1. Assessment of Gastric Compliance
Response to a Meal: Gastric Sensory
Motor Function in Bulimia Nervosa
JL Guss, HR Kissileff, E Zimmerli, M Devlin, B Walsh
Obesity Research Center-St Lukes-Roosevelt Hospital
Columbia University

2. Bulimia Nervosa (BN)-A Satiety Disturbance?
F Episodes of uncontrolled hyperphagia
F Rate of eating does not decline during meals
F Eat more than controls to reach same fullness
F Post-prandial CCK-release is diminished

3. Gastric Relaxation (Accommodation)
F Adaptive relaxation: Postprandial gastric
relaxation in response to ingested nutrient
F Increases gastric volume relative to fasting
F Impaired in BN

4. Impaired Relaxation Response to Food
Fundic Accommodation
(receptive relaxation)
Meal
Impaired Accommodation
food distributed to antrum

5. Gastric Relaxation-Healthy Control

6. Gastric Relaxation-Patient with BN

7. Blunted Relaxation Response in BN
Controls
Patients
Patients

8. Bulimia Nervosa: Gastric Capacity
1200
G
a
s
t
900
r
i
c
600
C
a
p
a
c 300
i
t
y
0
BN Patients Controls
Geliebter et al 1992

9. Gastric Emptying: Patients vs Controls
100
Bulimia Nervosa
Controls
90
Percent of Initial Remaining
80
70
60
50
40
0 10 20 30 40 50 60 70 80 90
Time (min)

10. Aim
F To determine whether meal-induced changes
in motor-sensory responses to gastric
distension are disturbed in BN.
F To test motor-sensory response to distension
by measuring gastric compliance: change in
gastric volume as a function of changing
pressure.

11. Hypothesis
F Motor and sensory response to the filling
effect of a large meal is impaired in BN.

12. Gastric Compliance
F Volume response to an imposed pressure
F Volume change at pressure increment pre & post meal
l Intragastric volume response on y-axis
l Imposed incremental pressure on x-axis
l Compliance = slope of the pressure-volume curve
F Measurement=response to increased isobaric stepwise
distension
F Accomplished with a barostat device: applies fixed
pressure & records corresponding gastric volume

13. Procedure
F Balloon swallowed @ 1500 hrs, after 6 hr fast
F MDP-minimal distending pressure- obtained
F Increase distending pressure by 2 mmHg per 2 min,
starting at minimal distending pressure (MDP)
F Barostat records balloon volume every second
F Subjects rate abdominal sensation on 6-pt scale at
each pressure
F Distensions end when volume =750mL or if subject
reports pain
F 200cc Ensure consumed po
F Process repeated from minimal distending pressure

14. Pre-prandial MDP
Patients
Controls
11
10
9
MDP (mmHg)
8
7
6
5
4
0 0.5 1 1.5 2 2.5
Group

15. Minimal Distending Pressure (MDP)
9
Patients
8 Controls
7
6
MDP (mmHg)
5
4
3
2
1
0
Preprandial Postprandial
Prandial State

16. Slope of Sensation vs Pressure
12
Preprandial
B Patients
10 B
C Controls
C C
8 B C B
B C C C
Sensation
6 B C B
C B
4 B C C
B B
2 C B
0
10 12 14 16 18 20 22
Pressure

17. Gastric Compliance
800 Preprandial: BN
Postprandial: BN
700 Preprandial: CN
Postprandial: CN
600
500
Volume (mL)
400
300
200
100
0
0 2 4 6 8 10 12
Pressure above MDP (mmHg)

18. Patients
700
600
500
Volume (mL)
400
300
200
100
0
0 2 4 6 8 10 12
Pressure above MDP (mmHg)
BN pre BN post

19. Controls
700
600
500
Volume (mL)
400
300
200
100
0
0 2 4 6 8 10 12
Pressure above MDP (mmHg)
NC pre NC Post

20. Post Meal Volume Change
800
Controls
750 regression
Post Meal Max Volume (ml)
Patients
700 regression
650
600
550
500
450
400
200 300 400 500 600 700 800
Premeal Max Volume (ml)

21. Gastric Relaxation-Postprandial Rise in Volume
400
p < .05
300
Post Meal Volume
200
100
0
-100
-200
BN (n=16) NC (n=16)

22. Summary of Results
F Post meal gastric relaxation is blunted in BN.
F Gastric compliance appears normal in BN.