The Arthritis, Diet, and Activity Promotion Trial

Study Overview
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Brief Summary
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The primary purpose of this study was to determine the effect of dietary weight-loss, exercise training, or a combination of both on physical function in overweight and obese adults with knee osteoarthritis (OA). In secondary analyses, the effect of weight-loss and/or exercise on OA progression, self-reported pain and inflammation were examined. In post-trial analyses, the effect of dietary weight-loss on total mortality was determined.

Official Title
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The Arthritis, Diet, and Activity Promotion Trial

Conditions
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Knee Osteoarthritis

Intervention / Treatment
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* Behavioral: Dietary Weight-loss
* Behavioral: Exercise


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age ≥ 60 years. BMI ≥ 28 kg/m2. Knee pain on most days of the month. Sedentary lifestyle pattern (<20 min exercise per week for last 6 months) Self-reported difficulty with at least one of the following: walking 1/4 mile, climbing stairs, kneeling, bending, stooping, shopping, lifting, self-care. Radiographic evidence of grade 1-3 knee osteoarthritis. Exclusion Criteria: Serious medical condition that precludes safe participation in exercise such as heart disease (angina, congestive heart failure), severe hypertension, COPD, renal or liver disease, insulin-dependent diabetes. Mini-mental state exam score <24. Inability to walks without a cane. Reported alcohol consumption >14 drinks/week. Inability to complete protocol. ST segment depression. Participation in another research study.

Ages Eligible for Study
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Minimum Age: 60 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 |
| --- | --- |
| Active Comparator: Dietary weight-loss<br>The goal of the dietary weight-loss intervention was to produce and maintain a mean weight-loss of 5% initial body weight during the 18-month intervention, using dietary counseling and behavior modification. | Behavioral: Dietary Weight-loss<br>* The goal of the dietary weight-loss intervention was to produce and maintain a mean weight-loss of 5% initial body weight during the 18-month intervention, using dietary counseling and behavior modification.<br>|
| Active Comparator: Exercise<br>Participants participated in resistance training (15 minutes) and aerobic exercise (30 minutes) 3d/week for 18-months. The first 4-months of the exercise training were facility-based. After 4-months, participants were allowed to transition to a home-based intervention if they chose to. | Behavioral: Exercise<br>* Participants participated in resistance training (15 minutes) and aerobic exercise (30 minutes) 3d/week for 18-months. The first 4-months of the exercise training were facility-based. After 4-months, participants were allowed to transition to a home-based intervention if they chose to.<br>|
| Active Comparator: Dietary weight-loss & exercise<br>Participants received both the dietary weight-loss and exercise interventions for 18-months | Behavioral: Dietary Weight-loss<br>* The goal of the dietary weight-loss intervention was to produce and maintain a mean weight-loss of 5% initial body weight during the 18-month intervention, using dietary counseling and behavior modification.<br>Behavioral: Exercise<br>* Participants participated in resistance training (15 minutes) and aerobic exercise (30 minutes) 3d/week for 18-months. The first 4-months of the exercise training were facility-based. After 4-months, participants were allowed to transition to a home-based intervention if they chose to.<br>|
| No Intervention: Health lifestyle control<br>The healthy-lifestyle control served as the usual care comparison group. For 3 months, participants met monthly with a health educator to discuss topics such as osteoarthritis, obesity, and exercise. Regular phone contact was maintained during months 4-18. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| self-reported physical function (WOMAC scale) |  | baseline, 6-months, 18-months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 6-minute walking distance |  | baseline, 6-months, 18-months | 
| timed stair climbing |  | baseline, 6-months, 18-months | 
| weight-loss |  | baseline, 6-months, 18-months | 
| self-reported pain |  | baseline, 6-months, 18-months | 
| progression of knee osteoarthritis, measured radiographically |  | baseline, 6-months, 18-months | 
| chronic inflammation, measured according to CRP, IL-6, IL-6 soluble receptor, TNF-alpha, TNF alpha receptors 1 and 2 |  | baseline and 18-months | 
| total mortality |  | 7-9 yrs post-trial | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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knee osteoarthritis, weight-loss, exercise, obesity, physical function, total mortality