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Trial registered on ANZCTR


Registration number
ACTRN12616000372482
Ethics application status
Approved
Date submitted
17/03/2016
Date registered
22/03/2016
Date last updated
29/06/2018
Type of registration
Prospectively registered

Titles & IDs
Public title
Effects of high-intensity exercise training among women with previous gestational diabetes
Scientific title
Effects of high-intensity exercise training among women with previous gestational diabetes
Secondary ID [1] 288754 0
nil
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Previous gestational diabetes 298002 0
Condition category
Condition code
Metabolic and Endocrine 298155 298155 0 0
Diabetes

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
After baseline tests are performed, subjects will be randomised to either the exercise training group or the usual care (exercise advice) group.

Exercise training:
Subjects randomly allocated to the exercise training group will undertake supervised high-intensity exercise training three times per week for eight weeks. Training will be conducted on a stationary exercise bike, located at either RPA Hospital or a gym close to the subject's home – whichever is more convenient for them. The training physiotherapist or exercise physiologist will supervise each training session and will monitor heart rate and symptom scores.
As all sessions are supervised, attendance will be recorded throughout the training period.
Participants will wear a heart rate monitor, i.e. sensing strap on their chest, and a watch.
In the first week of training, after a 5-min warm-up, cycling at a low load, subjects will do six 30-s efforts on the bike at a heart rate that is about 80-90% of their maximum heart rate. For two minutes between each effort subjects will pedal at an easy load at 60-70% of maximum heart rate. At the end of the session they will pedal at a low load for a 5-minute cool down. The physiotherapist/exercise physiologist will increase the exercise periods to 60 s in the second week of training; and to two minutes for the final 6 weeks of exercise training. Recovery periods between exercise bouts will remain at two minutes. Each exercise training session will therefore only take between 25 to 35 minutes.
Intervention code [1] 294190 0
Treatment: Other
Comparator / control treatment
Usual care/Exercise advice
Usual care constitutes exercise advice. Subjects randomly allocated to the usual care/exercise advice group will be provided written advice about exercise (recommended type - aerobic, strength, combined - and dosage based on American Diabetes Association/American College of Sports Medicine guidelines) and reducing sedentary behaviour (modifying some daily habits). This advice will be discussed with the participant after randomisation allocation is revealed at the start of the intervention period of eight weeks
Control group
Active

