diabetes research in children network pilot study of the navigator tm continuous glucose monitoring...
TRANSCRIPT
Diabetes Research in Children Network Pilot Study of the NavigatorTM
Continuous Glucose Monitoring Systemin Children with Type 1 Diabetes:
Safety, Tolerability, andFactors Associated with Use
Stuart A Weinzimer, MDfor the
Diabetes Research in Children Network Study Group26 Oct 2007
New Haven, CT
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
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
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
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
• 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
Abbott NavigatorTM
Study Subjects – Phase II
CSII MDI p-value
N (13-week Phase) 30 27
N (extension to 26 wk) 24 21
Age (y) 11.1 ± 3.7 10.3 ± 3.7 0.62
Female 8 (33%) 10 (48%) 0.37
T1D duration (y) 6.1 ± 3.3 3.5 ± 1.8 0.005
HbA1c (%) 7.1 ± 0.7 7.8 ± 0.9 0.01
Mean Glucose (mg/dL) 178 ± 27 190 ± 33 0.14
MAGE (mg/dL) 126 ± 32 151 ± 44 0.06
0
40
80
120
160
200 CSII
MDI
Nav
igat
or
Use
(h
ou
rs/w
eek)
Results – Sensor Use
BL 5-8 9-13 22-261-4 14-17 18-21
# subjects with zero use:
0 0 0 0 1 4 2
0 0 1 0 5 5 3
6.0
7.0
8.0
9.0CSII
MDI
Hb
A1c
(%
)
Baseline Wk 7 Wk 13 Wk 26
Results – Glycemic Control
Results – Glycemic Control
140
160
180
200
220CSII
MDI
BL 5-8 9-13 22-261-4 14-17 18-21
Mea
n B
loo
d G
luco
se (
mg
/dL
)
30%
40%
50%
60%
70%
80%CSII
MDI
BL 5-8 9-13 22-26
Per
cen
tag
e se
nso
r G
luco
se V
alu
es
In T
arg
et R
ang
e (7
1-18
0 m
g/d
L)
Results – Glycemic Targets
1-4 14-17 18-21
0%
2%
4%
6%
8%
Results – Hypoglycemia (MDI)P
erce
nta
ge
sen
sor
Glu
cose
Val
ues
B
elo
w T
arg
et R
ang
e (<
70
mg
/dL
)
BL 5-8 9-13 22-261-4 14-17 18-21
CSII
MDI
80
100
120
140
160
CSII
MDI
BL 5-8 9-13 22-26
Results – Glycemic Variability
1-4 14-17 18-21
Mea
n A
mp
litu
de
of
Gly
cem
icE
xcu
rsio
n (
MA
GE
, m
g/d
L)
Capillary Blood Glucose Testing
Need a graph like others showing meter use (tests/day)
over course of study
CGM Satisfaction
13 Wk 26 Wk
CSII – Subject
– Parent
3.6 ??
3.9 ??Need values
MDI – Subject
– Parent
3.5 0.5
3.8 0.4
3.6 0.5
3.8 0.5
Scores are out of a 5 point Likert scale
Factors Predictive of Continued Use
can be like table from paper,
but need p-values
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
• 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 Children’s 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
The following slides
are just audience questions
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
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
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
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
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
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