Continuous Glucose Monitoring for Diabetes, Obesity and Metabolism Research in Rodents
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Transcript of Continuous Glucose Monitoring for Diabetes, Obesity and Metabolism Research in Rodents
Continuous Glucose Monitoring for Diabetes, Obesity and Metabolism Research in Rodents
Christian Schnell
Lab Head in-vivo Pharmacology, Oncology ResearchNovartis AG
Ralf Dechend, MDGroup Leader, ECRC, Charité Campus BuchMax Delbruck Center for Molecular Medicine, Berlin, Germany
2015 R&D 100 Finalists - PhysioTel HD-XG
InsideScientific is an online educational environment designed for life science researchers. Our goal is to aid in
the sharing and distribution of scientific information regarding innovative technologies, protocols, research tools
and laboratory services.
Data Sciences International is seeking partners who are looking to change the way blood glucose monitoring is carried out in the research community.
Particularly, we wish to collaborate with researchers focused on the scientific and animal welfare benefits of the HD-XG implantable device.
Such research could include study designs to target:
• Increasing statistical power leading to a reduction in animal use
• Uncovering new and beneficial scientific evaluations that are currently not feasible
• Improving animal welfare and glucose measurements by decreasing animal stress
Learn More Here: www.crackit.org.uk
Learn more about PhysioTel HD-HX…
Click to watch Product and Calibration Videos
Continuous Glucose Measurement in a Novel Rat Model of Type II Diabetes: Implication for pregnancy and fetal programming
Ralf Dechend, MDGroup Leader,
Experimental and Clinical Research Center, Charite Campus Buch
Max Delbruck Center for Molecular Medicine, Berlin, Germany
Copyright 2015 R. Dechend, Data Sciences Int’l & InsideScientific. All Rights Reserved.
A Novel Diabetes Model in Rats
• Tetracyclin induces knockdown of the insulin receptor
• Specific characteristics:
diabetes can be induced reversibly
induces typ II diabetes (insulin resistance)
• 2 models: preexistant diabetes and gestational diabetes
Click to access publication online
Characterization of the Diabetic Mother
** p≤0.001 ** p≤0.0001
A complete picture of insulin resistance…
Santos SH et. al., Oral administration of angiotensin-(1-7) ameliorates type 2 diabetes in rats. J Mol Med (Berl). 2014 Mar;92(3):255-65.
The Model: A First Intervention
Getahun et al. Am J Obstet Gynecol; 2008Bellamy et al. Lancet 2009
Gestational Diabetes: An Enormous Problem
A process whereby an insultapplied at a sensitive period of development results in long term changes in the structure or function of the organism.
Fetal Programming (Barker Hypothesis)
Gestational Diabetes: An Enormous Problem
The Mating Protocol
Non-diabetic pregnancy with…
• healthy fetus (group 1)
• Diabetic fetus (group 2)
Diabetic pregnancy with…
• healthy fetus (group 3)
• Diabetic fetus (group 4)
Healthy fetus…
• After non-diabetic pregnancy (group 1)
• After diabetic pregnancy (group 3)
Diabetic fetus…
• After non-diabetic pregnancy (group 2)
• After diabetic pregnancy (group 3)
Implantable Glucose Telemetry
• The glucose sensor is placed directly in free flowing blood
• provides an accurate signal for at least 28 days
• reduces blood draws, less stressed animals; more accurate data with reduced variability
• also provides continuous temperature and activity
TetO Rats Doxycyclin Treatment vs. ControlTetO Rats Doxycyclin treatment vs. Control
10.0 11.0 12.0 13.0 14.0 15.0 16.0 17.0 18.0 19.0 20.0 21.0 22.0 23.0 24.0
80.0
160.0
240.0
320.0
400.0
480.0
560.0
640.0
mg
/dL
19.08.2014 17:27:00
P72TETONr804RN309.Glucose.Glucose P59TETONr781RN300.Glucose.GlucoseDays
Printed: 22 01 2015 13:16:56
Example of Diabetic vs. Control Rat (Non-Pregnant)
Black = Control [P72TetONr804RN309.Glucose.Glucose]
Red = Dox. Treated [P59TetONr781RN300.Glucose.Glucose]
0 25 50 75 100 125 1500
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t [min]B
lutz
ucker
[mg
/dL
]0 25 50 75 100 125 150
0
25
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t [min]
Blu
tzu
cker
[mg
/dL
]
2,05g/kg Glucose 2,7 g/kg Glucose
IP-GTTs in Normoglycemic Rats
Glucose in Normoglycemic Rats Pregnant vs. Non-Pregnant
• High variability
• Significant lower glucose levels in pregnancy
• Effect biggest at end of pregnancy
Glucose in Diabetic Rats Pregnant vs. Non-Pregnant
• Higher variability
• Tendency towards higher glucose levels in pregnancy
Preliminary Summary of Results – a work in progress...
