Clinical Trial Details
— Status: Recruiting
Administrative data
NCT number |
NCT05193175 |
Other study ID # |
265468 |
Secondary ID |
|
Status |
Recruiting |
Phase |
N/A
|
First received |
|
Last updated |
|
Start date |
November 29, 2021 |
Est. completion date |
June 1, 2023 |
Study information
Verified date |
March 2023 |
Source |
University of Bedfordshire |
Contact |
Abbie C Bell, MSc |
Phone |
07984545911 |
Email |
abbie.bell[@]study.beds.ac.uk |
Is FDA regulated |
No |
Health authority |
|
Study type |
Interventional
|
Clinical Trial Summary
Cardiovascular Disease (CVD) is one of the greatest causes of mortality and morbidity
globally, particularly in middle to high income countries. In the UK alone, it was
accountable for 124,641 deaths in 2017. Further to this, CVD contributes to a vast economic
burden, costing the National Health Service (NHS) £19billion annually. This is mainly due to
a significant number of hospital readmissions following a first cardiac event (198,000 per
annum).
Following a cardiac event, an individual is therefore recommended to reduce their risk
factors, including lipid profile, smoking status and physical inactivity, to reduce their
risk of a secondary event. In healthy individuals, regularly breaking up sitting time reduces
cardiometabolic risk markers. The aim of this study is to therefore observe if this effect is
replicated in the cardiac population and thus whether breaking up sitting time will reduce
the risk of a secondary cardiac event.
Potential participants will be required to meet an inclusion criteria to take part in the
study: aged 50 years or above and had a myocardial infarction within the past three months at
the time of recruitment to the study.
Participants will be randomised to each condition: 1) uninterrupted sitting; 2) sitting with
intermittent standing and 3) sitting with intermittent light physical activity (stepping to a
metronome beat). A number of physiological markers will be measured before, during and after
each condition and analysed to compare the effectiveness of each condition.
All measurements will be taken at the University of Bedfordshire Sport and Exercise Science
Laboratories.
Description:
Study design A repeated measures, randomised cross over study design will be used. All data
collection will take place at the Sport and Exercise Science Laboratories, University of
Bedfordshire, Polhill Avenue, Bedford, UK. After a preliminary testing session, participants
will complete three, 6-hour experimental conditions in a random order: 1) uninterrupted
sitting; 2) sitting interrupted with standing breaks, and 3) sitting interrupted with light
intensity stepping breaks. There will be a washout period of at least 72 hours between
conditions, as previous research suggests that a single session of exercise can affect blood
glucose levels for the following 48 hours (Mikines, et al., 1988). Participants will be
randomised to order of condition using computer generated random numbers. This will assign
them a trial order using block randomization with balanced block sizes. Participants will be
blinded to the trial condition until they arrive on the day of their first and second
experimental conditions.
Preliminary testing Patients will first attend a preliminary testing session where they will
become accustomed to light intensity stepping on the spot to the beat of a metronome and use
of the Borg RPE scale. This will ensure patients are familiar with an intensity that is
equivalent to an RPE of 8-11 (very light to light) that will be used in the respective
experimental condition. Participants will step to different metronome paces starting at a
slow pace and building up gradually every 1-2 minutes until an RPE of 8-11 is found. This
imitates the intensity recommended within the warm up of CR, as recommended by BACPR. Height
(cm) and weight (kg) will also be measured using a stadiometer (Harpenden 98.602, Holtain
Ltd., Crymych) and digital scales (Tanita BWB0800, Tanita Corp., Tokyo, Japan) respectively,
to calculate body mass index (kg/m2).
Experimental Protocol Participants will be asked to refrain from any alcohol and caffeine for
24 hours prior to each visit, as well as avoid exercise for 72 hours and complete an
overnight fast. This will be explained to them during the preliminary visit. To monitor this,
they will be asked prior to participation per visit whether they have fasted/ when they last
ate and drank.
Participants will be asked to perform an overnight fast for at least 10 hours before arrival
and minimise active travel to the laboratory (e.g. use a car for travel). They will rest for
30 minutes to achieve a steady state before baseline blood pressure (two measures with 2
minutes rest between each and the average taken) and blood samples are taken. Baseline
cardiac function measures (global strain, ejection fraction and systolic volume) will be
measured using an echocardiogram scan, as well as an electrocardiogram (ECG) to ensure there
are no electrical contraindications to the heart which would make the participant unsuitable
to complete the study intervention including ST depression / elevation or any arrythmias.
Baseline mood and wellbeing measures will then be assessed using questionnaires.
Following baseline measures, a standardised breakfast will be consumed (see meals section
below) and participants will then commence the experimental condition. See Figure 1 for
schematic of experimental conditions.
The three experimental conditions for this study are:
1. Uninterrupted sitting for 6 hours.
2. Sitting interrupted with 5 minutes of static standing every 30 minutes.
3. Sitting interrupted with 5 minutes of light intensity stepping every 30 minutes using a
metronome at the intensity determined during preliminary testing. This replicates active
recovery time currently performed in a phase III CR class.
A lunch meal will be provided at 12:00 during each condition. During sitting periods,
participants will be able to read books, magazines or newspapers and/or watch TV, DVDs or
media streaming services. Participants will be transported to the toilets and food
consumption areas using a wheelchair to ensure activity is minimised and standardised between
conditions.
Standardised food and water intake Each meal will provide approximately 30% of estimated
daily energy requirements. This will be calculated for each individual participant using a
prediction equation based on individual's height, weight and gender. Breakfast will consist
of bran flakes, whole milk, and a honey and granola bar and will consist of 54% carbohydrate,
34% fat and 12% protein. Lunch will consist of a chicken sandwich, salted crisps and jammie
dodger biscuit (54% carbohydrate, 34% fat and 12% protein). The macronutrient composition of
the meals are in general agreement with guidelines recommended for a balanced diet (Public
Health England, 2016). Participants will be encouraged to consume their meal within 15
minutes. The time taken will be recorded in the first condition and this time will then be
replicated in the latter two conditions. Water will be available for the participants ad
libitum during their first experimental condition visit. This volume of intake will be
recorded and the same amount provided in the following two conditions spread over the day.
Data collection Finger prick capillary whole blood samples will be collected at baseline, 30,
60, 120, 180, 210, 240, 300 and 360 minutes throughout the conditions to allow later analysis
of glucose, triglycerides, HDL-C, and insulin. Blood samples will be taken after the hand is
pre-warmed in warm water for approximately 5 minutes. Blood pressure and heart rate will be
measured 5 minutes before each of the blood samples are taken. Cardiac function measures and
mood and wellbeing will be measured at baseline and post-condition.