Outcomes
Primary outcome [1] 297666 0
Peak oxygen uptake measured using a standard cycle ergometry protocol with expired gas analysis and ventilation analysis using a standardised and calibrated metabolic cart system
Timepoint [1] 297666 0
1. Baseline (before randomization)
2. End of intervention period at 8 weeks
3. 6 months after the end of the intervention period, i.e. 8 months after randomization
Primary outcome [2] 297667 0
Glycaemic status (HbA1c; glycated haemoglobin) measured by high-performance liquid chromatography
Timepoint [2] 297667 0
1. Baseline (before randomization)
2. End of intervention period at 8 weeks
Secondary outcome [1] 321754 0
Stroke volume at rest and during 50% pre-training upright max workload cycling in left-leaning supine position measured by echocardiography
Timepoint [1] 321754 0
1. Baseline (before randomization)
2. End of intervention period at 8 weeks
Secondary outcome [2] 321755 0
Peak annulus velocity in early diastole (ventricular relaxation) at rest and during 50% pre-training upright max workload cycling in left-leaning supine position measured by echocardiography
Timepoint [2] 321755 0
1. Baseline (before randomization)
2. End of intervention period at 8 weeks
Secondary outcome [3] 321756 0
Peripheral nerve function: Motor and sensory nerve excitability of median nerve using standard surface electromyography (EMG)
Timepoint [3] 321756 0
1. Baseline (before randomization)
2. End of intervention period at 8 weeks
Secondary outcome [4] 321757 0
Endothelial Vasodilator Function measured by standardised EndoPAT Trademark protocol
Timepoint [4] 321757 0
1. Baseline (before randomization)
2. End of intervention period at 8 weeks
Secondary outcome [5] 321758 0
Expectations and experiences (including acceptability) of the aerobic interval training or usual care/exercise advice. These are qualitative outcomes that will be explored by semi-structured interview; and themes will be presented together in discussion..
Timepoint [5] 321758 0
1. End of intervention period at 8 weeks
2. 6 months after the end of the intervention period
Secondary outcome [6] 321759 0
Blood inflammatory markers (IL-6, TNF-alpha, CRP) measured by ELISA
Timepoint [6] 321759 0
At rest and during each of three submaximal exercise loads (20, 35, 50% of upright pre-training max workload) at:
1. Baseline (before randomization)
2. End of intervention period at 8 weeks
Secondary outcome [7] 321760 0
Heat shock proteins (Hsp90, 72) by serum (Hsp90) or plasma (Hsp72) assay
Timepoint [7] 321760 0
At rest and during each of three submaximal exercise loads (20, 35, 50% of upright pre-training max workload) at:
1. Baseline (before randomization)
2. End of intervention period at 8 weeks
Secondary outcome [8] 321761 0
Blood glucose measured by autoanalyzer
Timepoint [8] 321761 0
At rest and during each of three submaximal exercise loads (20, 35, 50% of upright pre-training max workload) at:
1. Baseline (before randomization)
2. End of intervention period at 8 weeks
Secondary outcome [9] 321932 0
Brachial artery flow-mediated dilation (FMD) utilising standardised Doppler method
Timepoint [9] 321932 0
1. Baseline (before randomization)
2. End of intervention period at 8 weeks
Secondary outcome [10] 321933 0
Lung volumes measured by body plethysmograph system.
Timepoint [10] 321933 0
1. Baseline (before randomization)
2. End of intervention period at 8 weeks
Secondary outcome [11] 321934 0
Pulmonary blood flow measured by intra breath acetylene dilution
Timepoint [11] 321934 0
1. Baseline (before randomization)
2. End of intervention period at 8 weeks
Secondary outcome [12] 321935 0
Barriers and motivators to exercise. These will be explored in an individual semi-structured interview.
Timepoint [12] 321935 0
1. End of intervention period at 8 weeks
2. 6 months after the end of the intervention period
Secondary outcome [13] 321936 0
Blood lactate measured by autoanalyzer
Timepoint [13] 321936 0
At rest and during each of three submaximal exercise loads (20, 35, 50% of upright pre-training max workload) at:
1. Baseline (before randomization)
2. End of intervention period at 8 weeks
Secondary outcome [14] 321937 0
Arterialized venous blood pH and PCO2 measured by autoanalzyer
Timepoint [14] 321937 0
At rest and during each of three submaximal exercise loads (20, 35, 50% of upright pre-training max workload) at:
1. Baseline (before randomization)
2. End of intervention period at 8 weeks
Secondary outcome [15] 321938 0
Free fatty acids measured by spectrophotometric method
Timepoint [15] 321938 0
At rest and during each of three submaximal exercise loads (20, 35, 50% of upright pre-training max workload) at:
1. Baseline (before randomization)
2. End of intervention period at 8 weeks
Secondary outcome [16] 321939 0
Serum insulin measured by ELISA
Timepoint [16] 321939 0
At rest and during 50% upright pre-training max workload (submaximal) exercise at:
1. Baseline (before randomization)
2. End of intervention period at 8 weeks
Secondary outcome [17] 321940 0
NT pro-BNP measured by ELISA
Timepoint [17] 321940 0
At rest and during 50% upright pre-training max workload (submaximal) exercise at:
1. Baseline (before randomization)
2. End of intervention period at 8 weeks
Secondary outcome [18] 321941 0
Matrix metalloproteinases (MMP-2, -9) by zymography and MMP-1, -7 and tissue inhibitor TIMP-1 by ELISA
Timepoint [18] 321941 0
1. Baseline (before randomization)
2. End of intervention period at 8 weeks
Secondary outcome [19] 321942 0
Monocyte number count isolated using a percoll gradient
Timepoint [19] 321942 0
At rest and during 50% upright pre-training max workload (submaximal) exercise at:
1. Baseline (before randomization)
2. End of intervention period at 8 weeks
Secondary outcome [20] 321943 0
Questionnaire: SF12v2 with PIQ-6 measures pain severity and impact along with measures of functional health and well-being
Timepoint [20] 321943 0
1. Baseline (before randomization)
2. End of intervention period at 8 weeks
3. 6 months after the end of the intervention period, i.e. 8 months after randomization
Secondary outcome [21] 321944 0
Questionnaire: Appraisal of diabetes scale
Timepoint [21] 321944 0
1. Baseline (before randomization)
2. End of intervention period at 8 weeks
3. 6 months after the end of the intervention period, i.e. 8 months after randomization
Secondary outcome [22] 321945 0
Questionnaire: Physical activity stages of change
Timepoint [22] 321945 0
1. Baseline (before randomization)
2. End of intervention period at 8 weeks
3. 6 months after the end of the intervention period, i.e. 8 months after randomization
Secondary outcome [23] 321946 0
Global Physical activity questionnaire (GPAQ)
Timepoint [23] 321946 0
1. Baseline (before randomization)
2. End of intervention period at 8 weeks
3. 6 months after the end of the intervention period, i.e. 8 months after randomization
Secondary outcome [24] 321947 0
Behavioural regulation in exercise questionnaire (BREQ-3) created by David Markland PhD, C.Psychol School of Sport, Health & Exercise Sciences, University of Wales, Bangor
Timepoint [24] 321947 0
1. Baseline (before randomization)
2. End of intervention period at 8 weeks
3. 6 months after the end of the intervention period, i.e. 8 months after randomization
Secondary outcome [25] 321948 0
Pittsburgh Sleep Quality Index questionnaire
Timepoint [25] 321948 0
1. Baseline (before randomization)
2. End of intervention period at 8 weeks
3. 6 months after the end of the intervention period, i.e. 8 months after randomization
Secondary outcome [26] 321949 0
Fatigue severity scale questionnaire and VAS fatigue
Timepoint [26] 321949 0
1. Baseline (before randomization)
2. End of intervention period at 8 weeks
3. 6 months after the end of the intervention period, i.e. 8 months after randomization
Secondary outcome [27] 321950 0
Questionnaire: Depression anxiety stress scale-21 (DASS21)
Timepoint [27] 321950 0
1. Baseline (before randomization)
2. End of intervention period at 8 weeks
3. 6 months after the end of the intervention period, i.e. 8 months after randomization
Secondary outcome [28] 321951 0
Questionnaire: Exercise benefits/barriers scale
Timepoint [28] 321951 0
1. Baseline (before randomization)
2. End of intervention period at 8 weeks
3. 6 months after the end of the intervention period, i.e. 8 months after randomization
Secondary outcome [29] 321952 0
Exercise self-efficacy questionnaire
Timepoint [29] 321952 0
1. Baseline (before randomization)
2. End of intervention period at 8 weeks
3. 6 months after the end of the intervention period, i.e. 8 months after randomization
Secondary outcome [30] 321953 0
Accelerometry to determine minutes per day of sedentary and moderate/vigorous intensity activity
Timepoint [30] 321953 0
1. Baseline (before randomization)
2. End of intervention period at 8 weeks
Secondary outcome [31] 321954 0
Accelerometry to determine steps per day
Timepoint [31] 321954 0
1. Baseline (before randomization)
2. End of intervention period at 8 weeks
Secondary outcome [32] 321955 0
Peripheral nerve function: H-reflex and M-wave of tibial nerve using the QTRAC system (semi-automated computerized system) and a multifunction data acquisition system.
Timepoint [32] 321955 0
1. Baseline (before randomization)
2. End of intervention period at 8 weeks
Secondary outcome [33] 321956 0
monocyte cell surface marker expression and mitochondrial DNA concentration performed on RNA and DNA isolated from whole blood using the Qiagen whole blood DNA or RNA isolation kit
Timepoint [33] 321956 0
At rest and during 50% upright pre-training max workload (submaximal) exercise at:
1. Baseline (before randomization)
2. End of intervention period at 8 weeks
Secondary outcome [34] 322036 0
Spirometry measured by body plethysmograph system.
Timepoint [34] 322036 0
1. Baseline (before randomization)
2. End of intervention period at 8 weeks
Secondary outcome [35] 322081 0
Single breath diffusing capacity measured by body plethysmograph system.
Timepoint [35] 322081 0
1. Baseline (before randomization)
2. End of intervention period at 8 weeks

