THE IMPACT OF STRESS
ON AUTONOMIC
FUNCTIONING IN
CHRONIC ABDOMINAL
PAIN PATIENTS
Davlyn M. Tillman
Under the Direction of Dr. Lynn Walker
INTRODUCTION
The main topic of this study was Chronic Abdominal
Pain. Chronic abdominal pain (CAP) is a recurring
pain in the abdomen common in childhood. The
criteria are three or more episodes of abdominal pain
that occur over at least three months and affect
normal daily activities (Apley, 1975).
 This study specifically focused on the physiological and
psychological Impact of Stress on participants with
Chronic Abdominal Pain
Specific Effects on Autonomic Functioning – Increases in
Blood Pressure
 Specific Effects on Positive and Negative Affect – Decreases
in Positive Affect and Increases in Negative Affect


Goal of Study


Non-recovered and recovered CAP patients and well controls were
subjected to a laboratory social stressor to measure physiological
and psychological responses
Hypotheses Tested
Non-recovered CAP patients will experience
greater physiological change in blood
pressure levels in relation to recovered CAP
Patients and well controls
 Non-recovered CAP patients will experience
lower positive affect and higher negative
affect in relation to recovered CAP Patients
and well controls

METHODS

Participants
317 recovered and non-recovered CAP patients and
control (“well”) participants from the Middle Tennessee
area
 Currently between ages 13-32


Measures

Health Interview (Rome III)


Social Competence Interview


Laboratory Stressor – in-depth discussion of work, school, friend,
neighborhood, money, or family stress
Physiological Assessment


Used to determine whether recovered or non-recovered CAP
Blood Pressure measurements taken during baseline and SCI
Symptom Emotion Report (SER)

Questionnaire to measure positive and negative affect

Procedure
 Participants complete 45-60 minute health interview by
phone
 Questions on subjects such as demographics, behavior,
and physical wellness
 Participants then come into research lab at Children’s
Hospital to complete the lab session and social stressor:
 Baseline blood pressure measurements during
landscape slideshow
 SER1 Survey
 Social Competence Interview (active and cool phase) –
participants discuss chosen social stressor with
interviewer
 SER2 Survey
 Recovery period blood pressure measurements during
slideshow
RESULTS

Demographics:





317 participants in the study
Mean age of 20.34 years, S.D. = 4.37
Participants were 59.6% female and 40.4% male
93 well participants, 143 recovered CAP participants,
and 81 non-recovered participants
92.7 Caucasian
RESULTS: BLOOD PRESSURE
MEASUREMENTS
Mean of baseline blood pressures were subtracted from
mean of two maximum blood pressures
 UNIANOVA statistical test
 All three groups experienced increase in BP due to
laboratory stressor
 No significant difference between groups in systolic
and diastolic blood pressure changes
 Systolic: p<0.47
 Diastolic: p<0.08

RESULTS: BLOOD PRESSURE
MEASUREMENTS
Changes in Systolic and Diastolic BP
Systolic and Diastolic BP Means
(mmHG)
140.00
120.00
100.00
80.00
60.00
40.00
20.00
0.00
Baseline
SCI Active
Maximum BP in SCI Active
Experiment Phases
Unrecovered CAP: Systolic
Unrecovered CAP: Diastolic
Recovered CAP: Systolic
Recovered CAP: Diastolic
Well: Systolic
Well: Diastolic
RESULTS: POSITIVE AND NEGATIVE
AFFECT

Mean score for Time 1 subtracted from mean scores for
Time 2




Calculated for both positive and negative affect
One way ANOVA statistical test
All three groups experienced a decrease in positive affect
and increase in negative affect in response to laboratory
stressor
No significant difference between groups in positive and
negative affect changes


Positive affect: p<0.052
Negative affect: p<0.605
RESULTS: POSITIVE AFFECT
4.0000
Wells
Resolved CAP
3.0000
Unresolved CAP
2.0000
1.0000
Positive Affect Time 1
(SER PA mean score)
Positive Affect Time 2
(SER PA mean score)
RESULTS: NEGATIVE AFFECT
5.0000
4.0000
3.0000
Wells
Resolved CAP
2.0000
Unresolved CAP
1.0000
Negative Affect Time 1 (SER Negative Affect Time 2 (SER
NA mean score)
NA mean score)
CONCLUSION

Key Findings
 The expected
changes in blood pressure, positive affect, and negative affect
were similar in all three sub-groups
 There were no significant differences in changes for non-recovered CAP
participants

Potential Implications
 All three groups
 The groups may
seem to have similar biological responses to social stressor
instead have different perceptions of stress that cause
differences in self-report of somatic symptoms
 Positive and Negative Affect results have implications for further studies on
coping strategies in patients with chronic abdominal pain patients

Limitations
 The exact
stressor discussed during the interview differed for each
participants
 Measurements of positive and negative affect were self-reports
 The SCI was a short-term stressor and different results may be seen for a
chronic stressor

Future Direction
 Studies focusing
on the cognitive effects of stress on chronic abdominal pain
patients such as differences in perception as opposed to the physiological
effects such as blood pressure
 Prospective studies that test types of coping strategies and success of
strategies used by those who have recovered from chronic abdominal pain
ACKNOWLEDGEMENTS
Dr. Lynn Walker, Walker Lab, Vanderbilt Children’s
Hospital
 Grace Shelby, Graduate Student,Walker Lab
 Dr. Craig Smith, Honors Program Director
