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Trial registered on ANZCTR


Registration number
ACTRN12619000175178
Ethics application status
Approved
Date submitted
31/01/2019
Date registered
6/02/2019
Date last updated
10/07/2019
Date data sharing statement initially provided
6/02/2019
Type of registration
Prospectively registered

Titles & IDs
Public title
Sitting, standing or breaking: Which is better for cardio-metabolic health? A randomised cross-over study
Scientific title
Sitting, standing or breaking: Which is better for cardio-metabolic health? A randomised cross-over study in healthy participants
Secondary ID [1] 297257 0
Nil Known
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Prolonged sitting 311327 0
Postprandial glycemia 311328 0
postprandial insulinemia 311329 0
endothelial function 311330 0
Condition category
Condition code
Cardiovascular 309968 309968 0 0
Diseases of the vasculature and circulation including the lymphatic system
Diet and Nutrition 309969 309969 0 0
Other diet and nutrition disorders
Metabolic and Endocrine 309970 309970 0 0
Metabolic disorders

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Participants will complete, in a random order, two intervention session and one control session. Each session will be separated by six days.
The two intervention sessions are as follows:
1) Regular activity breaks: Participants will walk on the treadmill at 5 km/h for 2 min every 30 min throughout the 6.5 h intervention session. At all other times they will remain seated
2) Continuous standing: Participants will stand at a standing desk continuously throughout the 6.5 h session.
The control session is: Continuous sitting, in which the participant will remain seated for the duration of the session.

During each intervention/control session participants will be fed a standardised breakfast (of Muesli, milk, toast, margarine, honey and juice providing 106 g of carbohydrate and 13 g fat) at 45 min, and a standardised snack (chocolate brownie, providing 44 g carbohydrate and 17 g fat) at 240 min.

Investigators will be in the laboratory with participants at all times to ensure compliance to these procedures
Intervention code [1] 313514 0
Lifestyle
Intervention code [2] 313543 0
Treatment: Other
Comparator / control treatment
The continuous, or prolonged sitting intervention is the control condition, Participants will remain seated for the duration (6.5 h) of the session. Feeding and all measurements will occur at as the other two sessions.
Control group
Active

Outcomes
Primary outcome [1] 318883 0
Flow-mediated dilation will be measured by inducing transient ischema by inflating a 12 cm cuff around the mid-calf 200 mm Hg within 2 seconds (SC12 contoured leg cuff, E20 Rapid Cuff Inflator and AG101 Cuff Inflator Air Source, Hokanson, Bellevue WA, USA). Occlusion will be maintained for 5 min and recording will be continued for 3 min following rapid release of the cuff. Baseline diameter (Dbase), blood flow velocity (v) and shear rate (SR) will be calculated as the mean of the last minute of recording prior to cuff inflation. Peak diameter post-deflation will be determined automatically using the edge-detection software. Flow-mediated dilation will be calculated as the percentage increase in diameter from the baseline (FMD = (Dpeak-Dbase) / Dbase x 100), following guidelines utilising allometric scaling to adjust for Dbase with a covariate-controlled approach
Timepoint [1] 318883 0
Measurements will be performed at the beginning and end of each intervention session (0 and 390 min)
Secondary outcome [1] 366313 0
Superficial popliteal artery haemodynamics will be investigated by assessing popliteal artery (PoPA) diameter and blood velocity using ultrasound (Terason uSmart 3300, MA, USA) with a 15 MHz lineal array transducer (bandwidth 4-15 MHz) by simultaneously recording a longitudinal section B-mode image and a spectral Doppler trace of blood velocity. The Doppler angle of insonation will be maintained at less than or equal to 60°. Measurements will be made in the popliteal fossa with the participant in a semi-recumbent position, in the prolonged sitting and regular activity breaks interventions, and in a standing position in the prolonged standing intervention. Video clips will be recorded using Camtasia Studio Screen Recording Software (TechSmith, MI, USA). Analysis of diameter and velocity, and calculation of shear rate will be performed using wall-tracking software (Cardiovascular Suite v 3.4, Quipu, Pisa, Italy). Haemodynamics will be assessed for ~60 seconds on each occasion.
Timepoint [1] 366313 0
Measurements will be performed baseline, and throughout the intervention ( 0, 60, 240, 300, 360, 390 min)
Secondary outcome [2] 366314 0
Postprandial glucose response will be assessed by collecting blood samples at the time points listed below, and using them to calculate incremental area under the curve. Concentrations of glucose will be measured in each sample using enzymatic calorimetric methods
Timepoint [2] 366314 0
Measurements will be performed baseline, and at even intervals throughout the intervention ( 0, 60, 120, 180, 240, 300, 360, 390 min)
Secondary outcome [3] 366315 0
Postprandial insulin response will be assessed by collecting blood samples at the time points listed below, and using them to calculate incremental area under the curve. Concentrations of insulin will be measured in each of these samples using an electrochemiluminescent immunoassay
Timepoint [3] 366315 0
Measurements will be performed baseline, and at even intervals throughout the intervention ( 0, 60, 120, 180, 240, 300, 360, 390 min)
Secondary outcome [4] 366316 0
The glucose profile for the 48 h following each intervention session will be assessed using a Freestyle Libre glucose monitoring sensor worn continuously on the back of the upper arm
Timepoint [4] 366316 0
48 h following each intervention session
Secondary outcome [5] 366317 0
Physical activity patterns will be assessed for 48 h after each intervention using an Actigraph accelerometer worn continuously on the right hip, and established cutoffs for sedentary, light and moderate-to-vigorous physical activity patterns
Timepoint [5] 366317 0
48 h after each intervention/control session