Eligibility
Key inclusion criteria
Glucose intolerance first diagnosed during pregnancy; at least 6 months post-partum; not currently breast-feeding; aged between 18 and 45 years of age. Current glucose intolerance not required.
Minimum age
18 Years
Maximum age
45 Years
Gender
Females
Can healthy volunteers participate?
No
Key exclusion criteria
Chronic respiratory disease; current history of smoking; chest wall disease; heart failure; stroke; overt cardiovascular disease; and any other condition in which exercise is contraindicated; any condition precluding the ability to provide informed consent; pregnancy; and residence > 50 km from the hospital.

Study design
Purpose of the study
Treatment
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
A researcher blinded to allocation will open an opaque envelope (labelled with the study participant number) in front of the participant (after all pre-intervention testing is complete) and reveal the allocation. This researcher is a supervisor, i.e. not the PhD student (who will remain blinded to the allocation).
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Another researcher generated the randomization sequence using a web-based program, put allocations in opaque envelopes, and sealed each envelope. The sealed envelopes are then stored on site at RPAH for access by the researcher revealing the allocation.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?


The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint(s)
Efficacy
Statistical methods / analysis

Recruitment
Recruitment status
Withdrawn
Reason for early stopping/withdrawal
Lack of funding/staff/facilities
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
Recruitment hospital [1] 5432 0
Royal Prince Alfred Hospital - Camperdown
Recruitment postcode(s) [1] 12917 0
2050 - Missenden Road

Funding & Sponsors
Funding source category [1] 293111 0
Self funded/Unfunded
Name [1] 293111 0
Unfunded
Address [1] 293111 0
Unfunded
Country [1] 293111 0
Primary sponsor type
Individual
Name
Dr Alison Harmer
Address
Discipline of Physiotherapy,
Faculty of Health Sciences,
The University of Sydney,
P.O. Box 170 Lidcombe, NSW 1825
Country
Australia
Secondary sponsor category [1] 291900 0
None
Name [1] 291900 0
nil
Address [1] 291900 0
n/a
Country [1] 291900 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 294610 0
Ethics Review Committee (RPAH Zone)
Ethics committee address [1] 294610 0
c/- Research Ethics and Governance Office (REGO)
Royal Prince Alfred Hospital
Missenden Road
CAMPERDOWN NSW 2050
Ethics committee country [1] 294610 0
Australia
Date submitted for ethics approval [1] 294610 0
Approval date [1] 294610 0
16/10/2015
Ethics approval number [1] 294610 0
X11-0060 & HREC/11/RPAH/72 with updates; date above is last update

Summary
Brief summary
The aim of our study is to investigate the effects of a novel intervention - high-intensity aerobic interval training - on aerobic fitness, heart volumes and function, metabolic control, substrate utilization, nerve function and cardiovascular risk factors among women with previous gestational diabetes mellitus (pGDM).

Women with pGDM have an exceptionally high (at least a 7-fold higher risk) risk of developing type 2 diabetes mellitus compared with women without pGDM. Previous GDM is associated with subclinical atherosclerosis prior to the development of the metabolic syndrome or T2D. There may also be subclinical heart dysfunction, however this has rarely been examined and responses to exercise training have not been investigated.

It has been demonstrated recently that peripheral nerve dysfunction precedes the development of neuropathy in T2D and given that pGDM is associated with subclinical atherosclerosis prior to the development of the metabolic syndrome or T2D, nerve dysfunction may also be evident among women with pGDM, however, this has not been examined.

There is an inverse relationship between physical activity and risk of type 2 diabetes mellitus (T2D) among women with pGDM. In fact, achieving the minimum recommended exercise targets (150 min of moderate-intensity exercise per week) halved the risk of developing T2D among women with pGDM. No studies have examined effects of high-intensity exercise training among women with pGDM.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 64354 0
Dr Alison Harmer
Address 64354 0
Discipline of Physiotherapy,
Faculty of Health Sciences,
The University of Sydney,
P.O. Box 170 Lidcombe, NSW 1825
Country 64354 0
Australia
Phone 64354 0
+61 2 9351 9706
Fax 64354 0
+61 2 9351 9278
Email 64354 0
alison.harmer@sydney.edu.au
Contact person for public queries
Name 64355 0
Dr Alison Harmer
Address 64355 0
Discipline of Physiotherapy,
Faculty of Health Sciences,
The University of Sydney,
P.O. Box 170 Lidcombe, NSW 1825
Country 64355 0
Australia
Phone 64355 0
+61 2 9351 9706
Fax 64355 0
+61 2 9351 9278
Email 64355 0
alison.harmer@sydney.edu.au
Contact person for scientific queries
Name 64356 0
Dr Alison Harmer
Address 64356 0
Discipline of Physiotherapy,
Faculty of Health Sciences,
The University of Sydney,
P.O. Box 170 Lidcombe, NSW 1825
Country 64356 0
Australia
Phone 64356 0
+61 2 9351 9706
Fax 64356 0
+61 2 9351 9278
Email 64356 0
alison.harmer@sydney.edu.au

No information has been provided regarding IPD availability
Summary results
No Results