• Significant lower glucose levels in pregnancy in normoglycemic rats
• Tendency towards higher glucose levels in pregnancy in diabetic rats
Reduction in Sample Size By Using Continuous Monitoring
• Simulation based on 1000 simulation runs with 100 animals per run
• sample sizes necessary to detect a 10% mean change with 80% power is computed
• Minimum of 28 days gives the ability to see results in both acute and chronic studies.
• The ability to see a complete, accurate, blood glucose profile from freely moving, unstressed animals.
• Complete iPTT or oGTT can be performed
• Direct connection to data-management-systems
• Risk of operation
• Adhesion, fibrosis, encapsulation, risk of infection of the electrodes
• Quality of data depends on calibration, several calibration needed
• Price…
Summary
• Current blood glucose monitoring use blood samples taken from restrained animals experiencing stress. The number of samples may be limited, and collection requires manual labor: The end result is an incomplete profile of blood glucose management.
Assessment of Drug Related Blood Hyperglycemia Profile Using Real-Time Continuous Glucose Monitoring via Radio-telemetry in Rats
Christian Schnell
Lab Head in-vivo Pharmacology,
Oncology ResearchNovartis AG
Copyright 2015 C. Schnell, Data Sciences Int’l & InsideScientific. All Rights Reserved.
The traditional way....
• In rats, mostly in isoflurane anaesthetized animals using the sub-lingual blood collection approach and a glucometer
2 | Glucose radio-telemetry | C. Schnell
Monitoring of blood glucose levels in rats:
(Courtesy of DSI)
(0.7 mm Ø)
Monitoring of blood glucose levels in rats:
The new radio-telemetry approach using the HD-XG transmitter from DSI
3 | Glucose radio-telemetry | C. Schnell
(Courtesy of DSI)
(0.7 mm Ø)
Monitoring of blood glucose levels in rats:
The new radio-telemetry approach using the HD-XG transmitter from DSI
4 | Glucose radio-telemetry | C. Schnell
(Courtesy of DSI)
Monitoring of blood glucose levels in BN rats:
• Ventral abdominal incision
• carefully separate the aorta from the vena cava just caudal to the point where the left renal vein crosses over the aorta and cranial to the iliac bifurcation
• placement of the cranial and caudal occlusion sutures (4-0 or 5-0)
The New Radio-Telemetry Approach: Abdominal Aorta Cannulation
5 | Glucose radio-telemetry | C. Schnell
(Courtesy of DSI)
← Abdominal Artery
Monitoring of blood glucose levels in BN rats:The New Radio-Telemetry Approach: Abdominal Aorta Cannulation
• Using the bent 25-gauge needle pierce the artery 1-2 mm cranial to the iliac bifurcation and insert the sensor upstream toward the heart
• Once the sensor is inserted into the vessel, withdraw the sensor introducer.
