Diabetes Research in Children Network Pilot Study of the NavigatorTM

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Diabetes Research in Children Network Pilot Study
of the NavigatorTM Continuous Glucose Monitoring
System in Children with Type 1 Diabetes Safety,
Tolerability, and Factors Associated with Use
Stuart A Weinzimer, MD for the Diabetes Research
in Children Network Study Group 26 Oct 2007 New
Haven, CT
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Background

• Real-time continuous glucose monitoring devices
  (CGM) are a potentially powerful tool in the
  management of type 1 diabetes (T1D)
• For successful adoption into clinical practice,
  however, they must be accurate, comfortable to
  wear, and easy to use, particularly in children
• A previous-generation CGM, the GlucoWatch
  Biographer, failed to improve glycemic control in
  200 children with T1D during a 6-mth trial

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Objectives

• The aims of this pilot study were to examine the
  tolerability and effectiveness of a continuous
  glucose monitor (Abbott Navigator) in children
  with type 1 diabetes using intensive insulin
  regimens
• CSII (insulin pump therapy)
• Glargine-based multiple daily injection (MDI)
• To identify demographic and/or clinical factors
  predictive of successful long-term use of CGM

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Study Design

• Subjects wore the Navigator as an outpatient for
  1 week but were blinded to sensor data in order
  to characterize baseline control
• Subjects wore the Navigator (unblinded) as an
  outpatient for 13 weeks
• Devices were downloaded weekly to subjects home
  computers and subjects were contacted frequently
  (q1-4wk) in order to monitor Navigator use
• CGM Satisfaction questionnaires were completed at
  baseline and 13 weeks
• Subjects then invited to continue use of
  Navigator for additional 13 weeks

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Outcome Measures

• Glycemic control
• Hemoglobin A1c
• Mean glucose levels
• Percentage of glucose values within, above, or
  below target
• Glycemic variability
• Mean amplitude of glycemic excursion (MAGE)
• Tolerability
• Continuous Glucose Satisfaction Scale

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Abbott NavigatorTM

• Measures interstitial glucose levels
• Requires calibration using fingerstick blood
  glucose at 10, 12, 24 and 72 hours after
  insertion
• After a 10-hr warm-up, provides glucose readings
  every 60 seconds for up to 120 hours
• Operating range 20 - 500 mg/dL
• Displays a trend arrow indicating glucose rate of
  change
• Alarms for actual or impending high or low
  glucose levels

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Study Subjects Phase II
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Results Sensor Use
200
CSII
MDI
160
120
80
Navigator Use (hours/week)
40
0
subjects with zero use 0 0
0 0 1 4
2 0 0 1
0 5 5 3
BL
5-8
9-13
22-26
1-4
14-17
18-21
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Results Glycemic Control
CSII
9.0
MDI
8.0
HbA1c ()
7.0
6.0
Baseline
Wk 7
Wk 13
Wk 26
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Results Glycemic Control
CSII
220
MDI
200
180
Mean Blood Glucose (mg/dL)
160
140
BL
5-8
9-13
22-26
1-4
14-17
18-21
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Results Glycemic Targets
CSII
80
MDI
70
60
Percentage sensor Glucose Values In Target Range
(71-180 mg/dL)
50
40
30
BL
5-8
9-13
22-26
1-4
14-17
18-21
12
Results Hypoglycemia (MDI)
CSII
MDI
8
6
Percentage sensor Glucose Values Below Target
Range (lt 70 mg/dL)
4
2
0
BL
5-8
9-13
22-26
1-4
14-17
18-21
13
Results Glycemic Variability
CSII
MDI
160
140
Mean Amplitude of Glycemic Excursion (MAGE, mg/dL)
120
100
80
BL
5-8
9-13
22-26
1-4
14-17
18-21
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Capillary Blood Glucose Testing

• Need a graph like others
• showing meter use (tests/day)
• over course of study

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CGM Satisfaction
Scores are out of a 5 point Likert scale
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Factors Predictive of Continued Use

• can be like table from paper,
• but need p-values

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Conclusions

• Navigator was well-tolerated in pediatric
  subjects using either CSII or glargine-based
  basal-bolus MDI over 26 weeks
• Decrease in sensor use over time
• Early improvements in A1c, percentage of glucose
  levels in range, and glycemic variability
• No baseline factors were predictive of successful
  extended use
• Short-term use, early drop in HbA1c, and higher
  levels of CGM satisfaction predict successful
  extended use

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• Barbara Davis Center
• H. Peter Chase
• Rosanna Fiallo-Scharer
• Laurel Messer
• Barbara Tallant
• University of Iowa
• Eva Tsalikian
• Michael Tansey
• Linda Larson
• Julie Coffey
• Joanne Cabbage
• Nemours Childrens Clinic
• Tim Wysocki
• Nelly Mauras
• Larry Fox
• Keisha Bird
• Kim Englert

• Stanford University
• Bruce Buckingham
• Darrell Wilson
• Jennifer Block
• Paula Clinton
• Yale University
• William Tamborlane
• Stuart Weinzimer
• Brett Ives
• Amy Steffen
• Jaeb Center for Health Research
• Roy Beck
• Katrina Ruedy
• Craig Kollman
• Dongyuan Xing
• Cynthia Stockdale

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• The following slides
• are just audience questions

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Audience Question 1(before presentation)

• On a scale of 1 (lowest) to 5 (highest), how
  would you rate the tolerability of continuous
  glucose sensors in the management of children
  with diabetes ?
• 1. Completely intolerable
• 2. Somewhat intolerable
• 3. Neither tolerable nor intolerable
• 4. Somewhat tolerable
• 5. Very tolerable

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Audience Question 2(before presentation)

• On a scale of 1 (lowest) to 5 (highest), how
  would you rate the usefulness of continuous
  glucose sensors in the management of children
  with diabetes ?
• 1. Completely useless
• 2. Somewhat useless
• 3. Neither useful nor useless
• 4. Somewhat useful
• 5. Very useful

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Audience Question 3(before presentation)

• On a scale of 1 (lowest) to 5 (highest), how
  likely would you be to recommend the use of
  continuous glucose sensors in the management of
  children with diabetes ?
• 1. Very unlikely
• 2. Somewhat unlikely
• 3. Neither unlikely nor likely
• 4. Somewhat likely
• 5. Very likely

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Audience Question 1(after presentation)

• On a scale of 1 (lowest) to 5 (highest), how
  would you rate the tolerability of continuous
  glucose sensors in the management of children
  with diabetes ?
• 1. Completely intolerable
• 2. Somewhat intolerable
• 3. Neither tolerable nor intolerable
• 4. Somewhat tolerable
• 5. Very tolerable

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Audience Question 2(after presentation)

• On a scale of 1 (lowest) to 5 (highest), how
  would you rate the usefulness of continuous
  glucose sensors in the management of children
  with diabetes ?
• 1. Completely useless
• 2. Somewhat useless
• 3. Neither useful nor useless
• 4. Somewhat useful
• 5. Very useful

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Audience Question 3(after presentation)

• On a scale of 1 (lowest) to 5 (highest), how
  likely would you be to recommend the use of
  continuous glucose sensors in the management of
  children with diabetes ?
• 1. Very unlikely
• 2. Somewhat unlikely
• 3. Neither unlikely nor likely
• 4. Somewhat likely
• 5. Very likely