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Trial registered on ANZCTR


Registration number
ACTRN12617001517369
Ethics application status
Approved
Date submitted
20/10/2017
Date registered
31/10/2017
Date last updated
12/06/2018
Type of registration
Prospectively registered

Titles & IDs
Public title
Breaking Up Sitting Time After Stroke (BUST-BP-Dose)
Scientific title
Breaking Up Sitting Time After Stroke - How much less sitting is needed to improve blood pressure after stroke (BUST-BP-Dose): A pilot study
Secondary ID [1] 293160 0
Nil
Universal Trial Number (UTN)
Trial acronym
BUST-BP-Dose
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Stroke 305142 0
Condition category
Condition code
Stroke 304461 304461 0 0
Haemorrhagic
Stroke 304462 304462 0 0
Ischaemic

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
A laboratory based, dose escalation study design will be used. Community dwelling stroke survivors with a moderate walking disability will be recruited to each cohort (n = 10/cohort).

All participants will complete 2 dose-escalation conditions, involving 10 min increments of light-intensity exercise whilst standing (STAND-EX), following a baseline (control) condition. STAND-EX will be split into 2 x 5 min breaks and consist of calf raises, mini squats and marching on the spot. The maximum dose of standing activities will be reached once the dose-limiting threshold (DLT) has been achieved.

DLT:
Failure to achieve at least 80% of the target time in STAND-EX due to fatigue, pain or effort required. The maximum dose for a cohort will be considered reached if 70% or more (n 'greater than or equal to' 7/10) of the cohort have met the DLT.

Dose escalation:
Cohort A – Prolonged, uninterrupted sitting (8 hours) will be broken up by 10 min STAND-EX, followed by 20 min STAND-EX on a separate occasion.
Cohort B – If DLT is not met, dose escalation will commence at 20 min STAND-EX and increase by a further 10 min.
Subsequent Cohorts will continue until DLT is met. Once DLT is met, a final cohort will repeat the dose escalation of the penultimate cohort to confirm this is the maximum tolerable dose. STAND-EX will be evenly distributed across the testing day (according to dose escalation). The initial dose escalation will involve 2 active standing breaks, each completed after the standardised meals (5 min at 09:00 and 5 min at 13:00). The frequency of breaks will increase until DLT is met, with breaks potentially been completed every half-hour across the testing day. Each testing day will be separated by a minimum 4 day washout period.

A standardised breakfast will be provided at approximately 8.30am and lunch at approximately 12.30pm. Meals will contain approximately one third of the participant's energy requirements and the combined macronutrient profile of testing day meals will be in line with the Acceptable Macronutrient Distribution Ranges as recommended by the Nutrient Reference Values for Australians and New Zealanders.

Experimental conditions:
1. Uninterrupted sitting – 8 hours of prolonged, uninterrupted sitting in a comfortable lounge chair (excluding toilet breaks).
2. Dose escalation 1 – Complete the prescribed dose of STAND-EX
3. Dose escalation 2 – Complete an additional 10 minutes of STAND-EX above Dose escalation 1.

Participants will be provided with an activity monitor and an ambulatory blood pressure monitor.
All testing days will be supervised and take place at the Hunter Medical research Institute (HMRI).
Intervention code [1] 299412 0
Treatment: Other
Comparator / control treatment
Prolonged bout of uninterrupted sitting (8 hours)
Control group
Active

Outcomes
Primary outcome [1] 303712 0
Blood pressure.

Blood pressure will be measured by an automated, microprocessor controlled ambulatory blood pressure monitor.
Timepoint [1] 303712 0
Every 30 min during each 8 hour condition
Primary outcome [2] 303713 0
Ambulatory blood pressure.

Ambulatory blood pressure will be measured by an automated, microprocessor controlled ambulatory blood pressure monitor.
Timepoint [2] 303713 0
Every 60 min during the 24 hour post each condition
Secondary outcome [1] 339949 0
Postprandial glucose. Postprandial glucose will be assessed using the i-STAT handheld blood analyser
Timepoint [1] 339949 0
Every 30 min for 2 hours after the breakfast meal in each condition
Secondary outcome [2] 339950 0
Postprandial Insulin concentration.

Postprandial Insulin will be measured using commercially available Human Insulin ELISA kits.
Timepoint [2] 339950 0
Every 30 min for 2 hours after the breakfast meal in each condition
Secondary outcome [3] 340033 0
Safety.

Safety will be assessed using the dose-limiting threshold (DLT). DLT if defined as failure to achieve at least 80% of the target time in active standing due to fatigue, pain or effort required.
Timepoint [3] 340033 0
Safety will be assesed one day and one week after each condition.
Secondary outcome [4] 340100 0
Feasibility.

Feasibility will be measured through meausres of trial fidelity, adherence to the protocol and number of participants able to complete all 3 conditions. Time on task during each condition will be recorded and any deviation to the protocol will be noted.
Timepoint [4] 340100 0
Feasibility will be assesed during each condition.

Eligibility
Key inclusion criteria
Stroke survivors who are:
• Between 3 months and 10 years post-stroke with moderate walking disability as defined as,
(1) Score of 'greater than or equal to' 3 on the Functional Ambulation Classification (i.e. can independently ambulate on level surfaces),
(2) Walking speed of 'greater than or equal to' 0.4 metres per second
• Able to toilet independently,
• Able to stand from sitting in a lounge chair independently or with minimal assistance of 'less than or equal to' 1 person,
• Highly sedentary (i.e. sit more than 7 hours during waking hours),
• Aged 'greater than or equal to' 18 years.
Minimum age
18 Years
Maximum age
No limit
Gender
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
• employment in a non-sedentary occupation (i.e. non-office based occupation),
• self-reported < 7 hours/day sitting,
• regularly engaged in physical activity (i.e. 'greater than or equal to' 150 min/week) as assessed by self-report,
• BMI > 45 kg/m2,
• current smoker,
• pregnant,
• clinically diagnosed with acute/chronic illness or other condition which has known physical activity contraindications or limits their ability to complete each experimental condition (i.e. chronic low back pain aggravated by prolonged sitting),
• urinary frequency and or urgency or requiring assistance with toileting (other than to mobilise to the toilet), and
• insulin dependent diabetes or who are taking diabetes medication other than metformin.

Study design
Purpose of the study
Treatment
Allocation to intervention
Non-randomised trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?


The people assessing the outcomes
Intervention assignment
Other
Other design features
A dose-escalation design.

The dose-escalation incorporates increasing amounts of standing activities across the 5 cohorts (n=10 per cohort), until a dose-limiting threshold (DLT) criteria is reached. The DLT is failure to achieve at least 80% of the target time in active standing due to fatigue, pain or effort required. The maximum dose for a cohort will be considered reached if 70% or more (n > 7/10) of the cohort have met the DLT.
Phase
Not Applicable
Type of endpoint(s)
Safety/efficacy
Statistical methods / analysis
We estimated the detectable difference in systolic blood pressure (SBP) between the maximum dose of STAND-EX and baseline condition, with 30 participants expected at the maximum dose achieved. This provides 80% power to detect a within-person, between condition difference of 3.5 mmHg in SBP, assuming a SD of 15 mmHg (based on previous exercise trials in stroke survivors) and a within-person correlation of 0.9 (a = 0.05).
SBP, blood glucose and insulin concentrations will be assessed using generalised linear mixed models with random intercepts to account for repeated measures on participants. On achieving the DLT, mean SBP, blood glucose and insulin will be compared with baseline to identify between condition differences. Safety and feasibility outcomes will be evaluated descriptively, and by comparing odds of adverse events across experimental conditions.

