Trial Outcomes & Findings for Impact of Exercise Training on Pain and Brain Function in Gulf War Veterans (NCT NCT01350492)

NCT ID: NCT01350492

Last Updated: 2020-10-20

Results Overview

The Short Form McGill Pain Questionnaire VAS ranges from 0 (No pain) to 100 (Worst possible pain). The respondent was asked to report how bad their pain has been over the past week. A higher score indicates a greater severity of pain.

Recruitment status

COMPLETED

Study phase

NA

Target enrollment

77 participants

Primary outcome timeframe

6 weeks, 11 weeks, 17 weeks and 6 and 12 months post intervention.

Results posted on

2020-10-20

Participant Flow

Between May 2013 and March 2018, participants were recruited through digital and print advertisements in area medical centers, presentations at Veteran Service Organizations and via a mailed letter targeting Veterans from a VA database search. The first participant was enrolled in June 2013 and the last participant was enrolled in March 2018.

Following phone screening, 119 participants were invited to participate. Of those, 77 were enrolled and underwent a more substantial screening process. 54 participants were randomly assigned to a group. The remaining 23 participants were not assigned to a group as they were ineligible (n=17) or declined to continue (n=6).

Participant milestones

Participant milestones
Measure
Resistance Exercise Training
Resistance Exercise Training: 16 weeks of resistance exercise training, performed twice weekly, for the treatment of chronic muscle pain.
Waitlist Control
Waitlist Control: Individuals assigned to this condition were asked to maintain their usual routine while enrolled. Upon completion they were offered the opportunity to undertake the resistance training protocol.
Intervention
STARTED
28
26
Intervention
6-week MRI Scan
24
22
Intervention
11-week MRI Scan
23
21
Intervention
COMPLETED
23
20
Intervention
NOT COMPLETED
5
6
Post Intervention Follow-Up
STARTED
23
20
Post Intervention Follow-Up
6-month MRI Scan
20
20
Post Intervention Follow-Up
COMPLETED
17
18
Post Intervention Follow-Up
NOT COMPLETED
6
2

Reasons for withdrawal

Reasons for withdrawal
Measure
Resistance Exercise Training
Resistance Exercise Training: 16 weeks of resistance exercise training, performed twice weekly, for the treatment of chronic muscle pain.
Waitlist Control
Waitlist Control: Individuals assigned to this condition were asked to maintain their usual routine while enrolled. Upon completion they were offered the opportunity to undertake the resistance training protocol.
Intervention
Lost to Follow-up
2
5
Intervention
Withdrawal by Subject
3
1
Post Intervention Follow-Up
Lost to Follow-up
6
1
Post Intervention Follow-Up
Withdrawal by Subject
0
1

Baseline Characteristics

Measures were considered valid if the participant wore the accelerometer for at least 10 hr/day for 4 days. In addition, one of those 4 days must have been a weekend day (i.e., Saturday or Sunday). The sample is limited to only those participants with a valid baseline measure.

