The Immune Function Intervention Trial

Study Overview
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Brief Summary
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The purpose of the study is to examine whether cardiovascular exercise training improves immune responses to vaccination in previously sedentary older adults.

Detailed Description
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The extent to which exercise training or long-term physical activity influences poorly regulated immune function in the elderly is unclear. Preliminary evidence suggests that exercise training may improve various immune function measures in older adults. Although such findings have the potential to be of substantial public health importance, the majority of studies have suffered from small sample sizes, inadequate measurement of physical fitness, and weak research designs. This study is designed to overcome these limitations by employing a longitudinal randomized controlled trial examining the effect of exercise training on clinically relevant immune function measures in older adults (65-80 years). Moreover, relationships between several factors known to be altered by exercise training and changes in immune function will be assessed. As such, there are two specific aims to be addressed. In Aim 1, a 10-month exercise trial will determine whether moderate intensity aerobic exercise training can improve immune function in previously sedentary older adults. In Aim 2, the role played by physiological, behavioral, and psychosocial factors in the relationship between exercise training and improved immune function will be examined. 150 sedentary participants will be randomly assigned to either a 10-month moderate aerobic exercise training program or a sedentary control group. Clinically relevant measures of immune function including the delayed-type hypersensitivity (DTH) response to a battery of antigens and the antibody response to tetanus toxoid and influenza virus vaccination will be assessed before, during and after the intervention. We hypothesize that exercise training will result in improved immune responses including higher peak antibody titers and DTH responses, and sustained levels of protective antibodies.

Official Title
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Physical Activity, Aging and Immune Function

Conditions
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Immune Response

Intervention / Treatment
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* Behavioral: cardiovascular exercise training
* Behavioral: flexibility/balance control


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Ages 62-82 Ability to participate in an exercise program Medical clearance by primary physician Non-smoker BMI 22-38 Independently living Post-menopausal Sedentary for over 6 months Exclusion Criteria: No recent history (within 6 months) of infection or vaccination History of systemic reactions to vaccination History of cancer Severe allergies/asthma requiring prescription medication Splenectomy or transplant patient Chronic Obstructive Pulmonary Disease (COPD) HIV positive Uncontrolled diabetes or hypertension Severe arthritis Mental illness or clinical depression Impaired cognitive status

Ages Eligible for Study
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Minimum Age: 62 Years
Maximum Age: 82 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

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: 1<br>a 10-month moderate aerobic exercise training program | Behavioral: cardiovascular exercise training<br> <br> |
| Placebo Comparator: 2<br>flexibility/balance control group | Behavioral: flexibility/balance control<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| antibody responses to influenza and tetanus toxoid vaccination and delayed type hypersensitivity responses to fungal antigens |  | baseline, 6 and 10 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| cardiovascular fitness |  |  | 
| psychosocial outcomes |  |  |