Eligibility
Key inclusion criteria
Healthy men and women who self report spending greater than 5 h per day, on average, engaged in sedentary behaviour, and who do not use a sit to stand work station or standing desk on a regular basis.
Minimum age
18 Years
Maximum age
40 Years
Gender
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
personal history of cardiovascular disease or diabetes, current smoker, BMI greater than 35 kg/m2, taking any medication, dietary supplements, vitamins or minerals, other than hormonal contraceptive agents, contraindications for participating in phsical activity or standing for long periods, intolerance/allergy to dairy of gluten

Study design
Purpose of the study
Prevention
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
The randomization sequence will be generated using STATA software and concealed electronically. The evening before each participant begins his or her first intervention session next sequential randomization will be revealed and assigned. Participants will not be notified of which intervention session they are completing until the arrive at the clinic on the morning of each intervention session. However, by a process of elimination they will know what their third and final intervention will be as soon as they begin their second intervention session.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Participants will be block randomized (block size n=6) to complete the three interventions in 1 of 6 possible orders. The randomization sequence will be generated using STATA software and concealed electronically.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?


The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Crossover
Other design features
Phase
Not Applicable
Type of endpoint(s)
Efficacy
Statistical methods / analysis
Sample size and statistical power
A sample size of 18 participants will provide 80% power to detect a 15% difference in Dbase-adjusted FMD (alpha = 0.05), and allow even numbers of participants to complete the three intervention in the six possible intervention orders. This sample size will also allow 80% power to detect a 10% difference in glucose AUC and a 15% difference in insulin AUC.

Statistical methods
Statistical analysis will be performed using STATA version 15 for Mac. Both incremental and total area under the curve will be calculated for plasma glucose and insulin, using the trapezoid rule, and used as summary measures. Mixed model regression will be used to examine between intervention changes in FMD and Dbase-adjusted FMD and glucose and insulin AUC controlling for any possible period or order effects.