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure
Resistance Exercise Training
n=28 Participants
Resistance Exercise Training: 16 weeks of resistance exercise training, performed twice weekly, for the treatment of chronic muscle pain.
Waitlist Control
n=26 Participants
Waitlist Control: Individuals assigned to this condition were asked to maintain their usual routine while enrolled. Upon completion they were offered the opportunity to undertake the resistance training protocol.
Total
n=54 Participants
Total of all reporting groups
Age, Continuous
49.71 years
STANDARD_DEVIATION 7.20 • n=28 Participants
50.19 years
STANDARD_DEVIATION 5.64 • n=26 Participants
49.94 years
STANDARD_DEVIATION 6.44 • n=54 Participants
Sex: Female, Male
Female
7 Participants
n=28 Participants
4 Participants
n=26 Participants
11 Participants
n=54 Participants
Sex: Female, Male
Male
21 Participants
n=28 Participants
22 Participants
n=26 Participants
43 Participants
n=54 Participants
Race/Ethnicity, Customized
White, not Hispanic
25 Participants
n=28 Participants
20 Participants
n=26 Participants
45 Participants
n=54 Participants
Race/Ethnicity, Customized
White Hispanic
2 Participants
n=28 Participants
3 Participants
n=26 Participants
5 Participants
n=54 Participants
Race/Ethnicity, Customized
Black, not Hispanic
1 Participants
n=28 Participants
3 Participants
n=26 Participants
4 Participants
n=54 Participants
Region of Enrollment
United States
28 Participants
n=28 Participants
26 Participants
n=26 Participants
54 Participants
n=54 Participants
Marital Status
Married
15 Participants
n=28 Participants
21 Participants
n=26 Participants
36 Participants
n=54 Participants
Marital Status
Divorced
6 Participants
n=28 Participants
4 Participants
n=26 Participants
10 Participants
n=54 Participants
Marital Status
Never married
3 Participants
n=28 Participants
1 Participants
n=26 Participants
4 Participants
n=54 Participants
Marital Status
Widowed
0 Participants
n=28 Participants
0 Participants
n=26 Participants
0 Participants
n=54 Participants
Marital Status
Separated
2 Participants
n=28 Participants
0 Participants
n=26 Participants
2 Participants
n=54 Participants
Marital Status
Living as married
2 Participants
n=28 Participants
0 Participants
n=26 Participants
2 Participants
n=54 Participants
Education
Did not finish high school
0 Participants
n=28 Participants
1 Participants
n=26 Participants
1 Participants
n=54 Participants
Education
High school graduate
4 Participants
n=28 Participants
6 Participants
n=26 Participants
10 Participants
n=54 Participants
Education
Some college
11 Participants
n=28 Participants
6 Participants
n=26 Participants
17 Participants
n=54 Participants
Education
College graduate (including associates degree)
9 Participants
n=28 Participants
11 Participants
n=26 Participants
20 Participants
n=54 Participants
Education
Some post-graduate
1 Participants
n=28 Participants
0 Participants
n=26 Participants
1 Participants
n=54 Participants
Education
Graduate degree
3 Participants
n=28 Participants
2 Participants
n=26 Participants
5 Participants
n=54 Participants
Pain Catastrophizing Scale (PCS)
11.79 units on a scale
STANDARD_DEVIATION 8.72 • n=28 Participants
8.65 units on a scale
STANDARD_DEVIATION 7.98 • n=26 Participants
10.28 units on a scale
STANDARD_DEVIATION 8.44 • n=54 Participants
State Trait Anxiety Inventory (STAI) - Y2 Form
37.57 units on a scale
STANDARD_DEVIATION 9.94 • n=28 Participants
36.00 units on a scale
STANDARD_DEVIATION 9.21 • n=26 Participants
36.81 units on a scale
STANDARD_DEVIATION 9.54 • n=54 Participants
Beck Depression Inventory (BDI)
9.07 units on a scale
STANDARD_DEVIATION 6.85 • n=28 Participants
6.73 units on a scale
STANDARD_DEVIATION 6.62 • n=26 Participants
7.94 units on a scale
STANDARD_DEVIATION 6.78 • n=54 Participants
Physical Activity (Accelerometer)
236520 Counts per day
STANDARD_DEVIATION 114918 • n=24 Participants • Measures were considered valid if the participant wore the accelerometer for at least 10 hr/day for 4 days. In addition, one of those 4 days must have been a weekend day (i.e., Saturday or Sunday). The sample is limited to only those participants with a valid baseline measure.
337629 Counts per day
STANDARD_DEVIATION 165554 • n=21 Participants • Measures were considered valid if the participant wore the accelerometer for at least 10 hr/day for 4 days. In addition, one of those 4 days must have been a weekend day (i.e., Saturday or Sunday). The sample is limited to only those participants with a valid baseline measure.
283704 Counts per day
STANDARD_DEVIATION 148202 • n=45 Participants • Measures were considered valid if the participant wore the accelerometer for at least 10 hr/day for 4 days. In addition, one of those 4 days must have been a weekend day (i.e., Saturday or Sunday). The sample is limited to only those participants with a valid baseline measure.
Physical Activity (Self-report)
4820 MET-minutes/week
STANDARD_DEVIATION 6094 • n=28 Participants
5848 MET-minutes/week
STANDARD_DEVIATION 7410 • n=26 Participants
5315 MET-minutes/week
STANDARD_DEVIATION 6715 • n=54 Participants
Fractional anisotropy (FA) at the corpus callosum
0.528 Scalar value b/w 0-1
STANDARD_DEVIATION 0.030 • n=28 Participants
0.521 Scalar value b/w 0-1
STANDARD_DEVIATION 0.031 • n=26 Participants
0.524 Scalar value b/w 0-1
STANDARD_DEVIATION 0.030 • n=54 Participants

PRIMARY outcome

Timeframe: 6 weeks, 11 weeks, 17 weeks and 6 and 12 months post intervention.