6 | Glucose radio-telemetry | C. Schnell
(Courtesy of DSI)
Monitoring of blood glucose levels in BN rats:The New Radio-Telemetry Approach: Abdominal Aorta Cannulation
• Advance the sensor cranially so that the maximum amount most of sensor is within the vessel
• Do not advance the sensor past the cranial occlusion suture
• Dry the aorta at the sensor entry site with cotton tip applicators
7 | Glucose radio-telemetry | C. Schnell
(Courtesy of DSI)
Monitoring of blood glucose levels in BN rats:The New Radio-Telemetry Approach: Abdominal Aorta Cannulation
• apply a very small amount of VetbondTM
tissue adhesive all the way around the entire sensor entry site
• Verify proper sensor placement by monitoring the live signal via a telemetry system
• Anchor the sensor in place with two small fiber patches
8 | Glucose radio-telemetry | C. Schnell
(Courtesy of DSI)
Monitoring of blood glucose levels in BN rats:The New Radio-Telemetry Approach: Intraperitoneal placement of the transmitter
• Close the abdominal wall using 4-0 or 5-0 non-absorbable suture with a simple interrupted pattern
• Incorporate the suture rib on the transmitter into the closure
• Close the skin incision using 4-0 or 5-0 absorbable suture
9 | Glucose radio-telemetry | C. Schnell
(Courtesy of DSI)
Monitoring of blood glucose levels in BN rats:
Frequency: 1 Hz Data sampling every minute
The New Radio-Telemetry Approach: Hardware…
Time (days)
-8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7
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Ch
an
ge
in
bo
dy w
eig
ht
(g)
Implantation
Single housing
Values are mean +/- SEM (n=6; initial body weight: 185 ± 3 g)
Monitoring of blood glucose levels in BN rats:The New Radio-Telemetry Approach: Recovery post-implantation…
• Rats are highly social animals
• When ever possible, group housing conditions should be privileged
• Body weight change was recorded daily in radio-telemetered rats post-implantation
11 | Glucose radio-telemetry | C. Schnell
Time (days)
-8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7
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an
ge
in
bo
dy w
eig
ht
(g)
12 | Glucose radio-telemetry | C. Schnell
Implantation
Single housing Group housing
Values are mean +/- SEM (n=6; initial body weight: 185 ± 3 g)
Monitoring of blood glucose levels in BN rats:The New Radio-Telemetry Approach: Recovery post-implantation…
• Body weight change was recorded daily in radio-telemetered rats post-implantation
• Body weight nearly normalized 8 days following implantation in single housed animals
• However, a clear tendency of enhanced body weight gain was observed when a pair mate was added into the cage
13 | Glucose radio-telemetry | C. Schnell
Time of the day (hours)
0 2 4 6 8 10 12 14 16 18 20 22 24
3.5
4.0
4.5
5.0
5.5
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6.5
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Mo
tor
Ac
tiv
ity
(co
unts
/min
, m
ea
n ±
SE
M)
Blo
od
Glu
co
se l
ev
els
(mm
ol/L
, m
ea
n ±
SE
M)
= inactive = active
Monitoring of blood glucose levels in BN rats:The New Radio-Telemetry Approach: Diurnal rhythms (n=12)
• For the first time, circadian rhythms of glucose and motor activity could be measured in unstressed freely moving Brown-Norway rats
• Values were significantly lower (P< 0.005) during the day (inactive phase, 6 AM to 6 PM) than during the night (active phase, 6 PM to 6 AM)
Time of the day (hours)
0 2 4 6 8 10 12 14 16 18 20 22 24
36.0
36.2
36.4
36.6
36.8
37.0
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37.8
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Mo
tor
Ac
tiv
ity (
co
unts
/min
, m
ea
n ±
SE
M)
Bo
dy T
em
pe
ratu
re
(°C
, m
ea
n ±
SE
M)
= inactive = active
14 | Glucose radio-telemetry | C. Schnell
Monitoring of blood glucose levels in BN rats:The New Radio-Telemetry Approach: Diurnal rhythms (n=12)
• Circadian rhythms of glucose and motor activity could also be concomitantly assessed in unstressed freely moving Brown-Norway rats
• Values were significantly lower (P< 0.005) during the day (inactive phase, 6 AM to 6 PM) than during the night (active phase, 6 PM to 6 AM)
15 | Glucose radio-telemetry | C. Schnell
Time of the day (hours)
0 2 4 6 8 10 12 14 16 18 20 22 24
3.5
4.0
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Mo
tor
Ac
tiv
ity
(co
unts
/min
, m
ea
n ±
SE
M)
Blo
od
Glu
co
se l
ev
els
(mm
ol/L
, m
ea
n ±
SE
M)
= inactive = active
• Blood glucose baseline values during the inactive phase were around 5 ± 0.3 mmol/L
• Historical data collected sublingually in the Lab (following a short isoflurane anesthesia) were more in the range of 8 to 10 mmol/L
• How can we explain this difference?
