Stress Disorders, Post-Traumatic
Conditions
Keywords
Exercise, Stress, PTSD, Mindfulness, Breathing, Cortisol
Brief summary
This study will explore the relationship between changes in plasma cortisol and symptom reduction resulting from individuals with posttraumatic stress disorder (PTSD) participating in an 8-week program of mindfulness-based stretching and breathing exercise. The investigators hypothesize that at the completion of participation in the 8-week program, exercise-induced symptom reduction will be associated with changes in cortisol levels.
Detailed description
This study will employ an intent-to-treat design to evaluate the relationship between exercise-induced posttraumatic stress disorder (PTSD) symptom reduction and exercise-induced changes in cortisol level. The participants consist of nurses and the intervention will be conducted at the Clinical and Translational Science Center of the University of New Mexico. The study was approved by the Human Research Protections Office of the university. Nurses who are screened positively for PTSD will be randomly assigned to either control or exercise group. At baseline and in weeks 4, 8, 12 and 16, immediately after the phlebotomy for serum cortisol, the investigators will ask the participants to rate the severity of their PTSD symptoms using the PTSD Checklist (PCL).
Interventions
BEHAVIORALMindfulness-based exercise
8-week program of mindfulness-based stretching and breathing exercises
Sponsors
University of New Mexico
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
21 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
* employed as a nurse * PCL-C score of at least 28 with at least a score of 3 on one or more items for inclusion in the PTSD symptomatic groups (EX and CON) * PCL-C score of 27 or lower for inclusion in the non-PTSD symptomatic group (BASE).
Exclusion criteria
* the inability to complete the exercise program * a positive answer to any of the seven screening questions on the Physical Activity Readiness Questionnaire (PAR-Q) * current use of prednisone or other forms of cortisone medication excluding cortisone in inhaled form
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change From Baseline in PTSD Checklist - Civilian Version (PCL-C) Score | Baseline and 8 weeks | The PCL-C is a 17-item self-report instrument that measures the symptoms of PTSD. A total score, ranging from 17 to 85, is found by summing the scores of the 17 items. Higher values are considered to be a worse outcome. The inclusion criteria in the PTSD symptomatic group is a PCL-C total score of at least 28 with a score of 3 or higher on 1 or more items.To detect a reduction in PTSD symptom severity with a 2-sided 5% significance level and a power of 80%, the mean difference of PCL-C scores of 5.16 or greater requires a sample size of 20 participants for Exercise and Control groups, given an anticipated dropout rate of 10%. Data analyses are conducted using an a priori intention-to-treat approach. The analysis for the between-group differences of the intervention is conducted using t-tests comparing Exercise and Control groups at post-intervention. The analysis for the within-group difference is conducted using repeated measures ANOVA for both groups at baseline and week 8. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Cortisol | baseline and 8 weeks | Change from baseline in serum cortisol levels at 8 weeks. Serum cortisol samples were collected at 8:00 Ante Meridian (AM). The changes are calculated from two time points as the values at 8 weeks minus the values at baseline. |
Countries
United States
Participant flow
Recruitment details
Nurse volunteers were recruited from the University of New Mexico Hospital through advertisement,between September 1, 2011 and March 31, 2012.
Pre-assignment details
Participants gave their informed written consent before participation. Inclusion criteria were age greater than 18 years and employment as a nurse at the University of New Mexico (UNM) Hospital. Exclusion criteria included an inability to participate in the exercise program, or current use of systemic glucocorticoid.
Participants by arm
| Arm | Count |
|---|---|
| Exercise Group Participants who are screened positive for PTSD and participate in the mindfulness-based exercise. | 11 |
| Control Group Participants who are screened positive for PTSD but do not participate in the mindfulness-based exercise. | 11 |
| Base Group Healthy volunteers who are not screened positive for PTSD and do not participate in the mindfulness-based exercise. | 7 |
| Total | 29 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 | FG002 |
|---|---|---|---|---|
| Overall Study | Family matter | 0 | 1 | 0 |
Baseline characteristics
| Characteristic | Control Group | Base Group | Exercise Group | Total |
|---|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 0 Participants | 1 Participants | 0 Participants | 1 Participants |
| Age, Categorical Between 18 and 65 years | 11 Participants | 6 Participants | 11 Participants | 28 Participants |
| Age, Continuous | 45 years STANDARD_DEVIATION 9.9 | 44 years STANDARD_DEVIATION 15.1 | 49 years STANDARD_DEVIATION 6.4 | 46 years STANDARD_DEVIATION 10.1 |
| Region of Enrollment United States | 11 participants | 7 participants | 11 participants | 29 participants |
| Sex: Female, Male Female | 11 Participants | 7 Participants | 10 Participants | 28 Participants |
| Sex: Female, Male Male | 0 Participants | 0 Participants | 1 Participants | 1 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk |
|---|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — | — / — |
| other Total, other adverse events | 0 / 11 | 0 / 11 | 0 / 7 |
| serious Total, serious adverse events | 0 / 11 | 0 / 11 | 0 / 7 |
Outcome results
Primary
Change From Baseline in PTSD Checklist - Civilian Version (PCL-C) Score
The PCL-C is a 17-item self-report instrument that measures the symptoms of PTSD. A total score, ranging from 17 to 85, is found by summing the scores of the 17 items. Higher values are considered to be a worse outcome. The inclusion criteria in the PTSD symptomatic group is a PCL-C total score of at least 28 with a score of 3 or higher on 1 or more items.To detect a reduction in PTSD symptom severity with a 2-sided 5% significance level and a power of 80%, the mean difference of PCL-C scores of 5.16 or greater requires a sample size of 20 participants for Exercise and Control groups, given an anticipated dropout rate of 10%. Data analyses are conducted using an a priori intention-to-treat approach. The analysis for the between-group differences of the intervention is conducted using t-tests comparing Exercise and Control groups at post-intervention. The analysis for the within-group difference is conducted using repeated measures ANOVA for both groups at baseline and week 8.
Time frame: Baseline and 8 weeks
Population: For Base Group, the values entered represent the mean value of the baseline PCL-C scores. The mean difference score for the Base Group is not available because the Base Group was assessed only at baseline.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Exercise Group | Change From Baseline in PTSD Checklist - Civilian Version (PCL-C) Score | -18.8 scores on a scale | Standard Deviation 10.6 |
| Control Group | Change From Baseline in PTSD Checklist - Civilian Version (PCL-C) Score | -5.2 scores on a scale | Standard Deviation 15.8 |
| Base Group | Change From Baseline in PTSD Checklist - Civilian Version (PCL-C) Score | 21.8 scores on a scale | Standard Deviation 3.4 |
p-value: <0.0195% CI: [-25.6, -1.6]t-test, 2 sided
Secondary
Cortisol
Change from baseline in serum cortisol levels at 8 weeks. Serum cortisol samples were collected at 8:00 Ante Meridian (AM). The changes are calculated from two time points as the values at 8 weeks minus the values at baseline.
Time frame: baseline and 8 weeks
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Exercise Group | Cortisol | 5.1 μg/dl | Standard Deviation 4.5 |
| Control Group | Cortisol | -0.7 μg/dl | Standard Deviation 6.5 |
| Base Group | Cortisol | -0.04 μg/dl | Standard Deviation 9.4 |
p-value: <0.0195% CI: [0.83, 10.8]t-test, 2 sided