Peripheral Arterial Disease
Conditions
Keywords
Exercise, Weight Loss, Mobility Limitation
Brief summary
This study is designed to examine the added benefits of weight loss to an exercise program in older obese Veterans with peripheral arterial disease. The investigators want to determine if weight loss in addition to exercise will 1) improve walking ability to a greater extent than exercise alone and 2) determine the underlying reasons why walking ability improves by measuring blood flow and the amount of muscle in the leg muscles.
Detailed description
Peripheral artery disease (PAD) affects an estimated 12 -15 million adults in the US and an estimated 20% of older Veterans. Those with PAD ambulate with slow gait and experience decreased leg strength, dysmobility, reduced quality of life, serious morbidity and often premature death. It is estimated that over 60% of individuals with PAD are overweight or obese. While PAD itself worsens mobility, obesity adds a further functional burden to older adults with PAD. Individuals diagnosed with PAD, who are also obese typically claudicate 40% more quickly than non-obese individuals and take 20% longer to recover after claudication. Studies of older obese adults without PAD have demonstrated that the combination of exercise and weight loss is more effective at improving physical function and body composition than exercise alone. While these findings likely translate to older adults with PAD, this hypothesis has yet to be tested. This study is designed to determine whether weight loss and exercise (WL+EX) versus exercise ( EX ) alone will 1) improve mobility function (walking ability) to a greater extent than exercise alone and 2) determine the mechanisms underlying changes in mobility function by measuring muscle microvascular perfusion and composition. The investigators hypothesize that a combined intervention of weight loss and exercise (aerobic and restive) will result in greater improvements in mobility function through improved muscle perfusion and reduced muscle fat infiltration than exercise alone in obese Veterans with PAD.
Interventions
OTHERExercise
Individuals will be asked to walk 3 times a week on a treadmill (initially starting at 15 minutes and progressing up to 40 minutes) and participate in a short weight training program focused on increasing strength in the legs.
OTHERWeight Loss
Individuals will be asked to meet with a registered dietitian once a week to discuss strategies to reduce daily caloric intake to gradually reduce body weight over 6 months.
Sponsors
VA Office of Research and Development
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
55 Years to 90 Years
Healthy volunteers
No
Inclusion criteria
* BMI \>25 kg/m2 * Ankle Brachial Index (ABI) \<.90 * Able to participate in a supervised exercise program at the Baltimore VA * No current plan for surgical revascularization * Claudication or leg symptoms when walking
Exclusion criteria
* Unstable angina or a recent heart attack * Active cancer * Dementia * Current foot or leg ulcers * Already exercise 2x/week or more.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Difference in Time to Onset of Calf Pain (Claudication Onset Time) Pre-intervention to Post-intervention | 6 months | The change in the amount of time it takes for calf pain to first appear while walking on a treadmill comparing pre and post-intervention |
| Difference in Ankle Brachial Index Pre-intervention to Post-intervention | 6 months | A change in the muscle blood flow to the legs determined by taking blood pressure in the arms and legs before and after cessation of exercise comparing the change pre to post exercise scores pre-intervention (baseline) and post intervention (6 months). There are no units because the ankle brachial index is a ratio. An improvement would be a higher number a post-intervention testing than pre-intervention testing. A negative number indicates improvement while a positive number indicates a worse score post-testing. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Score on the Modified Physical Performance Test Post-intervention | 6 months | A mobility measure that utilizes 9 tasks scored 0-4 (total possible score 36) to determine functional status. Scores from each of the nine items are summed for the total score. Scores are from 0-36 with higher scores considered to be better. The post-testing median score will be reported for post-testing. |
| Change in Muscle Composition of the Calf Muscles Pre-intervention to Post-intervention | 6 months | A measure of the amount of muscle and fat in the muscle using a CT scan of the legs. Pre-test levels will be compared to post-test levels. |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Exercise and Weight Loss Individuals assigned to this group will be asked to complete both the exercise and weight loss intervention for six months
Exercise: Individuals will be asked to walk 3 times a week on a treadmill (initially starting at 15 minutes and progressing up to 40 minutes) and participate in a short weight training program focused on increasing strength in the legs.
