Bloodflow Restricted Exercise in Healthy Ageing

Study Overview
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Brief Summary
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The overall objective of this study is to investigate the efficacy of low-intensity blood flow restricted resistance exercise (BFRRE) to promote health beneficial skeletal muscle adaptations and augment muscle function in a healthy older population. This objective will be achieved by in-dept evaluation of skeletal muscle cellular and functional characteristics prior to and after an intervention period comprising 6 weeks of BFRRE or non-exercise control intervention in healthy older subjects. A special focus is placed on the ability of BFRRE to stimulate skeletal muscle protein synthesis and augment muscle stem cell function. Furthermore, recent findings suggests that similar exercise interventions in a population of patients with heart failure (HF) does not stimulate the desired adaptations. In accordance, we aim to compare the adaptive response to BFRRE amongst HF patients and the enrolled age-matched healthy individuals from the present investigation. The findings of the current study will expand our understanding of how low-intensity resistance exercise alternatives might be viable in promoting muscle anabolism to combat the loss of muscle mass observed with ageing as well as the potential anabolic resistance accompanying HF diagnosis.

Official Title
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Bloodflow Restricted Exercise in Healthy Ageing

Conditions
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Aging

Intervention / Treatment
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* Other: Bloodflow restricted exercise


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Able to understand the written and spoken information and to give informed consent for inclusion. Age between 45 and 80 years Able to sit in a knee extension machine Able to deliver muscle biopsies Able to train 3 times per week during a 6-week period Exclusion Criteria: Known history of cardiac disease Habitual exercise with high intensity > 2 times pr. week within the past 6 months Pregnancy Diabetes mellitus Peripheral neuropathy Dialysis treatment Severe peripheral arterial disease Concomitant acute life threatening medical condition Intracranial aneurisms, arteriovenous malformation, cerebral neoplasm or abscess Severe arterial hypertension (≥ 180/≥ 110 mmHg) or moderate arterial hypertension (160-179/100-109) despite medical treatment Moderate or severe chronic obstructive pulmonary disease Decreased kidney function - eGFR < 60 ml/min

Ages Eligible for Study
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Minimum Age: 45 Years
Maximum Age: 80 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: Other
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Single center randomised controlled trial.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Bloodflow restricted exercise<br>Healthy subjects undergoing low intensity blood flow restricted resistance exercise (BFRRE) conducted as 4 sets of bilateral knee extensions at 30% of 1RM until voluntary fatigue. The sets are intercepted by 30 seconds of rest (during rest the cuff's are still inflated). | Other: Bloodflow restricted exercise<br>* Low-intensity bloodflow restricted resistance exercise is conducted as traditional knee extension exercise with a load corresponding to 30% of 1 repetition maximum (RM), with concurrent partial occlusion of the circulation by means of inflatable pneumatic cuffs wrapped around the proximal part of the thighs. Cuffs are inflated to a pressure corresponding to 50% of the arterial occlusion pressure, which only compromises venous but not arterial blood flow.<br>* Other names: BFRRE;|
| No Intervention: Non-exercise control<br>No intervention. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Subfractional muscle protein synthesis rates | Myofibrillar protein synthesis rate | 6 weeks | 
| Subfractional muscle protein synthesis rates | Mitochondrial protein synthesis rate | 6 weeks | 
| Segmental muscle mass of lower extremity | Dual Energi X-ray Absorption (DEXA) | 6 weeks | 
| Muscle fibre cross sectional area (CSA) | Histological examination of muscle biopsies | 6 weeks | 
| Muscle stem cell function | Time to first division | 6 weeks | 
| Muscle stem cell function | Proliferative capacity | 6 weeks | 
| Muscle stem cell function | Differentiation capacity | 6 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Maximal Voluntary Contraction (MVC) | Isometric muscle function | 6 weeks | 
| 1 repetition maximum | Dynamic muscle strength | 6 weeks | 
| Muscle strength-endurance capacity | Local muscle endurance | 6 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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bloodflow restricted exercise, skeletal muscle, muscle stem cells