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Trial registered on ANZCTR


Registration number
ACTRN12608000218392
Ethics application status
Approved
Date submitted
21/04/2008
Date registered
22/04/2008
Date last updated
11/09/2013
Type of registration
Prospectively registered

Titles & IDs
Public title
Effect of different diets on gestational diabetes
Scientific title
Can a low glycemic index (GI) diet during pregnancy reduce prevalence of large for gestation age (LGA) amongst women with gestational diabetes (GDM)? – a randomized, controlled trial
Secondary ID [1] 283193 0
GIBABY1
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Gestational Diabetes 3080 0
Condition category
Condition code
Diet and Nutrition 3236 3236 0 0
Other diet and nutrition disorders
Metabolic and Endocrine 3237 3237 0 0
Diabetes
Reproductive Health and Childbirth 3238 3238 0 0
Other reproductive health and childbirth disorders

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Low glycemic index diet - with a daily dietary GI less than 50, carbohydrate choices include low/lower GI alternatives, e.g. pasta, lower GI rice, multigrain bread, low GI breakfast cereals, sweet potatoes, etc. from diagnosis of gestational diabetes (at 26 - 30 weeks) till 36 weeks of gestation.
Participants in this diet group would receive 1 dietary education session fortnightly for at least 5 weeks to educate them how to follow a low GI diet. Phone reviews will be conducted in between the face-to-face sessions. The sessions will be given by the PhD student who is also an Accredited Practising Dietitian. Low/lower GI food samples baskets will be provided to the participants on a fortnightly basis, and a range of low/lower GI foods would be suggested and encouraged during the education sessions. Participants will be provided sample meal plans which are specially formulated to have a GI less than 50, and a 24 hour recall at the 2nd face-to-face dietary education session would assess their compliance.
Intervention code [1] 2821 0
Treatment: Other
Comparator / control treatment
Wholegrain high fibre - with a GI of around 60, carbohydrate choices include moderate to high GI but high fibre and/or wholegrain foods, e.g. wholemeal bread, wholegrain breakfast cereals, brown rice, potatoes, etc. from diagnosis of gestational diabetes (at 26 - 30 weeks) till 36 weeks of gestation.
Participants in this diet group would receive 1 dietary education session fortnightly for at least 5 weeks (i.e. at least 3 sessions) to educate them how to follow a wholegrain high fibre diet. Phone reviews will be conducted in between the face-to-face sessions. The sessions will be given by the PhD student who is also an Accredited Practising Dietitian. Wholegrain high fibre food samples baskets will be provided to the participants on a fortnightly basis, and a range of wholegrain high fibre foods would be suggested and encouraged during the education sessions. Participants will be provided sample meal plans which are specially formulated to have a GI approximately 60 (the GI of the usual Australian diet), and a 24 hour recall at the 2nd face-to-face dietary education session would assess their compliance.
Control group
Active

Outcomes
Primary outcome [1] 4120 0
birth weight z-score
Timepoint [1] 4120 0
birth of infant
Secondary outcome [1] 6935 0
ponderal index (weight/cube of length)
Timepoint [1] 6935 0
birth of infant
Secondary outcome [2] 6936 0
need for insulin to control blood glucose level during gestation (Yes or No).
Doctors/diabetes educators will determine whether the gravidas requires insulin for optimal blood glucose control or not, based on their home blood glucose monitoring readings.
results presented as a group percentage
Timepoint [2] 6936 0
from the start of the study till the birth of infant,
determined during their routine antenatal visits, which is fortnightly.

Eligibility
Key inclusion criteria
otherwise healthy pregnancy, singleton gestation
Minimum age
18 Years
Maximum age
45 Years
Gender
Females
Can healthy volunteers participate?
No
Key exclusion criteria
Pregnancy achieved via assited reproduction, pregnancy complicated with conditions other than gestational diabetes

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)
Allocation is concealed via central randomization. A stratified random number list (with blocking) will be maintained by a personel not involved in the study.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
subjects will be randomized by computer generated random numbers
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?



Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint(s)
Efficacy
Statistical methods / analysis

Recruitment
Recruitment status
Completed
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)
Recruitment postcode(s) [1] 658 0
2050

Funding & Sponsors
Funding source category [1] 3332 0
University
Name [1] 3332 0
The University of Sydney
Address [1] 3332 0
Research Office
A14 Quadrangle Building
Camperdown Campus
Parramatta Rd
Sydney NSW 2006
Country [1] 3332 0
Australia
Primary sponsor type
University
Name
The University of Sydney
Address
Research Office
A14 Quadrangle Building
Camperdown Campus
Parramatta Rd
Sydney NSW 2006
Country
Australia
Secondary sponsor category [1] 2978 0
None
Name [1] 2978 0
Address [1] 2978 0
Country [1] 2978 0
Other collaborator category [1] 273 0
Hospital
Name [1] 273 0
Diabetes Centre, Royal Prince Alfred Hospital
Address [1] 273 0
Level 6 West Wing
Royal Prince Alfred Hospital
Missenden Road
Camperdown NSW 2050
Country [1] 273 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 5344 0
South West Areath Health Service Human research Ethics Committee (RPAH Zone)
Ethics committee address [1] 5344 0
Research Development Office
Level 8, Building 14
Royal Prince Alfred Hospital
Missenden Road
CAMPERDOWN NSW 2050
Ethics committee country [1] 5344 0
Australia
Date submitted for ethics approval [1] 5344 0
30/04/2008
Approval date [1] 5344 0
05/06/2008
Ethics approval number [1] 5344 0
08/RPAH/208

Summary
Brief summary
This study aims to investigate the efficacy of a low glycemic index diet (GI) in reducing the prevalence of large-for-gestion-age (LGA) babies amongst gravidas with gestational diabetes (GDM). Study participants will be pregnant women diagnosed with GDM at ~26-30 week gestation. They will be randomized into two study groups, one receiving dietary education on how to follow a wholegrain high fibre diet for GDM, whereas the other group will receive education on how to follow a macronutrient and energy matched low GI diet. We hypothesize, based on our previous pilot study on healthy gravidas, gravidas with GDM following a low GI diet will have a lower risk of giving birth to LGA infant than those following a wholegrain high fibre diet. The size of the infants (as birth weight z-score) will be measured as the primary outcome.
Trial website
Trial related presentations / publications
Primary publication

Louie JC, Markovic TP, Perera N, Foote D, Petocz P, Ross GP, Brand-Miller JC. A randomized controlled trial investigating the effects of a low-glycemic index diet on pregnancy outcomes in gestational diabetes mellitus. Diabetes Care. 2011 Nov;34(11):2341-6. doi: 10.2337/dc11-0985. Epub 2011 Sep 6.

Secondary publications

Louie JC, Markovic TP, Ross GP, Foote D, Brand-Miller JC. Effect of a low glycaemic index diet in gestational diabetes mellitus on post-natal outcomes after 3 months of birth: a pilot follow-up study. Matern Child Nutr. 2013 May 3. doi: 10.1111/mcn.12039. [Epub ahead of print]

Louie JC, Markovic TP, Ross GP, Foote D, Brand-Miller JC. Higher glycemic load diet is associated with poorer nutrient intake in women with gestational diabetes mellitus.
Nutr Res. 2013 Apr;33(4):259-65. doi: 10.1016/j.nutres.2013.02.008. Epub 2013 Mar 26.
Public notes

Contacts
Principal investigator
Name 28548 0
Prof Jennie C Brand-Miller
Address 28548 0
G08 School of Molecular Bioscience
The University of Sydney NSW 2006
Country 28548 0
Australia
Phone 28548 0
+61293513759
Fax 28548 0
Email 28548 0
jennie.brandmiller@sydney.edu.au
Contact person for public queries
Name 11705 0
Dr Jimmy Chun Yu Louie
Address 11705 0
Room 453, Human Nutrition Unit,
G08 School of Molecular and Microbial Biosciences,
Cnr Butlin Ave and Maze Cres.
University of Sydney
Camperdown, NSW 2006
Country 11705 0
Australia
Phone 11705 0
+61 433 538 424
Fax 11705 0
Email 11705 0
jimmy.louie@sydney.edu.au
Contact person for scientific queries
Name 2633 0
Prof Jennie Brand-Miller
Address 2633 0
Room 476, Human Nutrition Unit,
G08 School of Molecular and Microbial Biosciences,
Cnr Butlin Ave and Maze Cres.
University of Sydney
Camperdown, NSW 2006
Country 2633 0
Australia
Phone 2633 0
+61 2 9351 3759
Fax 2633 0
+61 2 9351 6022
Email 2633 0
j.brandmiller@mmb.usyd.edu.au

No information has been provided regarding IPD availability
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary