Impact of Coronary Artery Bypass Graft (CABG) Surgery on Skeletal Muscle Mass and Insulin Sensitivity, Followed by Exercise Intervention

Study Overview
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Brief Summary
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In this study, the investigators want to examine the impact of coronary artery bypass graft (CABG) surgery on skeletal muscle mass, muscle metabolism, and insulin sensitivity in 90 subjects. In extent, the impact of a subsequent exercise intervention will be examined, with a follow-up up to 12 months after surgery.

Detailed Description
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90 subjects undergoing elective CABG surgery will be included. These subjects are free from orthopedic limitations, will have no severe complications during surgery, and are willing to participate in a 12-week exercise training intervention. At baseline (before surgery), following parameters will be assessed: blood parameters (glycemic control, lipid profile, anabolic/catabolic hormones, inflammatory markers), body composition (by dual x-ray absorptiometry), handgrip strength, and general subject features (medication, gender, age, etc.). The first three days after surgery, blood samples will be collected for the analysis of glycemic control, lipid profile, anabolic/catabolic hormones, inflammatory markers. Next, at the start of exercise intervention, after 6 and 12 weeks of exercise training, and after a 12-month follow-up, following parameters will be assessed: blood parameters (glycemic control, lipid profile, anabolic/catabolic hormones, inflammatory markers), body composition (by dual x-ray absorptiometry), handgrip strength, maximal exercise capacity (by ergospirometry testing), physical activity (by questionnaire), and quality of life ( by questionnaire). At 12 months of follow-up, cardiovascular mortality and morbidity (re-occurrence of angina, acute myocardial infarction, need for surgery, death) will be assessed. When initiating exercise intervention, subjects will randomly (n=30 in each group) be assigned to 12 weeks of standard exercise intervention (endurance exercise training), modified exercise intervention (endurance exercise training + strength training), or modified exercise intervention (endurance exercise training + strength training + oral protein supplements). This will be a cluster randomized clinical trial. Investigators executing the measurements will be blinded for treatment allocation.

Official Title
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Impact of CABG Surgery and Subsequent Exercise Intervention on Insulin Sensitivity and Muscle Mass: a Cluster Randomized Trial

Conditions
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Coronary Artery Disease

Intervention / Treatment
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* Other: exercise training


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Elective CABG surgery Willing to participate in 12-week exercise intervention Exclusion Criteria: Complicated surgery Severe complications during first days after CABG surgery Orthopedic limitations that interfere with proper exercise intervention participation
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: Single Group Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: standard exercise intervention<br>12 weeks of endurance exercise training | Other: exercise training<br>* endurance exercise training: 40 min of exercise at 65% of VO2peak, 3 days/week<br>* Other names: Rehabilitation;|
| Active Comparator: modified exercise intervention<br>combined endurance + strength exercise training | Other: exercise training<br>* endurance exercise training: 40 min of exercise at 65% of VO2peak, 3 days/week<br>* Other names: Rehabilitation;|
| Active Comparator: modified 2 exercise intervention<br>combined endurance + strength exercise training + oral protein supplements | Other: exercise training<br>* endurance exercise training: 40 min of exercise at 65% of VO2peak, 3 days/week<br>* Other names: Rehabilitation;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| change in muscle mass and insulin sensitivity | Baseline insulin sensitivity and muscle mass will be assessed ahead of surgery. Afterwards, the change in these parameters will be assessed at various predefined timepoints. | pre-operative, 1, 2, 3 days, and 2, 12, 54 weeks after surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| change in exercise capacity | Baseline exercise capacity will be assessed at 2 weeks after surgery. Afterwards, the change in this parameters will be assessed at various predefined timepoints. | 2, 12, 54 weeks after surgery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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CABG surgery, exercise intervention, insulin sensitivity, muscle mass