Recruitment
Recruitment status
Recruiting
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
NSW

Funding & Sponsors
Funding source category [1] 297787 0
Other
Name [1] 297787 0
Hunter Medical Research Institute
Address [1] 297787 0
Kookaburra Crt
New Lambton Heights
NSW 2305
Country [1] 297787 0
Australia
Funding source category [2] 299758 0
Charities/Societies/Foundations
Name [2] 299758 0
Heart Foundation Vanguard Grant
Address [2] 299758 0
Australia
Country [2] 299758 0
Australia
Primary sponsor type
University
Name
University of Newcastle
Address
University Drive
Callaghan NSW 2308
Country
Australia
Secondary sponsor category [1] 296823 0
None
Name [1] 296823 0
Address [1] 296823 0
Country [1] 296823 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 298846 0
Hunter New England Human Research Ethics Committee
Ethics committee address [1] 298846 0
Locked Bag No 1
New Lambton
NSW
2305
Ethics committee country [1] 298846 0
Australia
Date submitted for ethics approval [1] 298846 0
31/05/2017
Approval date [1] 298846 0
01/08/2017
Ethics approval number [1] 298846 0
17/06/21/4.04
Ethics committee name [2] 298861 0
University of Newcastle Human Research Ethics Committee
Ethics committee address [2] 298861 0
Research & Innovation Services
Research Integrity Unit
The University of Newcastle
Callaghan NSW 2308
Ethics committee country [2] 298861 0
Australia
Date submitted for ethics approval [2] 298861 0
16/08/2017
Approval date [2] 298861 0
06/09/2017
Ethics approval number [2] 298861 0
H-2017-0296

Summary
Brief summary
Living a sedentary lifestyle significantly increases the risk of developing cardiovascular disease and having a subsequent cardiovascular event, such as a stroke. People who have had a stroke spend 75% of their waking hours at home sitting down, which is much higher than healthy age-matched individuals without stroke. This sedentary behaviour is damaging for stroke survivors already comprised cardiovascular health, and is likely a significant contributing factor to the recurrent stroke which 30% of survivors have after their initial event.
Stroke survivors are very inactive; with very few able to engage in the level of physical activity recommended to improve their cardiovascular health. In people without stroke, breaking up prolonged sitting using regular activity breaks (walking or simple strengthening exercises) significantly improves cardiovascular disease risk factors such as blood pressure and glucose metabolism. Results from our recently completed pilot study indicates that breaking up prolonged sitting time in stroke survivors achieves similar cardiovascular benefits. Breaking up stroke survivor sitting time with simple resistance activities significantly reduced systolic blood pressure (mean 3.6 mmHg reduction). Lowering of blood pressure reduces the risk of hypertension, the leading modifiable risk factor associated with recurrent stroke, and thus has the potential to reduce the risk of recurrent stroke. Therefore, breaking up sitting time is a promising and innovative physical activity alternative to employ with stroke survivors to improve their cardiovascular health and subsequently, reduce recurrent stroke risk. The next important step is to determine the minimum amount and duration of activity breaks (dose) required to improve these cardiovascular risk factors in this population.
This study will be the first to determine the optimal dose of simple resistance activities needed to reduce blood pressure and improve glucose metabolism in stroke survivors. Stroke survivors (n = 10 per cohort) living at home who are able to stand and walk will complete a baseline uninterrupted sitting condition followed by 2 dose-escalation conditions. Breaks in sitting will be light-intensity exercise while standing which will increase in 10-min increments each condition. Blood samples will be taken at regular intervals throughout each condition and blood pressure and physical activity will be monitored during and up until 24-hours post-condition. Outcomes of blood pressure (primary), blood glucose, insulin levels (secondary) and safety and feasibility indicators will be collected.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 78426 0
A/Prof Coralie English
Address 78426 0
School of Health Sciences, University of Newcastle
University Drive
Callaghan
NSW 2308
Country 78426 0
Australia
Phone 78426 0
+61 2 49138102
Fax 78426 0
Email 78426 0
coralie.english@newcastle.edu.au
Contact person for public queries
Name 78427 0
A/Prof Coralie English
Address 78427 0
School of Health Sciences, University of Newcastle
University Drive
Callaghan
NSW 2308
Country 78427 0
Australia
Phone 78427 0
+61 2 49138102
Fax 78427 0
Email 78427 0
coralie.english@newcastle.edu.au
Contact person for scientific queries
Name 78428 0
A/Prof Coralie English
Address 78428 0
School of Health Sciences, University of Newcastle
University Drive
Callaghan
NSW 2308
Country 78428 0
Australia
Phone 78428 0
+61 2 49138102
Fax 78428 0
Email 78428 0
coralie.english@newcastle.edu.au

No data has been provided for results reporting
Summary results
Not applicable