Exercise and Weight Loss in PAD

Study Overview
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Brief Summary
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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
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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.

Official Title
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Exercise and Weight Loss to Improve Mobility Function in Veterans With PAD

Conditions
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Peripheral Arterial Disease

Intervention / Treatment
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* Other: Exercise
* Other: Weight Loss


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: BMI >30 kg/m2 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.

Ages Eligible for Study
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Minimum Age: 60 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Exercise and Weight Loss<br>Individuals assigned to this group will be asked to complete both the exercise and weight loss intervention for six months | Other: Exercise<br>* 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.<br>Other: Weight Loss<br>* 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.<br>|
| Active Comparator: Exercise<br>Individuals assigned to this group will be asked to complete the exercise intervention for xic months | Other: Exercise<br>* 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.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 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 | 6 months | 
| 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). | 6 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Difference in Modified Physical Performance Test scores pre-intervention to post-intervention | A mobility measure that utilizes 9 tasks scored 0-4 (total possible score 36) to determine functional status. Pre-test scores will be compared to post test scores | 6 months | 
| 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. | 6 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Exercise, Weight Loss, Mobility Limitation