter using Body
Composition Program.
Weight Gain and Diabetes Risk
2.11.01.0
5.33.6
2.5
21.1
9.1
6.3
0
5
10
15
20
25
<22 22-23 24+
<5 kg 5-10 kg 11+ kg
Body Mass Index at Age 21
Rela
tive R
isk
Weight Change Since Age 21
Adapted from Chan JM, et al. Diabetes Care 1994;17:960-969.
26 -Year Incidence of Coronary Heart Disease in Men
177
255
350333366
440
0
100
200
300
400
500
600
<25 25-<30 30+
<50 years 50+ years
Incid
en
ce/1
,000
BMI LevelsAdapted from Hubert HB, et al. Circulation 1983;67:968-977. Metropolitan Relative Weight of 110 is a BMI of approximately 25.
Relationship of BMI to Excess Mortality
300Age at Issue
Bray GA. Overweight is risking fate. Definition, classification, prevalence and risks. Ann NY Acad Sci 1987;499:14-28.
20-29250
Mort
alit
y R
ati
o
Body Mass Index (kg/[m2])
200
150
100
50
150
30-39
20 25 30
LowRisk
4035
High
Risk
ModerateRisk
STEP 7 Basal Metabolic Rate
BMR- is the amount of calories a person burns during a 24 hour period while at rest.
More lean body mass will increase the BMR
Higher is typically better. Each person is very unique Essential in establishing a
proper body composition program.