Population: Intent to treat population (all participants assigned to either resistance exercise training or wait-list control). Last observation carried forward (LOCF) imputation method.

The Short Form McGill Pain Questionnaire VAS ranges from 0 (No pain) to 100 (Worst possible pain). The respondent was asked to report how bad their pain has been over the past week. A higher score indicates a greater severity of pain.

Outcome measures

Outcome measures
Measure
Resistance Exercise Training
n=28 Participants
Resistance Exercise Training: 16 weeks of resistance exercise training, performed twice weekly, for the treatment of chronic muscle pain.
Waitlist Control
n=26 Participants
Waitlist Control: Individuals assigned to this condition were asked to maintain their usual routine while enrolled. Upon completion they were offered the opportunity to undertake the resistance training protocol.
Short Form McGill Pain Questionnaire Visual Analog Scale (VAS).
6 months
31.5 units on a scale
Standard Deviation 22.31
34.31 units on a scale
Standard Deviation 25.66
Short Form McGill Pain Questionnaire Visual Analog Scale (VAS).
6 weeks
29.82 units on a scale
Standard Deviation 22.12
37.08 units on a scale
Standard Deviation 25.92
Short Form McGill Pain Questionnaire Visual Analog Scale (VAS).
11 weeks
30.07 units on a scale
Standard Deviation 22.37
31.46 units on a scale
Standard Deviation 21.78
Short Form McGill Pain Questionnaire Visual Analog Scale (VAS).
17 weeks
30.68 units on a scale
Standard Deviation 24.12
35.12 units on a scale
Standard Deviation 24.05
Short Form McGill Pain Questionnaire Visual Analog Scale (VAS).
12 months
31.68 units on a scale
Standard Deviation 23.37
33.58 units on a scale
Standard Deviation 26.12

PRIMARY outcome

Timeframe: 6 weeks, 11 weeks, 17 weeks and 6 and 12 months post intervention.

Population: Intent to treat population (all participants assigned to either resistance exercise training or wait-list control). Last observation carried forward (LOCF) imputation method.

The PCS is a composite summary score of items from the VR-36 related to physical health. Individual subscale scores are z transformed using US normative data, multiplied by a factor score coefficient, summed, and transformed to a T-score of a distribution (Mean = 50; Standard Deviation = 10). Higher scores represent better physical health.

Outcome measures

Outcome measures
Measure
Resistance Exercise Training
n=28 Participants
Resistance Exercise Training: 16 weeks of resistance exercise training, performed twice weekly, for the treatment of chronic muscle pain.
Waitlist Control
n=26 Participants
Waitlist Control: Individuals assigned to this condition were asked to maintain their usual routine while enrolled. Upon completion they were offered the opportunity to undertake the resistance training protocol.
Physical Component Score (PCS) From the Veterans Rand 36 Item Heath Survey (VR-36).
17 weeks
42.66 units on a scale, T-score transformed
Standard Deviation 5.60
42.92 units on a scale, T-score transformed
Standard Deviation 5.80
Physical Component Score (PCS) From the Veterans Rand 36 Item Heath Survey (VR-36).
6 weeks
43.01 units on a scale, T-score transformed
Standard Deviation 5.17
44.53 units on a scale, T-score transformed
Standard Deviation 6.06
Physical Component Score (PCS) From the Veterans Rand 36 Item Heath Survey (VR-36).
11 weeks
41.82 units on a scale, T-score transformed
Standard Deviation 5.95
43.37 units on a scale, T-score transformed
Standard Deviation 6.68
Physical Component Score (PCS) From the Veterans Rand 36 Item Heath Survey (VR-36).
6 months
43.03 units on a scale, T-score transformed
Standard Deviation 5.96
43.94 units on a scale, T-score transformed
Standard Deviation 7.07
Physical Component Score (PCS) From the Veterans Rand 36 Item Heath Survey (VR-36).
12 months
41.14 units on a scale, T-score transformed
Standard Deviation 5.85
42.99 units on a scale, T-score transformed
Standard Deviation 6.59

PRIMARY outcome

Timeframe: 6 weeks, 11 weeks, 17 weeks and 6 and 12 months post intervention.