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 outside Australia
Country [1] 21240 0
New Zealand
State/province [1] 21240 0
Otago

Funding & Sponsors
Funding source category [1] 301814 0
University
Name [1] 301814 0
University of Otago Research Grant
Address [1] 301814 0
PO Box 56
Dunedin
9054
Country [1] 301814 0
New Zealand
Funding source category [2] 301822 0
Charities/Societies/Foundations
Name [2] 301822 0
National Heart Foundation of New Zealand
Address [2] 301822 0
9 Kalmia St, Ellerslie, PO Box 17160, Greenlane, Auckland 1546
Country [2] 301822 0
New Zealand
Primary sponsor type
Individual
Name
Meredith Peddie
Address
Department of Human Nutrition
University of Otago
PO Box 56
Dunedin
9054
Country
New Zealand
Secondary sponsor category [1] 301563 0
Individual
Name [1] 301563 0
Kate Thomas
Address [1] 301563 0
Department of Surgical Sciences, Dunedin School of Medicine
University of Otago
PO Box 56
Dunedin
9054
Country [1] 301563 0
New Zealand
Other collaborator category [1] 280509 0
Individual
Name [1] 280509 0
James Cotter
Address [1] 280509 0
School of Physical Education, Sport and Exercise Science
University of Otago
PO Box 56
Dunedin
9054
Country: New Zealand
Country [1] 280509 0
New Zealand
Other collaborator category [2] 280510 0
Individual
Name [2] 280510 0
Nancy Rehrer
Address [2] 280510 0
School of Physical Education, Sport and Exercise Science
University of Otago
PO Box 56
Dunedin
9054
Country: New Zealand
Country [2] 280510 0
New Zealand

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 302520 0
University of Otago Human Ethics Committee (Health)
Ethics committee address [1] 302520 0
University of Otago
PO Box 56
Dunedin
9054
Ethics committee country [1] 302520 0
New Zealand
Date submitted for ethics approval [1] 302520 0
26/11/2018
Approval date [1] 302520 0
14/12/2018
Ethics approval number [1] 302520 0
H18/138

Summary
Brief summary
This study will provide important evidence around how reducing sedentary behaviour by standing, or performing short bouts of activity regularly may improve postprandial metabolism and endothelial function, both of which are important for cardio-metabolic health. We will conduct a randomised cross-over study involving 18 healthy, normal weight participants. The study will include three experimental intervention sessions: prolonged sitting; prolonged standing; and regular activity breaks, each separated by a minimum six-day washout period. Flow-mediated dilation will be measured at baseline, and at the conclusion of each intervention, while popliteal artery haemodynamics will be measured hourly to assess changes in blood flow and shear stress. Area under the curve will be calculated for plasma glucose and insulin. Mixed model regression will be used to examine differences in the effect of the three different interventions on markers of endothelial function and postprandial metabolism.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 90498 0
Dr Meredith Peddie
Address 90498 0
Department of Human Nutrition
University of Otago
PO Box 56
Dunedin
9054
Country 90498 0
New Zealand
Phone 90498 0
+64 3 479 8157
Fax 90498 0
Email 90498 0
meredith.peddie@otago.ac.nz
Contact person for public queries
Name 90499 0
Dr Meredith Peddie
Address 90499 0
Department of Human Nutrition
University of Otago
PO Box 56
Dunedin
9054
Country 90499 0
New Zealand
Phone 90499 0
+64 3 479 8157
Fax 90499 0
Email 90499 0
meredith.peddie@otago.ac.nz
Contact person for scientific queries
Name 90500 0
Dr Meredith Peddie
Address 90500 0
Department of Human Nutrition
University of Otago
PO Box 56
Dunedin
9054
Country 90500 0
New Zealand
Phone 90500 0
+64 3 479 8157
Fax 90500 0
Email 90500 0
meredith.peddie@otago.ac.nz

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
Yes
What data in particular will be shared?
de-identified individual participant data underlying published results
When will data be available (start and end dates)?
immediately following publication and ending 5 years following main results publication
Available to whom?
case by case basis at the discretion of the primary investigator
Available for what types of analyses?
IPD meta-analysis
How or where can data be obtained?
access subject to approvals by principal investigator
What supporting documents are/will be available?
No other documents available
Summary results
No Results