Monitoring of blood glucose levels in BN rats:The New Radio-Telemetry Approach: Diurnal rhythms (n=12)
Time (min)
-15 -10 -5 0 5 10 15 20 25 30 35 40 45 50
35.0
35.5
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37.5
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39.5
40.0
-3
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dy T
em
pe
ratu
re
(oC
, m
ea
n ±
SE
M)
Blo
od
Glu
co
se L
ev
els
(mm
ol/L
)
16 | Glucose radio-telemetry | C. Schnell
Isofluran →
Monitoring of blood glucose levels in BN rats:The New Radio-Telemetry Approach: Acute effect of anaesthesia
• One possible explanation could be the stress effect of isoflurane anaesthesia on blood glucose levels
• To address this question, we measured baseline blood glucose levels in a rat via radio-telemetry in his home cage
• The rat was then anaesthetized with isoflurane for 5 min
Time (min)
-15 -10 -5 0 5 10 15 20 25 30 35 40 45 50
35.0
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em
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ratu
re
(oC
, m
ea
n ±
SE
M)
Blo
od
Glu
co
se L
ev
els
(mm
ol/L
)
17 | Glucose radio-telemetry | C. Schnell
Isofluran →
Monitoring of blood glucose levels in BN rats:The New Radio-Telemetry Approach: Acute effect of anaesthesia
• Following these 5 min of anaesthesia, the rat was returned to his cage and blood glucose / body temperature (BT) recorded continuously
• Blood glucose values very rapidly raised to levels of up to 8 mmol/L while BT decreased by 1.5 °C
• It took nearly 20 to 25 min until the blood glucose levels returned to initial values
Time (min)
-15 -10 -5 0 5 10 15 20 25 30 35 40 45 50
0
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Mo
tor
acti
vit
y
(co
unt
/ 2
min
)
Blo
od
Glu
co
se L
ev
els
(mm
ol/L
)
18 | Glucose radio-telemetry | C. Schnell
Isofluran →
Time (min)
-15 -10 -5 0 5 10 15 20 25 30 35 40 45 50
0
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Mo
tor
acti
vit
y
(co
unt
/ 2
min
)
Blo
od
Glu
co
se L
ev
els
(mm
ol/L
)
Isofluran →Isofluran →
Monitoring of blood glucose levels in BN rats:The New Radio-Telemetry Approach: Acute effect of anaesthesia
19 | Glucose radio-telemetry | C. Schnell
Is o flu r a n e T e le m e tr y
0
5
1 0
1 5
2 0
Blo
od
glu
co
se
le
ve
ls (
mm
ol/
L)
me
an
S
D
*( 8 .6 )
(5 .0 )
(n=42) (n=12)
Monitoring of blood glucose levels in BN rats:The New Radio-Telemetry Approach: Base line assessment
• Comparison of baseline blood glucose values in rats measured sublingually following isoflurane anesthesia (left) or via radio-telemetry (right). *: p< 0.0001, statistical significance, two tailed t-Test.
• Telemetry reduces blood glucose basal levels and variability (3R’s)
Time (min)
-15 -10 -5 0 5 10 15 20 25 30 35 40 45 50 55 60 65
35.0
35.5
36.0
36.5
37.0
37.5
38.0
38.5
39.0
39.5
40.0
-1
0
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Bo
dy T
em
pe
ratu
re
(oC
, m
ea
n ±
SE
M)
Blo
od
Glu
co
se L
ev
els
(mm
ol/L
)
20 | Glucose radio-telemetry | C. Schnell
← Vehicle p.o. • Furthermore, we wanted to assess the stress effect of oral administration on blood glucose levels
• A very minor effect on blood glucose levels (+ 0.5 mmol/L) and BT could be evidenced
• Blood glucose levels and BT normalized after 20 min
Monitoring of blood glucose levels in BN rats:The New Radio-Telemetry Approach: Effect of vehicle p.o. (n=5)
Time (hours)
Day 1 Day 2 Day 3 Day 4 Day 5
Blo
od
Glu
co
se L
evels
( m
mol/L )
4.0
4.5
5.0
5.5
6.0
6.5
7.0
Active
Time (hours)
Day 1 Day 2 Day 3 Day 4 Day 5
Bo
dy T
em
pera
ture
( d
egre
e C
els
ius )
36.5
37.0
37.5
38.0
38.5
Active
Time (hours)
Day 1 Day 2 Day 3 Day 4 Day 5
Lo
co
mo
tor
Acti
vit
y (
counts
/min
)
0
1
2
3
4
5
6
7
8
Active
21 | Glucose radio-telemetry | C. Schnell
Monitoring of blood glucose levels in BN rats:The New Radio-Telemetry Approach: Base line assessment (n=9)
Blood Glucose Locomotor Activity Body Temperature
Conclusions:
• At day 1 of treatment, hyperglycemia could be managed by insulin production
• At steady state (Day 4-5), a clear hyperglycemia profile was observed
• Telemetry monitoring allows the assessment of degree and duration of pathway inhibition
Dosed at 10 a.m. before the inactive period (n=6)
Time (hours)
Day 0 Day 1 Day 2 Day 3Blo
od
Glu
co
se L
evels
(
mm
ol/L,
mean ±
SE
M)
0
2
4
6
8
10
12
14
16
18
20
22
24
26
28
30
32
BYL719Vehicle BYL719 BYL719
Day 4 Day 5 Day 6 Day 7
BYL719 BYL719 Active
22 | Glucose radio-telemetry | C. Schnell
Monitoring of blood glucose levels in BN rats:The New Radio-Telemetry Approach: BYL719 50 mg/kg p.o.
