Monitoring Obesity and Hyperinsulinemia in HIV Positive Children A Practical Approach

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Monitoring Obesity and Hyperinsulinemia in HIV
Positive Children A Practical Approach

• Peggy R. Borum, Ph.D.
• Professor of Human Nutrition
• University of Florida
• Gainesville, Florida

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Disclosure of Financial Relationships

• This speaker has no significant financial
  relationships with commercial entities to
  disclose.

This slide set has been peer-reviewed to ensure
that there are no conflicts of interest
represented in the presentation.
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Metabolic Syndrome in Adults
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Metabolic Syndrome in Pediatrics
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HAMD

• Controversy concerning the term Metabolic
  Syndrome
• Different groups have different definitions for
  metabolic Syndrome in adults
• Metabolic Syndrome in pediatric population is
  even less well defined
• We use the term HIV Associated Metabolic
  Dysfunction (HAMD)

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HIV Associated Metabolic Syndrome (HAMD)
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Practical Way to Monitor?
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Hypertension
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Dyslipidemia
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Growth
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Obesity
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Insulin Resistance
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Practical Way to Monitor?
Hypertension
Dyslipidemia
Growth
Obesity
Insulin Resistance
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Obesity
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Visceral Adiposity

• Visceral adiposity linked to dyslipidemia,
  insulin resistance, other CVD risk factors.
• Current measures of visceral adiposity
  MRI-expensive, BMI-not as accurate.
• Waist circumference considered one of the best
  anthropometric predictors of visceral obesity.

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Waist Circumference Z-score

• Fernandez et al. nationally representative
  sample of AA, EA, MA children and adolescents
  percentiles
• Z score
• X( measured WC) µ (meanWC at 50th
  percentile)
• d(SDDiff.WC at 68th
  50th percentile)

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Gator Circle

• Currently unable to measure visceral obesity by
  anthropometric measurements
• Developing the Gator Circle to address this
  issue
• Gator circle uses umbilical skinfold, suprailiac
  skinfold, mid-back skinfold and waist
  circumference to calculate visceral cavity area.

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Visceral Cavity Area

• The visceral cavity area area within the
  abdominal cavity.

Visceral Cavity
Subcutaneous Tissue
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Visceral Cavity Area
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Visceral Cavity Area
Our appreciation to Cade Fields-Gardener for
discussions concerning measurements
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Visceral Cavity Area Equation

• Arm Muscle Area (C (p x TSF))
• 4p
• C mid upper arm circumference
• TSF triceps skinfold thickness
• Visceral Cavity Area (VCA)
• (UCcmm (p x ((VUSF 2VSISF VMBSF)/4))2
• 4p
• UCcmm umbilical cavity circumference (Measured
  in cm converted to mm)
• VUSF vertical umbilical skinfold (measured in
  millimeters)
• VSISF vertical supra iliac skinfold (measured in
  millimeters)
• VMBSFvertical mid back skinfold (measured in
  millimeters)

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Visceral Cavity
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Creating the Gator Circle

• Use VCA equation to obtain the VCA
• VC VCA/UCcmm x 100
• VC shows what percentage of total umbilical
  cavity is found in the VCA
• Gator Circle VC x WC z-score
• Addition of WC Z-score establishes relationship
  to a comparative population

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Insulin Resistance
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Insulin Indices Which Is Best?
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Not easily utilized in the clinical setting.
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Insulin Indices

• Each index has a different threshold therefore,
  each index relies on a different scale.
• The difference in directional change (increasing
  or decreasing) of the parameter with insulin
  resistance makes rapid assessment of values
  relative to each indexs threshold complicated.
• Therefore, the percent difference from each
  indexs respective threshold was calculated
• all positive percentages indicate being beyond
  the threshold
• all negative percentages indicate having not yet
  reached the threshold

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Cumulative Indices Assessment

• A single value to diagnose insulin resistance
• Smoothes out discrepancies between indices
  diagnosis
• Easy to use in clinical and research practice.

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Practical Clinical Monitoring

• Insulin resistance is defined as being beyond the
  most extreme threshold for the given index
• Need a method to show all indices as they are
  used in a collaborative assessment of insulin
  resistance status due to the lack of information
  concerning the superiority of one index over any
  other.
• Created a graph in which the x-axis (0.000)
  represents each indexs most extreme threshold,
  which is used to diagnose insulin resistance by
  that specific index.

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Insulin Resistance Indices Graphs

• All red (bad) bars indicate percent differences
  that are beyond this threshold (in the positive
  percent directions).
• All green (good) bars indicate percent
  differences below the indexs threshold (in the
  negative percent direction).
• The y-axis (percentage) has been normalized to be
  100 in either direction. This was done so that
  all bars appear in the same proportions in every
  graph.

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No Indication Of Insulin Resistance
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Mixed Indication Of Insulin Resistance
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Indication Of Insulin Resistance
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Cumulative Indices Assessment

• The average percent difference from the five
  indices was calculated to create a single value
  (Cumulative Indices Assessment, CIA) that
  represents a patients insulin resistance
• A positive CIA diagnoses insulin resistance,
  while a negative CIA indicates not having insulin
  resistance.
• This method has the advantage of a single value
  to indicate insulin resistance, while dealing
  with a system that utilizes five different
  indices.

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What does the CIA tell you?

• 6/1931.59 diagnosed with IR
• Results skewed somewhat due to selection of
  patients - Still indicates that IR is present
• The CIA can be plotted against the clinical
  abnormalities associated with IR
• Determine which factors are more strongly
  correlated
• Attempt to predict IR from retrospective data
  when no insulin data is available

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r0.9006 p
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Correlation (preliminary results)

• STRONG
• Insulin
• Triglycerides

• Present
• VCA
• Gator Circle
• Waist z-score

• None
• BMI z-score
• HDL
• Total Cholesterol
• LDL
• Glucose

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Impaired Fasting Glucose????

• Our population does not exhibit significant
  glucose problems
• No significant correlation with glucose and the
  CIA
• Not a good tool for diagnosis
• Do not usually have IFG without IR
• BUT do have IR without IFG

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Practical Way to Monitor?