Population: Intent to treat population (all participants assigned to either resistance exercise training or wait-list control). Last observation carried forward (LOCF) imputation method. THE PGIC, however, was not administered until the 6-week in-person visit. So participants who were withdrawn or lost to follow up before the 6-week visit were not included.

The PGIC is a 7-item, self-report scale indicating the degree to which a patient has experienced any change since starting treatment. Each respondent was asked to rate "...the change (if any) in activity limitations, symptoms, emotions, and overall quality of life." related to their pain since beginning treatment. Scores range from 1, "No change (or condition has got worse)" to 7, "A great deal better, and a considerable improvement that has made all the difference." A higher score indicates greater improvement.

Outcome measures

Outcome measures
Measure
Resistance Exercise Training
n=24 Participants
Resistance Exercise Training: 16 weeks of resistance exercise training, performed twice weekly, for the treatment of chronic muscle pain.
Waitlist Control
n=22 Participants
Waitlist Control: Individuals assigned to this condition were asked to maintain their usual routine while enrolled. Upon completion they were offered the opportunity to undertake the resistance training protocol.
Patients' Global Impression of Change (PGIC).
6 weeks
3.58 units on a scale
Standard Deviation 1.59
1.77 units on a scale
Standard Deviation 1.02
Patients' Global Impression of Change (PGIC).
11 weeks
3.67 units on a scale
Standard Deviation 1.52
2.00 units on a scale
Standard Deviation 0.87
Patients' Global Impression of Change (PGIC).
17 weeks
3.88 units on a scale
Standard Deviation 1.83
2.05 units on a scale
Standard Deviation 0.95
Patients' Global Impression of Change (PGIC).
6 months
3.21 units on a scale
Standard Deviation 2.00
2.18 units on a scale
Standard Deviation 1.47
Patients' Global Impression of Change (PGIC).
12 months
2.71 units on a scale
Standard Deviation 1.81
2.45 units on a scale
Standard Deviation 1.47

SECONDARY outcome

Timeframe: 6 weeks, 11 weeks, 17 weeks and 6 and 12 months post intervention.

Population: Intent to treat population (all participants assigned to either resistance exercise training or wait-list control). Last observation carried forward (LOCF) imputation method. Sample is limited to only those participants with a valid baseline measure.

Physical activity is measured via accelerometer. The measure is a unit-less average of the number of counts per day. The higher the count, the greater the amount and intensity of physical activity accumulated over course of the day. Values range from 30,000 (sedentary) to 800,000 (highly active).

Outcome measures

Outcome measures
Measure
Resistance Exercise Training
n=24 Participants
Resistance Exercise Training: 16 weeks of resistance exercise training, performed twice weekly, for the treatment of chronic muscle pain.
Waitlist Control
n=21 Participants
Waitlist Control: Individuals assigned to this condition were asked to maintain their usual routine while enrolled. Upon completion they were offered the opportunity to undertake the resistance training protocol.
Physical Activity (Accelerometer)
6 weeks
261012 Counts per day
Standard Deviation 131113
299872 Counts per day
Standard Deviation 124379
Physical Activity (Accelerometer)
11 weeks
267376 Counts per day
Standard Deviation 133327
321253 Counts per day
Standard Deviation 121150
Physical Activity (Accelerometer)
17 weeks
285157 Counts per day
Standard Deviation 181804
305315 Counts per day
Standard Deviation 122002
Physical Activity (Accelerometer)
6 months
267067 Counts per day
Standard Deviation 168249
295661 Counts per day
Standard Deviation 126297
Physical Activity (Accelerometer)
12 months
252940 Counts per day
Standard Deviation 144748
300769 Counts per day
Standard Deviation 132518

SECONDARY outcome

Timeframe: 6 weeks, 11 weeks, 17 weeks and 6 and 12 months post intervention.

Total weekly self-reported physical activity was quantified using the International Physical Activity Questionnaire (IPAQ). The outcome is expressed as the number of metabolic equivalent (MET) minutes per week. One MET is defined as the amount of oxygen consumed while sitting at rest and is equal to 3.5 ml O2 per kg body weight x min, so 1 minute spent at rest is equal to 1 MET-minute. Respondents are only asked to report on physical activity of a light intensity or greater (≥3 METs, e.g., briskly walking). Higher values equal greater amount/intensity of activity.