Weight Loss: Individuals will be asked to meet with a registered dietitian once a week to discuss strategies to reduce daily caloric intake to gradually reduce body weight over 6 months. | 9 |
| Exercise Individuals assigned to this group will be asked to complete the exercise intervention for xic months
Exercise: Individuals will be asked to walk 3 times a week on a treadmill (initially starting at 15 minutes and progressing up to 40 minutes) and participate in a short weight training program focused on increasing strength in the legs. | 9 |
| Total | 18 |
Baseline characteristics
| Characteristic | Exercise and Weight Loss | Exercise | Total |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 5 Participants | 8 Participants | 13 Participants |
| Age, Categorical Between 18 and 65 years | 4 Participants | 1 Participants | 5 Participants |
| Age, Continuous | 66 years | 72 years | 67 years |
| Ethnicity (NIH/OMB) Hispanic or Latino | 0 Participants | 1 Participants | 1 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 9 Participants | 8 Participants | 17 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Black or African American | 7 Participants | 7 Participants | 14 Participants |
| Race (NIH/OMB) More than one race | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants | 1 Participants | 1 Participants |
| Race (NIH/OMB) White | 2 Participants | 1 Participants | 3 Participants |
| Region of Enrollment United States | 9 Participants | 9 Participants | 18 Participants |
| Sex: Female, Male Female | 1 Participants | 0 Participants | 1 Participants |
| Sex: Female, Male Male | 8 Participants | 9 Participants | 17 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 9 | 0 / 9 |
| other Total, other adverse events | 4 / 9 | 2 / 9 |
| serious Total, serious adverse events | 2 / 9 | 3 / 9 |
Outcome results
Primary
Difference in Ankle Brachial Index Pre-intervention to Post-intervention
A change in the muscle blood flow to the legs determined by taking blood pressure in the arms and legs before and after cessation of exercise comparing the change pre to post exercise scores pre-intervention (baseline) and post intervention (6 months). There are no units because the ankle brachial index is a ratio. An improvement would be a higher number a post-intervention testing than pre-intervention testing. A negative number indicates improvement while a positive number indicates a worse score post-testing.
Time frame: 6 months
Population: 6 individuals in the exercise and weight loss group and 2 individuals in the exercise group completed pre/post measures for ankle brachial index
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Exercise and Weight Loss | Difference in Ankle Brachial Index Pre-intervention to Post-intervention | 0.04 ratio |
| Exercise | Difference in Ankle Brachial Index Pre-intervention to Post-intervention | -0.16 ratio |
Primary
Difference in Time to Onset of Calf Pain (Claudication Onset Time) Pre-intervention to Post-intervention
The change in the amount of time it takes for calf pain to first appear while walking on a treadmill comparing pre and post-intervention
Time frame: 6 months
Population: 6 individuals in the exercise and weight loss group and 2 individuals in the exercise group completed pre/post measures for Claudication onset time
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Exercise and Weight Loss | Difference in Time to Onset of Calf Pain (Claudication Onset Time) Pre-intervention to Post-intervention | 396 seconds |
| Exercise | Difference in Time to Onset of Calf Pain (Claudication Onset Time) Pre-intervention to Post-intervention | 140 seconds |
Comparison: Wilxocon signed Rank test to compare pre to post onset of pain time in the Exercise + Weight loss group. Due to low sample size were unable to compare changes between the Exercise + Weight Loss group and the Exercise only groups.p-value: 0.028Wilxocon signed Rank test
Secondary
Change in Muscle Composition of the Calf Muscles Pre-intervention to Post-intervention
A measure of the amount of muscle and fat in the muscle using a CT scan of the legs. Pre-test levels will be compared to post-test levels.
Time frame: 6 months
Population: This measure was not conducted due to staffing and pandemic related limitations in acquiring the CT scans.
Secondary
Score on the Modified Physical Performance Test Post-intervention
A mobility measure that utilizes 9 tasks scored 0-4 (total possible score 36) to determine functional status. Scores from each of the nine items are summed for the total score. Scores are from 0-36 with higher scores considered to be better. The post-testing median score will be reported for post-testing.
Time frame: 6 months
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Exercise and Weight Loss | Score on the Modified Physical Performance Test Post-intervention | 33 score on a scale |
| Exercise | Score on the Modified Physical Performance Test Post-intervention | 31 score on a scale |