Time post treatment (hours)
0 2 4 6 8 10 12 14 16 18 20 22 24
0
2
4
6
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10
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28
30
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34
4
6
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26
28
Sim
ula
ted
Pla
sm
a c
on
cen
trati
on
(µm
ol/L
, m
ea
n ±
SE
M)
BYL719 50 mg/kg p.o.
Blo
od
Glu
co
se lev
els
(mm
ol/L
, m
ea
n ±
SE
M)
• Values are mean +/- SEM at day 4 (n=6)
• BYL719 treatment in BN rats induced a transient glucose level increase suggestive of glucose metabolism impairment
• A clear PK/PD relationship could be demonstrated
23 | Glucose radio-telemetry | C. Schnell
Monitoring of blood glucose levels in BN rats:The New Radio-Telemetry Approach: BYL719 50 mg 10 a.m.
1
2
3
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5
6
7
8
9
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11
12
13
14
15
16
Time post-implantation (days)
1 - 10 11 - 20 21 - 30 31 - 40 41 - 50 51 - 60 61 - 70 71 - 80 81 - 90
24 | Glucose radio-telemetry | C. Schnell
DSI success rate ≥ 28 days → 80%
Monitoring of blood glucose levels in BN rats:Radio-Telemetry : Success Rate ≥ 28 days → 92%
.
1 → Battery
2
3
4 → signal quality
5
6
7
8
9
10
11 → Battery
12
13 → signal quality
14
15
16
Time post-implantation (days)
1 - 10 11 - 20 21 - 30 31 - 40 41 - 50 51 - 60 61 - 70 71 - 80 81 - 90
25 | Glucose radio-telemetry | C. Schnell
DSI success rate ≥ 28 days → 80% : Hardware related failure
Monitoring of blood glucose levels in BN rats:Radio-Telemetry : Success Rate ≥ 60 days → 85%
.
• The HD-XG glucose telemetry implant offers a novel solution to obtain continuous, real-time, blood glucose measurements in laboratory animals in preclinical research
• We can now collect data for up to 84 days while reducing animal stress and measurement variability commonly associated with glucose test strip (3R’s)
• For the first time, a continuous 24h profile on blood glucose for NVP-BYL719 could be obtained. This profile is reproducible over time and a clear PK/PD relationship could be demonstrated
• It can be emphasized that the use of such a novel technology will enable advances in the understanding of the physiology of glucose metabolism regulation following PI3K inhibition possibly leading to improved therapies in the clinic
26 | Glucose radio-telemetry | C. Schnell
Monitoring of blood glucose levels in BN rats:Radio-Telemetry : Conclusions…
Data Sciences International is seeking partners who are looking to change the way blood glucose monitoring is carried out in the research community.
Particularly, we wish to collaborate with researchers focused on the scientific and animal welfare benefits of the HD-XG implantable device.
Such research could include study designs to target:
• Increasing statistical power leading to a reduction in animal use
• Uncovering new and beneficial scientific evaluations that are currently not feasible
• Improving animal welfare and glucose measurements by decreasing animal stress
Learn More Here: www.crackit.org.uk
Thank You!
Christian [email protected]
For additional information on Data Sciences International PhysioTel HD-XG implant for continuous glucose recordings and additional implantable telemetry solutions for physiological monitoring please visit:
http://www.datasci.com
Dr. Ralf [email protected]