Outcome measures

Outcome measures
Measure
Resistance Exercise Training
n=28 Participants
Resistance Exercise Training: 16 weeks of resistance exercise training, performed twice weekly, for the treatment of chronic muscle pain.
Waitlist Control
n=26 Participants
Waitlist Control: Individuals assigned to this condition were asked to maintain their usual routine while enrolled. Upon completion they were offered the opportunity to undertake the resistance training protocol.
Physical Activity (Self-report)
6 weeks
4535 MET-minutes/week
Standard Deviation 5948
6824 MET-minutes/week
Standard Deviation 7944
Physical Activity (Self-report)
11 weeks
5856 MET-minutes/week
Standard Deviation 5912
4978 MET-minutes/week
Standard Deviation 7601
Physical Activity (Self-report)
17 weeks
4629 MET-minutes/week
Standard Deviation 4280
6491 MET-minutes/week
Standard Deviation 9020
Physical Activity (Self-report)
6 months
4232 MET-minutes/week
Standard Deviation 3771
6273 MET-minutes/week
Standard Deviation 9161
Physical Activity (Self-report)
12 months
4492 MET-minutes/week
Standard Deviation 4739
6113 MET-minutes/week
Standard Deviation 8709

SECONDARY outcome

Timeframe: 6 weeks, 11 weeks, 17 weeks and 6 and 12 months

Fractional anisotropy (FA) is a scalar value between 0 and 1 that describes the degree of anisotropy of a diffusion process. In the case of brain white matter integrity, it gives us an indication of the tract integrity at a particular region within the brain. 0 would indicate flow is completely unrestricted (no integrity), 1 that all flow is in the same direction (high integrity). In this instance we are using the FA at the body of the corpus callosum as an indicator of overall brain white matter integrity.

Outcome measures

Outcome measures
Measure
Resistance Exercise Training
n=28 Participants
Resistance Exercise Training: 16 weeks of resistance exercise training, performed twice weekly, for the treatment of chronic muscle pain.
Waitlist Control
n=26 Participants
Waitlist Control: Individuals assigned to this condition were asked to maintain their usual routine while enrolled. Upon completion they were offered the opportunity to undertake the resistance training protocol.
Brain Structure: White Matter Tract Integrity, Operationalized With Fractional Anisotropy (FA) Measures at the Body of the Corpus Callosum.
6 weeks
0.5263 Scalar value b/w 0 and 1
Standard Deviation 0.0310
0.5213 Scalar value b/w 0 and 1
Standard Deviation 0.0325
Brain Structure: White Matter Tract Integrity, Operationalized With Fractional Anisotropy (FA) Measures at the Body of the Corpus Callosum.
12 months
0.5219 Scalar value b/w 0 and 1
Standard Deviation 0.0343
0.5203 Scalar value b/w 0 and 1
Standard Deviation 0.0329
Brain Structure: White Matter Tract Integrity, Operationalized With Fractional Anisotropy (FA) Measures at the Body of the Corpus Callosum.
11 weeks
0.5256 Scalar value b/w 0 and 1
Standard Deviation 0.0312
0.5213 Scalar value b/w 0 and 1
Standard Deviation 0.0323
Brain Structure: White Matter Tract Integrity, Operationalized With Fractional Anisotropy (FA) Measures at the Body of the Corpus Callosum.
17 weeks
0.5261 Scalar value b/w 0 and 1
Standard Deviation 0.0298
0.5224 Scalar value b/w 0 and 1
Standard Deviation 0.0313
Brain Structure: White Matter Tract Integrity, Operationalized With Fractional Anisotropy (FA) Measures at the Body of the Corpus Callosum.
6 months
0.5262 Scalar value b/w 0 and 1
Standard Deviation 0.0303
0.5217 Scalar value b/w 0 and 1
Standard Deviation 0.0325

Adverse Events

Resistance Exercise Training

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Waitlist Control

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Aaron J. Stegner, Ph.D.

William S. Middleton Memorial Veterans Hospital

Phone: 608-262-1290

Results disclosure agreements

  • Principal investigator is a sponsor employee
  • Publication restrictions are in place