Breaking up Sedentary Time in Rheumatoid Arthritis

Study Overview
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Brief Summary
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This study will verify the effects of breaking up sitting time with short bouts of light intensity walking on vascular function in women with rheumatoid arthritis.

Detailed Description
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Women diagnosed with rheumatoid arthritis will participate in this randomized crossover trial. In one of the experimental sessions, the participants will remain 4-h on uninterrupted sitting, and in another day they will perform 3-min light intensity walk every 30 min to break up the sitting position. Vascular function will be assessed before and after each intervention using the following devices/techniques: a) transcranial Doppler ultrasound to assess the middle cerebral artery blood flow velocity at baseline and in response to CO2 breathing (5% CO2 mixture for 3 min), and to repeated sit-to-stand transitions; b) a multi-frequency linear transducer (7-12 MHz) attached to a high-resolution ultrasound machine to assess femoral artery dilation after reactive hyperemia (i.e., flow-mediated dilation); c) a laser Doppler probe attached to the skin surface of the right shin in order to quantify the Laser Doppler flux at baseline and during reactive hyperemia. Additionally, healthy age- and body mass-matched women will be recruited and will only perform the pre-intervention tests.

Official Title
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Breaking up Sedentary Time in Rheumatoid Arthritis: Effects on Vascular Function

Conditions
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Rheumatoid Arthritis, Sedentary Behavior, Endothelial Dysfunction

Intervention / Treatment
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* Behavioral: Physical activity


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult women diagnosed with RA From the Rheumatology Clinic at the Liverpool University Hospitals NHS Foundation Trust Aged 18-60 yr Non-smoker for at least 6months Able to provide written informed consent. Exclusion Criteria: Cannot readily read and understand English. Currently smoking or within last 6 months. Alcohol consumption >14units per week. Symptoms of or established cardiovascular disease (except hypertension) Previous stroke or myocardial infarction. History of diabetes or respiratory disease or chronic kidney disease. Musculoskeletal impairment/disability precluding physical activity Unstable medication (change in medication within the 3 months) Aged <18 or > 60 yr Currently pregnant

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 60 Years

Sexes Eligible for Study
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Female

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: Other
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: Participants with rheumatoid arthritis will attend the laboratory at Liverpool John Moores University on 2 occasions. During these visits, they will be submitted to the intervention or the control and will also undertake a series vascular tests prior- and post-intervention/control.
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Walking breaks (WALK)<br>During this session, participants will be requested to remain seated during 4 hours, but the sitting will be interrupted every 30 min with a 3-min light-intensity walking. | Behavioral: Physical activity<br>* Multiple bouts of 3-min brisk walking, every 30 min, for 4 hours.<br>* Other names: Walking;|
| No Intervention: Prolonged sitting (SIT)<br>During this session, participants be requested to remain seated during 4 uninterrupted hours (excepted for visiting the toilet) in a comfortable chair | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Middle cerebral artery mean velocity (MCAV) | MCAV will be assessed using continuous bilateral transcranial Doppler ultrasound. | Change from baseline (hour 0) to hour 4 (post-intervention/control) | 
| Middle cerebral artery mean velocity reactivity to carbon dioxide | Participants will breathe a 5% carbon dioxide mixture for 3 min during which time MCAV reactivity to CO2 will be assessed using continuous bilateral transcranial Doppler ultrasound. | Change from baseline (hour 0) to hour 4 (post-intervention/control) | 
| Cerebral autoregulation | Participants will be asked to complete a series of repeated sit to stand moves (coached by a member of the research team) for a 5-minute period, during which time MCAV will be assessed using continuous bilateral transcranial Doppler ultrasound. Beat by beat blood pressure will also be assessed using finger photoplethysmography. | Change from baseline (hour 0) to hour 4 (post-intervention/control) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Brachial artery endothelial function | Brachial artery endothelial function will be assessed through flow-mediated dilation using vascular ultrasound. | Change from baseline (hour 0) to hour 4 (post-intervention/control) | 
| Finger blood pressure | During all procedures, beat by beat finger blood pressure will be measured on the middle finger of the right hand using photoplethysmography. | Change from baseline (hour 0) to hour 4 (post-intervention/control) | 
| Superficial femoral artery endothelial function | Superficial femoral artery endothelial function will be assessed through flow-mediated dilation using vascular ultrasound. | Change from baseline (hour 0) to hour 4 (post-intervention/control) | 
| Skin blood flow response to hyperemia | Skin blood flow response to hyperemia will be assessed using a laser doppler probe attached to the shin and forearm. | Change from baseline (hour 0) to hour 4 (post-intervention/control) | 
| Stroop color-word test | The Stroop color-word test will be implemented to assess attention and inhibitory control. | Change from baseline (hour 0) to hour 4 (post-intervention/control) | 
| California Verbal Learning Test-2 | Immediate recall of the California Verbal Learning Test-2 will be used to assess verbal learning and memory. | Change from baseline (hour 0) to hour 4 (post-intervention/control) | 
| Brachial artery blood flow | Vascular ultrasound will be used to assess brachial artery blood flow every hour during the intervention | Change from baseline to 1-hour/2-hour/3-hour/4-hour | 
| Femoral artery blood flow | Vascular ultrasound will be used to assess femoral artery blood flow every hour during the intervention | Change from baseline to 1-hour/2-hour/3-hour/4-hour | 
| Pain intensity | Pain intensity will be assessed using a 10cm visual analogue scale. | Change from baseline to 1-hour/2-hour/3-hour/4-hour | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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physical activity, rheumatic diseases, vascular function